Oxygen evolution reaction catalyst and preparation method thereof, water electrolysis hydrogen production anode material and application

Abstract

The invention provides an oxygen evolution reaction catalyst, a preparation method thereof, a water electrolysis hydrogen production anode material and application, and belongs to the technical field of electrocatalysis and nanometer materials. The preparation method of the oxygen evolution reaction catalyst comprises the following steps: (1) growing a compact nickel sulfide nano material on a nickel substrate in situ through a hydrothermal method, a thermal injection method or a chemical vapor deposition method to obtain a nickel sulfide / nickel composite material; and (2) growing a ferro-nickel hydroxide nano material on at least one part of the surface of the nickel sulfide / nickel composite material by a hydrothermal method or an electrodeposition method to obtain the oxygen evolution reaction catalyst. The oxygen evolution reaction catalyst obtained by the preparation method has high efficiency and high stability, and is suitable for efficient and stable actual industrial hydrogen production by electrolysis of water.

Description

Technical Field

[0001] The present invention belongs to the technical fields of electrocatalysis and nanomaterials, and particularly relates to an oxygen evolution reaction catalyst, a preparation method thereof, an anode material for electrolytic water hydrogen production, and an application thereof. Background Art

[0002] Producing high-purity green hydrogen by electrocatalytic water splitting is a promising strategy to address the challenges of fossil resource consumption and environmental pollution. The oxygen evolution reaction (OER) is a half-reaction of the water splitting reaction, which involves four electron transfers and an oxygen-oxygen bond formation step with a high energy barrier, and is the main bottleneck of water electrolysis. Among numerous catalysts, nickel-iron hydroxide has a unique electronic structure for adsorbing OER intermediates and has become one of the most promising OER catalysts in alkaline media, with great application potential. However, nickel-iron hydroxide has not been used in actual water electrolysis due to its poor activity and stability under industrial conditions.

[0003] Currently, most studies are committed to improving the OER performance of nickel-iron hydroxide through various strategies such as nanostructure design, composition regulation, heteroatom doping, and heterostructure engineering. Heterostructure engineering can change the nanostructure characteristics, electronic structure properties, and conductivity of the catalyst, thereby achieving directional optimization of electrochemical performance. By constructing a specific heterointerface between nickel-iron hydroxide and other components, it is expected to further optimize the electronic structure and thus improve the OER performance. In addition, nickel-iron hydroxide usually has poor conductivity, and its electrocatalytic performance at high current densities is greatly limited. Considering that the actual water electrolysis process requires the electrode to have long-term durability under harsh conditions, there are still many challenges in designing more efficient and stable integrated electrodes.

[0004] Therefore, developing a non-precious metal oxygen evolution reaction catalyst with both high activity and high stability is of great significance for realizing the industrial application of efficient and stable electrolytic water hydrogen production. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, an embodiment of the present invention provides an oxygen evolution reaction catalyst, a preparation method thereof, an anode material for electrolytic water hydrogen production, and an application thereof.

[0006] In a first aspect, an embodiment of the present invention provides a preparation method of an oxygen evolution reaction catalyst, including the following steps:

[0007] (1) In-situ grow a dense nickel sulfide nanomaterial on a nickel substrate by a hydrothermal method, a thermal injection method, or a chemical vapor deposition method to obtain a nickel sulfide / nickel composite material;

[0008] (2) Nickel iron hydroxide nanomaterials are grown on at least a part of the surface of the nickel sulfide / nickel composite material by a hydrothermal method or an electrodeposition method to obtain an oxygen evolution reaction catalyst.

[0009] The advantages and technical effects brought by the preparation method of the embodiment of the present invention are as follows:

[0010] Nickel sulfide nanomaterials have intrinsic metallic behavior with high carrier concentration and low resistivity, so they are conducive to the transfer of charges to the surface catalytic layer. The construction of the heterostructure between nickel sulfide nanomaterials and nickel iron hydroxide nanomaterials and the optimization of the interfacial electronic structure are beneficial to the improvement of the catalytic performance of the oxygen evolution reaction catalyst. The in-situ chemical derivation of nickel sulfide nanomaterials on the nickel substrate forms a stable layer with close contact, which can ensure effective charge transfer and strong binding strength with the nickel substrate, and is beneficial to the improvement of the catalytic performance of the oxygen evolution reaction catalyst. These favorable characteristics can make nickel sulfide nanomaterials an ideal medium for promoting the electrochemical oxidation of water on nickel iron hydroxide nanomaterials, and are used for more efficient and stable industrial electrolytic water hydrogen production.

[0011] In some embodiments, in step (1), the nickel substrate can be selected from nickel felt, nickel foam or nickel mesh, etc.

