A transition metal corrosion foam nickel loaded rare earth oxide composite electrode material and a preparation method and application thereof

Abstract

The present application relates to a kind of transition metal corrosion foam nickel load rare earth oxide composite electrode material and its preparation method and application, method includes: after pretreatment, foam nickel is immersed in the corrosion liquid containing transition metal salt and is carried out chemical corrosion treatment, obtain transition metal corrosion foam nickel;Transition metal corrosion foam nickel is working electrode, in the deposition liquid containing rare earth salt is carried out electrodeposition, obtain composite electrode material precursor;Finally, by calcination treatment, obtain composite electrode material.The present application constructs micro-nano rough structure on the surface of foam nickel by chemical corrosion, significantly increases electrochemical active area, realizes the uniform loading of active component and interface optimization in combination with rare earth oxide electrodeposition, the composite electrode material obtained has the advantages such as large specific surface area, active site is rich, electron transmission is efficient, catalytic performance is excellent and stability is good, can be widely applied to electrocatalysis field, provides a general platform for non-noble metal electrocatalyst.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalytic materials technology, specifically relating to a transition metal-corroded nickel foam supported rare earth oxide composite electrode material, its preparation method, and its application. Background Technology

[0002] With the increasing urgency of global energy structure transformation and sustainable development, electrocatalysis technology, as a clean and efficient means of energy conversion and chemical synthesis, has received widespread attention from academia and industry. Electrocatalytic oxygen evolution reaction (OER), electrocatalytic hydrogen evolution reaction (HER), electrocatalytic oxidation of small organic molecules (such as the oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid, and the oxidation of alcohols to carboxylic acids), and electrocatalytic reduction of carbon dioxide (CO2RR) are key technological pathways for achieving renewable energy storage and conversion, high-value utilization of biomass resources, and carbon emission reduction targets.

[0003] The efficiency of the aforementioned electrocatalytic reactions largely depends on the performance of the electrode materials. An ideal electrocatalytic electrode material should simultaneously possess high catalytic activity, excellent stability, good electron conductivity, and abundant active sites. However, while traditional noble metal-based catalysts (such as Pt, IrO2, and RuO2) exhibit excellent catalytic performance, their high cost and scarce resources severely limit their large-scale application. Therefore, developing low-cost, highly active, and highly stable non-noble metal electrocatalytic materials has become a research hotspot in the field of electrocatalysis.

[0004] Nickel foam, a porous metallic material with a three-dimensional network structure, is widely used as a support material for electrocatalytic electrodes due to its advantages such as large specific surface area, high porosity, good conductivity, and light weight. However, the surface of untreated nickel foam is relatively smooth, with limited active sites, resulting in insufficient catalytic activity when used directly as an electrode material. To improve the electrochemical active area and catalytic performance of nickel foam, researchers have explored various modification strategies, among which chemical etching has attracted attention due to its simplicity and low cost.

[0005] On the other hand, rare earth oxides (such as CeO2, La2O3, Pr6O) 11 Rare earth oxides (such as Sm₂O₃ and Er₂O₃) have broad application prospects in electrocatalysis due to their unique 4f electronic structure and excellent oxygen storage / release capabilities. Studies have shown that rare earth oxides possess abundant oxygen vacancies, which can effectively regulate the electronic states of adjacent active metal ions, promoting electron transfer rates and thus significantly improving catalytic performance. However, current methods for loading rare earth oxides onto nickel foam electrodes primarily involve co-deposition or doping, lacking a technical solution for systematically pre-etching the nickel foam support to maximize its structural advantages.

[0006] Therefore, developing a general-purpose composite electrode material preparation method that can comprehensively utilize the advantages of transition metal synergistic corrosion treatment and rare earth oxide electrodeposition and is applicable to a variety of electrocatalytic reactions has significant academic and industrial application value. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a transition metal-corroded nickel-foamed rare earth oxide composite electrode material, its preparation method, and its application, thereby resolving the existing issues. To achieve this objective, this invention adopts the following technical solution: A method for preparing a transition metal-corroded nickel foam-supported rare earth oxide composite electrode material, the method comprising the following steps: S101. After pretreatment, the nickel foam is immersed in a corrosion solution containing transition metal salts for chemical corrosion treatment. After rinsing and drying, transition metal etched nickel foam is obtained. S102. Using the aforementioned transition metal-corroded nickel foam as the working electrode, electrodeposition is performed in a deposition solution containing rare earth salts. After rinsing and drying, a precursor of transition metal-corroded nickel foam loaded with rare earth oxide composite electrode material is obtained. S103. The precursor is calcined to obtain a transition metal-corroded nickel foam-supported rare earth oxide composite electrode material.

[0008] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the transition metal salt includes any one or more combinations of iron salts, cobalt salts, nickel salts, molybdenum salts, manganese salts, copper salts, zinc salts, or chromium salts; or includes any one of transition metal nitrates, chlorides, or sulfates; The rare earth salts include any one of the following: cerium nitrate, lanthanum nitrate, praseodymium nitrate, samarium nitrate, erbium nitrate, yttrium nitrate, neodymium nitrate, dysprosium nitrate, cerium chloride, lanthanum chloride, praseodymium chloride, samarium chloride, erbium chloride, cerium acetate, lanthanum acetate, praseodymium acetate, and their hydrates; The pH of the corrosive solution is 1-4; The sediment contains a supporting electrolyte, which includes any one of NaNO3, Na2SO4, KNO3, or K2SO4.

[0009] In addition to the aspects and any possible implementations described above, an implementation is further provided in which the transition metal salt includes any combination of two of iron salt, cobalt salt, nickel salt, molybdenum salt, manganese salt, copper salt, zinc salt or chromium salt, and the molar ratio of the two transition metal salts is (1-9):(1-9).

[0010] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the concentration of transition metal ions in the corrosive solution is 0.01-0.5 M; The concentration of rare earth ions in the deposition solution is 0.01-0.1 M, and the concentration of the supporting electrolyte is 0.01-0.2 M.

[0011] In addition to the aspects described above and any possible implementation, a further implementation is provided in which the temperature of the chemical etching treatment in step S101 is 20-80 °C and the treatment time is 10-180 min.

[0012] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the electrodeposition in step S102 employs a three-electrode system of a working electrode, a reference electrode, and a counter electrode, wherein the reference electrode is a saturated calomel electrode or an Ag / AgCl electrode, and the counter electrode is a platinum sheet; constant potential deposition is employed, with the deposition potential relative to the reference electrode being -0.7 V to -1.3 V, the deposition time being 5-40 min, the deposition temperature being room temperature, and magnetic stirring at 100-600 rpm being used during the deposition process.

[0013] In addition to the aspects described above and any possible implementation, a further implementation is provided in which the calcination treatment in step S103 is carried out at a temperature of 400-700 °C, for a treatment time of 1-4 h, and at a heating rate of 1-5 °C / min.

[0014] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the rinsing in steps S101 and S102 both include a first rinsing and a second rinsing: the washing solution for the first rinsing includes anhydrous ethanol; the number of times the first rinsing is performed is 2-4 times; the washing solution for the second rinsing includes deionized water; the number of times the second rinsing is performed is 2-4 times. In steps S101 and S102, the drying temperature is 60-80 ℃ and the drying time is 8-12 h.

[0015] This invention also discloses a transition metal-corroded nickel foam-supported rare earth oxide composite electrode material, wherein the composite electrode material has a BET specific surface area of ​​45-120 m². 2 / g, electron transfer impedance R ct The Ω is as low as 1.8-8.5; the catalytic performance decay rate is less than 5% after 1000 h of continuous electrocatalytic cycling.

