Nanomaterials in which single atoms of a noble metal are dispersed on the surface of a non-noble metal substrate, methods for manufacturing the same, and uses

Abstract

The present invention belongs to the technical field of advanced inorganic nanomaterials, and specifically relates to a nanomaterial in which a single atom of a precious metal is dispersed on the surface of a non-precious metal substrate, and a manufacturing method and use thereof. The nanomaterial includes a non-precious metal substrate and a precious metal dispersed as a single atom on the surface of the non-precious metal substrate, and a halogen and oxygen are simultaneously coordinated to the surface of the single atom of the precious metal. The material of the present invention has a large specific surface area of ​​the substrate, a large electrochemically active area, and the dispersion of the single atom of the precious metal causes the surface coordination environment to have a great influence on the electronic structure and catalytic activity of the catalyst, resulting in higher catalytic activity. In the present invention, the surface coordination structure of the precious metal is adjusted and controlled by the synthesis temperature, pH, reaction time, and electrodeposition voltage range, and both hydroxide and halogen are coordinated to the precious metal, resulting in the characteristic of five-coordinated unsaturated coordination, and the substrate is doped with reductive metal ions to improve the loading amount of the single atom, achieve directional fixation of the single atom, and improve the activity of the seawater electrolysis material for anodic oxygen generation and cathodic hydrogen generation.

Description

[Technical Field]

[0001] This invention belongs to the field of advanced inorganic nanomaterials, and more specifically, relates to a nanomaterial in which a single atom of a noble metal is dispersed on the surface of a non-noble metal substrate, a method for producing the same, and its use. [Background technology]

[0002] With increasing human energy demands, the world's existing conventional energy resources are severely depleted, and the environmental problems caused by the combustion of conventional fossil fuels are becoming increasingly serious. Therefore, the development of new renewable energy sources is urgently needed. Currently, solar energy, wind energy, biomass energy, water energy, and hydrogen energy are widely considered to be renewable and clean energy sources. Among these, hydrogen energy is attracting attention because it is lightweight, non-toxic, has a high calorific value, has large reserves, and is recyclable. Currently, electrolysis of water is an important method for producing hydrogen. However, the freshwater resources available to humans are very limited, and their total storage capacity is less than 1% of the Earth's total water volume. Therefore, simply producing hydrogen using pure water is insufficient to meet humanity's hydrogen energy demand. On the other hand, the Earth's seawater resources are extremely abundant, with 70.8% of the Earth's total surface area covered by seawater. If hydrogen can be produced by electrolyzing seawater, it would not only enable the effective use of seawater resources but also help solve the increasingly serious energy and environmental problems.

[0003] Catalysts are central to electrolysis and play a crucial role in the voltage and efficiency of the process. Currently, anode reactions require large overpotentials, and in seawater electrolysis, there is an urgent need to solve the problems of catalyst selectivity and stability due to the presence of large amounts of chloride ions. The concentration of chloride ions in seawater is approximately 0.5 mol / L, and while the theoretical potential for the oxidation reaction of chloride ions (1.36 V) is not much different from the theoretical potential for oxygen evolution (1.23 V), the chlorine evolution reaction is 2e -Because chlorine evolution is a reaction and is kinetically more favorable, it is more likely to occur, affecting the selectivity of the reaction. Furthermore, chloride ions readily interact with catalysts, causing corrosion, affecting catalyst stability, and shortening the catalyst's service life. Therefore, developing highly active, selective, and stable catalysts for seawater electrolysis is extremely important. Currently, much research focuses on avoiding the adsorption of chloride ions to prevent or mitigate the chlorine evolution reaction. However, this also reduces oxygen evolution activity, and this "shielding" of chloride ion adsorption does not function at high voltages, making it unsuitable for industrial electrolysis under high current density operating conditions.

[0004] The present invention is proposed to solve the above problems. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] This invention designs nanomaterials in which single atoms of a precious metal are dispersed on a non-precious metal surface, which, due to their highly dispersed precious metal properties, reduce the amount of precious metal used, enhance sensitivity to the surrounding environment, and allow for adjustment and control of the material's structure by adsorbing chloride ions onto the surface, thereby influencing its performance.

[0006] When a precious metal is supported on the surface of a non-precious metal, the precious metal strongly adsorbs chloride ions, making them difficult to desorb and imparting high selectivity for oxygen evolution reactions. At the same time, the precious metal protects the non-precious metal substrate from corrosion. Because the non-precious metal substrate strongly interacts with single atoms of the precious metal, the precious metal is less likely to detach, resulting in high stability. [Means for solving the problem]

[0007] A first aspect of the present invention provides a nanomaterial comprising a non-precious metal substrate and a precious metal dispersed as a single atom on the surface of the non-precious metal substrate, wherein chlorine and oxygen are simultaneously coordinated to the surface of the single atom of the precious metal.

[0008] The oxygen coordinated to the surface of the single atom of the noble metal exists in the form of an oxygen-containing functional group. The oxygen-containing functional group may be a hydroxide.

[0009] The dispersion of the noble metal as single atoms means that the noble metal is uniformly distributed on the surface of the non-noble metal substrate, there is no metal-metal bond or metal-oxygen-metal bond between the noble metals, and the noble metal and the non-noble metal substrate are connected via a chemical bond.

[0010] Preferably, the halogen is one or more selected from chlorine, bromine, fluorine, and iodine.

[0011] Preferably, the noble metal is one or more selected from iridium, ruthenium, gold, platinum, rhodium, palladium, silver, and osmium. For example, the noble metal is one, two, three, four, or five or more selected from iridium, ruthenium, gold, platinum, rhodium, palladium, silver, and osmium.

[0012] Preferably, the non-noble metal substrate is one or more selected from non-noble metal hydroxides, non-noble metal oxides, non-noble metal sulfides, non-noble metal phosphides, and non-noble metal selenides. When the non-noble metal substrate is a sulfide, phosphide, or selenide, halogen or oxygen is coordinated to the surface of the noble metal atom, and sulfur, phosphorus, or selenium is coordinated.

[0013] Preferably, the non-noble metal in the non-noble metal substrate is one or more selected from iron, cobalt, nickel, aluminum, manganese, cerium, vanadium, zinc, copper, strontium, indium, and cadmium.

[0014] Preferably, the non-noble metal substrate is doped with a reducing metal ion, and the single atom of the noble metal is selectively fixed to the reducing metal ion.

[0015] Preferably, the reducing metal ion is one or more selected from divalent iron ions, divalent manganese ions, and divalent cobalt ions. Specifically, a single atom of a noble metal is selectively immobilized on the reducing metal ion.

[0016] Preferably, the nanomaterial further comprises a conductive carrier, and the non-precious metal substrate is supported on the conductive carrier.

[0017] More preferably, the conductive carrier is selected from foamed metal, carbon paper, or carbon cloth. The foamed metal may be selected from foamed iron, foamed nickel, or the like.

[0018] A second aspect of the present invention provides a method for producing a nanomaterial in which a single atom of a noble metal is dispersed on the surface of a non-noble metal substrate as described in the first aspect. This chemical precipitation method includes the steps of: dispersing a non-precious metal substrate in water; adding a water-soluble precious metal precursor and a dilute alkaline solution dropwise to obtain a mixture; reacting the mixture at 10-95°C for 4-120 hours while stirring; separating the solid and liquid; washing and drying the solid to obtain the nanomaterial. In the aforementioned dilute solution of water-soluble precious metal precursor and alkali, the concentration of the water-soluble precious metal precursor is 0.001 to 200 mmol / L, and the concentration of the hydroxide is 0.5 to 1000 mmol / L. The water-soluble precious metal precursor contains halogen elements. In chemical deposition, it is an important step to control the concentrations of the water-soluble precious metal precursor and hydroxide in the dilute solution so that the hydroxide and halogen elements coordinate simultaneously. For example, the water-soluble precious metal precursor may be one or more of chlorides, bromides, or fluorides. If the water-soluble precious metal precursor contains two or three different halides, the two or three different halogen elements can coordinate simultaneously to the surface of a single atom of the precious metal.

[0019] Preferably, if the non-precious metal substrate is doped with reducing metal ions, the chemical precipitation method requires the removal of dissolved oxygen from the water.

[0020] Preferably, when the non-precious metal substrate is a non-precious metal hydroxide, the manufacturing method involves coprecipitation of an alkaline solution and a water-soluble non-precious metal precursor solution, crystallization, solid-liquid separation, drying of the solid, and obtaining the non-precious metal hydroxide. When the non-precious metal substrate is a non-precious metal oxide, the method of producing it is to directly calcine a non-precious metal hydroxide to obtain the non-precious metal oxide. When the non-precious metal substrate is a non-precious metal sulfide, a non-precious metal phosphide, or a non-precious metal selenide, the method for producing it is: Method 1 involves hydrothermally treating a non-precious metal hydroxide in a sulfur-containing substance, a selenium-containing substance, or a phosphorus-containing substance solution to obtain the corresponding non-precious metal sulfide, non-precious metal selenide, or non-precious metal phosphide. Method 1 is selected from the following: a non-precious metal hydroxide is placed in a tubular furnace together with a sulfur-containing substance, a selenium-containing substance, or a phosphorus-containing substance, respectively, and calcined to obtain the corresponding non-precious metal sulfide, non-precious metal selenide, or non-precious metal phosphide.

[0021] More preferably, the alkaline solution is a mixed solution of sodium hydroxide and sodium carbonate, with a sodium hydroxide concentration of 0.004 to 0.3 mol / L and a sodium carbonate concentration of 0.0001 to 0.1 mol / L; the water-soluble non-precious metal precursor solution is a nitrate, sulfate, or chloride corresponding to the non-precious metal, with a precursor concentration of 0.002 to 0.3 mol / L; and the conditions for the coprecipitation reaction between the alkaline solution and the water-soluble non-precious metal precursor solution are pH = 8 to 12, temperature 20 to 80°C, and reaction time 6 to 48 hours.

[0022] Preferably, in method 1 above, The conditions for the hydrothermal treatment are as follows: the solution volume is 36 ml, the temperature is 100-120°C, the time is 3-6 hours, and the concentration of the sulfide solution, phosphide solution, or selenide solution is 3-10 mmol / 36 ml; and the conditions for the calcination are as follows: the temperature is 300-500°C, and the time is 2-5 hours.

[0023] Preferably, in method 2 described above, the baking conditions are a temperature of 300 to 500°C and a time of 2 to 5 hours.

[0024] A third aspect of the present invention also provides a method for producing a nanomaterial in which a single atom of a noble metal is dispersed on the surface of a non-noble metal substrate, the nanomaterial further comprising a conductive carrier, the non-noble metal substrate being supported on the conductive carrier, The aforementioned manufacturing method, specifically, This electrodeposition method involves preparing an electrolyte mainly composed of a water-soluble precious metal precursor and alkali, and performing electrochemical deposition at an electrodeposition voltage of -1.2 to 1.2 V using a conductive carrier on which a non-precious metal substrate is supported as the working electrode. In the electrolyte, the concentration of the water-soluble precious metal precursor is 0.001 to 1000 mmol / L, the concentration of the hydroxide is 0.1 to 6 mol / L, and the water-soluble precious metal precursor contains a halogen element. Preferably, a water-soluble precious metal precursor and alkali are prepared as an electrolyte, Preferably, a three-electrode system is configured with a conductive carrier on which a non-precious metal substrate is supported, a carbon rod, and a reference electrode. Preferably, the concentration of the water-soluble precious metal precursor in the electrolyte is 0.001 to 10 mmol / L.

[0025] In electrodeposition, a crucial step is to control the concentrations of the water-soluble precious metal precursor and hydroxide (alkali) in the electrolyte, as well as the electrodeposition voltage range, so that the hydroxide and halogen elements coordinate simultaneously. For example, the water-soluble precious metal precursor may be one or more of chlorides, bromides, or fluorides. If the water-soluble precious metal precursor contains two or three different halides, the two or three different halogen elements can simultaneously coordinate to the surface of a single atom of the precious metal.

[0026] Preferably, if the non-precious metal substrate is doped with reducing metal ions, the electrodeposition method requires the removal of dissolved oxygen from the electrolyte.

[0027] More specifically, a method for removing dissolved oxygen from an electrolyte involves heating the experimental deionized water or electrolyte at 80°C while introducing nitrogen gas, and after 1 hour obtaining deionized water or electrolyte from which dissolved oxygen has been removed.

[0028] Preferably, if the non-precious metal substrate is doped with reducing metal ions, it is necessary to add the reducing metal ions involved in the reaction during the production of the non-precious metal substrate.

[0029] Preferably, the number of electrodeposition cycles is 3 to 20 cycles.

[0030] More preferably, a method for manufacturing a conductive carrier on which the non-precious metal substrate is supported is as follows. When the non-precious metal substrate is a non-precious metal hydroxide, the manufacturing method involves hydrothermally treating a conductive carrier, urea, and a water-soluble non-precious metal precursor solution, crystallizing them, washing and drying them to obtain a conductive carrier on which the non-precious metal hydroxide is supported, or manufacturing a conductive carrier on which the non-precious metal hydroxide is supported by electrodeposition. When the non-precious metal substrate is a non-precious metal hydroxide, the manufacturing method involves directly calcining a conductive carrier on which the non-precious metal hydroxide is supported to obtain a conductive carrier on which the non-precious metal oxide is supported. When the non-precious metal substrate is a non-precious metal sulfide, a non-precious metal phosphide, or a non-precious metal selenide, the method for producing it is: Method 1 involves placing a conductive carrier on which a non-precious metal hydroxide is supported into a sulfur-containing substance, a selenium-containing substance, or a phosphorus-containing substance solution, subjecting it to hydrothermal treatment, followed by calcination, to obtain a conductive carrier on which a non-precious metal sulfide is supported, a conductive carrier on which a non-precious metal selenide is supported, or a conductive carrier on which a non-precious metal phosphide is supported, respectively. Method 1 is one of two methods selected from the following: Method 2 involves placing a conductive carrier on which a non-precious metal hydroxide is supported together with a sulfur-containing substance, a selenium-containing substance, or a phosphorus-containing substance, respectively, in a tubular furnace and calcining it to obtain a conductive carrier on which a non-precious metal sulfide is supported, a conductive carrier on which a non-precious metal selenide is supported, or a conductive carrier on which a non-precious metal phosphide is supported, respectively.

[0031] The phosphorus-containing substance in this specification may be any of the appropriate forms selected, for example, sodium hypophosphate or sodium phosphite, or elemental phosphorus.

[0032] The sulfur-containing substance in this specification may be any form selected from appropriate forms, such as thiourea or elemental sulfur.

[0033] The selenium-containing substance in this specification may be any form selected from appropriate forms, such as elemental selenium.

[0034] In this specification, a method for producing a conductive carrier on which a non-precious metal hydroxide is supported by electrodeposition, Electrochemical deposition is performed on an electrochemical workstation using a conductive carrier as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode, with a non-precious metal aqueous solution as the electrolyte.

[0035] Preferably, in the hydrothermal treatment reaction of the above conductive carrier, urea, and water-soluble non-precious metal precursor solution, In the solution, the urea concentration is 3-10 mmol / 36 ml, the water-soluble non-precious metal precursor solution is a nitrate, sulfate, or chloride corresponding to the non-precious metal, and the concentration of any of them is 1 mmol / 36 ml, and the conditions for the hydrothermal treatment are a temperature of 100-120°C and a reaction time of 8-12 hours.

[0036] Preferably, in method 1 described above, The conditions for the hydrothermal treatment are as follows: the volume of the solution is 36 ml, the temperature is 100-120°C, the time is 3-6 hours, and the concentration of the sulfide solution, phosphide solution, or selenide solution is 3-10 mmol / 36 ml. The conditions for the calcination are as follows: the temperature is 300-550°C, and the time is 2-5 hours.