[0012] In some embodiments, in step (1), the hydrothermal method for growing the nickel sulfide nanomaterials includes the following steps: mixing the nickel substrate, pure water, methanol and thioacetamide to obtain a first mixture, placing the first mixture in a reaction kettle, and carrying out hydrothermal reaction at 150°C to 190°C for 2h to 6h to obtain the nickel sulfide nanomaterials.

[0013] Optionally, the ratio between the area of the nickel substrate and the mass of the thioacetamide is 20 cm 2 : 1 g to 60 cm 2 : 1 g.

[0014] Optionally, the volume ratio of the pure water to the methanol is 1:1 to 3:1.

[0015] In some embodiments, in step (1), the thermal injection method for growing the nickel sulfide nanomaterials includes the following steps: mixing the nickel substrate and triethylene glycol to obtain a second mixture, placing the second mixture in a container, and adding a sulfur source at room temperature to 220°C for a sulfidation reaction for 1 min to 1 h to obtain the nickel sulfide nanomaterials.

[0016] Optionally, the ratio between the area of the nickel substrate and the mass of the sulfur source is 1 cm 2 : 1 g to 1000 cm 2 : 1 g.

[0017] Optionally, the sulfur source includes a liquid sulfur source and / or a solid sulfur source, wherein the liquid sulfur source is 2-mercaptoethanol, and the solid sulfur source is selected from at least one of thiourea, thioacetamide, and sulfur powder.

[0018] Optionally, the volume ratio of the triethylene glycol to the liquid sulfur source is 1:1 to 20:1.

[0019] Optionally, the ratio of the volume of the triethylene glycol to the mass of the solid sulfur source is 5 mL:1 g to 20 mL:1 g.

[0020] In some embodiments, in step (1), the chemical vapor deposition method for growing the nickel sulfide nanomaterial includes the following steps: placing sulfur powder upstream in the temperature zone of the chemical vapor deposition equipment, placing the nickel substrate downstream in the temperature zone of the chemical vapor deposition equipment, and reacting at 350 °C to 550 °C for 0.5 h to 4 h under an argon protection atmosphere to obtain the nickel sulfide nanomaterial.

[0021] Optionally, the ratio of the area of the nickel substrate to the mass of the sulfur powder is 3 cm 2 :1 g to 30 cm 2 :1 g.

[0022] Optionally, the heating rate and the cooling rate of the chemical vapor deposition equipment are both 1 °C / min to 10 °C / min.

[0023] In some embodiments, in step (2), the electrodeposition method for growing the nickel iron hydroxide nanomaterial includes the following steps: using the nickel sulfide / nickel composite material as the working electrode, using Hg / HgO as the reference electrode, using a carbon rod as the counter electrode, using a mixed solution containing a nickel source and an iron source as the plating solution, and electrodepositing at a voltage of -2.0 V to -0.2 V for 100 to 1000 s to obtain the nickel iron hydroxide nanomaterial, and the nickel iron hydroxide nanomaterial is nanoparticles.

[0024] Optionally, the molar ratio of the nickel source to the iron source is 4:1 to 12:1;

[0025] Optionally, the nickel source is nickel nitrate and / or nickel chloride, and the iron source is iron nitrate and / or iron chloride.

[0026] In some embodiments, in step (2), the hydrothermal method for growing the nickel iron hydroxide nanomaterial includes the following steps: mixing the nickel sulfide / nickel composite material, the nickel source, the iron source, urea, and ammonium fluoride to obtain a third mixture, placing the third mixture in a reaction kettle, and performing a hydrothermal reaction at 100 °C to 140 °C for 2 h to 8 h to obtain the nickel iron hydroxide nanomaterial, and the nickel iron hydroxide nanomaterial is a nanosheet array.

[0027] Optionally, the molar ratio of the nickel source to the iron source is 4:1 to 12:1.

[0028] Optionally, the molar ratio of the sum of the nickel source and the iron source, the urea, and the ammonium fluoride is 1:10:2 to 1:4:1.

[0029] In a second aspect, an oxygen evolution reaction catalyst provided by an embodiment of the present invention is obtained by the preparation method described in the first aspect.

[0030] The advantages and technical effects brought by the oxygen evolution reaction catalyst of the embodiment of the present invention are as follows:

[0031] Due to the adoption of the preparation method of the first aspect, the oxygen evolution reaction catalyst of the embodiment of the present invention has both high activity and high stability, which is of great significance for realizing the industrial application of efficient and stable water electrolysis for hydrogen production.

[0032] In a third aspect, an anode material for water electrolysis hydrogen production provided by an embodiment of the present invention includes the oxygen evolution reaction catalyst described in the second aspect.

[0033] The advantages and technical effects brought by the anode material for water electrolysis hydrogen production of the embodiment of the present invention are as follows:

[0034] Due to the adoption of the oxygen evolution reaction catalyst described in the second aspect, the anode material for water electrolysis hydrogen production of the embodiment of the present invention has both high activity and high stability, which is of great significance for realizing the industrial application of efficient and stable water electrolysis for hydrogen production.