[0016] The present invention also discloses an application of the composite electrode material as described above, wherein the composite electrode material is applied to an electrocatalytic reaction, the electrocatalytic reaction including at least one of the following: electrocatalytic oxygen evolution reaction, electrocatalytic hydrogen evolution reaction, 5-hydroxymethylfurfural electrocatalytic oxidation reaction, biomass-derived alcohol / aldehyde / acid small molecule electrocatalytic oxidation reaction, or carbon dioxide electrocatalytic reduction reaction.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: (1) The present invention uses a three-step method of “chemical corrosion + electrodeposition + calcination” to synthesize composite electrode materials. The preparation method is simple and easy to operate. The use of transition metals to replace precious metals significantly reduces the preparation cost of catalysts.

[0018] (2) By chemically corroding the surface of nickel foam with transition metal salt solution, a micro-nano rough structure is constructed, which significantly increases the electrochemical active area and the number of active sites. The uniform loading of rare earth oxide nanoparticles is achieved by electrodeposition, and a tight interface is formed by calcination treatment, thus realizing the synergistic optimization of controllable construction of carrier microstructure and efficient loading of active components.

[0019] (3) The introduction of rare earth oxides (such as CeO2) can regulate the electronic environment of the catalyst and promote the activity of high-valence species of active metals (such as Ni). 3+ The formation of [various substances] optimizes the adsorption of reactants on the catalyst surface and reduces the activation energy of various reaction intermediates, thereby achieving a significant improvement in reaction kinetics in a variety of electrocatalytic reactions.

[0020] (4) The composite electrode material of the present invention has excellent versatility and can be applied to a variety of reaction types such as electrocatalytic oxygen evolution reaction, hydrogen evolution reaction, electrocatalytic oxidation of biomass-derived organic small molecules (such as HMF oxidation to FDCA) and CO2 electrocatalytic reduction, showing good multifunctional electrocatalytic properties. Attached Figure Description

[0021] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a performance graph of the Fe-corroded nickel foam-supported CeO2 composite electrode material of the present invention, where the vertical axis represents Current Density (mA cm⁻¹). -2 The x-axis represents current density, in milliamperes per square centimeter; the x-axis, Potential (Vvs. RHE), represents the potential relative to the reversible hydrogen electrode (RHE), in volts. Figure 3 This is a schematic diagram of the Fe-corroded nickel foam-supported CeO2 composite electrode material of the present invention; Figure 4 This is a schematic diagram of the Fe-Mo etched nickel foam supported CeO2 composite electrode material of the present invention; Figure 5 This is a schematic diagram of the Co-corroded nickel foam-supported La2O3 composite electrode material of the present invention; Figure 6 The present invention provides a method for Ni-Mo corrosion-resistant nickel foam loaded with Pr6O. 11 Schematic diagram of composite electrode material; Figure 7 This is a schematic diagram of the Cu-corroded nickel-foamed Sm2O3 composite electrode material of the present invention; Figure 8 This is a schematic diagram of the Fe-Mn corroded nickel foam supported Er2O3 composite electrode material of the present invention. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0024] like Figure 1 As shown, this invention provides a method for preparing a transition metal-corroded nickel foam-supported rare earth oxide composite electrode material, the preparation method comprising the following steps: S101: After pretreatment, the nickel foam is immersed in an etching solution containing transition metal salts (iron salts, cobalt salts, nickel salts, molybdenum salts, manganese salts, copper salts, zinc salts, or chromium salts, etc.) for chemical etching. After rinsing and drying, transition metal etched nickel foam is obtained. This step uses an acidic etching solution containing transition metal ions to perform controlled temperature etching on the nickel foam substrate. The hydrolysis of transition metal ions produces a weak etching effect, simultaneously constructing a micro-nano rough porous structure with interlaced micron-level wrinkles and nano-level pits on the originally smooth and dense nickel foam metal skeleton surface. This structure can significantly widen the contact interface between the electrode and the electrolyte, directly increasing the specific surface area (BET) of the material to 45-120 m². 2 / g, the electrochemical active area ECSA is increased to 3.2-6.5 times that of the original foamed nickel, exposing a large number of active sites that can be used for anchoring of active components and catalytic reactions. This solves the defects of pure foamed nickel in terms of lack of active sites and large mass transfer resistance from the perspective of support structure, and provides sufficient attachment sites for the uniform loading of rare earth oxides.

[0025] S102: Using the aforementioned transition metal-corroded nickel foam as the working electrode, electrodeposition is performed in a deposition solution containing rare earth salts (cerium salt, lanthanum salt, praseodymium salt, samarium salt, erbium salt, etc.). After rinsing and drying, a precursor for a transition metal-corroded nickel foam-supported rare earth oxide composite electrode material is obtained. In this step, the high specific surface area nickel foam after corrosion is used as the working substrate. In a deposition solution containing rare earth ions and supporting electrolyte, constant potential electrodeposition is used to uniformly deposit the rare earth hydroxide precursor on the surface of the three-dimensional framework of the nickel foam and the inner wall of the internal pores. The high roughness of the carrier can effectively inhibit the aggregation of rare earth precursors, achieve uniform dispersion and loading of 5-30 nm rare earth nanoparticles, and form a tight contact interface between the rare earth components and the nickel substrate. The unique 4f electronic structure of rare earths regulates the distribution of the metal electron cloud on the substrate, inducing the generation of high-valence Ni. 3+ Intrinsic active sites are introduced, and a large number of oxygen vacancies are introduced to optimize the adsorption configuration of reaction substrates and reduce the activation energy of reaction intermediates, thereby improving the intrinsic catalytic activity of the electrode from the perspective of active components. Supporting electrolytes can improve the conductivity of the deposition solution, ensure the uniformity of current during the deposition process, further enhance the uniformity of rare earth component loading, and simultaneously improve the overall electron transport efficiency of the electrode.

[0026] S103: The precursor is calcined to obtain a transition metal-corroded nickel foam-supported rare earth oxide composite electrode material. This step involves temperature-controlled calcination of the electrodeposited precursor, which completely transforms the rare earth hydroxide precursor into well-crystallized rare earth oxides, forming a stable heterojunction interface and significantly reducing the interfacial charge transfer impedance R. ct (As low as 1.8-8.5 Ω), enabling rapid electron transport; on the other hand, the calcination process strengthens the interfacial bonding between rare earth oxide nanoparticles and the corroded nickel foam substrate, preventing the loss of active components during long-term electrocatalytic operation, significantly improving the electrochemical cycle stability of the electrode, with a catalytic performance decay rate of less than 6% after 50 hours of continuous operation; at the same time, calcination can eliminate residual impurities from the preparation process, clear the pore structure, further ensure the diffusion mass transfer efficiency of the electrolyte inside the porous framework, and synergistically amplify the high specific surface area advantage brought by the corrosion structure.

[0027] In summary, the S101 transition metal salt corrosion process forms the structural basis for achieving a large specific surface area and abundant active sites in the material; the S102 rare earth electrodeposition process introduces rare earth oxide active components, completes electronic environment regulation, and significantly improves the electrode's catalytic activity; the S103 calcination process stabilizes the heterogeneous interface and strengthens the bonding strength, achieving efficient electron transport and long-term stability. These three steps work synergistically and are indispensable, ultimately yielding a composite electrode material with high specific surface area, abundant active sites, rapid electron transport, excellent catalytic activity, and ultra-long cycle stability. Corrosion without rare earth deposition lacks electronic regulation sites, resulting in a significant decrease in catalytic activity; direct rare earth deposition without corrosion modification leads to insufficient carrier specific surface area, severe rare earth particle agglomeration, and a limited number of active sites, making high-performance electrocatalysis impossible.