[0037] In this invention, by adjusting and controlling the types of raw materials, it is possible to arbitrarily combine four types: a non-precious metal substrate type, a non-precious metal type, a precious metal type, and a halogen type. Furthermore, it is possible to arbitrarily combine each element in the non-precious metal and each element in the precious metal.

[0038] Both chemical deposition and electrodeposition methods are suitable for producing any of the above materials.

[0039] A fourth aspect of the present invention provides the use of a nanomaterial described in any of the first aspects as a water electrolysis electrode, wherein a halide is added to the electrolyte of the electrolyzed water to improve the water electrolysis performance of the nanomaterial.

[0040] The electrolyte in the aforementioned electrolyzed water contains alkali.

[0041] Preferably, the performance includes activity, selectivity, and stability.

[0042] Preferably, the nanomaterial can function simultaneously as both an anode and a cathode for water electrolysis.

[0043] The aforementioned nanomaterial can function simultaneously as both an anode and a cathode for water electrolysis. The aforementioned nanomaterial can function as an anode for water electrolysis on its own. The aforementioned nanomaterial functions as a cathode for water electrolysis on its own. The same nanomaterial can function simultaneously as both an anode and a cathode for water electrolysis. This means that the different nanomaterials include forms that function as anodes and cathodes for water electrolysis, respectively.

[0044] Preferably, the halide is one or more selected from chlorides, bromides, and fluorides. The halogens in the halide (fluorine, bromine, chlorine, and iodine) may further coordinate with a single atom of a noble metal to adjust and control the coordination environment and electronic structure of the nanomaterial and to improve the stability of the electrode material.

[0045] The alkali in this specification may be one or more selected from sodium hydroxide and potassium hydroxide, etc. The halide is one or more selected from sodium chloride, potassium chloride, sodium fluoride, potassium fluoride, sodium bromide, potassium bromide, potassium iodide, and sodium iodide, etc.

[0046] A fifth aspect of the present invention provides the use of the nanomaterial described in any of the first aspects as a seawater electrolytic electrode.

[0047] Preferably, the nanomaterial can function simultaneously as both an anode and a cathode for seawater electrolysis.

[0048] The aforementioned nanomaterial can simultaneously function as both an anode and a cathode for seawater electrolysis. The aforementioned nanomaterial can function on its own as an anode for seawater electrolysis. The aforementioned nanomaterial functions independently as a cathode for seawater electrolysis. The same nanomaterial can function simultaneously as both an anode and a cathode for seawater electrolysis. This means that the different nanomaterials include forms that function as anodes and cathodes for seawater electrolysis, respectively.

[0049] The above technical solutions may be combined freely, as long as they do not contradict each other. [Effects of the Invention]

[0050] Compared to conventional technology, the present invention has the following beneficial effects.

[0051] (1) The material of the present invention has a large specific surface area, a large electrochemical active area, and high catalytic activity because single atoms of the noble metal are dispersed. Similarly, the dispersion of single atoms of the noble metal greatly influences the surface coordination environment, which in turn significantly affects the electronic structure and catalytic activity of the catalyst. The surface coordination structure of the noble metal in the present invention can be adjusted and controlled by the synthesis temperature, pH, reaction time, and electrodeposition voltage range (in the case of electrodeposition). In the material of the present invention, hydroxides and halogens (chlorine, bromine, fluorine, and iodine) are simultaneously coordinated to the noble metal, resulting in a five-coordinate unsaturated coordination, which improves the activity of anode oxygen generation and cathode hydrogen generation in seawater electrolysis materials.

[0052] (2) The materials of the present invention can be used for anode oxygen generation and cathode hydrogen generation in seawater electrolysis. In the electrolysis reaction of seawater, halogens (chlorine, bromine, fluorine, and iodine) in the electrolyte are adsorbed onto the surface of single atoms of the noble metal and are difficult to desorb, thus forming metal-halogen bonds. As a result, the coordination environment and electronic structure of the noble metal are further adjusted and controlled, improving the reactivity, selectivity (suppression of chlorine generation side reactions), and material stability of anode oxygen generation and cathode hydrogen generation.

[0053] (3) The single atom of the noble metal in the catalyst of the present invention is firmly bonded to the non-noble metal substrate by chemical bonds. Therefore, the catalytic activity of the material of the present invention is not simply due to the addition of a non-noble metal substrate catalyst and a noble metal. There is a strong interaction between the noble metal and the non-noble metal substrate, making it difficult for the noble metal to fall off, improving stability, redistributing the electron cloud, and further improving the activity of the material of the present invention. In a preferred embodiment, when the non-noble metal substrate is a sulfide, phosphide, or selenide, halogens or oxygen coordinate to the surface of the noble metal atom, and at the same time sulfur, phosphorus, or selenium coordinates, so a strong interaction is formed between the surface of the noble metal atom and the metal substrate.

[0054] (4) Since the precious metals in the material are dispersed as single atoms, the precious metal content is significantly reduced, which in turn reduces the cost of the catalyst and facilitates large-scale commercialization.

[0055] (5) In particular, the experiment in Comparative Example 1 showed that the oxygen generation performance of the water electrolysis / seawater electrolysis material of the present invention is closely related to the local coordination structure of a single atom of the noble metal, and that the performance is best when both halogen and oxygen-containing functional groups are coordinated to the metal.

[0056] (6) In a preferred embodiment, the introduction of reducing metal ions (e.g., divalent iron, divalent manganese ions, or divalent cobalt ions) into the non-precious metal substrate (hydrotalcite laminate) of the present invention has the following beneficial effects.

[0057] 1) As a result of ultimately supporting the precious metal, it was unexpectedly discovered that not only could the dispersion of single atoms of the precious metal be achieved, but the amount of single atoms of the precious metal that could be supported could also be increased.

[0058] In conventional materials, the only way to disperse precious metals as single atoms on the substrate is to reduce the concentration of the precious metal, resulting in a final mass content of precious metals generally less than 0.5%. Therefore, there is a dilemma between the dispersion of single atoms of precious metals and the high load capacity of precious metals.

[0059] Therefore, the present invention solves the above dilemma by introducing reducing metal ions into a hydrotalcite laminate, which not only protects the dispersion of single atoms of noble metals but also increases the amount of noble metals supported.

[0060] The reason for this is that reducing metal ions have the property of being able to disperse as single atoms within a laminate, allowing them to selectively fix precious metal ions. Therefore, even if the amount of precious metal added is increased, there is no risk of the precious metals agglomerating and forming particles. The precious metals are fixed by the reducing metal ions and can maintain a monodisperse state.

[0061] 2) Furthermore, by introducing reducing divalent iron, divalent manganese ions, or divalent cobalt ions into the laminate to selectively reduce the noble metal, the strong reducing properties enhance the interaction between the single atom of the noble metal and the hydrotalcite substrate, resulting in the noble metal becoming more firmly immobilized and less prone to detachment, thereby improving the stability of the single-atom catalyst.

[0062] 3) Reducing divalent iron, divalent manganese, or divalent cobalt ions in the laminate lower the valence of the precious metals, improving their activity and stability in water electrolysis and seawater electrolysis.

[0063] The reason for this is that the interaction between the precious metal and the reducing metal ions is strengthened, making the precious metal and the reducing metal ions more firmly fixed and less likely to detach, thus improving stability. In addition, the initial valency of the precious metal is lowered by the reducing metal ions, improving its activity. On the other hand, in conventional precious metal-supported materials, the precious metal is fixed to the surface of the substrate by MOM action, resulting in a high valency of the precious metal and poor stability.

[0064] Taking Ru as an example, if reduced divalent iron is present in the laminate, Ru and Fe 2+ Due to the action of Fe 2+ As Ru donates electrons, oxidation and reduction occur, and electrons move in and out, making this force stronger. When reducing divalent iron is not present in the laminate and only trivalent iron is present, Ru and Fe 3+ There is no redox action between them, and they are Ru-OM(M is Fe 3+ Because it is bound only via (and other stacked metal ions), its action force is reduced.

[0065] 4) A single atom of a precious metal is dispersed in divalent iron / manganese-doped hydrotalcite, M-Fe 2+ or M-Mn 2+ A catalyst pair is formed. Also, noble metals and Fe 2+ The interaction between the two alters the electron cloud density around the Fe, improving its performance. Consequently, the hydrotalcite laminate becomes more active. [Brief explanation of the drawing]

[0066] [Figure 1] This is a transmission electron microscope (TEM) image of the iridium / cobalt iron hydroxide material obtained in Example 1. [Figure 2] This is the X-ray diffraction pattern (XRD) of the iridium / cobalt iron hydroxide material obtained in Example 1. [Figure 3] This is the selected-region electron diffraction pattern (SAED) of the iridium / cobalt iron hydroxide material obtained in Example 1. [Figure 4] This is the elemental distribution map (mapping) of the iridium / cobalt iron hydroxide material obtained in Example 1. [Figure 5] This is a spherical aberration electron microscope (STEM) image of the iridium / cobalt iron hydroxide material obtained in Example 1. [Figure 6] This is the X-ray photoelectron spectroscopy (XPS) analysis of the iridium / cobalt iron hydroxide material obtained in Example 1. [Figure 7] This is the X-ray absorption near-end spectrum of the iridium / cobalt iron hydroxide material obtained in Example 1. [Figure 8] This is the X-ray absorption fine structure spectrum of the iridium / cobalt iron hydroxide material obtained in Example 1. [Figure 9] This shows the fitting of the X-ray absorption fine structure spectrum of the iridium / cobalt iron hydroxide material obtained in Example 1, and a schematic diagram of the structure of single-atom iridium. [Figure 10] This is a polarization curve chart of oxygen evolution in iridium / cobalt iron hydroxide material, cobalt iron hydroxide material, or a commercially available iridium dioxide 6 mol / L NaOH solution in Application Example 1. [Figure 11] The polarization curve chart for iridium / cobalt iron hydroxide material in a 6 mol / L NaOH + 2.8 mol / L NaCl solution, and the polarization curve for oxygen evolution in a 6 mol / L NaOH solution, are shown in Application Example 1. [Figure 12]These are constant voltage test curves for the iridium / cobalt iron hydroxide material in Application Example 1, when tested in a 1 mol / L NaOH solution and when a 0.5 mol / L NaCl solution was added during the test. [Figure 13] This is the high-current stability test curve of the iridium / cobalt iron hydroxide material in real seawater in Example 1. [Figure 14] This is an in-situ synchrotron radiation characteristics evaluation of iridium / cobalt iron hydroxide material in Application Example 1. [Figure 15] These are the polarization curves for oxygen evolution in iridium / cobalt iron hydroxide materials in NaOH + NaF, NaOH + NaBr, and NaOH in Application Example 1. [Figure 16] This is the X-ray absorption fine structure spectrum of the iridium chlorine / cobalt iron hydroxide material in Comparative Example 1. [Figure 17] This is a polarization curve chart of oxygen evolution in a 6 mol / L NaOH solution of iridium chlorine / cobalt iron hydroxide material in Comparative Example 1. [Figure 18] This is the X-ray absorption fine structure spectrum of the iridium oxygen / cobalt iron hydroxide material in Comparative Example 2. [Figure 19] This chart shows the polarization curves of oxygen evolution in a 6 mol / L NaOH solution for the iridium oxygen / cobalt iron hydroxide material in Comparative Example 2 and the iridium / cobalt iron hydroxide material in Example 1. [Figure 20] This is a scanning electron microscope (SEM) image of the iridium / nickel iron hydroxide array material in Example 2. [Figure 21] This is a polarization curve chart of oxygen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for the iridium / nickel-iron hydroxide array material in Application Example 2 or the nickel-iron hydroxide array material obtained in step (1) of Example 2. [Figure 22] This is a transmission electron microscope (TEM) image of the rhodium / cobalt hydroxide material in Example 3. [Figure 23]This is a polarization curve chart of oxygen evolution in a 1 mol / L NaOH solution of rhodium / cobalt hydroxide material or cobalt hydroxide material in Application Example 3. [Figure 24] This is a polarization curve chart of oxygen evolution in a rhodium / cobalt hydroxide material in a 1 mol / L NaOH + 0.5 mol / L NaCl solution or a 1 mol / L NaOH solution in Application Example 3. [Figure 25] This is a polarization curve chart of oxygen evolution in rhodium / nickel iron hydroxide material in 1 mol / L NaOH + 0.5 mol / L NaCl solution and 1 mol / L NaOH solution in Application Example 4. [Figure 26] This is a polarization curve chart of oxygen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for gold / nickel-iron sulfide materials and nickel-iron sulfide materials in Application Example 5. [Figure 27] This is a transmission electron microscope image of the gold particle / nickel-iron sulfide material of Comparative Example 3. [Figure 28] This is a polarization curve chart comparing oxygen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for the gold particle / nickel-iron sulfide material in Application Example 3 and the gold / nickel-iron sulfide material in Example 5. [Figure 29] This is a scanning electron microscope image of the platinum / nickel sulfide cobalt iron material in Example 6. [Figure 30] These are the polarization curves for oxygen evolution in the platinum / nickel-cobalt-iron sulfide material in 6 mol / L NaOH + 2.8 mol / L NaCl (dashed line) and 6 mol / L NaOH (solid line) solutions in Application Example 6. [Figure 31] This is the stability curve for the platinum / nickel-cobalt-iron sulfide material in Application Example 6 at a current density of 100 mA / cm² with 6 mol / L NaOH + 2.8 mol / L NaCl. [Figure 32] These are the polarization curves for oxygen evolution in palladium / nickel-cobalt-zinc-iron-aluminum sulfide solutions of 6 mol / L NaOH + 2.8 mol / L NaCl (dashed line) and 6 mol / L NaOH (solid line) in Application Example 7. [Figure 33] This is a scanning electron microscope image of the ruthenium / nickel iron vanadium phosphide material in Example 8. [Figure 34] This is the X-ray diffraction spectrum of the ruthenium / nickel iron vanadium phosphide material in Example 8. [Figure 35] This chart shows the polarization curves of oxygen evolution in a 1 mol / L NaOH + 0.5 mol / L NaCl (dashed line) solution for ruthenium / nickel iron vanadium phosphide material (dashed line) and nickel iron vanadium phosphide material (solid line) in Example 8. [Figure 36] These are the polarization curves for oxygen evolution in the gold / nickel iron manganese phosphide material in 1 mol / L NaOH + 0.5 mol / L NaCl (dashed line) and 1 mol / L NaOH (solid line) solutions. [Figure 37] These are the polarization curves for hydrogen evolution in the platinum / cobalt phosphide material and the cobalt phosphide material in Example 10 with 1 mol / L NaOH + 0.5 mol / L NaCl (dashed line). [Figure 38] These are the polarization curves for hydrogen evolution in the silver / nickel-cobalt-indium phosphide material and the nickel-cobalt-indium phosphide material in Example 11 with 1 mol / L NaOH + 0.5 mol / L NaCl (dashed line). [Figure 39] These are the polarization curves for oxygen evolution in 6 mol / L NaOH + 2.8 mol / L NaCl (dashed line) for platinum / nickel cobalt cerium selenide material (dashed line) and nickel cobalt cerium selenide material (solid line) in Example 12. [Figure 40] This is a polarization curve chart comparing oxygen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for the platinum-oxygen / nickel-cobalt-cerium selenide material in Application Example 4 and the platinum-nickel-cobalt-cerium selenide material in Example 12. [Figure 41] This is a scanning electron microscope image of the ruthenium / cobalt selenide material in Example 13. [Figure 42]These are the polarization curves for oxygen evolution in ruthenium / cobalt selenide materials in 6 mol / L NaOH + 2.8 mol / L NaCl (dashed line) and 6 mol / L NaOH (solid line) solutions in Application Example 13. [Figure 43] These are the polarization curves for oxygen evolution in iridium / nickel iron selenide solutions with 6 mol / L NaOH + 2.8 mol / L NaCl (dashed line) and 6 mol / L NaOH (solid line) in Application Example 14. [Figure 44] This chart shows the polarization curves of oxygen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for iridium platinum / nickel iron vanadium selenide and nickel iron vanadium selenide materials in Application Example 15. [Figure 45] This chart shows the polarization curves of hydrogen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for iridium platinum / nickel iron vanadium selenide and nickel iron vanadium selenide materials in Application Example 15. [Figure 46] This is a polarization curve chart of oxygen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for osmium / nickel cobalt cadmium selenide and nickel cobalt cadmium selenide materials in Application Example 16. [Figure 47] This is a scanning electron microscope (SEM) image of the iridium / tricobalt tetroxide material in Example 17. [Figure 48] This is the X-ray diffraction pattern of the iridium / tricobalt tetroxide material in Example 17. [Figure 49] This is a polarization curve chart of oxygen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for iridium / tricobalt tetroxide material and tricobalt tetroxide material in Application Example 17. [Figure 50] This chart shows the polarization curves of oxygen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for ruthenium-palladium / nickel-iron-copper-strontium oxide and nickel-iron-copper-strontium oxide materials in Application Example 18. [Figure 51]This chart shows the polarization curves of hydrogen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for ruthenium-palladium / nickel-iron-copper-strontium oxide and nickel-iron-copper-strontium oxide materials in Application Example 18. [Figure 52] This is a polarization curve chart of oxygen evolution in a 6 mol / L NaOH solution of gold / nickel-cobalt-iron sulfide material and nickel-cobalt-iron sulfide material in Application Example 19. [Figure 53] This chart shows the polarization curves for oxygen evolution in a 6 mol / L NaOH solution and a 6 mol / L NaOH + 2.8 mol / L NaCl solution of gold / nickel-cobalt-iron sulfide material in Application Example 19. [Figure 54] This chart shows the polarization curves of oxygen evolution in a 6 mol / L NaOH solution and a 6 mol / L NaOH + 2.0 mol / L NaBr solution of gold / nickel-cobalt-iron sulfide material in Application Example 19. [Figure 55] This is an in-situ Raman property evaluation map of a gold / nickel-cobalt-iron sulfide material in a 6 mol / L NaOH + 2.0 mol / L NaBr solution in Application Example 19. [Figure 56] This chart shows the polarization curves for oxygen evolution in a 6 mol / L NaOH solution and a 6 mol / L NaOH + 2.0 mol / L NaF solution of gold / nickel-cobalt-iron sulfide material in Application Example 19. [Figure 57] This is a spherical aberration electron microscope image of the iridium ruthenium / nickel-iron sulfide material in Example 20. [Figure 58] This is the synchrotron radiation characteristic evaluation spectrum of the iridium ruthenium / nickel-iron sulfide material in Example 20. [Figure 59] This is a polarization curve chart of hydrogen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution of iridium ruthenium / nickel iron sulfide and nickel iron sulfide materials in Application Example 20. [Figure 60]This is a polarization curve chart of hydrogen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution of iridium ruthenium / nickel iron sulfide and nickel iron sulfide materials in Application Example 20. [Figure 61] This chart shows the polarization curves of oxygen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for iridium platinum / nickel iron vanadium phosphide and nickel iron vanadium phosphide materials in Application Example 21. [Figure 62] This chart shows the polarization curves of hydrogen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for iridium platinum / nickel iron vanadium phosphide and nickel iron vanadium phosphide materials in Application Example 21. [Figure 63] This is the polarization curve for complete electrolysis of water at two electrodes using a 6 mol / L NaOH + 2.8 mol / L NaCl solution with iridium platinum / nickel iron vanadium phosphide material as the cathode and anode, as in Application Example 21. [Figure 64] This is a transmission electron microscope (TEM) image of ruthenium / nickel iron(2+) iron hydrotalcite obtained in Example 22. [Figure 65] This is the elemental distribution map (mapping) of ruthenium / nickel iron(2+) iron hydrotalcite obtained in Example 22. [Figure 66] This is a spherical aberration electron microscope (STEM) image of ruthenium / nickel iron(2+) iron hydrotalcite obtained in Example 22. [Figure 67] This is the X-ray diffraction pattern (XRD) spectrum of ruthenium / nickel iron(2+) iron hydrotalcite obtained in Example 22. [Figure 68] This is an X-ray photoelectron spectroscopy analysis comparing the ruthenium / nickel iron hydrotalcite in Application Example 22 with the ruthenium / nickel iron(2+) iron hydrotalcite obtained in Example 1. [Figure 69]This is a polarization curve chart of hydrogen evolution in the ruthenium / nickel iron(2+) iron hydrotalcite material obtained in Example 22 and in a 1 mol / L NaOH solution of commercially available ruthenium dioxide. [Figure 70] This is a polarization curve chart of oxygen evolution in a 1 mol / L NaOH + 0.5 mol / L NaCl solution of iridium / nickelmanganese(2+) iron hydrotalcite material obtained by performing Application Example 23. [Figure 71] This chart shows the polarization curves of hydrogen evolution in a 6 mol / L NaOH solution for platinum / nickel-cobalt-iron phosphide materials and nickel-cobalt-iron phosphide materials obtained by carrying out Application Example 24. [Figure 72] This is a polarization curve chart of hydrogen evolution in a platinum / nickel-cobalt-iron phosphide material obtained by performing Application Example 24, using a 6 mol / L NaOH + 2.8 mol / L NaCl solution and a 6 mol / L NaOH solution. [Figure 73] This is a polarization curve chart of hydrogen evolution in a 6 mol / L NaOH + 2 mol / L NaI solution and a 6 mol / L NaOH solution of platinum / nickel-cobalt-iron phosphide material obtained by performing Application Example 24. [Figure 74] This is a polarization curve chart of oxygen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for platinum / nickel-cobalt-iron phosphide materials and nickel-cobalt-iron phosphide materials obtained by carrying out Application Example 25. [Figure 75] This is the polarization curve for the complete decomposition of water in a 6 mol / L NaOH + 2.8 mol / L NaCl solution using a two-electrode system consisting of a platinum / nickel-cobalt-iron phosphide material (anode) and a commercially available iridium / carbon (cathode), obtained by implementing Application Example 25. [Modes for carrying out the invention]