[0035] In a fourth aspect, an embodiment of the present invention provides an application of the anode material for water electrolysis hydrogen production described in the third aspect in a water electrolysis hydrogen production device. Description of the Drawings

[0036] Figure 1 It is an X-ray diffraction pattern of the oxygen evolution reaction catalyst of Example 1;

[0037] Figure 2 It is a scanning electron microscope image of the oxygen evolution reaction catalyst of Example 1;

[0038] Figure 3 It is a polarization curve graph of the oxygen evolution reaction catalysts of Example 1 and Comparative Examples 1 to 2;

[0039] Figure 4 It is a polarization curve graph of the oxygen evolution reaction catalysts of Examples 2 to 4;

[0040] Figure 5 It is a polarization curve graph of the oxygen evolution reaction catalysts of Examples 5 to 7. Detailed Embodiments

[0041] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation of the present invention.

[0042] In a first aspect, an embodiment of the present invention provides a method for preparing an oxygen evolution reaction catalyst, comprising the following steps:

[0043] (1) In-situ grow a dense nickel sulfide (Ni3S2) nanomaterial on a nickel substrate by a hydrothermal method, a thermal injection method or a chemical vapor deposition method to obtain a nickel sulfide / nickel composite material;

[0044] (2) Grow a nickel iron hydroxide (NiFe-OH) nanomaterial on at least a part of the surface of the nickel sulfide / nickel composite material by a hydrothermal method or an electrodeposition method to obtain an oxygen evolution reaction catalyst.

[0045] The nickel sulfide nanomaterial has an intrinsic metallic behavior with a high carrier concentration and a low resistivity, so it is beneficial for charge transfer to the surface catalytic layer. The construction of a heterostructure between the nickel sulfide nanomaterial and the nickel iron hydroxide nanomaterial and the optimization of the interfacial electronic structure are beneficial to improving the catalytic performance of the oxygen evolution reaction catalyst. The in-situ chemical derivation of the nickel sulfide nanomaterial on the nickel substrate forms a stable layer with close contact, which can ensure effective charge transfer and a strong binding strength with the nickel substrate, and is beneficial to improving the catalytic performance of the oxygen evolution reaction catalyst. These advantageous features can make the nickel sulfide nanomaterial an ideal medium for promoting the electrochemical oxidation of water on the nickel iron hydroxide nanomaterial for more efficient and stable practical industrial water electrolysis for hydrogen production.

[0046] In some embodiments, in step (1), the nickel substrate is selected from nickel felt, nickel foam or nickel mesh.

[0047] In some embodiments, in step (1), the hydrothermal method for growing the nickel sulfide nanomaterial comprises the following steps: Mix the nickel substrate, pure water, methanol and thioacetamide to obtain a first mixture, place the first mixture in a reaction kettle, and carry out a hydrothermal reaction at 150 °C to 190 °C (such as 150 °C, 160 °C, 170 °C, 180 °C, 190 °C, etc.) for 2 h to 6 h (such as 2 h, 3 h, 4 h, 5 h, 6 h, etc.) to obtain the nickel sulfide nanomaterial. The above in-situ synthesis process is beneficial to improving the binding strength between the nickel sulfide nanomaterial and the nickel substrate.

[0048] Optionally, the ratio between the area of the nickel substrate and the mass of the thioacetamide is 20 cm 2 : 1 g to 60 cm 2 : 1 g, such as 20 cm 2 : 1 g, 30 cm 2: 1 g, 40 cm 2 : 1 g, 50 cm 2 : 1 g, 60 cm 2 : 1 g, etc. When this ratio is too small, thioacetamide is in excess, which is not conducive to cost reduction and efficiency improvement. When this ratio is too large, thioacetamide is too little, which is not conducive to forming a dense nickel sulfide nanomaterial on the nickel substrate.

[0049] Optionally, the volume ratio of the pure water to the methanol is 1:1 to 3:1, such as 1:1, 1.5:1, 2:1, 2.5:1, 3:1, etc. When this ratio is too small or too large, it is not conducive to forming a dense nickel sulfide nanomaterial on the nickel substrate.

[0050] In some embodiments, in step (1), the thermal injection method for growing the nickel sulfide nanomaterial includes the following steps: mixing the nickel substrate and triethylene glycol to obtain a second mixture, placing the second mixture in a container, and adding a sulfur source at room temperature to 220 °C (such as room temperature, 30 °C, 50 °C, 100 °C, 150 °C, 200 °C, 220 °C, etc.) for a sulfidation reaction for 1 min to 1 h (such as 1 min, 10 min, 20 min, 30 min, 40 min, 50 min, 1 h, etc.) to obtain the nickel sulfide nanomaterial. The above in-situ synthesis process is conducive to improving the bonding strength between the nickel sulfide nanomaterial and the nickel substrate.