[0028] This invention constructs a micro-nano rough structure on the surface of nickel foam through chemical etching with transition metal salt solutions, significantly increasing the electrochemical active area. Rare earth oxide nanoparticles are uniformly loaded onto the etched nickel foam surface and the inner walls of the three-dimensional framework using electrodeposition. Further calcination forms a composite electrode material with good crystallinity and tight interfacial bonding. The introduction of rare earth oxides can regulate the electronic environment of the catalyst, promote the formation of active high-valence species, optimize reactant adsorption, and lower the reaction energy barrier, thereby achieving a synergistic improvement in catalytic performance in various electrocatalytic reactions. This invention combines "transition metal etching" with "rare earth oxide loading," and both are synergistic and indispensable, fully leveraging the advantages of the three-dimensional porous structure of nickel foam and the catalytic activity of rare earth oxides. This results in a green synthesis characterized by inexpensive raw materials, simple processes, no precious metal addition, and diverse reaction types, providing a universal platform for developing low-cost, high-performance, and multifunctional novel non-precious metal electrocatalysts.

[0029] In a preferred embodiment, the transition metal salt includes any one or more combinations of iron salts, cobalt salts, nickel salts, molybdenum salts, manganese salts, copper salts, zinc salts, or chromium salts. Non-limiting combinations include combinations of iron salts and molybdenum salts, or combinations of cobalt salts and nickel salts, or combinations of iron salts and manganese salts.

[0030] In a preferred embodiment, the transition metal salt includes any one of a transition metal nitrate, chloride, or sulfate.

[0031] In a preferred embodiment, the rare earth salt includes any one of cerium nitrate, lanthanum nitrate, praseodymium nitrate, samarium nitrate, erbium nitrate, yttrium nitrate, neodymium nitrate, dysprosium nitrate, cerium chloride, lanthanum chloride, praseodymium chloride, samarium chloride, erbium chloride, cerium acetate, lanthanum acetate, praseodymium acetate rare earth salts and their hydrates.

[0032] In a preferred embodiment, the pH of the etching solution is 1-4. When the pH is less than 1, the system is too acidic, and hydrogen ions will cause severe and indiscriminate erosion of the three-dimensional framework of the nickel foam, which can easily lead to substrate breakage and a significant decrease in electrode conductivity. When the pH is greater than 4, the acidity is insufficient, the degree of hydrolysis of transition metal ions is extremely low, and it is impossible to generate active species of hydroxyl oxides with etching capabilities, making it difficult to construct micro-nano rough porous structures. At the same time, metal ions are prone to directly generate hydroxide flocculent precipitates, causing the etching solution to fail. However, the weakly acidic environment with a pH of 1-4 can precisely control the hydrolysis rate of transition metal salts. The active species generated by hydrolysis can gently and uniformly etch the surface of the nickel foam, forming a concave-nano structure that is adapted to the anchoring of rare earth particles while completely preserving the three-dimensional conductive framework of the substrate. Under this acidity range, metal ions can exist stably in the etching solution and continue to exert the etching effect. Moreover, the residual acidic impurities after etching are easy to clean and remove, and will not interfere with the subsequent rare earth electrodeposition process, ensuring that the rare earth oxide nanoparticles are uniformly dispersed and loaded.

[0033] In a preferred embodiment, the deposition solution contains a supporting electrolyte, which includes any one of NaNO3, Na2SO4, KNO3, or K2SO4. NaNO3, Na2SO4, KNO3, and K2SO4 are selected as the supporting electrolytes for the deposition solution because these inorganic salts have excellent solubility and can completely ionize into a large number of cations and anions after dissolving in the deposition solution, significantly improving the overall ionic conductivity of the deposition solution, reducing the ohmic voltage drop of the system during the electrodeposition process, ensuring uniform potential throughout the corrosion of the nickel foam substrate, and enabling the rare earth precursor to be deposited synchronously and uniformly on the carrier surface and the inner wall of the pores, avoiding excessive local deposition and rare earth particle agglomeration. Nitrate and sulfate ions have strong electrochemical inertness and will not undergo redox side reactions within the constant potential deposition range set in this invention, will not competitively consume electrons, interfere with the growth of rare earth hydroxide precursors, and prevent the formation of impurity phases. The Na+ dissociated from sodium and potassium salts... + K + It does not participate in rare earth deposition reactions and can be completely removed by simple water washing after the reaction. It will not remain on the electrode surface to block pores or cover catalytic active sites. At the same time, this type of salt raw material is inexpensive, readily available, and stable. There is no risk of decomposition or deterioration during storage and use, making it suitable for large-scale preparation.

[0034] In a preferred embodiment, the transition metal salt can be any combination of one or more. If it is a combination of two, the molar ratio of the two transition metal salts is (1-9):(1-9), for example, it can be 1:9, 1:5, 1:1, 5:1 or 9:1. The molar ratio of the two transition metal salts is controlled in the range of (1-9):(1-9) because the surface morphology of the nickel foam obtained by etching with a single transition metal salt is uniform, and it can only form a single-scale pore structure, with limited improvement in active sites. When two transition metal ions coexist, they can synergistically regulate the hydrolysis etching rate. The hydroxyl oxide etching species generated by the hydrolysis of different metal ions have different etching capabilities. The molar ratio of 1:9 to 9:1 can flexibly regulate the composite micro-nano structure of micron-folds and nano-pits on the surface of the nickel foam, realize multi-level pore matching, and further increase the electrochemical active area. At the same time, the small amount of doping of the two transition metal elements into the surface layer of the nickel substrate can pre-regulate the electronic structure of the substrate, which is conducive to the subsequent construction of rare earth oxides. Heterogeneous interfaces provide a better basis for electronic synergy. If the proportion of a certain component is less than 1 / 10 (i.e., the molar ratio exceeds the 9:1 or 1:9 range), the metal ions with too low content are difficult to exert synergistic etching and pre-doping modification effects, which is only equivalent to single metal salt corrosion. It is impossible to obtain multi-level composite porous morphology and electronic regulation gain. However, the synergistic effect of two metal ions can be achieved in the full ratio range of 1:9-9:1, which takes into account both the tunability of etching morphology and electrode conductivity. Moreover, the raw material ratio is simple to adjust and can be adapted to the different requirements of electrode pore structure and electronic characteristics in different catalytic scenarios. However, it is not limited to the values ​​listed. Other unlisted values ​​within the range are also applicable.