[0067] The present invention will be further described below with reference to examples, but the present invention is not limited to these examples. Experimental methods in the examples that do not specify particular conditions generally follow conventional conditions and conditions described in the manual, or conditions recommended by the manufacturer. The general equipment, materials, and reagents used are obtained through commercial means unless otherwise specified. All raw materials required in the following examples and comparative examples are commercially available. Example 1 - Chemical deposition method

[0068] A chemical deposition method described in the second aspect of the present invention is used to produce a nanomaterial (iridium / cobalt iron hydroxide) in which a single atom of a noble metal is dispersed on the surface of a non-noble metal substrate, and specifically, it is as follows. Step (1): Manufacturing of non-precious metal substrate-cobalt iron hydroxide material Preparation of 40 ml of alkaline solution A: 0.48 g of sodium hydroxide and 0.106 g of sodium carbonate were mixed with an appropriate amount of deionized water to prepare 40 ml of alkaline solution A. Preparation of 40 ml of salt solution B: 0.291 g of cobalt nitrate and 0.202 g of iron nitrate were combined with an appropriate amount of deionized water to prepare 40 ml of salt solution B. Solution A and Solution B were simultaneously added dropwise to 40 ml of rapidly stirred water. The pH was maintained at approximately 8.5 until the addition of salt solution B was complete, and the mixture was stirred for a further 12 hours. The precipitate was then centrifuged to obtain a precipitate, which was washed three times each with deionized water and ethanol. The precipitate was then vacuum-dried at 60°C to obtain the cobalt iron hydroxide material. Step (2): Manufacturing of nanomaterials 1 g of the cobalt iron hydroxide material obtained in step (1) was weighed, 30 ml of deionized water was added to it, and the mixture was sonicated for 2-3 hours to uniformly distribute the material in water. Preparation of 20 ml of alkaline dilute solution of iridium chloride: 20 ml of alkaline dilute solution of iridium chloride was prepared using 0.6 mg (0.1 mmol / L) of iridium chloride, 0.4 mg (0.5 mmol / L) of sodium hydroxide, and deionized water. Then, under high-speed stirring conditions (500 R / min), the above alkaline dilute solution of iridium chloride was added dropwise to the uniformly dispersed cobalt iron hydroxide material at a dropping rate of 5 drops / minute. After the dropwise addition was complete, the mixture was stirred continuously for 4 hours under heating conditions of 95°C, centrifuged to obtain a precipitate, washed three times each with water and ethanol, and vacuum-dried at 60°C to obtain nanosheets (iridium / cobalt iron hydroxide) in which single atoms of iridium were supported on the surface of a cobalt iron bimetallic hydroxide. Figure 1 shows a transmission electron microscope image of the obtained iridium / cobalt iron hydroxide. From Figure 1, it was found that the iridium / cobalt iron hydroxide was in the form of hexagonal sheets with a diameter of 50-100 μm and a thickness of 5-10 μm. The XRD spectra of the obtained iridium / cobalt iron hydroxide are shown in Figure 2. From Figure 2, it can be seen that after supporting iridium as a single atom, the diffraction peaks coincide with those of cobalt iron hydroxide, and there are no diffraction peaks for iridium or iridium oxide. This suggests that crystallization into iridium or iridium oxide particles does not occur during the synthesis process. The selected region electron diffraction pattern of the obtained iridium / cobalt iron hydroxide is shown in Figure 3. From Figure 3, it can be seen that the diffraction rings of this material are the 100 and 110 crystal planes of the bimetallic hydroxide, and there are no diffraction rings for iridium or iridium oxide, which is consistent with the XRD results. This also suggests that Ir or iridium oxide particles are not present. Figure 4 shows the elemental distribution of the obtained iridium / cobalt iron hydroxide, and Figure 5 shows a spherical aberration electron microscope image. From Figure 4, it can be seen that the elements iridium, cobalt, iron, and chlorine are uniformly distributed in the material. When combined with the spherical aberration electron microscope image in Figure 5, it can be seen that single atoms of the precious metal iridium are distributed on the surface of the cobalt iron hydroxide. The X-ray photoelectron spectroscopy analysis of the obtained iridium / cobalt iron hydroxide is shown in Figure 6. From the iridium bond energy in Figure 6, it was found that the iridium is in a state where both Ir-O and Ir-Cl are simultaneously coordinated. The obtained X-ray near-edge absorption spectrum of iridium / cobalt iron hydroxide is shown in Figure 7. The X-ray absorption fine structure spectrum of iridium / cobalt iron hydroxide is shown in Figure 8. The fitting of the X-ray absorption fine structure of iridium / cobalt iron hydroxide is shown in Figure 9. As can be seen from Figure 7, single atoms Ir are dispersed on the cobalt iron bimetallic nanosheet, and their valence is close to that of iridium oxide (+4). From Figures 8 and 9, it was found that single atoms Ir are bonded to the cobalt iron bimetallic hydroxide via Ir-OM, and that Ir-O and Ir-Cl are coordinated to the surface. Application Example 1

[0069] 1. Testing of water electrolysis performance The oxygen evolution performance of the iridium / cobalt iron hydroxide of the present invention in water electrolysis was tested in a 6.0 M sodium hydroxide solution using a three-electrode system with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the iridium / cobalt iron hydroxide material obtained in Example 1, the cobalt iron hydroxide material obtained in Step (1) of Example 1, or commercially available iridium dioxide as the working electrode. The resulting polarization curves are shown in Figure 10. Clearly from Figure 10, the iridium / cobalt iron hydroxide material obtained in Example 1 exhibited superior oxygen evolution performance in water electrolysis (solid line in Figure 10, starting potential of 1.428 V), and its oxygen evolution performance in water electrolysis was superior to that of the sheet-like cobalt iron complex metal hydroxide material (dashed line in Figure 10, starting potential of 1.554 V), with a 126 mV decrease in the starting potential. Furthermore, the nanosheet-like material of iridium / cobalt iron hydroxide exhibits far superior oxygen generation performance in water electrolysis compared to commercially available iridium dioxide (dotted line in Figure 10, starting potential of 1.65V). Section 2: Performance Test of Electrolytic Sodium Hydroxide + Sodium Chloride Solution Referring to the first aspect of Application Example 1, in a similar three-electrode test system, sodium chloride was added to the electrolyte, i.e., the electrolyte was changed to 6.0 M sodium hydroxide and 2.8 M sodium chloride, and the iridium / cobalt iron hydroxide material obtained in Example 1 was used as the working electrode. The resulting polarization curve is shown in Figure 11. Clearly from Figure 11, the oxygen evolution performance of the cobalt iron hydroxide material was superior to that tested in sodium hydroxide due to the addition of chloride ions, and the onset potential decreased by approximately 50 mV (the onset potential was 1.428 V when tested in sodium hydroxide, and 1.38 V when tested in sodium hydroxide and sodium chloride). The electrolytic oxygen generation stability of the iridium / cobalt iron hydroxide material obtained in Example 1 was tested. As shown in Figure 12, the material showed a gradual decrease in current density after 7 hours of testing in 6.0 M sodium hydroxide (decaying to 93.02% of the initial current density within 7 hours). When 2.8 M sodium chloride was added to the electrolyte, the current gradually increased and stabilized at approximately 80 mA, and the OER Faraday efficiency consistently exceeded 99%. After the test was completed, no discoloration was observed when the electrolytic solution reacted with the potassium iodide starch solution. Therefore, the chlorine oxidation reaction did not occur. The material was tested in a chloride ion-containing solution and was suggested to have good activity, stability, and OER selectivity. Section 3. Test of Oxygen Generation Performance in Seawater Electrolysis Test of the oxygen generation performance of the iridium / cobalt iron hydroxide material of Example 1 in the electrolysis of real seawater using a three-electrode system Referring to the first aspect of Application Example 1, a saturated calomel electrode was used as the reference electrode, a platinum electrode was used as the counter electrode, and the iridium / cobalt iron hydroxide material obtained in Example 1 was used as the working electrode. As the electrolytic solution, 24 g of sodium hydroxide was added to 100 ml of real seawater, and after filtration, the supernatant was used as the electrolytic solution. The stability curve of the obtained material is shown in Fig. 13. Clearly from Fig. 13, at an industrial-level high current density (specifically, 400 mA / cm 2 , 600 mA / cm 2 or 800 mA / cm 2 ), it was stabilized for more than 1000 hours, suggesting that industrial applications of this material can be expected. Section 4. In-situ Characterization of the Interaction between the Material and Chloride Ions in the Oxygen Generation Reaction Process Using beamline 1W1B and the fluorescence mode in the synchrotron radiation facility from the Institute of High Energy Physics, Beijing, in cooperation with an electrochemical workstation, the radiation absorption spectra of the iridium / cobalt iron hydroxide material at different voltages were collected and are shown in Fig. 14. From Fig. 14, it was found that during the oxygen generation reaction process, chlorine in the solution was adsorbed on the surface of iridium, and the local coordination structure of single-atom iridium was adjusted and controlled, contributing to the occurrence of the oxygen generation reaction. Section 5. Improvement of the Oxygen Generation Performance of Single Atoms by Fluorine and Bromine, Other Halogens Referring to the first aspect of Application Example 1, a similar three-electrode test system is obtained by adding sodium fluoride or sodium bromide to the electrolyte, i.e., changing the electrolyte to 1.0 M sodium hydroxide, or 1.0 M sodium hydroxide and 0.5 M sodium fluoride, or 1.0 M sodium hydroxide and 0.5 M sodium bromide, and using the iridium / cobalt iron hydroxide material obtained in Example 1 as the working electrode, and the resulting polarization curve is shown in Figure 15. Figure 15 shows that adding fluoride ions to the test solution can raise the onset potential (1.46V) of the iridium / cobalt iron hydroxide material to 1.424V, making it advantageous for catalyzing water splitting and oxygen evolution. Adding bromide ions to the test solution can also raise the onset potential of iridium / cobalt iron hydroxide to 1.41V, making it advantageous for catalyzing water splitting and oxygen evolution. During electrolysis, fluorine or bromine elements in the electrolyte can coordinate with a single atom of a noble metal. In materials during the electrolysis process, iridium atoms are simultaneously coordinated with oxygen, chlorine, and fluorine, or iridium atoms are simultaneously coordinated with oxygen, chlorine, and bromine. Comparative Example 1 - Chemical Deposition Method