[0051] Optionally, the ratio between the area of the nickel substrate and the mass of the sulfur source is 1 cm 2 : 1 g to 1000 cm 2 : 1 g. When this ratio is too small, the sulfur source is in excess, which is not conducive to cost reduction and efficiency improvement. When this ratio is too large, the sulfur source is too little, which is not conducive to forming a dense nickel sulfide nanomaterial on the nickel substrate.

[0052] Optionally, the sulfur source includes a liquid sulfur source and / or a solid sulfur source, wherein the liquid sulfur source is 2-mercaptoethanol, and the solid sulfur source is selected from at least one of thiourea, thioacetamide, and sulfur powder.

[0053] Optionally, the volume ratio of the triethylene glycol to the liquid sulfur source is 1:1 to 20:1, such as 1:1, 5:1, 10:1, 15:1, 20:1, etc. When this ratio is too small, it is not conducive to improving the uniformity of the sulfidation reaction. When this ratio is too large, it is not conducive to forming a dense nickel sulfide nanomaterial on the nickel substrate.

[0054] Optionally, the ratio between the volume of the triethylene glycol and the mass of the solid sulfur source is 5 mL:1 g to 20 mL:1 g, such as 5 mL:1 g, 10 mL:1 g, 15 mL:1 g, 20 mL:1 g, etc. When this ratio is too small, it is not conducive to improving the uniformity of the sulfidation reaction. When this ratio is too large, it is not conducive to forming a dense nickel sulfide nanomaterial on the nickel substrate.

[0055] In some embodiments, in step (1), the chemical vapor deposition method for growing the nickel sulfide nanomaterial includes the following steps: placing sulfur powder upstream in the temperature zone of the chemical vapor deposition equipment, placing the nickel substrate downstream in the temperature zone of the chemical vapor deposition equipment, and reacting at 350°C to 550°C (such as 350°C, 400°C, 450°C, 500°C, 550°C, etc.) for 0.5 h to 4 h (such as 0.5 h, 1 h, 2 h, 3 h, 4 h, etc.) under an argon protective atmosphere to obtain the nickel sulfide nanomaterial. The above in-situ synthesis process is conducive to improving the bonding strength between the nickel sulfide nanomaterial and the nickel substrate, thereby being conducive to improving the catalytic activity and stability of the oxygen evolution reaction catalyst.

[0056] Optionally, the ratio between the area of the nickel substrate and the mass of the sulfur powder is 3 cm 2 :1 g to 30 cm 2 :1 g. When this ratio is too small, the sulfur source is excessive, which is not conducive to cost reduction and efficiency improvement. When this ratio is too large, the sulfur source is too little, which is not conducive to forming a dense nickel sulfide nanomaterial on the nickel substrate.

[0057] Optionally, the heating rate and the cooling rate of the chemical vapor deposition equipment are both 1°C / min to 10°C / min. When the heating rate or the cooling rate is too small, it is not conducive to improving production efficiency. When the heating rate and the cooling rate are too large, it is not conducive to improving the uniformity of the sulfidation reaction.

[0058] In some embodiments, in step (2), the electrodeposition method for growing the nickel iron hydroxide nanomaterial includes the following steps: using the nickel sulfide / nickel composite material as the working electrode, using Hg / HgO as the reference electrode, using a carbon rod as the counter electrode, using a mixed solution containing a nickel source and an iron source as the plating solution, and electrodepositing at a voltage of -0.2 V to -2.0 V (such as -2.0 V, -1.5 V, -1.0 V, -0.5 V, -0.2 V, etc.) for 100 to 1000 s (such as 100 s, 200 s, 400 s, 600 s, 800 s, 1000 s, etc.) to obtain the nickel iron hydroxide nanomaterial, and the nickel iron hydroxide nanomaterial is nanoparticles.

[0059] Optionally, the molar ratio of the nickel source to the iron source is 4:1 to 12:1, such as 4:1, 6:1, 8:1, 10:1, 12:1, etc. When the molar ratio of the nickel source to the iron source is within this range, it is beneficial to maximize the generation of nickel sulfide nanomaterials.

[0060] Optionally, the nickel source is nickel nitrate and / or nickel chloride, and the iron source is iron nitrate and / or iron chloride. It is preferred to prepare a mixed solution by combining nickel nitrate and iron nitrate, or preferably to prepare a mixed solution by combining nickel chloride and iron chloride. When the anions of the nickel source and the iron source are the same, the effect of the grown nickel-iron hydroxide nanomaterials is better and the growth is more uniform.