[0035] In a preferred embodiment, the concentration of transition metal ions in the etching solution is 0.01-0.5 M, for example, 0.01 M, 0.05 M, 0.1 M, 0.2 M, 0.3 M, or 0.5 M. When the concentration is below 0.01 M, the total amount of active metal species that can participate in hydrolytic etching within the system is insufficient, resulting in a slow etching rate. Even with extended etching time, it is difficult to form sufficient micro / nano wrinkles and nano-pits on the surface of the nickel foam, leading to a weak increase in the carrier's specific surface area. When the concentration is above 0.5 M, the content of transition metal ions in the solution is too high, resulting in a violent hydrolysis reaction and the generation of a large amount of hydroxyl oxide precipitation in a short time. This not only causes excessive etching of the nickel foam surface and damage to the three-dimensional porous framework, reducing the overall conductivity and mechanical strength of the electrode, but also excessive precipitation covers the pores on the substrate surface, blocking the attachment sites for subsequent rare earth deposition. However, a concentration of 0.01-0.5 M is insufficient. The concentration range of M allows for flexible adjustment of etching intensity. Low concentrations favor light etching and preserve the complete framework, while high concentrations enable deep etching and the construction of multi-level porous structures. Within the range, each concentration can achieve uniform and controllable surface modification, stably increasing the electrochemical active area without generating a large amount of precipitated impurities. Residual metal precipitates can be removed by simple rinsing with ethanol and deionized water, without interfering with the subsequent rare earth electrodeposition process. It is suitable for different catalytic requirements to control the electrode microstructure, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0036] In a preferred embodiment, the concentration of rare earth ions in the deposition solution is 0.01-0.1 M, for example, 0.01 M, 0.03 M, 0.05 M, 0.07 M, or 0.1 M. When the rare earth ion concentration is below 0.01 M, there are too few rare earth active ions in the solution that can participate in electrodeposition, resulting in a slow electrodeposition reaction rate, extremely low rare earth precursor loading, and an inability to form sufficient rare earth oxide active components on the nickel foam surface. This makes it difficult to regulate the electronic structure of the substrate, and the improvement in catalytic performance is limited. When the rare earth ion concentration is above 0.1 M, the ion concentration in the deposition solution is too high, the nucleation rate of rare earth precursors during electrodeposition is too fast, and large-sized agglomerates are easily generated, clogging the porous channels of the nickel foam and significantly reducing the exposed catalytic active sites. At the same time, an excessively thick rare earth layer weakens the conductivity advantage of the nickel foam substrate and increases charge transport resistance. However, a concentration of 0.01-0.1 M is not ideal. The concentration range of M allows for precise control of the loading and grain size of rare earth oxides. Low concentrations can achieve uniform thin-layer coating, while high concentrations can moderately increase the loading of active components. Under all concentration conditions within the range, rare earth precursors can uniformly nucleate and grow on the surface of the hierarchical channels of corroded nickel foam, forming 5-30 nm well-dispersed rare earth nanoparticles. This ensures sufficient oxygen vacancies and electronic regulation effects without clogging the carrier pores or hindering electrolyte diffusion, thus balancing electrode conductivity and electrocatalytic activity. However, this range is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0037] In a preferred embodiment, the concentration of the supporting electrolyte in the deposition solution is 0.01-0.2 M, for example, 0.01 M, 0.05 M, 0.08 M, 0.1 M, 0.15 M, or 0.2 M. If the concentration is below 0.01 M, the overall ionic conductivity of the deposition solution is insufficient, the ohmic impedance of the electrodeposition system is high, the potential distribution on the working electrode surface is uneven, and local rare earth deposition thickness varies and particle agglomeration easily occurs, making it difficult to achieve uniform loading of rare earth precursors. If the concentration is above 0.2 M, the ionic strength in the solution is too high, which will significantly compress the diffusion layer of rare earth ions, inhibiting the migration of rare earth ions into the pores of the corroded nickel foam. Only active components can be deposited on the outer surface of the electrode, and rare earth oxides cannot be loaded inside the framework. At the same time, high concentrations of inorganic salts easily crystallize and precipitate, adhering to the electrode pores and blocking the mass transfer channels. 0.01-0.2 The concentration range of M can effectively improve the conductivity of the deposition solution, reduce the cell pressure, and ensure the uniformity of the overall deposition potential of the electrode, allowing rare earth precursors to grow uniformly on the surface and internal three-dimensional channels of the nickel foam. It will not hinder the diffusion of rare earth ions due to excessive ionic strength. The deposition rate can also be flexibly controlled by adjusting the electrolyte concentration according to actual needs. In addition, salt impurities in this concentration range can be completely removed by simple rinsing with ethanol and deionized water, without leaving any residue to cover the catalytic active sites. It takes into account the uniformity of deposition, the unobstructedness of electrode pores, and the convenience of subsequent cleaning. However, it is not limited to the values ​​listed. Other unlisted values ​​within the range are also applicable.

[0038] In a preferred embodiment, the pretreatment of the nickel foam includes: immersing the nickel foam in acetone, anhydrous ethanol and deionized water in sequence, cleaning each with ultrasonic waves for 5-15 minutes, and vacuum drying at 60-80 °C.

[0039] In a preferred embodiment, the temperature of the chemical etching process in S101 is 20-80 °C, for example, 20 °C, 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, or 80 °C. Below 20 °C, the kinetic rate of the transition metal ion hydrolysis reaction is extremely low, the etching process is slow, and even with prolonged treatment, it is difficult to generate sufficient micro-nano uneven structures on the nickel foam surface, resulting in poor improvement in the carrier's specific surface area. Above 80 °C, the evaporation of water in the etching solution is accelerated, causing localized supersaturation and precipitation of metal salts. Simultaneously, the hydrolysis reaction becomes violently uncontrolled, and excessive etching damages the three-dimensional conductive framework of the nickel foam, reducing the electrode's mechanical strength and conductivity. 20-80 °C The temperature range of ℃ allows for linear control of the metal ion hydrolysis etching rate. The low-temperature range enables gentle shallow etching, preserving the original framework of the nickel foam. The high-temperature range enables deep multi-level pore etching, increasing the number of active sites. The corrosion reaction is stable and controllable at each temperature within the range. It can uniformly construct a rough morphology that is compatible with rare earth particle anchoring on the inner and outer walls of the nickel foam, without producing a large amount of difficult-to-clean metal hydroxide precipitates. The process conditions are mild and easy to operate, requiring no high-pressure sealed equipment, which facilitates large-scale preparation.

[0040] However, this is not limited to the listed values; other unlisted values ​​within the range are also applicable. In a preferred embodiment, the chemical etching time is 10-180 min, for example, 10 min, 30 min, 60 min, 90 min, 120 min, 150 min, or 180 min. When the etching time is less than 10 min, the transition metal ion hydrolysis etching reaction is insufficient, and only a few shallow indentations are produced on the surface of the nickel foam, failing to form continuous micro-nano folds and hierarchical porous structures, resulting in a minimal increase in electrochemical active area. When the etching time exceeds 180 min, the continuous etching action will excessively erode the nickel foam metal skeleton, causing a significant reduction in metal wall thickness, local skeleton fracture and collapse, impairing the mechanical stability and conductivity of the electrode, while a large amount of hydrolysis precipitate accumulates and blocks the pores; 10-180 The etching degree can be flexibly adjusted within a time range of min. A short time can achieve only slight surface roughening modification, while a long time can complete the construction of deep multi-level pores. Uniform and controllable etching can be achieved at any time within the range. It can obtain abundant surface anchoring points for subsequent rare earth oxide loading, and can completely preserve the three-dimensional through conductive channels of nickel foam. It can adapt to the different requirements of different catalytic reactions for electrode microstructure and specific surface area. It has a wide process window and high operational tolerance, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0041] In a preferred embodiment, the rinsing in S101 includes a first rinse and a second rinse: The washing solution for the first rinse includes anhydrous ethanol; the number of first rinses is 2-4 times, for example, 2 times, 3 times or 4 times; The washing solution for the second rinse includes deionized water; the number of rinses for the second rinse is 2-4 times, for example, 2 times, 3 times or 4 times.