[0070] Referring to the method of Example 1, in step (2), 0.16 mg (0.2 mmol / L) of sodium hydroxide and 5 mg of iridium chloride were added. Specifically, 20 ml of iridium chloride solution was prepared using 5 mg of iridium chloride, 0.16 mg of sodium hydroxide, and deionized water. The final material obtained was iridium chlorine / cobalt iron hydroxide. The X-ray absorption fine structure spectrum of the obtained material is shown in Figure 16. From Figure 16, it was found that only chlorine was coordinated to the surface of a single iridium atom in the material, and that it was connected to a cobalt iron hydroxide laminate via Ir-OM. M is an iron or cobalt atom. Comparison with Application Example 1

[0071] Referring to the seawater electrolysis test method in Application Example 1, the oxygen generation performance of the iridium / cobalt iron hydroxide material of Example 1 in the electrolysis of real seawater was tested using a three-electrode system with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the iridium chlorine / cobalt iron hydroxide (dashed line) of Comparative Example 1 as the working electrode. The electrolytes used were 6.0 M sodium hydroxide and 2.8 M sodium chloride. Figure 17 shows the results, indicating a current density of 10 mA / cm². 2 In this case, the overpotential of iridium chlorine / cobalt iron hydroxide was 1.441V, which was found to be approximately 15mV higher than that of the iridium / cobalt iron hydroxide in Example 1 (solid line). Therefore, when used in seawater electrolysis, the iridium chlorine / cobalt iron hydroxide of Comparative Example 1 had lower activity than that of the iridium / cobalt iron hydroxide in Example 1. From these results, it became clear that the oxygen evolution performance of materials in water electrolysis / seawater electrolysis is closely related to the local coordination structure of a single atom of the noble metal, and that the best performance is obtained when a halogen and an oxygen-containing functional group are simultaneously coordinated to the noble metal. Comparative Example 2 - Chemical Deposition Method

[0072] Referring to the method of Example 1, in step (2), 1000 mg (1250 mmol / L) of sodium hydroxide and 5 mg of iridium chloride were added. Specifically, 20 ml of iridium chloride solution was prepared using 5 mg of iridium chloride, 1000 mg of sodium hydroxide, and deionized water. The final material obtained was iridium oxygen / cobalt iron hydroxide. The X-ray absorption fine structure spectrum of the obtained material is shown in Figure 18. From Figure 18, it can be seen that the single iridium atoms in the material have only oxygen coordinated to their surface, lacking Ir-O-Ir and Ir-Ir bonds, maintaining a single-atom state, and are connected to the cobalt iron hydroxide laminate via Ir-OM, where M is an iron or cobalt atom. The reason that only oxygen coordinates to the surface of the single iridium atoms and no chlorine coordinates is that the coordination of the Ir precursor in the dilute solution is adjusted and controlled by the excess OH in the solution, all of the Cl is replaced, and complete oxygen coordination is achieved. Comparison with Application Example 2

[0073] Referring to the test method for seawater electrolysis in Application Example 1, the working electrode was changed to iridium oxygen / cobalt iron hydroxide (dashed line) as in Comparative Example 2. A saturated calomel electrode was used as the reference electrode, and a platinum electrode was used as the counter electrode. The electrolyte was changed to 6.0 M sodium hydroxide and 2.8 M sodium chloride. As shown in Figure 19, the current density was 10 mA / cm². 2 In this case, the overpotential of iridium oxygen / cobalt iron hydroxide was 1.455V, which was found to be approximately 15mV higher than that of the iridium / cobalt iron hydroxide in Example 1 (solid line). Therefore, when used in seawater electrolysis, the iridium chlorine / cobalt iron hydroxide of Comparative Example 1 had lower activity than the iridium / cobalt iron hydroxide of Example 1. From these results, it became clear that the oxygen generation performance of materials in water electrolysis / seawater electrolysis is closely related to the local coordination structure of a single atom of the noble metal, and that the best performance is obtained when a halogen and an oxygen-containing functional group are simultaneously coordinated to the noble metal. Example 2 - Electrodeposition Method

[0074] A method for producing a nanomaterial in which a single atom of a noble metal is dispersed on the surface of a non-noble metal substrate employs the electrodeposition method described in the third aspect of the present invention, which is specifically as follows. Step (1): Production of conductive carrier-supported nickel-iron hydroxide foamed nickel with non-precious metal substrate support. A solution of 36 ml was prepared using 0.6 g of urea, 0.121 g of iron nitrate, 0.174 g of nickel nitrate, 0.037 g of ammonium fluoride, and deionized water. 40 ml of the solution was poured into a reaction vessel, and a washed 3 x 4 square centimeter foamed nickel was immersed in the solution. The vessel was then placed in an oven and subjected to hydrothermal treatment at a reaction temperature of 100°C for 12 hours to crystallize. After crystallization, the material was washed and dried to obtain a nickel-iron hydroxide array material as foamed nickel supported with nickel-iron hydroxide. Step (2): Preparation of 50 ml of electrolyte solution 50 ml of electrolyte solution was prepared using 2.0 g (1 mol / L) of sodium hydroxide, 2.98 mg (0.1 mmol / L) of iridium chloride, and an appropriate amount of deionized water. Step (3): Electroplating In the electrolyte obtained in (2), a three-electrode system was used in which foamed nickel on which nickel iron hydroxide obtained in (1) was supported was used as the working electrode, a saturated calomel electrode as the reference electrode, and a carbon rod as the counter electrode. The material was electrodeposited by linear voltammetry with the following parameters: voltage range -1.2 to -0.5V, scanning direction reverse, scanning speed 0.005V / sec, and number of cycles 10. Step (4): The material obtained in Step (3) was washed three times each with deionized water and ethanol, and dried in a vacuum drying box at 60°C to obtain an iridium / nickel-iron hydroxide array material in which single atoms of iridium were dispersed on the surface of nickel-iron hydroxide and foamed nickel was used as the support. Figure 20 shows scanning electron microscope images of the obtained iridium / nickel-iron hydroxide array material. From Figure 20, it was found that the iridium / nickel-iron hydroxide array consists of nanohexagonal nanosheets with a diameter of 50-100 nanometers and a thickness of 5-10 nanometers, and that there are no obvious particles. Application Example 2

[0075] Referring to the third aspect of Application Example 1 (test of oxygen generation performance in seawater electrolysis), a similar three-electrode test system was used, with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the iridium / nickel-iron hydroxide array material obtained in Example 2 or the nickel-iron hydroxide array material obtained in Step (1) of Example 2 as the working electrode. The electrolyte was changed to the supernatant obtained by adding 24 g of sodium hydroxide to 100 ml of real seawater and filtering it. The catalytic performance of the seawater electrolysis anode of the iridium / nickel-iron hydroxide array material obtained in Example 2 is shown in Figure 21, with a current density of 100 mA / cm². 2 In this case, the overvoltage was 1.564V, which was 50mV lower than that of the nickel-iron hydroxide array material. It was also revealed that the iridium / nickel-iron hydroxide array material plays a role in promoting seawater electrolysis. Example 3 - Chemical deposition method

[0076] A method for producing a nanomaterial (rhodium / cobalt hydroxide material) in which a single atom of a noble metal is dispersed on the surface of a non-noble metal substrate employs the chemical deposition method described in the second aspect of the present invention, which is specifically as follows. Referring to the method of Example 1, when preparing 40 ml of salt solution B in step (1), the mass of cobalt nitrate was changed to 0.436 g, iron nitrate was omitted, and the alkaline solution was changed to 0.48 g of sodium hydroxide. Finally, the cobalt hydroxide material obtained in step (1) was obtained. In step (2), the preparation of 1 ml of dilute iridium chloride solution was changed to preparing a dilute rhodium chloride solution using 41.2 mg (200 mmol / L) of rhodium chloride and 40 mg (1000 mmol / L) of sodium hydroxide. Reaction conditions: The mixture was stirred at 10°C for 120 hours. Otherwise, the reaction conditions were the same as in Example 1. Finally, the rhodium / cobalt hydroxide material was obtained in step (2). From the transmission electron microscope images of the rhodium / cobalt hydroxide material shown in Figure 22, it was found that the material is in the shape of a flower, consisting of nanosheets with a diameter of 100 to 200 nanometers, and that its surface is smooth and particle-free. Application Example 3

[0077] The test was performed using a three-electrode test system with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the rhodium / cobalt hydroxide material obtained in Example 3 or the cobalt hydroxide material obtained in Step (1) of Example 3 as the working electrode. When the electrolyte is 1.0 M sodium hydroxide, the polarization curves of the two materials described above are shown in Figure 23. From Figure 23, it can be seen that the oxygen evolution performance of the rhodium / cobalt hydroxide material, in which rhodium is supported on a single atom, is improved compared to the cobalt hydroxide material. Compared to the cobalt hydroxide material, the starting potential of the rhodium / cobalt hydroxide material was 1.575 V, which was 95 mV lower. When the electrolyte was a 1.0 M sodium hydroxide + 0.5 M sodium chloride solution, the starting potential of the rhodium / cobalt hydroxide material was 1.473 V, as shown in Figure 24, which was 102 mV lower than in the case of pure sodium hydroxide. From this result, it was clear that chloride ions in the electrolyte (seawater) interact with single-atom rhodium, improving the oxygen evolution activity of rhodium and thus favoring the progress of the reaction. Example 4 - Chemical deposition method

[0078] A method for producing a nanomaterial (rhodium / nickel iron hydroxide) in which a single atom of a noble metal is dispersed on the surface of a non-noble metal substrate employs the chemical deposition method described in the second aspect of the present invention, which is specifically as follows. Referring to the method of Example 1, when preparing 40 ml of salt solution B in step (1), the mass of nickel nitrate was changed to 0.436 g, the mass of iron nitrate to 0.202 g, and the alkaline solution was changed to 0.14 g of sodium hydroxide and 0.053 g of sodium carbonate. In step (2), the preparation of 100 ml of dilute iridium chloride solution was changed to preparing a dilute rhodium chloride solution (0.001 mmol / L) using 0.03 mg (0.001 mmol / L) of rhodium chloride and 40 mg of sodium hydroxide. Conditions: 10°C, 120 hours. Application Example 4

[0079] The test was performed using a three-electrode test system with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the rhodium / nickel-iron hydroxide material obtained in Example 4 as the working electrode. When the electrolyte was a 1.0 M sodium hydroxide + 0.5 M sodium chloride solution, the starting potential of the rhodium / nickel iron hydroxide material was 1.464 V, as shown in Figure 25, which was 57 mV lower than in the case of pure sodium hydroxide. From this result, it was found that chloride ions in the electrolyte (seawater) interact with single atoms of rhodium, improving the oxygen evolution activity of rhodium and thus favoring the progress of the reaction. Example 5 - Electrodeposition Method

[0080] A method for producing a nanomaterial in which a single atom of a noble metal is dispersed on the surface of a non-noble metal substrate employs the electrodeposition method described in the third aspect of the present invention, which is specifically as follows. Step (1): Manufacturing of a nickel-iron hydroxide array Prepare 36 ml of solution using 0.6 g of urea, 0.291 g of nickel nitrate, 0.133 g of iron nitrate, 0.037 g of ammonium fluoride, and deionized water. Pour 40 ml of the solution into a reaction vessel, and wash the area to a size of 3 x 4 cm. 2 The foamed nickel iron was immersed in a solution and placed in an oven. Hydrothermal treatment was performed at a reaction temperature of 100°C for 12 hours to crystallize the material. The resulting material was washed three times each with water and ethanol, and vacuum-dried at 60°C for 10 hours to obtain foamed nickel iron (nickel-iron hydroxide array) on which nickel-iron hydroxide was supported. Step (2): The obtained nickel-iron hydroxide array was placed in a thiourea-benzyl alcohol solution (13.7 mg thiourea, 36 ml) and subjected to hydrothermal treatment at 120°C for 5 hours to sulfide it, thereby obtaining nickel-iron sulfide material, which was used for single-atom electrodeposition. Step (3): Preparation of 50 ml of electrolyte solution 2.0 g of sodium hydroxide, 1.8 mg of chloroauric acid, and an appropriate amount of water were mixed to prepare 50 ml of electrolyte solution. Step (4): Electroplating In the electrolyte obtained in step (3), a three-electrode system was used with the nickel-iron sulfide material obtained in step (2) as the working electrode, a saturated calomel electrode as the reference electrode, and a carbon rod as the counter electrode. Linear voltammetry was performed with the following parameters: voltage range of 0 to 1.2 V, scanning direction in the reverse direction, scanning speed of 0.005 V / sec, and number of cycles of 10. The obtained material was washed three times each with water and ethanol, and vacuum-dried at 60°C for 10 hours to obtain the gold / nickel-iron sulfide material. Application Example 5

[0081] Similarly, the oxygen generation performance of the materials obtained in the present invention in seawater electrolysis was tested using a three-electrode system with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the gold / nickel-iron sulfide material obtained in Example 5 or the nickel-iron sulfide material obtained in Step (2) of Example 5 as the working electrode. The electrolyte was a mixed solution of 6.0 M sodium hydroxide and 2.8 M sodium chloride, and the resulting polarization curve is shown in Figure 26. Figure 25 shows that the obtained gold / nickel-iron sulfide material exhibits good oxygen evolution performance in seawater electrolysis (dashed curve in Figure 26). This performance is superior to that of the nickel-iron sulfide sheet material (solid curve in Figure 26), with a current density of 200 mA / cm². 2 In this case, the potential was 1.47V, which was found to be 30mV lower than the potential of the nickel-cobalt-iron sulfide electrode. Comparative Example 3 - Electrodeposition Method

[0082] Referring to the method of Example 5, in step (4), the voltage range was changed from 0 to 1.2V to -2.1 to -0.2V to obtain a gold particle / nickel-iron sulfide material. Figure 27 is a transmission electron microscope image of the material, and from this figure it can be seen that because the voltage range was too wide, gold particles were formed on the surface of the substrate and a distribution of single atoms could not be obtained. Comparison with Application Example 3

[0083] Similarly, the oxygen generation performance of the material obtained in the present invention in seawater electrolysis was tested using a three-electrode system employing a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, a mixed solution of 6.0 M sodium hydroxide and 2.8 M sodium chloride as the electrolyte, and the gold particle / nickel-iron sulfide material (dashed line) from Comparative Example 3 or the gold / nickel-iron sulfide material from Example 5 as the working electrode. Figure 28, showing the results, indicates a current density of 10 mA / cm². 2In this case, the overpotential of the gold particle / nickel-iron sulfide material was 1.441V, which was found to be approximately 15mV higher than that of the gold / nickel-iron sulfide material in Example 5 (solid line). Therefore, the gold particle / nickel-iron sulfide material of Comparative Example 3 had lower activity than the gold / nickel-iron sulfide material of Example 5 when used in seawater electrolysis. From these results, it became clear that water electrolysis / seawater electrolysis performance is closely related to the catalyst structure, and catalysts with single atoms formed showed the best performance. Example 6 - Electrodeposition Method

[0084] Referring to the method of Example 5, 0.2 g of cobalt nitrate was added to the raw materials in step (1), foamed nickel was replaced with carbon paper, and 1.8 mg of chloroauric acid in step (3) was replaced with 1.3 mg of chloroplatinic acid to obtain a platinum / nickel sulfide cobalt iron material. Figure 29, which shows scanning electron microscope (SEM) images of the obtained material, preliminaryly indicates that this material has a morphology similar to gold / nickel sulfide iron material, with a smooth surface, no visible particles, and a high degree of gold dispersion. Application Example 6