[0061] In some embodiments, in step (2), the hydrothermal method for growing the nickel-iron hydroxide nanomaterials includes the following steps: mixing the nickel sulfide / nickel composite material, the nickel source, the iron source, urea, and ammonium fluoride to obtain a third mixture, placing the third mixture in a reaction kettle, and performing hydrothermal reaction at 100°C to 140°C (such as 100°C, 110°C, 120°C, 130°C, 140°C, etc.) for 2 h to 8 h (such as 2 h, 4 h, 6 h, 8 h, etc.) to obtain the nickel-iron hydroxide nanomaterials, and the nickel-iron hydroxide nanomaterials are nanosheet arrays.

[0062] Optionally, the molar ratio of the nickel source to the iron source is 4:1 to 12:1, such as 4:1, 6:1, 8:1, 10:1, 12:1, etc. When the molar ratio of the nickel source to the iron source is within this range, it is beneficial to maximize the generation of nickel sulfide nanomaterials.

[0063] Optionally, the molar ratio of the sum of the nickel source and the iron source (i.e., metal salt), the urea, and the ammonium fluoride is 1:10:2 to 1:4:1, such as 1:10:2, 1:8:2, 1:4:2, 1:10:1.5, 1:10:1, 1:4:1, etc. When the ratio of these three is within the above range, it is beneficial for the nickel-iron hydroxide nanomaterials to coat the entire surface of the nickel sulfide nanomaterials.

[0064] In a second aspect, an oxygen evolution reaction catalyst provided by an embodiment of the present invention is obtained by the preparation method described in the first aspect.

[0065] Due to the adoption of the preparation method in the first aspect, the oxygen evolution reaction catalyst in the embodiment of the present invention has both high activity and high stability, which is of great significance for realizing the industrial application of efficient and stable water electrolysis for hydrogen production.

[0066] In a third aspect, an anode material for electrolytic water hydrogen production provided by an embodiment of the present invention includes the oxygen evolution reaction catalyst described in the second aspect.

[0067] Due to the use of the oxygen evolution reaction catalyst described in the second aspect, the anode material for hydrogen production by electrolysis of water in the embodiments of the present invention has both high activity and high stability, which is of great significance for realizing the industrial application of efficient and stable hydrogen production by electrolysis of water.

[0068] Fourthly, the embodiments of the present invention provide an application of the anode material for hydrogen production by electrolysis of water described in the third aspect in an electrolytic water hydrogen production device.

[0069] The present invention will be described in detail below with reference to embodiments and drawings.

[0070] Example 1

[0071] Based on the above research, 40 mL of triethylene glycol and a piece of nickel felt (NF, 1 cm × 3 cm) were placed in a container and heated in a heating jacket. 2.5 mL of mercaptoethanol was quickly added at 180 °C, and the reaction was carried out for 20 min. The sample was taken out after cooling and rinsed several times with absolute ethanol, and then vacuum dried at 50 °C for 10 h. Dense nickel sulfide nanoparticles were in-situ grown on the nickel felt to obtain the Ni3S2 / NF sample.

[0072] Then, using Ni3S2 / NF (1 cm × 1 cm), a carbon rod, and Hg / HgO as the working electrode, counter electrode, and reference electrode respectively, and using a mixed aqueous solution containing nickel nitrate and iron nitrate as the plating solution, with the molar ratio of nickel to iron in the plating solution being 8:1, electroplating was carried out at -1.2 V for 400 s. The sample was taken down and rinsed several times with pure water, and then vacuum dried at 50 °C for 10 h. NiFe-OH nanoparticles were uniformly grown on the surface of Ni3S2 / NF to obtain the NiFe-OH / Ni3S2 / NF material.

[0073] Example 2

[0074] Other steps were the same as in Example 1, except that the electroplating nickel-to-iron ratio was changed from 8:1 to 10:1. A layer of NiFe-OH nanoparticles was uniformly grown on the surface of Ni3S2 / NF.

[0075] Example 3

[0076] Other steps were the same as in Example 1, except that the electroplating nickel-to-iron ratio was changed from 8:1 to 6:1. NiFe-OH nanoparticles were uniformly grown on the surface of Ni3S2 / NF.

[0077] Example 4

[0078] Other steps were the same as in Example 1, except that the electroplating nickel-to-iron ratio was changed from 8:1 to 4:1. NiFe-OH nanoparticles were uniformly grown on the surface of Ni3S2 / NF.

[0079] Example 5

[0080] Other steps are the same as those in Example 1, except that the electrodeposition potential is changed from -1.2 V to -0.8 V. Similarly, NiFe-OH nanoparticles are uniformly grown on the surface of Ni3S2 / NF.

[0081] Example 6

[0082] Other steps are the same as those in Example 1, except that the electrodeposition potential is changed from -1.2 V to -1.0 V. Similarly, NiFe-OH nanoparticles are uniformly grown on the surface of Ni3S2 / NF.

[0083] Example 7

[0084] Other steps are the same as those in Example 1, except that the electrodeposition potential is changed from -1.2 V to -1.4 V. Similarly, NiFe-OH nanoparticles are uniformly grown on the surface of Ni3S2 / NF.