[0042] In a preferred embodiment, the drying temperature in S101 is 60-80 °C, for example, 60 °C, 65 °C, 70 °C, 75 °C, or 80 °C. Below 60 °C, the solvent evaporation rate is slow, significantly prolonging the drying time. Residual ethanol and water inside the pores of the nickel foam are difficult to completely remove, and the residual liquid will dilute the subsequent etching and deposition solutions, interfering with the etching and rare earth deposition processes. It also easily causes the metal substrate to slowly oxidize, forming a thick oxide layer with no catalytic activity. Above 80 °C, the temperature rises too quickly, and the vapor generated by the rapid vaporization of the solvent inside the pores easily impacts the newly etched micro / nano rough structure, causing the surface unevenness to collapse and the pores to close. Simultaneously, the high temperature accelerates the non-selective oxidation of the nickel foam, forming a dense passivation oxide film that blocks active sites. 60-80 °C The temperature range of ℃ falls within the mild low-temperature vacuum drying range, where the solvent evaporation rate is gradual and controllable. This effectively removes anhydrous ethanol and deionized water from the electrode surface and pores without damaging the multi-level micro / nano porous structure formed by corrosion. It also avoids excessive substrate oxidation, resulting in a clean electrode surface free of excess oxide impurities after drying. This ensures stable support for subsequent electrodeposition processes and guarantees uniform loading of rare earth oxides. However, the drying time is not limited to the listed values; other unlisted values ​​within the range are also applicable. In a preferred embodiment, the drying time is 8-12 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0043] In a preferred embodiment, the electrodeposition in S102 adopts a three-electrode system, the working electrode is the transition metal-corroded nickel foam synthesized in step (1), the reference electrode is a saturated calomel electrode or an Ag / AgCl electrode, and the counter electrode is a platinum sheet. In a preferred embodiment, the electrodeposition process in S102 is constant potential deposition, with the deposition potential relative to the saturated calomel electrode ranging from -0.7 V to -1.3 V, for example, -0.7 V, -0.8 V, -0.9 V, -1.0 V, -1.1 V, -1.2 V, or -1.3 V. When the potential is higher than -0.7 V (more positive), the reduction driving force provided by the system is insufficient, making it difficult for rare earth ions to gain electrons for hydrolysis to generate rare earth hydroxide precursors. The deposition loading is extremely low, failing to form sufficient rare earth active components, making it difficult to control the electronic structure of the nickel substrate. When the potential is lower than -1.3 V (more negative), the applied voltage is too strong, triggering a large amount of hydrogen evolution side reaction in the deposition solution. The violently generated hydrogen bubbles continuously impact the electrode surface, causing uneven nucleation of rare earth precursors and particle agglomeration and detachment. At the same time, excessive reduction easily leads to excessive reduction corrosion of the substrate foam nickel, destroying the previously constructed micro-nano porous structure. -0.7 V -1.3 V The potential range of V can stably regulate the nucleation and growth rate of rare earth precursors. A positive potential range allows for uniform coating of thin-layered, small-sized rare earth nanoparticles, while a negative potential range can moderately increase the rare earth loading. Within this range, there is no severe hydrogen evolution side reaction interference. Rare earth precursors can simultaneously and uniformly nucleate and grow on the outer surface and within the three-dimensional channels of the corroded nickel foam, forming well-dispersed rare earth precursor particles with a size of 5-30 nm. This ensures that the rare earth oxides have sufficient oxygen vacancies and electronic regulation capabilities after subsequent calcination, while also preserving the multi-level porous structure of the carrier and ensuring unobstructed electrolyte mass transfer channels. However, this is not limited to the listed values; other unlisted values ​​within the range are also applicable. This is to uniformly deposit rare earth oxide nanoparticles on the surface of the corroded nickel foam.

[0044] In a preferred embodiment, the deposition time is 5-40 min. To control the loading of rare earth oxides, it can be, for example, 5 min, 10 min, 15 min, 20 min, 30 min, or 40 min. When the deposition time is less than 5 min, the rare earth ion reduction deposition reaction time is too short, the loading of rare earth hydroxide precursor is extremely low, and the content of rare earth oxides after calcination is too low. This makes it impossible to effectively control the electronic environment of the nickel foam substrate and generate sufficient oxygen vacancies and high-valence Ni. 3+The effect of improving catalytic performance at active sites is weak. If the deposition time exceeds 40 min, continuous deposition will result in an excessively thick rare earth precursor layer, with a large number of particles agglomerating and clogging the three-dimensional interconnected channels of the nickel foam, hindering electrolyte diffusion and transport. At the same time, the thick layer of rare earth oxides will increase the overall charge transfer impedance of the electrode, weakening the excellent conductivity of the nickel foam substrate. A time window of 5-40 min allows for precise gradient control of the loading of rare earth active components. Short-time deposition can obtain an ultra-thin, highly dispersed rare earth nanoparticle layer, while long-time deposition can moderately increase the rare earth loading to enhance the electronic control effect. Any deposition time within the range can achieve uniform adhesion of rare earth precursors to the internal and external channels of the carrier without large-area agglomeration or pore blockage. The deposition time can be flexibly adjusted according to the requirements of different electrocatalytic reactions for the content of active components. The process has a large control space and good reproducibility, but it is not limited to the values ​​listed. Other unlisted values ​​within the range are also applicable. In a preferred embodiment, the deposition temperature is room temperature, and the deposition process is accompanied by magnetic stirring at 100-600 rpm, for example, 100 rpm, 200 rpm, 300 rpm, 400 rpm, 500 rpm or 600 rpm, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0045] In a preferred embodiment, the rinsing and drying conditions in S102 are the same as in step (1).

[0046] In a preferred embodiment, the calcination temperature in S103 is 400-700 °C, for example, 400 °C, 450 °C, 500 °C, 550 °C, 600 °C, 650 °C, or 700 °C. Below 400 °C, the heat supply is insufficient, resulting in incomplete dehydration and crystallization of the rare earth hydroxide precursor obtained by electrodeposition. The product is mainly amorphous hydroxide with few oxygen vacancies, making it difficult to form crystalline rare earth oxides with electronic control capabilities. Simultaneously, the interface between the precursor and the nickel foam substrate is loose, making it easy for the active component to detach during electrocatalysis. Above 700 °C, the calcination temperature is too high, causing rapid growth of rare earth oxide grains and particle agglomeration, significantly reducing active sites. High temperatures also cause the nickel foam substrate to form a dense, thick nickel oxide passivation film, blocking porous channels and reducing electrode conductivity. 400-700 °C The temperature range of ℃ allows for precise control of the crystallinity and grain size of rare earth oxides. The low-temperature range (400-500 ℃) yields small-sized rare earth nanoparticles with high oxygen vacancy content, while the high-temperature range (550-700 ℃) enhances crystal integrity and strengthens the interfacial bonding between the active component and the substrate. Within this range, the precursor can be completely converted into rare earth oxides, fully preserving the three-dimensional micro / nano porous structure built by the corrosion-coated nickel foam. This approach balances abundant catalytic active sites, rapid electron transport, and long-term electrochemical stability, adapting to various electrocatalytic scenarios such as OER, HER, HMFOR, and CO2RR. However, the values ​​are not limited to those listed; other unlisted values ​​within the range are also applicable. In a preferred embodiment, the calcination time is 1-4 h, for example, 1 h, 2 h, 3 h, or 4 h, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.In a preferred embodiment, the heating rate of the calcination treatment is 1-5 °C / min, for example, it can be 1 °C / min, 2 °C / min, 3 °C / min, 4 °C / min or 5 °C / min. When the calcination is less than 1 h, the heat is difficult to penetrate into the internal pores of the electrode, the rare earth hydroxide precursor is not completely dehydrated and decomposed, there are more amorphous impurities, the rare earth oxide has low crystallinity and few oxygen vacancies, and the active component is loosely bonded to the substrate interface. Calcination exceeding 4 h will cause the rare earth oxide grains to continue to sinter and agglomerate, significantly consuming the small active sites, and will also thicken the passivation oxide layer on the surface of the nickel foam, blocking the mass transfer channels and increasing the charge transfer resistance. The degree of crystallization can be flexibly controlled within the 1-4 h range. A short time can achieve complete decomposition of the precursor, and a long time can strengthen the bonding strength of the heterogeneous interface. Highly active rare earth oxides can be obtained while retaining the micro-nano porous structure of the carrier at any time within the range. The calcination heating rate is limited to 1-5 °C / min, and the heating rate exceeding 5 °C / min is not allowed. At ℃ / min, the rapid vaporization of water and hydroxyl groups in the precursor generates a large number of bubbles, which can easily cause the rare earth active layer to crack and fall off. At the same time, the severe thermal stress can damage the multi-level micro-nano structure formed by nickel foam etching. Heating rates below 1 ℃ / min will significantly prolong the preparation cycle and increase energy consumption. Furthermore, prolonged low-temperature holding can cause the substrate to form a dense passivation oxide film prematurely. A slow heating range of 1-5 ℃ / min can achieve stable and phased removal of solvent and hydroxyl groups, gently release thermal stress, maintain the morphology of the porous support, promote the uniform and slow crystallization of the rare earth precursor, and generate small-sized, highly dispersible rare earth oxide nanoparticles. The process stability and sample reproducibility are better. And it is not limited to the values ​​listed. Other unlisted values ​​within the value range are also applicable.