[0085] Similarly, the oxygen generation performance of the material obtained in the present invention in seawater electrolysis was tested using a three-electrode system with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, the platinum / nickel-cobalt-iron sulfide material obtained in Example 6 as the working electrode, and a 6.0 M sodium hydroxide solution and a mixed solution of 6.0 M sodium hydroxide and 2.8 M sodium chloride as the electrolyte, and polarization curve chart 30 was obtained. From the polarization curve, the platinum / nickel-cobalt-iron sulfide material exhibits a current density of 100 mA / cm² in simulated seawater (a mixed solution of 6.0 M sodium hydroxide and 2.8 M sodium chloride, represented by the dashed curve in Figure 30). 2 In this case, the potential is 1.444V, and when electrolysis is performed with alkaline deionized water (6.0 M sodium hydroxide, solid curve in Figure 30), the current density is 100 mA / cm². 2 In this case, the potential was found to be 1.446V. This indicates that supporting a single atom of platinum effectively improves seawater electrolysis performance. The current density was 100 mA / cm². 2 The stability curve in this case is shown in Figure 31. The test time was long at 250 hours, and the voltage change was almost negligible. Example 7 - Electrodeposition Method

[0086] Referring to the method of Example 5, the metal nitrates in step (1) "0.291 g nickel nitrate, 0.133 g iron nitrate" were changed to 0.291 g cobalt nitrate, 0.182 g nickel nitrate, 0.202 g iron nitrate, 0.189 g zinc nitrate, and 0.115 g aluminum nitrate, foamed nickel was changed to carbon cloth, and 1.8 mg chloroauric acid in step (3) was changed to 1.7 mg palladium chloride, ultimately obtaining a palladium / nickel sulfide cobalt zinc iron aluminum material. Application Example 7

[0087] Similarly, the oxygen generation performance of the material obtained in the present invention in seawater electrolysis was tested using a three-electrode system with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, the palladium / nickel-cobalt zinc-iron-aluminum material obtained in Example 7 as the working electrode, and a 6.0 M sodium hydroxide solution and a mixed solution of 6.0 M sodium hydroxide and 2.8 M sodium chloride as the electrolyte, and polarization curve chart 32 was obtained. From the polarization curve, it was found that the starting potential of the palladium / nickel-cobalt zinc-iron-aluminum material was 1.472 V in alkaline deionized water (6.0 M sodium hydroxide), and the starting potential of the palladium / nickel-cobalt zinc-iron-aluminum material was 1.45 V in simulated seawater (a mixed solution of 6.0 M sodium hydroxide and 2.8 M sodium chloride, dashed curve in Figure 32). This revealed that in simulated seawater, the onset potential of palladium / nickel-cobalt zinc-iron-aluminum sulfide was earlier, indicating that chlorine in the solution plays a role in promoting the catalytic activity of oxygen evolution in seawater electrolysis. Example 8 - Electrodeposition Method

[0088] A method for producing a nanomaterial in which a single atom of a noble metal is dispersed on the surface of a non-noble metal substrate employs the electrodeposition method described in the third aspect of the present invention, which is specifically as follows. Step (1): Manufacturing of a nickel-iron-vanadium hydroxide array Prepare 30 ml of solution using 0.6 g of urea, 0.291 g of cobalt nitrate, 0.404 g of iron nitrate, 0.015 g of vanadium chloride, and water. Pour 50 ml of the solution into a 50 ml reaction vessel and wash a 3 x 4 cm 2 Foamed nickel-cobalt was immersed in a solution and placed in an oven, with a reaction temperature of 120°C and a duration of 12 hours. The resulting material was washed three times each with water and ethanol, and vacuum-dried at 60°C for 10 hours to obtain a nickel-iron-vanadium hydroxide array. Step (2): The nickel-iron-vanadium hydroxide array obtained in Step (1) and 500 mg of sodium hypophosphite were placed together in a tubular furnace, heated to 300°C, and maintained at that temperature for 2 hours to phosphate the mixture and obtain nickel-iron-vanadium phosphide material. The obtained material was used for single-atom electrodeposition. Step (3): Preparation of 50 ml of electrolyte solution 50 ml of electrolyte solution was prepared using 2.8 g of potassium hydroxide, 5.1 mg of ruthenium chloride, and water. Step (4): Electroplating In the electrolyte obtained in step (2), a three-electrode system was used with the array electrode obtained in step (2) as the working electrode, the saturated calomel electrode as the reference electrode, and the carbon rod as the counter electrode. Three linear voltammetries were performed with the following parameters: voltage range of 0 to 1 V, scanning direction forward, scanning speed of 0.005 V / sec, and number of cycles of 20. The obtained material was washed three times each with water and ethanol, and vacuum-dried at 60°C for 10 hours to obtain a ruthenium / nickel iron phosphide vanadium material. Figure 33, showing a scanning electron microscope (SEM) image of the obtained material, shows that the ruthenium / nickel iron phosphide vanadium material was formed by growing smooth-surfaced nanoarrays on a foamed nickel support. The nanoarrays were needle-shaped or flower-shaped, consisting of multiple nanoneedles, with a width of 50-100 nm and a length of 3-5 μm. Figure 34, showing the XRD of the obtained material, shows that the diffraction peaks of the obtained material match those of nickel iron phosphide vanadium. This indicates that the noble metal ruthenium was not individually crystallized into metal or metal oxide particles, but rather dispersed as single atoms. Application Example 8

[0089] A three-electrode system was used, with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the ruthenium / nickel-iron-vanadium phosphide material obtained in Example 8 or the nickel-iron-vanadium phosphide material obtained in step (2) as the working electrode. The oxygen evolution performance of the material from Example 8 in seawater electrolysis was tested in a mixed solution of 1.0 M sodium hydroxide and 0.5 M sodium chloride, and the resulting polarization curves are shown in Figure 35. From Figure 35, it was found that the ruthenium / nickel-iron-vanadium phosphide material had a potential of 1.473V at a current of 10 mA, while the nickel-iron-vanadium phosphide material had a potential of 1.535V at a current of 10 mA. Therefore, the obtained ruthenium / nickel-iron-vanadium phosphide material exhibited superior oxygen evolution performance in seawater electrolysis (dashed line in Figure 35), and its oxygen evolution performance in seawater electrolysis was superior to that of the nickel-iron-vanadium phosphide material (solid line in Figure 35). We have shown that a single ruthenium atom effectively improves oxygen evolution performance in seawater electrolysis. Example 9 - Electrodeposition Method

[0090] Referring to the method of Example 5, the "0.291 g nickel nitrate and 0.133 g iron nitrate" in step (1) was changed to "0.12 g iron nitrate, 0.108 g nickel nitrate, and 0.015 g manganese sulfate," foamed nickel iron was changed to foamed nickel cobalt, and the 1.8 mg chloroauric acid in step (3) was changed to 3.4 mg chloroauric acid to obtain the gold / nickel iron phosphide manganese material. Application Example 9

[0091] A three-electrode system, using a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the gold / nickel-ferromanganese phosphide material manufactured in Example 9 as the working electrode, was used to test the oxygen generation performance of the material from Example 9 in seawater electrolysis using a mixed solution of 1.0 M sodium hydroxide and 0.5 M sodium chloride, and a 1.0 M sodium hydroxide solution, and polarization curve chart 36 was obtained. Figure 36 shows that in the gold / nickel iron phosphide manganese material, the potential at a current of 10 mA was 1.46 V in a mixed solution of 1.0 M sodium hydroxide and 0.5 M sodium chloride, and the potential at a current of 10 mA was 1.51 V in a 1.0 M sodium hydroxide solution. Therefore, the obtained gold / nickel iron phosphide manganese material exhibited excellent oxygen evolution performance in seawater electrolysis (dashed line in Figure 36), and its oxygen evolution performance in seawater electrolysis was superior to its performance in alkaline electrolysis of pure water (solid line in Figure 36). From this, it is clear that noble metals interact with OH and Cl in the electrolyte to significantly improve the oxygen evolution performance of the electrode. Example 10 - Electrodeposition Method

[0092] Referring to the method of Example 5, the metal nitrate in step (1) was replaced with 0.291 g of cobalt nitrate, and the chloroauric acid in step (3) was replaced with 3.3 mg of platinum chloride to obtain a platinum / cobalt phosphide material. The cobalt phosphide material obtained in step (2) was used in application example 10 for comparative experiments. Application Example 10

[0093] A three-electrode system was used, with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the platinum / cobalt phosphide material obtained in Example 10 or the cobalt phosphide material obtained in Example 10 as the working electrode. The hydrogen generation performance of the material obtained in Example 10 in seawater electrolysis was tested in a mixed solution of 1.0 M sodium hydroxide and 0.5 M sodium chloride, and the resulting polarization curves are shown in Figure 37. From Figure 37, the current density for the platinum / cobalt phosphide material was -10 mA / cm². 2 In this case, the potential is -0.025V, and in the cobalt phosphide material, the current density is -10mA / cm². 2 The potential in this case was found to be -0.081V. Therefore, the platinum / cobalt phosphide material exhibits superior hydrogen generation performance in seawater electrolysis, and its hydrogen generation performance in seawater electrolysis is superior to that of the cobalt phosphide material. Example 11 - Electrodeposition Method

[0094] Referring to the method of Example 5, the metal nitrates in step (1) were changed to 0.291 g of cobalt nitrate, 0.03 g of indium nitrate, and 0.404 g of iron nitrate, and the chloroauric acid in step (3) was changed to 8.49 g of silver nitrate (1000 mmol / L) to obtain a silver / nickel phosphide cobalt indium material. The nickel-cobalt-indium phosphide material obtained in step (2) was used in application example 11 for comparative experiments. Application Example 11

[0095] A three-electrode system using a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the silver / nickel-cobalt-indium phosphide material obtained in Example 11 or the nickel-cobalt-indium phosphide material obtained in Example 11 as the working electrode was used to test the hydrogen generation performance of the material obtained in Example 11 in seawater electrolysis using a mixed solution of 1.0 M sodium hydroxide and 0.5 M sodium chloride. The resulting polarization curves are shown in Figure 38. From Figure 38, the silver / nickel-cobalt-indium phosphide material showed a current density of 10 mA / cm². 2 In this case, the potential is 1.45V, and in the nickel-cobalt-indium phosphide material, the current density is 10mA / cm². 2The potential in this case was found to be 1.55V. Therefore, the silver / nickel-cobalt-indium phosphide material exhibits superior hydrogen generation performance in seawater electrolysis, and its hydrogen generation performance in seawater electrolysis is superior to that of the nickel-cobalt-indium phosphide material. Example 12 - Electrodeposition Method

[0096] Step (1): 0.366 g of cobalt nitrate, 0.182 g of nickel nitrate, and 0.033 g of cerium nitrate, along with 90 ml of water, were added to an electrolytic cell. Using a three-electrode system with a 3 cm x 3 cm foamed nickel as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode, electrochemical deposition was performed on an electrochemical workstation to produce a conductive support on which non-precious metal hydroxide was supported. The deposition potential was set to -1.2 V and the deposition time to 3600 seconds. The obtained material was washed three times each with water and ethanol, and then vacuum dried to obtain a nickel-cobalt-cerium hydroxide array material (nickel-cobalt-cerium metal hydroxide on which foamed nickel was supported). Step (2): 3 x 3 cm produced in Step (1) 2 The nickel-cobalt-cerium array material was transferred to a magnetic boat and placed downstream of a tubular furnace. 0.3 g of selenium powder was placed in another magnetic boat and placed upstream of the tubular furnace. The furnace was then calcined in an N2 atmosphere at 400°C for 2 hours at a heating rate of 5°C / min, and subsequently cooled to room temperature. The final product was washed three times with ethanol to obtain the nickel-cobalt-cerium selenide material. Step (3): Preparation of 100 ml of electrolyte solution Chloroplatanic acid, NaOH, NaCl, and water were mixed to obtain 100 ml of electrolyte. In the electrolyte, the concentration of chloroplatanic acid was 100 mM, the concentration of NaOH was 6 mol / L, and the concentration of NaCl was 2.8 mol / L. Step (4): Electroplating Using a three-electrode system with the nickel-cobalt-cerium selenide material produced in step (2) as the working electrode, single atoms of the noble metal were deposited on the working electrode by electrodeposition in the electrolyte of step (3). The deposition potential was 0.03~0.73V (VS SCE), the number of cycles was 3, and the scanning speed was 5mv / s. The obtained material was washed three times each with water and ethanol, and then vacuum dried to obtain platinum / nickel-cobalt-cerium selenide. The nickel-cobalt-cerium selenide material obtained in step (2) was used in application example 12 for comparative experiments. Application Example 12

[0097] A three-electrode system using a platinum / nickel-cobalt-cerium selenide material or a nickel-cobalt-cerium selenide material as the working electrode, a saturated calomel electrode as the reference electrode, and a platinum electrode as the counter electrode was used to test the hydrogen generation performance of the materials obtained in Example 12 in seawater electrolysis using a mixed solution of 1.0 M sodium hydroxide and 0.5 M sodium chloride, and polarization curve chart 39 was obtained. From the polarization curve, it was found that the performance of the platinum / nickel-cobalt-cerium selenide material as an anode for seawater electrolysis was superior to that of the nickel-cobalt-cerium selenide material. The platinum / nickel-cobalt-cerium selenide material had an onset potential of only 1.44 V, which is about 50 mV lower than the onset potential of the nickel-cobalt-cerium selenide material. From this, it was revealed that the dispersion of single atoms of platinum on the surface of nickel-cobalt-cerium selenide has a good effect in improving the intrinsic oxygen generation activity of the material in seawater electrolysis. Comparative Example 4 - Electrodeposition Method

[0098] Referring to the method of Example 12, the concentrations of chloroplatinic acid (100 mM), NaOH (6 mol / L), and NaCl (2.8 mol / L) in step (3) were changed to chloroplatinic acid (100 mM), NaOH (6 mol / L), and NaCl (0.1 mol / L). Platinum-oxygen / nickel-cobalt-cerium selenide was obtained. In this case, only oxygen coordinated to the platinum, and no halogen coordinated. Comparative Application Example 4

[0099] The working electrode was changed to the platinum-oxygen / nickel-cobalt-cerium selenide mixture of Comparative Example 4. Using a three-electrode system with a saturated calomel electrode as the reference electrode and a platinum electrode as the counter electrode, the hydrogen generation performance of the material obtained in Comparative Example 4 during seawater electrolysis was tested in a mixed solution of 1.0 M sodium hydroxide and 0.5 M sodium chloride. The results are shown in Figure 40. From Figure 40, the current density was 10 mA / cm². 2 In this case, the starting potential of platinum oxygen / nickel cobalt cerium selenide was 1.45V (dashed line), which was found to be approximately 10mV higher than that of platinum / nickel cobalt cerium selenide in Example 12 (solid line). Therefore, when used in seawater electrolysis, the activity of platinum oxygen / nickel cobalt cerium selenide in Comparative Example 4 was lower than that of platinum / nickel cobalt cerium selenide in Example 12. From these results, it became clear that the hydrogen generation performance of materials in water electrolysis / seawater electrolysis is closely related to the local coordination structure of a single atom of the noble metal, and that the performance is best when halogen and oxygen-containing functional groups are simultaneously coordinated to the noble metal. It was also confirmed that the coordination structure when manufacturing platinum / nickel cobalt cerium selenide materials is related to the concentration of sodium chloride. Example 13 - Electrodeposition Method