[0085] Example 8

[0086] A piece of nickel foam substrate (NF, 1 cm × 3 cm) is placed in a reaction kettle containing a mixed solution of 15 mL of pure water, 15 mL of methanol, and 0.1 g of thioacetamide, and reacted at 180 °C for 4 h. After cooling, the sample is taken out and rinsed several times with absolute ethanol, and then vacuum dried at 60 °C for 8 h. Dense nickel sulfide nanoparticles are in-situ grown on the nickel foam substrate to obtain a Ni3S2 / NF sample.

[0087] Then, a piece of Ni3S2 / NF sample is placed in a reaction kettle containing a mixed solution of 1.75 mmol of nickel chloride, 0.25 mmol of iron chloride, 10 mmol of urea, and 4 mmol of ammonium fluoride, and reacted at 120 °C for 6 h. After cooling, the sample is taken out and rinsed several times with pure water, and then vacuum dried at 60 °C for 8 h. Nickel-iron hydroxide nanosheet arrays are uniformly grown on the surface of the Ni3S2 / NF sample to obtain a NiFe-OH / Ni3S2 / NF material.

[0088] Example 9

[0089] A piece of nickel foam substrate (NF, 1 cm × 3 cm) is placed in the temperature zone of a chemical vapor deposition device. Sulfur powder and the nickel foam substrate are respectively placed upstream and downstream of the temperature zone. Under an argon protection atmosphere, the heating rate and the cooling rate are both 5 °C / min, and the reaction is carried out at 400 °C for 2 h. Nickel sulfide nanoparticles are in-situ grown on the nickel foam substrate to obtain a Ni3S2 / NF sample.

[0090] Then, a piece of Ni3S2 / NF sample was placed in a reaction kettle containing a mixed solution of 1.75 mmol nickel chloride, 0.25 mmol iron chloride, 10 mmol urea and 4 mmol ammonium fluoride, and reacted at 120 °C for 6 h. After cooling, the sample was taken out and rinsed several times with pure water. After vacuum drying at 60 °C for 8 h, nickel-iron hydroxide nanosheet arrays grew uniformly on the surface of the Ni3S2 / NF sample, and the NiFe-OH / Ni3S2 / NF material was obtained.

[0091] Comparative Example 1

[0092] 40 mL of triethylene glycol and a piece of nickel felt (NF, 1 cm × 3 cm) were placed in a container and heated in a heating mantle. When the temperature reached 180 °C, 2.5 mL of mercaptoethanol was quickly added, and the reaction was carried out for 20 min. After cooling, the sample was taken out and rinsed several times with absolute ethanol. After vacuum drying at 50 °C for 10 h, dense nickel sulfide nanoparticles grew in-situ on the nickel felt, and the Ni3S2 / NF sample was obtained.

[0093] Comparative Example 2

[0094] Using a nickel felt (1 cm × 1 cm), a carbon rod and Hg / HgO as the working electrode, counter electrode and reference electrode respectively, and using a mixed solution containing nickel nitrate and iron nitrate as the plating solution, with the nickel-iron molar ratio in the plating solution being 8:1, electroplating was carried out at -1.2 V for 400 s. After taking down the sample and rinsing it several times with pure water, NiFe-OH nanoparticles grew on the surface of NF after vacuum drying at 50 °C for 10 h, and the NiFe-OH / NF material was obtained.

[0095] Comparative Example 3

[0096] A piece of nickel foam substrate (NF, 1 cm × 3 cm) was placed in a reaction kettle containing a mixed solution of 15 mL pure water, 15 mL methanol and 0.1 g thioacetamide, and reacted at 180 °C for 4 h. After cooling, the sample was taken out and rinsed several times with absolute ethanol. After vacuum drying at 60 °C for 8 h, dense nickel sulfide nanoparticles grew in-situ on the nickel substrate, and the Ni3S2 / NF sample was obtained.

[0097] Comparative Example 4

[0098] A piece of nickel foam substrate (NF, 1 cm × 3 cm) was placed in a reaction kettle containing a mixed solution of 1.75 mmol nickel chloride, 0.25 mmol iron chloride, 10 mmol urea and 4 mmol ammonium fluoride, and reacted at 120 °C for 6 h. After cooling, the sample was taken out and rinsed several times with pure water. After vacuum drying at 60 °C for 8 h, nickel-iron hydroxide nanosheet arrays grew uniformly on the surface of the Ni3S2 / NF sample, and the NiFe-OH / NF material was obtained.

[0099] Comparative Example 5

[0100] A nickel foam substrate (NF, 1 cm × 3 cm) was placed in the temperature zone of a chemical vapor deposition device. Sulfur powder and the nickel foam substrate were placed upstream and downstream of the temperature zone respectively. Under an argon protection atmosphere, the heating rate and the cooling rate were both 5 °C / min, and the reaction was carried out at 400 °C for 2 h. Nickel sulfide nanoparticles were in-situ grown on the nickel foam substrate to obtain the Ni3S2 / NF sample.