[0047] As an embodiment of the present invention, the present invention also discloses a composite electrode material, obtained by the preparation method of the present invention, wherein the composite electrode material has a BET specific surface area of ​​45-120 m². 2 / g, the electrochemically active surface area (ECSA) is 3.2-6.5 times that of the original uncorroded nickel foam; the material interface has abundant oxygen vacancies, which can stably generate high-valence Ni. 3+ Active site, electron transfer impedance R ct It has an Ω as low as 1.8-8.5; the catalytic performance decay rate is less than 5% after 1000 h of continuous electrocatalytic cycling, and it has high activity, excellent conductivity and long-term electrochemical stability.

[0048] As an embodiment of the present invention, the present invention also discloses an application of the composite electrode material as described in the first aspect, wherein the composite electrode material is applied to an electrocatalytic reaction, the electrocatalytic reaction including at least one of the following: electrocatalytic oxygen evolution reaction, electrocatalytic hydrogen evolution reaction, 5-hydroxymethylfurfural electrocatalytic oxidation reaction, biomass-derived alcohol / aldehyde / acid small molecule electrocatalytic oxidation reaction, or carbon dioxide electrocatalytic reduction reaction.

[0049] In a preferred embodiment, the electrocatalytic reaction is carried out in an alkaline aqueous solution.

[0050] In a preferred embodiment, the alkaline aqueous solution comprises either potassium hydroxide or sodium hydroxide, with a concentration of 0.01-2 mol / L, such as 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.5 mol / L, 1 mol / L, or 2 mol / L, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0051] In a preferred embodiment, the reaction potential of the electrocatalytic reaction is 0.2-2.0 V. RHE For example, it could be 0.2 V RHE 0.5 V RHE 0.8 V RHE 1.0 V RHE 1.2 V RHE 1.45 V RHE 1.5 V RHE Or 2.0 V RHE However, this does not limit the listed values; other unlisted values ​​within the range are also applicable.

[0052] The following specific examples illustrate this: Example 1: This embodiment describes a method for preparing a Fe(NO3)3-corroded nickel foam-supported CeO2 composite electrode material, the steps of which are as follows: (1) Pretreatment of nickel foam Before use, place the nickel foam (2×4 cm) 2 Immerse the nickel foam in acetone, anhydrous ethanol, and deionized water respectively, and clean each with ultrasonic waves for 10 minutes to remove oil and impurities from the surface. Then dry them in a 60°C oven for later use.

[0053] (2) Chemical corrosion treatment of nickel foam Weigh an appropriate amount of Fe(NO3)3·9H2O and dissolve it in deionized water to prepare a 0.1 M Fe(NO3)3 solution. Adjust the pH to 2.0 with dilute HNO3. Immerse the pretreated nickel foam in the etching solution and perform hydrothermal treatment at 60 °C for 12 h, utilizing Fe... 3+ Hydrolytic etching was used to corrode the nickel foam. After removal, it was rinsed three times with anhydrous ethanol and three times with deionized water, and then vacuum dried at 60 °C for 12 h to obtain Fe-corroded nickel foam.

[0054] (3) Electrodeposition of CeO2 Preparation of the deposition solution: Dissolve 0.05 M Ce(NO3)3·6H2O and 0.1 M NaNO3 in deionized water and stir until completely dissolved. A three-electrode system was used, with Fe-corroded nickel foam as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Constant potential electrodeposition was performed in the deposition solution. The deposition potential was -0.95 V vs. SCE, the deposition time was 10 min, and the deposition was carried out at room temperature with magnetic stirring at 200 rpm. After deposition, the material was removed, rinsed three times with deionized water, and vacuum dried at 60 ℃ for 12 h to obtain the Fe-corroded nickel foam-supported CeO2 composite electrode material precursor.

[0055] (4) Calcination treatment The above precursor was placed in a muffle furnace and heated to 500 °C at a rate of 2 °C / min, then calcined in air for 2 h. After furnace cooling to room temperature, Fe-corroded nickel foam supported CeO2 composite electrode material was obtained. Figure 2 and Figure 3 This indicates that the CeO2 loading is beneficial to improving the catalytic activity of Fe corrosion foam nickel.

[0056] The performance of the prepared composite electrode material in the electrocatalytic oxygen evolution reaction in 1.0 M KOH electrolyte is as follows: at 10 mA / cm 2 The overpotential at the current density is 240 mV, and the Tafel slope is 58 mV / dec.

[0057] Example 2: This embodiment describes a method for preparing a FeCl3+MoCl5-corroded nickel foam-supported CeO2 composite electrode material, the steps of which are as follows: (1) Pretreatment of nickel foam Before use, place the nickel foam (2×4 cm) 2 Immerse the nickel foam in acetone, anhydrous ethanol, and deionized water respectively, and clean each with ultrasonic waves for 10 minutes to remove oil and impurities from the surface. Then dry them in a 60°C oven for later use.

[0058] (2) Chemical corrosion treatment of nickel foam Weigh appropriate amounts of FeCl3·6H2O and MoCl5 and dissolve them in deionized water to prepare a mixed etching solution of 0.1 M FeCl3 and 0.02 M MoCl5. Immerse the pretreated nickel foam in the etching solution and etch at 40 °C for 60 min. After removal, perform deep dechlorination treatment: ultrasonically clean with hot deionized water at 60 °C 5-8 times, rinse with anhydrous ethanol 3 times, and vacuum dry at 60 °C for 12 h to obtain Fe-Mo bimetallic etched nickel foam.

[0059] (3) Electrodeposition of CeO2 Preparation of the deposition solution: Dissolve 0.05 M Ce(NO3)3·6H2O and 0.1 M NaNO3 in deionized water and stir until completely dissolved. A three-electrode system was used, with Fe-Mo corroded nickel foam as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Constant potential electrodeposition was performed in the deposition solution. The deposition potential was -0.95 V vs. SCE, the deposition time was 10 min, and the deposition was carried out at room temperature with magnetic stirring at 200 rpm. After deposition, the material was removed, rinsed three times with deionized water, and vacuum dried at 60 ℃ for 12 h to obtain the Fe-Mo corroded nickel foam-supported CeO2 composite electrode material precursor.

[0060] (4) Calcination treatment The above precursor was placed in a muffle furnace and heated to 500 °C at a rate of 2 °C / min, calcined in air for 2 h, and then cooled to room temperature in the furnace to obtain Fe-Mo etched nickel foam supported CeO2 composite electrode material, such as... Figure 4 As shown.

[0061] The performance of the prepared composite electrode material in the electrocatalytic hydrogen evolution reaction in 1.0 M KOH electrolyte is as follows: at 10 mA / cm 2 The overpotential at the current density is 150 mV, and the Tafel slope is 65 mV / dec.

[0062] Example 3: This embodiment describes a method for preparing a Co(NO3)2-corroded nickel foam-supported La2O3 composite electrode material, the steps of which are as follows: (1) Pretreatment of nickel foam Before use, place the nickel foam (2×4 cm) 2 Immerse the nickel foam in acetone, anhydrous ethanol, and deionized water respectively, and clean each with ultrasonic waves for 10 minutes to remove oil and impurities from the surface. Then dry them in a 60°C oven for later use.