[0100] Referring to the method of Example 12, the metal nitrate in step (1) was replaced with 0.732 g of cobalt nitrate, and the soluble noble metal salt in step (3) was replaced with potassium chloruthenate to obtain a ruthenium / cobalt selenide material, which is a nanoarray in which ruthenium is dispersed on the surface of cobalt selenide. Compared with Example 12, selenides are produced in both cases, but sodium chloride is not added in the production of this material. Figure 41, which shows a scanning electron microscope (SEM) image of the obtained material, shows a "dandelion"-shaped array of nanowires grown on a foamed nickel support. The nanowires have a diameter of approximately 10-50 nanometers and a length of approximately 1-2 μm, with a smooth surface and no particles. Application Example 13

[0101] The working electrode was changed to the ruthenium / cobalt selenide material or cobalt selenide material of Example 13, and a three-electrode system using a saturated calomel electrode as the reference electrode and a platinum electrode as the counter electrode was used to test the hydrogen generation performance of the material obtained in seawater electrolysis using seawater (a mixed solution of 6 M sodium hydroxide and 2.8 M sodium chloride) or alkaline deionized water (6 M sodium hydroxide solution), and polarization curve chart 42 was obtained. From the polarization curve, when the ruthenium / cobalt selenide electrode is used as the anode for seawater electrolysis, the current density was 200 mA / cm² in seawater (6 M sodium hydroxide + 2.8 M sodium chloride solution, dashed line in Figure 42) and alkaline deionized water (6 M sodium hydroxide solution, solid line in Figure 42). 2 The potentials in these cases were found to be 1.51V and 1.56V, respectively. From this, it became clear that when a material with a single ruthenium atom supported is used in seawater electrolysis, chloride ions in the seawater interact with the single ruthenium atom, adjusting and controlling the structure of the active site, and effectively improving the seawater electrolysis performance. Example 14 - Electrodeposition Method

[0102] Referring to the method of Example 12, the metal nitrate in step (1) was changed to 0.291 g of nickel nitrate and 0.404 g of iron nitrate, and the soluble noble metal salt in step (3) was changed to iridium chloride to obtain an iridium / nickel selenide iron material, which is a nanoarray in which iridium is dispersed on the surface of nickel selenide. The nickel iron selenide material obtained in step (2) was used in application example 14 for comparative experiments. Application Example 14

[0103] The working electrode was changed to the iridium / nickel-iron selenide material or the nickel-iron selenide material of Example 14, and a saturated calomel electrode was used as the reference electrode and a platinum electrode as the counter electrode in a three-electrode system. The hydrogen generation performance of the material obtained in Example 14 during seawater electrolysis was tested in seawater (a mixed solution of 6 M sodium hydroxide and 2.8 M sodium chloride) or alkaline deionized water (a 6 M sodium hydroxide solution), and polarization curve chart 43 was obtained. From the polarization curve, it was found that when the iridium / nickel-iron selenide material is used as the anode for seawater electrolysis, the current density is 200 mA / cm² in seawater (dashed line in Figure 43) and alkaline deionized water (solid line in Figure 43). 2 The potentials in these cases were found to be 1.51V and 1.56V, respectively. From this, it became clear that when a material with a single iridium atom supported is used in seawater electrolysis, chloride ions in the seawater interact with the single iridium atom, adjusting and controlling the structure of the active site, and effectively improving the seawater electrolysis performance. Example 15 - Multi-precious metal support - Electrodeposition method

[0104] Referring to the method of Example 12, the metal nitrates in step (1) were changed to 0.174 g of nickel nitrate, 0.121 g of iron nitrate, and 0.037 g of vanadium nitrate, and the soluble noble metal salts in step (3) were changed to 2 mg of iridium chloride and 1 mg of platinum chloride to obtain an iridium platinum / nickel iron selenide vanadium material, which is a nanoarray in which iridium platinum is dispersed on the surface of nickel iron selenide vanadium. The nickel iron vanadium selenide material from step (2) was used in application example 15 for comparative experiments. Application Example 15

[0105] A three-electrode test system was used, with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the iridium platinum / nickel iron selenide vanadium material or the nickel iron selenide vanadium material from Example 15 as the working electrode. The voltage range was set to 0-1V (relative to saturated calomel), and the electrolyte was changed to 6.0M sodium hydroxide and 2.8M saturated sodium chloride. The oxygen generation performance of the material obtained in Example 15 during seawater electrolysis was tested. As shown in Figure 44, the iridium platinum / nickel iron selenide vanadium material exhibited superior oxygen generation performance during seawater electrolysis, and it was found to be superior to that of the nickel iron selenide vanadium material. Testing the hydrogen generation performance in seawater electrolysis using a three-electrode system of the material obtained in Example 15. Using a saturated calomel electrode as the reference electrode and a platinum electrode as the counter electrode, with a voltage range of -1 to -2V (relative to saturated calomel), and with 6.0M sodium hydroxide and 2.8M saturated sodium chloride as the electrolytes, the cathode hydrogen generation performance of the material in seawater electrolysis was represented, and the obtained test results are shown in Figure 45. From Figure 45, it was found that the iridium platinum / nickel iron selenide vanadium material also possesses good cathode hydrogen generation performance. Specifically, the onset overpotential for hydrogen generation in the iridium platinum / nickel iron selenide vanadium material was approximately 20mV, and the onset overpotential for hydrogen generation in the nickel iron selenide vanadium material was approximately 80mV. Therefore, it was confirmed that the distribution of iridium platinum as a single atom is advantageous in improving the catalytic activity of the hydrogen generation reaction by approximately 60mV, thus advancing the onset potential of hydrogen generation. Example 16 - Electrodeposition Method

[0106] Referring to the method of Example 8, the metal nitrates in step (1) were changed to 0.174 g of nickel nitrate, 0.191 g of cobalt nitrate, and 0.023 g of cadmium nitrate, and the soluble noble metal salts in step (3) were changed to 0.148 mg (0.001 mmol / L) of osmium chloride and 0.2 mg (0.1 mmol / L) of sodium hydroxide to obtain an osmium / nickel-cobalt-cadmium selenide material, which is a nanoarray in which osmium is dispersed on the surface of nickel-cobalt-cadmium selenide. The nickel-cobalt-cadmium selenide material from step (2) was used in application example 16 for comparative experiments. Application Example 16

[0107] A three-electrode test system was used, with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the osmium / nickel-cobalt-cadmium selenide material or the nickel-cobalt-cadmium selenide material from Example 16 as the working electrode. The electrolyte was changed to 6.0 M sodium hydroxide and 2.8 M saturated sodium chloride, and the oxygen generation performance of the materials in seawater electrolysis was tested. Figure 46 shows that the obtained osmium / nickel-cobalt-cadmium selenide material exhibited superior oxygen generation performance in water electrolysis, and its oxygen generation performance in water electrolysis was superior to that of the nickel-cobalt-cadmium selenide material. In the osmium / nickel-cobalt-cadmium selenide material, the overpotential at a current of 10 mA was only about 218 mV, which was about 86 mV lower than that of the nickel-cobalt-cadmium selenide material. Example 17 - Electrodeposition Method

[0108] Step (1): Manufacturing of cobalt hydroxide material A 36 ml solution was prepared using 0.6 g of urea, 0.291 g of cobalt nitrate, 0.037 g of ammonium fluoride, and water. 40 ml of the solution was poured into a reaction vessel, and the washed foamed nickel was immersed in the solution. The vessel was then placed in an oven and the reaction temperature was set to 100°C for 12 hours. The resulting material was washed three times each with water and ethanol, and then vacuum-dried at 60°C for 10 hours. Step (2): The cobalt hydroxide material obtained in Step (1) was placed in the center of a tubular furnace and baked at 200°C for 4 hours to obtain tricobalt tetroxide material. Step (3): Preparation of 50 ml of electrolyte solution 50 ml of electrolyte solution was prepared using 2.0 g of sodium hydroxide, 1.8 mg of iridium chloride, and water. Step (4): Electroplating In the electrolyte obtained in (3), a three-electrode system was used, with the array electrode obtained in step (2) as the working electrode, the saturated calomel electrode as the reference electrode, and the carbon rod as the counter electrode. Linear voltammetry was performed with the following parameters: voltage range of -0.7 to -0.5 V, scanning direction in the reverse direction, scanning speed of 0.005 V / sec, and number of cycles of 10. The obtained material was washed three times each with water and ethanol, and vacuum-dried at 60°C for 10 hours to obtain iridium / tricobalt tetroxide material. Figure 47, showing a scanning electron microscope image of the obtained material, reveals that the material's surface is smooth and free of noble metal particles. Figure 48, showing the XRD of the obtained material, shows that the diffraction peak matches that of tricobalt tetroxide, indicating that iridium has not individually crystallized into a metal or metal oxide. The tricobalt tetroxide material from step (2) was used in application example 17 for comparative experiments. Application Example 17

[0109] In a mixed solution of 6.0 M sodium hydroxide and 2.8 M sodium chloride, the oxygen evolution performance of the iridium / tricobalt tetroxide material and the tricobalt tetroxide material of Example 17 in seawater electrolysis was tested using a three-electrode system, and the resulting polarization curves are shown in Figure 49. From Figure 49, it was found that the obtained iridium / tricobalt tetroxide material exhibited superior oxygen evolution performance in seawater electrolysis (dashed line in Figure 49), and that its oxygen evolution performance in seawater electrolysis was superior to that of the tricobalt tetroxide material (solid line in Figure 49). The iridium / tricobalt tetroxide material had a current density of 200 mA / cm². 2 In this case, the potential was 1.49V, which was 90mV lower than that of the tricobalt tetroxide electrode. Example 18 - Multi-precious metal support - Electrodeposition method

[0110] Referring to the method of Example 17, the metal nitrates in step (1) were changed to 271 g of nickel nitrate, 0.404 g of iron nitrate, 0.050 g of copper nitrate, and 0.050 g of strontium nitrate, and the iridium chloride in step (3) was changed to 3 mg of ruthenium chloride and 2 mg of palladium chloride to obtain a ruthenium-palladium / nickel-iron-copper-strontium oxide material. The nickel-iron-copper-strontium oxide material from step (2) was used in application example 18 for comparative experiments. Application Example 18

[0111] Testing the oxygen generation performance of the material obtained in Example 18 in seawater electrolysis using a three-electrode test system. A saturated calomel electrode was used as the reference electrode, a platinum electrode as the counter electrode, and the ruthenium palladium / nickel iron copper strontium oxide or nickel iron copper strontium oxide material manufactured in Example 18 was used as the working electrode. The voltage range was 0 to 1 V, and the electrolytes were 6.0 M sodium hydroxide and 2.8 M sodium chloride. The oxygen generation performance of the material in seawater electrolysis is shown. From Figure 50, it was found that the obtained ruthenium palladium / nickel iron copper strontium oxide material exhibited excellent oxygen generation performance in water electrolysis (starting potential of 1.393 V), and that its oxygen generation performance in water electrolysis was superior to that of the nickel iron copper strontium oxide material (starting potential of 1.425 V). Testing the hydrogen generation performance of the material obtained in Example 18 in seawater electrolysis using a three-electrode test system: A saturated calomel electrode was used as the reference electrode, a platinum electrode as the counter electrode, and the ruthenium palladium / nickel iron copper strontium oxide or nickel iron copper strontium oxide material manufactured in Example 18 was used as the working electrode. The voltage range was -1 to -2V, and the electrolytes were 6.0M sodium hydroxide and 2.8M sodium chloride. The cathode hydrogen generation performance of the material in seawater electrolysis was represented, and the obtained test results are shown in Figure 51. From Figure 51, it was found that the ruthenium palladium / nickel iron copper strontium oxide material also possesses good cathode hydrogen generation performance. Specifically, the hydrogen generation initiation potential was approximately 17mV for the ruthenium palladium / nickel iron copper strontium oxide material, and approximately 88mV for the nickel iron copper strontium oxide material. It was confirmed that the hydrogen generation initiation potential was advanced by approximately 60mV due to the distribution of the ruthenium palladium complex precious metal as a single atom, and that the distribution of the ruthenium palladium complex precious metal as a single atom is advantageous for improving the catalytic activity of the hydrogen generation reaction. Example 19 - Electrodeposition Method

[0112] A method for producing a nanomaterial in which a single atom of a noble metal is dispersed on the surface of a non-noble metal substrate employs the electrodeposition method described in the third aspect of the present invention, which is specifically as follows. Step (1): Manufacturing of a nickel-cobalt iron hydroxide array Prepare 36 ml of solution using 0.6 g of urea, 0.291 g of nickel nitrate, 0.291 g of cobalt nitrate, 0.266 g of iron nitrate, 0.037 g of ammonium fluoride, and deionized water. Pour 40 ml of the solution into a reaction vessel, and wash the area to a size of 3 x 4 cm. 2 The foamed nickel iron was immersed in a solution and placed in an oven. Hydrothermal treatment was performed at a reaction temperature of 100°C for 12 hours to crystallize the material. The resulting material was washed three times each with water and ethanol, and vacuum-dried at 60°C for 10 hours to obtain foamed nickel iron (nickel-cobalt-iron hydroxide array) on which nickel-cobalt-iron hydroxide was supported. Step (2): The obtained nickel-cobalt-iron hydroxide array was placed in a thiourea-benzyl alcohol solution (13.7 mg of thiourea, 36 ml) and subjected to hydrothermal treatment at 120°C for 5 hours to sulfide it, thereby obtaining nickel-cobalt-iron sulfide material, which was used for single-atom electrodeposition. Step (3): Preparation of 50 ml of electrolyte solution 2.0 g of sodium hydroxide, 1.8 mg of chloroauric acid, and an appropriate amount of water were mixed to prepare 50 ml of electrolyte solution. Step (4): Electroplating In the electrolyte obtained in step (3), a three-electrode system was used, with the nickel-cobalt-iron sulfide material obtained in step (2) as the working electrode, a saturated calomel electrode as the reference electrode, and a carbon rod as the counter electrode. Linear voltammetry was used with the following parameters: voltage range of 0 to 1.2 V, scanning direction in the reverse direction, scanning speed of 0.005 V / sec, and number of cycles of 10. The obtained material was washed three times each with water and ethanol, and vacuum-dried at 60°C for 10 hours to obtain the gold / nickel-cobalt-iron sulfide material. Application Example 19

[0113] 1. Seawater electrolysis performance Similarly, the oxygen generation performance of the materials obtained in the present invention in seawater electrolysis was tested using a three-electrode system with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the gold / nickel-cobalt-iron sulfide material obtained in Example 19 or the nickel-cobalt-iron sulfide material obtained in Step (2) of Example 19 as the working electrode. The electrolyte was a 6.0 M sodium hydroxide solution, and the resulting polarization curves are shown in Figure 52. A saturated calomel electrode was used as the reference electrode, a platinum electrode as the counter electrode, and the gold / nickel-cobalt-iron sulfide material obtained in Example 19 was used as the working electrode. The electrolyte was a mixed solution of 6.0 M sodium hydroxide and 2.8 M sodium chloride, and the resulting polarization curve is shown in Figure 53. As shown in Figure 52, the obtained gold / nickel-cobalt-iron sulfide material exhibits good oxygen evolution performance in alkaline water electrolysis, and its oxygen evolution performance in alkaline water electrolysis is superior to that of the nickel-cobalt-iron sulfide material, with a current density of 100 mA / cm². 2In this case, the potential was 1.50V, which was found to be 19mV lower than that of the nickel-cobalt-iron sulfide electrode. As shown in Figure 53, the obtained gold / nickel-cobalt-iron sulfide material exhibits good oxygen generation performance in seawater electrolysis, achieving 100 mA / cm² in seawater. 2 The overvoltage required to reach this point was 1.485V, which is 15mV lower than that of the alkaline pure solution, indicating superior catalytic activity. 2. Effect of bromine ions on seawater electrolysis performance Referring to the first aspect of Application Example 19, a similar three-electrode test system is obtained by adding sodium bromide to the electrolyte, i.e., changing the electrolyte to a 6.0 M sodium hydroxide solution or a mixed solution of 6.0 M sodium hydroxide and 2.0 M sodium bromide, and using the gold / nickel sulfide cobalt iron material obtained in Example 19 as the working electrode, and the resulting polarization curve is shown in Figure 54. Figure 54 shows that adding bromide ions to the test solution accelerated the onset potential of gold / nickel-cobalt iron sulfide (1.50V) to 1.482V, indicating its favorability as a catalyst for water splitting and oxygen evolution. Real-time characterization using on-site Raman spectroscopy during electrolysis (Figure 55) revealed that bromine in the electrolyte can coordinate with a single atom of a noble metal. In the electrolyzed material, oxygen, chlorine, and bromine are simultaneously coordinated to the gold atom. III. Effect of fluoride ions on seawater electrolysis performance Referring to the first aspect of Application Example 19, a similar three-electrode test system is constructed by adding sodium fluoride to the electrolyte, i.e., changing the electrolyte to 6.0 M sodium hydroxide, or 6.0 M sodium hydroxide and 2.0 M sodium fluoride, and using the gold / nickel-cobalt-iron sulfide material obtained in Example 19 as the working electrode. The resulting polarization curve is shown in Figure 56. Figure 56 shows that adding fluoride ions to the test solution accelerated the starting potential of gold / nickel-cobalt iron sulfide (1.50V) to 1.475V, indicating its favorability as a catalyst for water splitting and oxygen evolution. During electrolysis, oxygen, chlorine, and fluorine are simultaneously coordinated to the gold atom. Example 20 - Multi-precious metal support - Electrodeposition method