[0101] Comparative Example 6

[0102] A nickel foam substrate (NF, 1 cm × 3 cm) was placed in a reaction kettle containing a mixed solution of 1.75 mmol nickel chloride, 0.25 mmol iron chloride, 10 mmol urea and 4 mmol ammonium fluoride, and the reaction was carried out at 120 °C for 6 h. After cooling, the sample was taken out and rinsed several times with pure water. After vacuum drying at 60 °C for 8 h, nickel-iron hydroxide nanosheet arrays were uniformly grown on the surface of the Ni3S2 / NF sample to obtain the NiFe-OH / NF material.

[0103] Performance test:

[0104] (1) The NiFe-OH / Ni3S2 / NF material of Example 1 was subjected to X-ray diffraction test, and the obtained XRD pattern was as Figure 1 shown.

[0105] (2) The NiFe-OH / Ni3S2 / NF material of Example 1 was subjected to scanning electron microscopy test, and the obtained SEM pattern was as Figure 2 shown, where the magnification of a was smaller and the magnification of b was larger.

[0106] (3) The oxygen evolution reaction catalysts prepared in Examples 1-9 and Comparative Examples 1-6 were respectively subjected to polarization tests. Using a three-electrode system, the oxygen evolution reaction catalysts prepared in Examples 1-9 and Comparative Examples 1-6 were used as the working electrode, Hg / HgO was used as the reference electrode, and a platinum sheet was used as the counter electrode. Electrochemical catalytic tests were carried out at room temperature in 1.0 M KOH electrolyte, and the LSV curves of OER performance were collected, as Figures 3 to 5 shown.

[0107] Figure 1 The XRD pattern shown indicates that Ni3S2 / NF and NiFe-OH / Ni3S2 / NF were successfully synthesized in Example 1, and the nickel-iron hydroxide was in amorphous phase. Figure 2 The SEM pattern shown indicates that NiFe-OH nanoparticles were uniformly grown on Ni3S2 / NF. Figure 3 The LSV curve of OER shown indicates that the NiFe-OH / Ni3S2 / NF of Example 1 had a current density reaching 500 mA / cm 2The overpotential at this time is only 260 mV, which is significantly better than the overpotential of 430 mV of NiFe-OH / NF in Comparative Example 2 and the overpotential of 490 mV of Ni3S2 / NF in Comparative Example 1.

[0108] The NiFe-OH / Ni3S2 / NF materials prepared in Examples 2 to 4 were applied to OER. The NiFe-OH / Ni3S2 / NF material prepared in Example 2 required an overpotential of 310 mV to reach a current density of 500 mA / cm 2 The NiFe-OH / Ni3S2 / NF material prepared in Example 3 required an overpotential of 285 mV to reach a current density of 500 mA / cm 2 The NiFe-OH / Ni3S2 / NF material prepared in Example 4 required an overpotential of 330 mV to reach a current density of 500 mA / cm 2 The specific polarization curves of the NiFe-OH / Ni3S2 / NF materials prepared in Examples 2 to 4 are as Figure 4 shown.

[0109] The NiFe-OH / Ni3S2 / NF materials prepared in Examples 5 to 7 were applied to OER. The NiFe-OH / Ni3S2 / NF material prepared in Example 5 required an overpotential of 322 mV to reach a current density of 500 mA / cm 2 The NiFe-OH / Ni3S2 / NF material prepared in Example 6 required an overpotential of 310 mV to reach a current density of 500 mA / cm 2 The NiFe-OH / Ni3S2 / NF material prepared in Example 7 required an overpotential of 275 mV to reach a current density of 500 mA / cm 2 The specific polarization curves of the NiFe-OH / Ni3S2 / NF materials prepared in Examples 5 to 7 are as Figure 5 shown.

[0110] The NiFe-OH / Ni3S2 / NF material prepared in Example 8 was applied to OER. The NiFe-OH / Ni3S2 / NF of Example 8 required only an overpotential of 280 mV to reach a current density of 500 mA / cm 2 which is better than the overpotential of 410 mV of NiFe-OH / NF in Comparative Example 4 and the overpotential of 500 mV of Ni3S2 / NF in Comparative Example 3.

[0111] The NiFe-OH / Ni3S2 / NF material prepared in Example 9 was applied to OER. The NiFe-OH / Ni3S2 / NF of Example 9 reached 500 mA / cm 2The current density only requires an overpotential of 271 mV, which is better than the overpotential of 410 mV of NiFe-OH / NF in Comparative Example 6 and the overpotential of 480 mV of Ni3S2 / NF in Comparative Example 5.