[0063] (2) Chemical corrosion treatment of nickel foam Weigh an appropriate amount of Co(NO3)2·6H2O and dissolve it in deionized water to prepare a 0.1 M Co(NO3)2 solution. Adjust the pH to 3.0 with dilute HNO3. Immerse the pretreated nickel foam in the etching solution and etch it at 50 °C for 90 min. After removal, rinse three times with anhydrous ethanol and three times with deionized water, and vacuum dry at 60 °C for 12 h to obtain Co-etched nickel foam.

[0064] (3) Electrodeposition of La2O3 Preparation of the deposition solution: Dissolve 0.05 M La(NO3)3·6H2O and 0.1 M NaNO3 in deionized water and stir until completely dissolved. A three-electrode system was used, with Co-corroded nickel foam as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Constant potential electrodeposition was performed in the deposition solution. The deposition potential was -1.0 V vs. SCE, the deposition time was 15 min, and the deposition was carried out at room temperature with magnetic stirring at 300 rpm. After deposition, the material was removed, rinsed three times with deionized water, and vacuum dried at 60 ℃ for 12 h to obtain the precursor of the Co-corroded nickel foam-supported La2O3 composite electrode material.

[0065] (4) Calcination treatment The above precursor was placed in a muffle furnace and heated to 600 °C at a rate of 3 °C / min, calcined in air for 2 h, and then cooled to room temperature in the furnace to obtain a Co-corroded nickel foam-supported La2O3 composite electrode material. Figure 5 As shown.

[0066] 10 mmol / L HMF was dissolved in 1.0 M KOH solution, and the above-mentioned composite electrode material was used at 1.45 V. RHE Electrocatalytic oxidation of HMF to FDCA was performed at a specific potential. The performance indicators are as follows: HMF conversion rate 99.8%, FDCA yield 99.2%, and Faraday efficiency 99.0%.

[0067] Example 4: This embodiment contains a NiSO4+(NH4)6Mo7O 24 Corrosion of nickel-supported Pr6O foam 11 The preparation method of composite electrode materials includes the following steps: (1) Pretreatment of nickel foam Before use, place the nickel foam (2×4 cm) 2 Immerse the nickel foam in acetone, anhydrous ethanol, and deionized water respectively, and clean each with ultrasonic waves for 10 minutes to remove oil and impurities from the surface. Then dry them in a 60°C oven for later use.

[0068] (2) Chemical corrosion treatment of nickel foam Weigh out appropriate amounts of NiSO4·6H2O and (NH4)6Mo7O 24 • 4H₂O was dissolved in deionized water to prepare 0.05 M NiSO₄ and 0.02 M (NH₄)₆Mo₇O₄. 24 The pH of the mixed etching solution was adjusted to 2.5 with dilute H2SO4. The pretreated nickel foam was immersed in the etching solution and etched at 70 °C for 120 min. After removal, it was rinsed three times with anhydrous ethanol and three times with deionized water, and then vacuum dried at 60 °C for 12 h to obtain Ni-Mo bimetallic etched nickel foam.

[0069] (3) Pr6O 11 electrodeposition Preparation of the deposition solution: Dissolve 0.04 M Pr(NO3)3·6H2O and 0.08 M Na2SO4 in deionized water and stir until completely dissolved. A three-electrode system was used, with Ni-Mo etched nickel foam as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Constant potential electrodeposition was performed in the deposition solution. The deposition potential was -1.05 V vs. SCE, the deposition time was 12 min, and the deposition was carried out at room temperature with magnetic stirring at 250 rpm. After deposition, the material was removed, rinsed three times with deionized water, and vacuum dried at 60 ℃ for 12 h to obtain Ni-Mo etched nickel foam loaded with Pr6O. 11 Precursor for composite electrode materials.

[0070] (4) Calcination treatment The above precursor was placed in a muffle furnace and heated to 550 °C at a rate of 2 °C / min, then calcined in air for 2 h. After cooling to room temperature in the furnace, Ni-Mo etched nickel foam supported on Pr6O was obtained. 11 Composite electrode materials, such as Figure 6 As shown.

[0071] 0.5 M ethanol was dissolved in 1.0 M KOH solution, and the above-mentioned composite electrode material was used for the electrocatalytic oxidation of ethanol. The performance indicators are as follows: at 1.5 V... RHE The current density at the potential reaches 120 mA / cm 2 It exhibits excellent ethanol oxidation activity.

[0072] Example 5: This embodiment describes a method for preparing a CuCl2-corroded nickel-foamed Sm2O3 composite electrode material (including dechlorination treatment), the steps of which are as follows: (1) Pretreatment of nickel foam Before use, place the nickel foam (2×4 cm) 2Immerse the nickel foam in acetone, anhydrous ethanol, and deionized water respectively, and clean each with ultrasonic waves for 10 minutes to remove oil and impurities from the surface. Then dry them in a 60°C oven for later use.

[0073] (2) Chemical corrosion treatment of nickel foam Weigh an appropriate amount of CuCl2·2H2O and dissolve it in deionized water to prepare a 0.08 M CuCl2 solution. Adjust the pH to 2.0 with dilute HCl. Immerse the pretreated nickel foam in the etching solution and etch it at room temperature for 30 min. After removal, perform deep dechlorination treatment: ultrasonically clean with 0.1 M NaOH solution at 60 ℃ for 15 min (twice), then ultrasonically clean with hot deionized water at 60 ℃ for 5-8 times until no white precipitate is formed when 0.01 M AgNO3 is added to the cleaning solution. Finally, rinse three times with anhydrous ethanol and vacuum dry at 60 ℃ for 12 h to obtain Cu-etched nickel foam.

[0074] (3) Electrodeposition of Sm2O3 Preparation of the deposition solution: Dissolve 0.05 M Sm(NO3)3·6H2O and 0.1 M KNO3 in deionized water and stir until completely dissolved. A three-electrode system was used, with Cu-etched nickel foam as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Constant potential electrodeposition was performed in the deposition solution. The deposition potential was -0.9 V vs. SCE, the deposition time was 10 min, and the deposition was carried out at room temperature with magnetic stirring at 200 rpm. After deposition, the material was removed, rinsed three times with deionized water, and vacuum dried at 60 ℃ for 12 h to obtain the Cu-etched nickel foam-supported Sm2O3 composite electrode material precursor.

[0075] (4) Calcination treatment The above precursor was placed in a muffle furnace and heated to 500 °C at a rate of 2 °C / min, calcined in air for 2 h, and then cooled to room temperature in the furnace to obtain a Cu-corroded nickel-foamed Sm₂O₃ composite electrode material, such as... Figure 7 As shown.

[0076] The performance of the prepared composite electrode material in the electrocatalytic oxygen evolution reaction in 1.0 M KOH electrolyte is as follows: at 10 mA / cm 2 The overpotential at the current density is 255 mV, and the Tafel slope is 62 mV / dec.

[0077] Example 6: This embodiment describes a method for preparing a Fe2(SO4)3+MnSO4-corroded nickel foam-supported Er2O3 composite electrode material, the steps of which are as follows: (1) Pretreatment of nickel foam Before use, place the nickel foam (2×4 cm) 2 Immerse the nickel foam in acetone, anhydrous ethanol, and deionized water respectively, and clean each with ultrasonic waves for 10 minutes to remove oil and impurities from the surface. Then dry them in a 60°C oven for later use.

[0078] (2) Chemical corrosion treatment of nickel foam Weigh appropriate amounts of Fe2(SO4)3 and MnSO4·H2O and dissolve them in deionized water to prepare a mixed etching solution of 0.08 M Fe2(SO4)3 and 0.03 M MnSO4. Adjust the pH to 2.0 with dilute H2SO4. Immerse the pretreated nickel foam in the etching solution and perform hydrothermal treatment at 80 °C for 8 h. After removal, rinse three times with anhydrous ethanol and three times with deionized water, and vacuum dry at 60 °C for 12 h to obtain Fe-Mn bimetallic etched nickel foam.