[0114] Referring to the method of Example 19, the metal nitrate in step (1) was changed to 0.810 g of nickel nitrate and 0.404 g of iron nitrate, and the iridium chloride in step (3) was changed to 3 mg of iridium chloride and 2 mg of ruthenium chloride, ultimately yielding an iridium-ruthenium / nickel-iron sulfide material. Here, referring to the method of Example 19, a nickel iron sulfide material was obtained in step (2) of Example 20. As shown in Figure 57, spherical aberration electron microscopy reveals that the distribution of Ru and Ir is uniformly distributed on the surface of nickel iron sulfide as single atoms. Synchrotron radiation reveals the local coordination environment of Ru and Ir, as shown in Figure 58. Figure 58a shows that Ir is coordinated with oxygen and chlorine, and Figure 58b shows that Ru is coordinated with oxygen. Analysis combining Figures 58a and 58b shows that Ru and Ir have a strong interaction, which is different from a simple combination of Ir and Ru. Application Example 20

[0115] 1. Oxygen generation performance in seawater electrolysis The oxygen generation performance of the material obtained in Example 20 in seawater electrolysis was tested using a three-electrode test system with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the iridium ruthenium / nickel-iron sulfide material manufactured in Example 20 or the nickel-iron sulfide material obtained in Step (2) of Example 20 as the working electrode. The voltage range was 0 to 1V, and the electrolyte was a mixed solution of 6.0M sodium hydroxide and 2.8M sodium chloride. The oxygen generation performance of the material in seawater electrolysis is expressed. Figure 59 shows the polarization curve chart for hydrogen evolution in iridium ruthenium / nickel iron sulfide and nickel iron sulfide materials in a 6 mol / L NaOH + 2.8 mol / L NaCl solution in Application Example 20. Figure 59 shows that the obtained iridium ruthenium / nickel-iron sulfide material exhibited superior oxygen evolution performance in water electrolysis (starting potential of 1.475V), and that this oxygen evolution performance in water electrolysis was superior to that of the nickel-iron sulfide material (starting potential of 1.512V). 2. Hydrogen generation performance in seawater electrolysis A three-electrode test system was used, with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the iridium ruthenium / nickel-iron sulfide material manufactured in Example 20 or the nickel-iron sulfide material obtained in Step (2) of Example 20 as the working electrode. The hydrogen generation performance of the material obtained in seawater electrolysis was tested using a voltage range of -1 to -2V and electrolytes of 6.0M sodium hydroxide and 2.8M sodium chloride. The cathode hydrogen generation performance of the material in seawater electrolysis is represented, and the test results are shown in Figure 60. Figure 60 shows that the iridium ruthenium / nickel-iron sulfide material also possesses good cathode hydrogen generation performance. Specifically, the hydrogen generation initiation potential is approximately 32.6 mV for the iridium ruthenium / nickel-iron sulfide material and approximately 116 mV for the nickel-iron sulfide material. The distribution of iridium ruthenium as a single atom accelerates the hydrogen generation initiation potential by approximately 84 mV, and it was confirmed that the distribution of iridium ruthenium as a single atom is advantageous in improving the catalytic activity of the hydrogen generation reaction. Example 21 - Multi-precious metal support - Chemical deposition method

[0116] The method for producing a nanomaterial (iridium platinum / nickel iron vanadium phosphide) in which a single atom of a noble metal is dispersed on the surface of a non-noble metal substrate employs the chemical deposition method described in the second aspect of the present invention, which is specifically as follows. Step (1): Fabrication of non-precious metal substrate-nickel-iron-vanadium complex metal hydroxide nanosheets Preparation of 40 ml of alkaline solution A: 0.48 g of sodium hydroxide and 0.106 g of sodium carbonate were mixed with an appropriate amount of deionized water to prepare 40 ml of alkaline solution A. Preparation of 40 ml of salt solution B: 0.291 g of nickel nitrate, 0.096 g of vanadium chloride, and 0.202 g of iron nitrate were mixed with an appropriate amount of deionized water to prepare 40 ml of salt solution B. Solution A and Solution B were simultaneously added dropwise to 40 ml of rapidly stirred water. The pH was maintained at approximately 8.5 until the addition of salt solution B was complete, and the mixture was stirred for a further 12 hours. The precipitate was then centrifuged to obtain a precipitate, which was washed three times each with deionized water and ethanol. The precipitate was then vacuum-dried at 60°C to obtain nickel-iron-vanadium hydroxide nanosheets. Step (2): Manufacturing of phosphide nanomaterials The nickel-iron vanadium hydroxide obtained in step (1) and 300 mg of sodium hypophosphite were placed together in a tubular furnace, heated to 300°C, and maintained at that temperature for 1 hour to phosphate, thereby obtaining nickel-iron vanadium phosphide material. The obtained material was used for the deposition of single atoms in the next step. Step (3): Manufacturing of single-atom materials of compound noble metals 1 g of the nickel iron vanadium phosphide nanosheet obtained in step (2) was weighed, and 30 ml of deionized water was added to it. The mixture was sonicated for 2-3 hours until the nanosheet was uniformly distributed in the water. Preparation of 20 ml of alkaline dilute solution of iridium chloride and chloroplatinic acid: 20 ml of alkaline dilute solution of iridium chloride was prepared using 5 mg of iridium chloride, 2 mg of chloroplatinic acid, 0.4 mg of sodium hydroxide (0.5 mmol / L), and deionized water. Then, under high-speed stirring conditions (500 R / min), the above alkaline dilute solution was added dropwise to the uniformly dispersed nickel iron vanadium phosphide at a dropwise rate of 5 drops / minute. After the dropwise addition was complete, the mixture was stirred continuously for 4 hours under heating conditions of 95°C, centrifuged to obtain a precipitate, washed three times each with water and ethanol, and vacuum-dried at 60°C to obtain a nanomaterial (iridium platinum / nickel iron vanadium phosphide) in which two single atoms of iridium and platinum were supported on nickel iron vanadium phosphide. Application Example 21

[0117] 1. Oxygen generation performance in seawater electrolysis The oxygen generation performance of the material obtained in Example 21 in seawater electrolysis was tested using a three-electrode test system with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the iridium platinum / nickel iron vanadium phosphide material manufactured in Example 21 or the nickel iron vanadium phosphide material obtained in Step (2) of Example 21 as the working electrode. The voltage range was 0 to 1V, and the electrolytes were 6.0M sodium hydroxide and 2.8M sodium chloride. The oxygen generation performance of the material in seawater electrolysis is expressed. Figure 61 shows the polarization curve charts for oxygen evolution in a 6 mol / L NaOH + 2.8 mol / L NaCl solution for iridium platinum / nickel iron vanadium phosphide and nickel iron vanadium phosphide materials in Application Example 21. Figure 61 shows that the obtained iridium platinum / nickel iron phosphide vanadium material exhibited superior oxygen evolution performance in water electrolysis (starting potential of 1.488V), and that this oxygen evolution performance in water electrolysis was superior to that of the nickel iron phosphide vanadium material (starting potential of 1.528V). 2. Hydrogen generation performance in seawater electrolysis A three-electrode test system was used, with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the iridium-platinum / nickel-iron-vanadium phosphide material manufactured in Example 21 or the nickel-iron-vanadium phosphide material obtained in Step (2) of Example 21 as the working electrode. The hydrogen generation performance of the material obtained in seawater electrolysis was tested using a voltage range of -1 to -2V and electrolytes of 6.0M sodium hydroxide and 2.8M sodium chloride. The cathode hydrogen generation performance of the material in seawater electrolysis is represented, and the test results are shown in Figure 62. Figure 62 shows that the iridium platinum / nickel iron phosphide vanadium material also possesses good cathode hydrogen generation performance. Specifically, the iridium platinum / nickel iron phosphide vanadium material exhibits a hydrogen generation current density of 10 mA / cm². 2 The potential required to reach this level is approximately 33.4 mV, and in nickel iron vanadium phosphide material, the current density for hydrogen generation is 10 mA / cm². 2The potential required to reach this point is approximately 66.7 mV. The distribution of iridium-platinum complex precious metals as single atoms accelerates the hydrogen evolution initiation potential by approximately 33 mV, confirming that the distribution of iridium-platinum complex precious metals as single atoms is advantageous in improving the catalytic activity of the hydrogen evolution reaction. Figure 63 shows the moisture polarity curve for a dual-function complete electrolysis when the iridium platinum / nickel iron vanadium phosphide material produced in Example 21 functions simultaneously as both the cathode and anode, with a current density of 400 mA / cm². 2 The voltage required to reach this point is only about 2.55V, demonstrating excellent performance. It has been confirmed that the material of this invention can be used simultaneously as both the cathode and anode. Example 22 - Chemical deposition method

[0118] The manufacturing method for a nanomaterial (ruthenium / nickel-iron(2+) iron hydrotalcite) in which ruthenium is dispersed as a single atom on the surface of nickel-iron hydrotalcite doped with divalent iron is as follows: Step (1): Production of divalent iron-doped nickel-iron hydrotalcite nanomaterials (nickel-iron(2+)-iron hydrotalcite nanosheets) Nitrogen gas was introduced into the water for 30 minutes to remove dissolved oxygen, and the nitrogen gas flow rate was controlled to 200 ml / min. After saturation, the water was subjected to the following steps. Preparation of 40 ml of alkaline solution A: 0.40 g of sodium hydroxide (10 mmol) and 0.106 g of sodium carbonate (1 mmol) were mixed with an appropriate amount of deionized water to prepare 40 ml of alkaline solution A. Preparation of 40 ml of salt solution B: 0.162 g (1 mmol) of iron chloride, 0.126 g (1 mmol) of ferrous chloride, and 0.129 g (1 mmol) of nickel chloride were mixed with an appropriate amount of deionized water to prepare 40 ml of salt solution B. Under a nitrogen gas atmosphere, solutions A and B were simultaneously added dropwise to 40 ml of rapidly stirred water. The pH was maintained at approximately 8.5 until the addition of salt solution B was complete, and the mixture was stirred for a further 12 hours. The precipitate was then centrifuged to obtain a precipitate, which was washed three times each with deionized water from which dissolved oxygen had been removed and with ethanol. The precipitate was then vacuum-dried at 60°C to obtain nickel iron(2+) iron hydrotalcite nanosheets. Step (2): Manufacturing of nanomaterials After removing dissolved oxygen from the water, 1 g of nickel iron(2+) iron hydrotalcite nanosheets obtained in step (1) was weighed, and 30 ml of deionized water was added to it. The mixture was sonicated for 2-3 hours until the nanosheets were uniformly distributed in the water. Preparation of 10 ml of dilute ruthenium chloride solution: 10 ml of dilute ruthenium chloride solution was prepared using 5 mg of ruthenium chloride (ruthenium concentration 2.22 mmol / L) and deionized water. Then, under a nitrogen gas atmosphere and high-speed stirring conditions (500 R / min), the above ruthenium chloride solution was added dropwise to the uniformly dispersed nickel iron(2+) iron hydrotalcite. After the addition was complete, stirring was continued for 6 hours under heating conditions of 20°C, and the precipitate was obtained by centrifugation. The precipitate was washed three times each with water and ethanol, and vacuum dried at 60°C to obtain ruthenium / nickel iron(2+) iron hydrotalcite. In any of the above operations, the effects of oxygen gas were removed. Figure 64, which shows the transmission electron microscope image of the obtained ruthenium / nickel iron(2+) hydrotalcite, reveals that the ruthenium / nickel iron(2+) hydrotalcite consists of hexagonal sheets with a diameter of 50-100 nm and a thickness of 5-10 nm, with a smooth surface and no apparent particles. The elemental distribution of the obtained ruthenium / nickel-iron(2+) iron hydrotalcite is shown in Figure 65, and its spherical aberration electron microscope image is shown in Figure 66. From Figure 65, it can be seen that the elements are uniformly distributed in the material. Combining this with the spherical aberration electron microscope image 66, it was found that the noble metal ruthenium is highly dispersed on the surface of the nickel-iron(2+) iron hydrotalcite in the form of single atoms. Figure 67, showing the XRD spectrum of the obtained ruthenium / nickel iron(2+) iron hydrotalcite, revealed that the diffraction peaks matched those of hydrotalcite (abbreviated as LDH in the figure). This clearly indicates that the ruthenium synthesized did not crystallize into ruthenium oxide or elemental ruthenium. Chlorine and oxygen atoms are simultaneously coordinated to the surface of the single atom of the noble metal. The single atom of the noble metal is selectively fixed on the divalent iron ion. Figure 68, which shows the results of the surface electronic structure (XPS) characterization of the obtained material, indicates that the introduction of divalent iron was successful, and that the valence of single Ru atoms decreased as divalent iron was introduced. Inductively coupled plasma emission spectroscopy (EMF) analysis was performed on ruthenium / nickel iron(2+) iron hydrotalcite, and the result showed that the ruthenium content in this material is 1.36% by mass relative to the total mass of the material. Application Example 22