[0112] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0113] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A preparation method of an oxygen evolution reaction catalyst, characterized in that, It includes the following steps: (1) In-situ grow dense nickel sulfide nanomaterials on a nickel substrate by hydrothermal method, thermal injection method or chemical vapor deposition method to obtain a nickel sulfide / nickel composite material; (2) Grow nickel-iron hydroxide nanomaterials on at least a part of the surface of the nickel sulfide / nickel composite material by hydrothermal method or electrodeposition method to obtain an oxygen evolution reaction catalyst.

2. The preparation method according to claim 1, wherein In step (1), the nickel substrate is selected from nickel felt, nickel foam or nickel mesh.

3. The preparation method according to claim 1, wherein In step (1), the hydrothermal method for growing the nickel sulfide nanomaterials includes the following steps: Mix the nickel substrate, pure water, methanol and thioacetamide to obtain a first mixture, place the first mixture in a reaction kettle, and carry out hydrothermal reaction at 150°C to 190°C for 2h to 6h to obtain the nickel sulfide nanomaterials; Optionally, the ratio between the area of the nickel substrate and the mass of the thioacetamide is 20 cm 2 : 1 g to 60 cm 2 : 1 g; Optionally, the volume ratio of the pure water to the methanol is 1:1 to 3:

1.

4. The preparation method according to claim 1, characterized in that, In step (1), the thermal injection method for growing the nickel sulfide nanomaterials includes the following steps: Mix the nickel substrate and triethylene glycol to obtain a second mixture, place the second mixture in a container, and add a sulfur source at room temperature to 220°C for sulfidation reaction for 1min to 1h to obtain the nickel sulfide nanomaterials; Optionally, the ratio between the area of the nickel substrate and the mass of the sulfur source is 1 cm 2 : 1 g to 1000 cm 2 : 1 g; Optionally, the sulfur source includes a liquid sulfur source and / or a solid sulfur source, wherein the liquid sulfur source is mercaptoethanol, and the solid sulfur source is selected from at least one of thiourea, thioacetamide and sulfur powder; Optionally, the volume ratio of the triethylene glycol to the liquid sulfur source is 1:1 to 20:1; Optionally, the ratio of the volume of the triethylene glycol to the mass of the solid sulfur source is 5mL:1g to 20mL:1g.

5. The preparation method according to claim 1, wherein In step (1), the chemical vapor deposition method for growing the nickel sulfide nanomaterials includes the following steps: Place sulfur powder upstream of the temperature zone of the chemical vapor deposition equipment, place the nickel substrate downstream of the temperature zone of the chemical vapor deposition equipment, and react at 350°C to 550°C for 0.5h to 4h in an argon protective atmosphere to obtain the nickel sulfide nanomaterials; Optionally, the ratio between the area of the nickel substrate and the mass of the sulfur powder is 3 cm 2 : 1 g to 30 cm 2 : 1 g; Optionally, the heating rate and the cooling rate of the chemical vapor deposition equipment are both 1°C / min to 10°C / min.

6. The preparation method according to claim 1, characterized in that, In step (2), the electrodeposition method for growing the nickel-iron hydroxide includes the following steps: Use the nickel sulfide / nickel composite material as the working electrode, Hg / HgO as the reference electrode, a carbon rod as the counter electrode, and a mixed solution containing a nickel source and an iron source as the plating solution, and electrodeposit at -2.0V to -0.2V for 100 to 1000s to obtain the nickel-iron hydroxide nanomaterials, and the nickel-iron hydroxide nanomaterials are nanoparticles; Optionally, the molar ratio of the nickel source to the iron source is 4:1 to 12:1; Optionally, the nickel source is nickel nitrate and / or nickel chloride, and the iron source is iron nitrate and / or iron chloride.

7. The preparation method according to claim 1, characterized in that, In step (2), the hydrothermal method for growing the nickel-iron hydroxide nanomaterial includes the following steps: mixing nickel sulfide / nickel composite, a nickel source, an iron source, urea, and ammonium fluoride to obtain a third mixture, placing the third mixture in a reaction kettle, and performing hydrothermal reaction at 100 °C to 140 °C for 2 h to 8 h to obtain the nickel-iron hydroxide nanomaterial, and the nickel-iron hydroxide nanomaterial is a nanosheet array; Optionally, the molar ratio of the nickel source to the iron source is 4:1 to 12:1; Optionally, the molar ratio of the sum of the nickel source and the iron source, the urea, and the ammonium fluoride is 1:10:2 to 1:4:

1.

8. An oxygen evolution reaction catalyst, characterized in that, Obtained by the preparation method according to claims 1 to 7.

9. An anode material for hydrogen production by electrolyzing water, characterized in that, Comprising the oxygen evolution reaction catalyst according to claim 8.

10. Application of the electrolytic water hydrogen production anode material according to claim 9 in an electrolytic water hydrogen production device.

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