[0119] Testing water electrolysis performance A three-electrode system using a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the ruthenium / nickel iron(2+) hydrotalcite obtained in Example 22 as the working electrode was used to test the oxygen generation performance of the ruthenium / nickel iron(2+) hydrotalcite obtained in Example 22 of the present invention in water electrolysis using a 1.0 M potassium hydroxide solution. The obtained polarization curve is shown in Figure 69. Figure 69 shows that the current density for ruthenium / nickel iron(2+) iron hydrotalcite is 10 mA / cm². 2 Under these conditions, the required potential was found to be only 1.424V, which is about 300mV lower than that of commercially available ruthenium dioxide. Example 23 - Chemical deposition method The manufacturing method for the nanomaterial (iridium / nickelmanganese(2+) iron hydrotalcite) in which iridium is dispersed as a single atom on the surface of divalent manganese-doped nickel-iron hydrotalcite is as follows: Step (1): Fabrication of divalent manganese-doped nickel-iron hydrotalcite nanomaterials (nickel-manganese(2+) iron hydrotalcite nanosheets) Nitrogen gas was introduced into the water for 30 minutes to remove dissolved oxygen, and the nitrogen gas flow rate was controlled to 200 ml / min. After saturation, the water was subjected to the following steps. Preparation of 40 ml of alkaline solution A: 0.40 g of sodium hydroxide (10 mmol) and 0.106 g of sodium carbonate (1 mmol) were mixed with an appropriate amount of deionized water to prepare 40 ml of alkaline solution A. Preparation of 40 ml of salt solution B: 0.162 g (1 mmol) of iron chloride, 0.125 g (1 mmol) of manganese chloride, and 0.129 g (1 mmol) of nickel chloride were mixed with an appropriate amount of deionized water to prepare 40 ml of salt solution B. Under a nitrogen gas atmosphere, solutions A and B were simultaneously added dropwise to 40 ml of rapidly stirred water. The pH was maintained at approximately 8.5 until the addition of salt solution B was complete, and the mixture was stirred for a further 12 hours. The precipitate was then centrifuged to obtain a precipitate, which was washed three times each with deionized water from which dissolved oxygen had been removed and with ethanol. The precipitate was then vacuum-dried at 60°C to obtain nickel manganese(2+) iron hydrotalcite nanosheets. Step (2): Manufacturing of nanomaterials After boiling to remove dissolved oxygen from the water, 0.5 g of nickel manganese(2+) iron hydrotalcite nanosheets obtained in step (1) were weighed, and 30 ml of deionized water was added to them. The mixture was sonicated for 2-3 hours until the nanosheets were uniformly distributed in the water. Preparation of 1 ml of dilute iridium chloride solution: 1 ml of dilute iridium chloride solution (iridium concentration 100 mmol / L) was prepared using 31.6 mg of iridium chloride and deionized water. Then, under a nitrogen gas atmosphere and high-speed stirring conditions (500 R / min), the above iridium chloride solution was added dropwise to the uniformly dispersed nickel manganese(2+) iron hydrotalcite. After the addition was complete, stirring was continued at -4°C for 24 hours, and the precipitate was obtained by centrifugation. The precipitate was washed three times each with water and ethanol, and vacuum dried at 60°C to obtain iridium / nickel manganese(2+) iron hydrotalcite. Application Example 23

[0120] A three-electrode system using a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the iridium / nickelmanganese(2+) iron hydrotalcite material obtained in Example 2 as the working electrode was used to test the oxygen generation performance of the iridium / nickelmanganese(2+) iron hydrotalcite of Example 23 of the present invention in water electrolysis using a mixed solution of 1.0 M sodium hydroxide and 0.5 M sodium chloride. The resulting polarization curve is shown in Figure 70. Figure 70 shows that for iridium / nickelmanganese(2+) iron hydrotalcite material, the current density is 10 mA / cm². 2 Under these conditions, the required potential was only 1.447, indicating good performance. Example 24 - Electrochemical Deposition Method

[0121] Step (1): Manufacturing of a nickel-cobalt iron hydroxide array Prepare 36 ml of solution using 0.6 g of urea, 0.291 g of nickel nitrate, 0.291 g of cobalt nitrate, 0.266 g of iron nitrate, 0.037 g of ammonium fluoride, and deionized water. Pour 40 ml of the solution into a reaction vessel, and wash the area to a size of 3 x 4 cm. 2 The foamed nickel was immersed in a solution and placed in an oven. A hydrothermal treatment was performed at a reaction temperature of 100°C for 12 hours to crystallize the material. The resulting material was washed three times each with water and ethanol, and vacuum-dried at 60°C for 10 hours to obtain foamed nickel (nickel-cobalt-iron hydroxide array) on which nickel-cobalt-iron hydroxide was supported. Step (2): The nickel-cobalt iron hydroxide obtained in Step (1) and 600 mg of sodium hypophosphite were placed together in a tubular furnace, heated to 300°C, and maintained at that temperature for 2 hours to phosphate the mixture and obtain nickel-cobalt iron phosphide material. The obtained material was used for single-atom electrodeposition. Step (3): Preparation of 50 ml of electrolyte solution 2.0 g of sodium hydroxide and 2.6 mg of chloroplatinic acid were mixed with an appropriate amount of water to prepare 50 ml of electrolyte solution. Step (4): Electroplating In the electrolyte obtained in step (3), a three-electrode system was used, with the nickel-cobalt-iron phosphide material obtained in step (2) as the working electrode, a saturated calomel electrode as the reference electrode, and a carbon rod as the counter electrode. Linear voltammetry was performed with the following parameters: voltage range of 0.3 to 0.6 V, forward scanning direction, scanning speed of 0.005 V / sec, and 5 cycles. The obtained material was washed three times each with water and ethanol, and vacuum-dried at 60°C for 10 hours to obtain the platinum / nickel-cobalt-iron phosphide material. Application Example 24

[0122] 1. Hydrogen generation performance in water electrolysis A three-electrode test system was used, with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the platinum / nickel-cobalt-iron phosphide material manufactured in Example 24 or the nickel-cobalt-iron phosphide material obtained in Step (2) of Example 24 as the working electrode. The hydrogen generation performance of the material obtained in water electrolysis was tested using a voltage range of -1 to -2V and a 6M sodium hydroxide electrolyte. The cathode hydrogen generation performance of the material in electrolyzed water is represented, and the test results are shown in Figure 71. Figure 71 shows that the platinum / nickel-cobalt-iron phosphide material also possesses good cathode hydrogen generation performance. Specifically, the platinum / nickel-cobalt-iron phosphide material exhibits a hydrogen generation current density of 10 mA / cm². 2 The potential required to reach this level is approximately 49.6 mV, and in nickel-cobalt-iron phosphine material, the current density for hydrogen generation is 10 mA / cm². 2 The potential required to reach this point is approximately 111.7 mV. The presence of platinum as a single atom accelerated the hydrogen evolution initiation potential by approximately 62.1 mV, confirming that a single atom of platinum is advantageous in improving the catalytic activity of the hydrogen evolution reaction. 2. Hydrogen generation performance in seawater electrolysis Referring to the first aspect of Application Example 24, in a similar three-electrode test system, sodium chloride was added to the electrolyte, i.e., the electrolyte was changed to 6.0 M sodium hydroxide and 2.8 M sodium chloride, and the platinum / nickel-cobalt-iron phosphide material obtained in Example 24 was used as the working electrode. The resulting polarization curve is shown in Figure 72. From Figure 72, it can be seen that the hydrogen generation performance of the platinum / nickel-cobalt-iron phosphide material was better than that tested with sodium hydroxide, and the current density was 100 mA / cm², due to the addition of chloride ions. 2 The potential required to reach this point dropped by approximately 20 mV (when tested with sodium hydroxide, with a current density of 100 mA / cm²). 2 The potential required to reach this level is approximately 108.3 mV, and when tested with sodium hydroxide and sodium chloride, the current density is 100 mA / cm². 2 It was found that the potential required to reach this level is approximately 88.1 mV. 3. Effect of iodine on hydrogen generation performance Referring to the first aspect of Application Example 24, in a similar three-electrode test system, sodium iodide is added to the electrolyte, i.e., the electrolyte is changed to a mixed solution of 6.0 M sodium hydroxide and 2.0 M sodium iodide, and the platinum / nickel-cobalt-iron phosphide material obtained in Example 24 is used as the working electrode, and the resulting polarization curve is shown in Figure 73. Figure 73 shows that by adding fluoride ions to the test solution, the current density of the platinum / nickel-cobalt-iron phosphide test becomes 100 mA / cm². 2 The potential required to reach this point was reduced to 96.7 mV, which is favorable for the material's catalysis of water splitting and oxygen evolution, and it was found that the coordination of iodide ions during electrolysis is advantageous for improving the material's electrolytic performance. Example 25 - Electrochemical Deposition Method

[0123] Nickel cobalt iron phosphide material was synthesized by the method of steps (1) and (2), referring to the method of Example 24. In step (3), the process changes to preparing 50 ml of electrolyte solution. 20.0 g of sodium hydroxide, 2 g of sodium sulfate, 0.203 g of chlorinated iridium acid (10 mmol / L), and an appropriate amount of water were mixed to prepare 50 ml of electrolyte. Finally, an iridium / nickel-cobalt-iron phosphide material was obtained. Application Example 25

[0124] 1. Oxygen evolution reaction in seawater electrolysis The oxygen generation performance of the material obtained in Example 25 in seawater electrolysis was tested using a three-electrode test system with a saturated calomel electrode as the reference electrode, a platinum electrode as the counter electrode, and the iridium / nickel-cobalt-iron phosphide material manufactured in Example 25 or the nickel-cobalt-iron phosphide material obtained in Step (2) of Example 25 as the working electrode. The voltage range was 0 to -1V, and the electrolytes were 6M sodium hydroxide and 2.8M sodium chloride. The test results show the cathode oxygen generation performance of the material in water electrolysis, and the obtained test results are shown in Figure 74. For the iridium / nickel-cobalt-iron phosphide material, the current density for oxygen generation was 100 mA / cm². 2 The voltage required to reach this point is approximately 1.49V, and in nickel-cobalt-iron phosphine material, the current density for hydrogen generation is 100mA / cm². 2 The voltage required to reach this point is approximately 1.53V. The presence of iridium as a single atom accelerates the hydrogen evolution initiation potential by approximately 40mV, confirming that a single iridium atom is advantageous in improving the catalytic activity of the oxygen evolution reaction. 2. Seawater electrolysis using two electrodes The hydrogen generation performance of the material obtained in Example 25 by seawater electrolysis was tested using a two-electrode test system with the iridium / nickel-cobalt-iron phosphide material manufactured in Example 25 as the anode and the platinum / nickel-cobalt-iron phosphide material manufactured in Example 24 as the cathode. The polarization curve of hydrogen generation in seawater electrolysis using two electrodes is shown in Figure 75. 100 mA / cm 2 The overvoltage required to reach this level was only 358mV, suggesting that the material also performs extremely well in two-electrode seawater electrolysis systems.

Claims

1. The use of nanomaterials as water electrolysis electrodes involves adding halides to the electrolyte of electrolyzed water to improve the performance of anode oxygen generation in the nanomaterial electrolyzed water. The electrolyte of the electrolyzed water contains alkali, The nanomaterial comprises a non-precious metal substrate and a precious metal dispersed as a single atom on the surface of the non-precious metal substrate, wherein a halogen and oxygen are simultaneously coordinated to the surface of the single atom of the precious metal. The halogen is one or more selected from chlorine, bromine, fluorine, and iodine. The aforementioned precious metal is one or more selected from iridium, ruthenium, gold, platinum, rhodium, palladium, silver, and osmium. The oxygen coordinating to the surface of a single atom of the aforementioned noble metal exists in the form of an oxygen-containing functional group. A characteristic use.

2. The use according to claim 1, characterized in that the halogenated compound is one or more selected from chlorides, bromides, and fluorides.

3. The use according to claim 1, characterized in that the nanomaterial can simultaneously function as an anode and cathode for water electrolysis.

4. The non-precious metal substrate is one or more selected from non-precious metal hydroxides, non-precious metal oxides, non-precious metal sulfides, non-precious metal phosphides, and non-precious metal selenides. The non-precious metal in the non-precious metal substrate is one or more selected from iron, cobalt, nickel, aluminum, manganese, cerium, vanadium, zinc, copper, strontium, indium, and cadmium. The use described in feature 1.

5. The use according to claim 1, characterized in that the non-precious metal substrate is doped with reducing metal ions.

6. The method for producing the nanomaterial is, This chemical precipitation method includes the steps of: dispersing a non-precious metal substrate in water; dropping a water-soluble precious metal precursor and a dilute alkaline solution onto the mixture; reacting the mixture at 10 to 95°C for 4 to 120 hours while stirring; separating the solid and liquid; washing and drying the solid to obtain the nanomaterial. In the aforementioned dilute solution of the water-soluble precious metal precursor and alkali, the concentration of the water-soluble precious metal precursor is 0.001 to 200 mmol / L, the concentration of the hydroxide is 0.5 to 1000 mmol / L, and the water-soluble precious metal precursor contains a halogen element. The halogen is one or more selected from chlorine, bromine, fluorine, and iodine. The aforementioned precious metal is one or more selected from iridium, ruthenium, gold, platinum, rhodium, palladium, silver, and osmium. The use described in feature 1.

7. The method for producing the nanomaterial is, This electrodeposition method involves preparing an electrolyte mainly composed of a water-soluble precious metal precursor and alkali, and performing electrochemical deposition at an electrodeposition voltage of -1.2 to 1.2 V using a conductive carrier on which a non-precious metal substrate is supported as the working electrode. In the electrolyte, the concentration of the water-soluble precious metal precursor is 0.001 to 1000 mmol / L, the concentration of the hydroxide is 0.1 to 6 mol / L, and the water-soluble precious metal precursor contains a halogen element. The halogen is one or more selected from chlorine, bromine, fluorine, and iodine. The aforementioned precious metal is one or more selected from iridium, ruthenium, gold, platinum, rhodium, palladium, silver, and osmium. The use described in feature 1.

8. The use according to claim 6 or 7, characterized in that, if reducing metal ions are doped into the non-precious metal substrate, it is necessary to remove dissolved oxygen from the water or electrolyte.

9. The use of nanomaterials as seawater electrolytic electrodes, The nanomaterial comprises a non-precious metal substrate and a precious metal dispersed as a single atom on the surface of the non-precious metal substrate, wherein a halogen and oxygen are simultaneously coordinated to the surface of the single atom of the precious metal. The halogen is one or more selected from chlorine, bromine, fluorine, and iodine. The aforementioned precious metal is one or more selected from iridium, ruthenium, gold, platinum, rhodium, palladium, silver, and osmium. The oxygen coordinating to the surface of a single atom of the aforementioned noble metal exists in the form of an oxygen-containing functional group. A characteristic use.

10. The use according to claim 9, characterized in that the nanomaterial can function as an anode and cathode for seawater electrolysis.

11. The non-precious metal substrate is one or more selected from non-precious metal hydroxides, non-precious metal oxides, non-precious metal sulfides, non-precious metal phosphides, and non-precious metal selenides. The use according to claim 9, characterized in that the non-precious metal in the non-precious metal substrate is one or more selected from iron, cobalt, nickel, aluminum, manganese, cerium, vanadium, zinc, copper, strontium, indium, and cadmium.

12. The use according to claim 9, characterized in that the non-precious metal substrate is doped with reducing metal ions.

13. The method for producing the nanomaterial is, This chemical precipitation method includes the steps of: dispersing a non-precious metal substrate in water; dropping a water-soluble precious metal precursor and a dilute alkaline solution onto the mixture; reacting the mixture at 10 to 95°C for 4 to 120 hours while stirring; separating the solid and liquid; washing and drying the solid to obtain the nanomaterial. In the aforementioned dilute solution of the water-soluble precious metal precursor and alkali, the concentration of the water-soluble precious metal precursor is 0.001 to 200 mmol / L, the concentration of the hydroxide is 0.5 to 1000 mmol / L, and the water-soluble precious metal precursor contains a halogen element. The halogen is one or more selected from chlorine, bromine, fluorine, and iodine. The aforementioned precious metal is one or more selected from iridium, ruthenium, gold, platinum, rhodium, palladium, silver, and osmium. The use described in feature 9.

14. The method for producing the nanomaterial is, This electrodeposition method involves preparing an electrolyte mainly composed of a water-soluble precious metal precursor and alkali, and performing electrochemical deposition at an electrodeposition voltage of -1.2 to 1.2 V using a conductive carrier on which a non-precious metal substrate is supported as the working electrode. In the electrolyte, the concentration of the water-soluble precious metal precursor is 0.001 to 1000 mmol / L, the concentration of the hydroxide is 0.1 to 6 mol / L, and the water-soluble precious metal precursor contains a halogen element. The halogen is one or more selected from chlorine, bromine, fluorine, and iodine. The aforementioned precious metal is one or more selected from iridium, ruthenium, gold, platinum, rhodium, palladium, silver, and osmium. The use described in feature 9.

15. The use according to claim 13 or 14, characterized in that, if reducing metal ions are doped into the non-precious metal substrate, it is necessary to remove dissolved oxygen from the water or electrolyte.

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