[0079] (3) Electrodeposition of Er2O3 Preparation of the deposition solution: Dissolve 0.04 M Er(NO3)3·6H2O and 0.08 M NaNO3 in deionized water and stir until completely dissolved. A three-electrode system was used, with Fe-Mn-corroded nickel foam as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Constant potential electrodeposition was performed in the deposition solution. The deposition potential was -1.0 V vs. SCE, the deposition time was 15 min, and the deposition was carried out at room temperature with magnetic stirring at 300 rpm. After deposition, the material was removed, rinsed three times with deionized water, and vacuum dried at 60 ℃ for 12 h to obtain the precursor of the Fe-Mn-corroded nickel foam-supported Er2O3 composite electrode material.

[0080] (4) Calcination treatment The above precursor was placed in a muffle furnace and heated to 600 °C at a rate of 2 °C / min, calcined in air for 2 h, and then cooled to room temperature in the furnace to obtain Fe-Mn etched nickel foam supported Er2O3 composite electrode material, such as... Figure 8 As shown.

[0081] The performance of the prepared composite electrode material in the CO2 electrocatalytic reduction reaction in 0.5 M KHCO3 solution is as follows: at -1.0 V RHE At the given potential, CO achieves a Faraday efficiency of 85%, demonstrating excellent CO2 reduction activity.

[0082] Comparative Example 1: This comparative example describes a method for preparing an uncorroded nickel-foamed CeO2-supported composite electrode material, the steps of which are as follows: (1) Pretreatment of nickel foam Before use, place the nickel foam (2×4 cm) 2Immerse the nickel foam in acetone, anhydrous ethanol, and deionized water respectively, and clean each with ultrasonic waves for 10 minutes to remove oil and impurities from the surface. Then dry them in a 60°C oven for later use.

[0083] (2) Electrodeposition of CeO2 Preparation of the deposition solution: Dissolve 0.05 M Ce(NO3)3·6H2O and 0.1 M NaNO3 in deionized water and stir until completely dissolved. A three-electrode system was used, with the pretreated raw nickel foam as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Constant potential electrodeposition was performed in the deposition solution. The deposition potential was -0.95 V vs. SCE, the deposition time was 10 min, and the deposition was carried out at room temperature with magnetic stirring at 200 rpm. After deposition, the material was removed, rinsed three times with deionized water, and vacuum dried at 60℃ for 12 h to obtain the precursor of the raw nickel foam-supported CeO2 composite electrode material.

[0084] (3) Calcination treatment The above precursor was placed in a muffle furnace and heated to 500 °C at a rate of 2 °C / min. It was then calcined in air for 2 h and cooled to room temperature with the furnace to obtain an uncorroded nickel foam-supported CeO2 composite electrode material.

[0085] The performance of the uncorroded nickel-supported CeO2 composite electrode material in the electrocatalytic oxygen evolution reaction in 1.0 M KOH electrolyte is as follows: at 10 mA / cm 2 The overpotential at the current density was 320 mV, and the Tafel slope was 82 mV / dec, which was significantly worse than the corrosion sample in Example 1.

[0086] Comparative Example 2: This comparative example describes a method for preparing an electrode material of Fe(NO3)3-corroded nickel foam without rare earth oxide loading, the steps of which are as follows: (1) Pretreatment of nickel foam Before use, place the nickel foam (2×4 cm) 2 Immerse the nickel foam in acetone, anhydrous ethanol, and deionized water respectively, and clean each with ultrasonic waves for 10 minutes to remove oil and impurities from the surface. Then dry them in a 60°C oven for later use.

[0087] (2) Chemical corrosion treatment of nickel foam Weigh an appropriate amount of Fe(NO3)3·9H2O and dissolve it in deionized water to prepare a 0.1 M Fe(NO3)3 solution. Adjust the pH to 2.0 with dilute HNO3. Immerse the pretreated nickel foam in the etching solution and perform hydrothermal treatment at 60 °C for 12 h. After removal, rinse three times with anhydrous ethanol and three times with deionized water, and vacuum dry at 60 °C for 12 h to obtain Fe-etched nickel foam.

[0088] (3) Calcination treatment The Fe-corroded nickel foam was placed in a muffle furnace and heated to 500 °C at a rate of 2 °C / min. It was then calcined in air for 2 hours and cooled to room temperature in the furnace to obtain the Fe-corroded nickel foam electrode material.

[0089] The performance of the Fe-corroded nickel foam electrode material in the electrocatalytic oxygen evolution reaction in 1.0 M KOH electrolyte is as follows: at 10 mA / cm 2 The overpotential at current density was 350 mV, and the Tafel slope was 95 mV / dec, which was significantly worse than the rare earth oxide-loaded sample of Example 1.

[0090] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for preparing a transition metal-corroded nickel foam-supported rare earth oxide composite electrode material, characterized in that, The preparation method includes the following steps: S101. After pretreatment, the nickel foam is immersed in a corrosion solution containing transition metal salts for chemical corrosion treatment. After rinsing and drying, transition metal etched nickel foam is obtained. S102. Using the aforementioned transition metal-corroded nickel foam as the working electrode, electrodeposition is performed in a deposition solution containing rare earth salts. After rinsing and drying, a precursor of transition metal-corroded nickel foam loaded with rare earth oxide composite electrode material is obtained. S103. The precursor is calcined to obtain a transition metal-corroded nickel foam-supported rare earth oxide composite electrode material.

2. The preparation method according to claim 1, characterized in that: The transition metal salts include any one or more combinations of iron salts, cobalt salts, nickel salts, molybdenum salts, manganese salts, copper salts, zinc salts, or chromium salts; or any one of transition metal nitrates, chlorides, or sulfates. The rare earth salts include any one of the following: cerium nitrate, lanthanum nitrate, praseodymium nitrate, samarium nitrate, erbium nitrate, yttrium nitrate, neodymium nitrate, dysprosium nitrate, cerium chloride, lanthanum chloride, praseodymium chloride, samarium chloride, erbium chloride, cerium acetate, lanthanum acetate, praseodymium acetate, and their hydrates; The pH of the corrosive solution is 1-4; The sediment contains a supporting electrolyte, which includes any one of NaNO3, Na2SO4, KNO3, or K2SO4.

3. The preparation method according to claim 1, characterized in that, The transition metal salt includes any two of the following: iron salt, cobalt salt, nickel salt, molybdenum salt, manganese salt, copper salt, zinc salt, or chromium salt, and the molar ratio of the two transition metal salts is (1-9):(1-9).

4. The preparation method according to claim 1, characterized in that: The concentration of transition metal ions in the corrosive solution is 0.01-0.5 M; The concentration of rare earth ions in the deposition solution is 0.01-0.1 M, and the concentration of the supporting electrolyte is 0.01-0.2 M.

5. The preparation method according to claim 1, characterized in that, The temperature of the chemical etching treatment in step S101 is 20-80 ℃, and the treatment time is 10-180 min.

6. The preparation method according to claim 1, characterized in that, The electrodeposition in step S102 employs a three-electrode system consisting of a working electrode, a reference electrode, and a counter electrode. The reference electrode is a saturated calomel electrode or an Ag / AgCl electrode, and the counter electrode is a platinum sheet. Constant potential deposition is used, with the deposition potential relative to the reference electrode ranging from -0.7 V to -1.3 V. The deposition time is 5-40 min, the deposition temperature is room temperature, and magnetic stirring at 100-600 rpm is employed during the deposition process.

7. The preparation method according to claim 1, characterized in that, The calcination treatment in step S103 is carried out at a temperature of 400-700 ℃, for a time of 1-4 h, and at a heating rate of 1-5 ℃ / min.

8. The preparation method according to claim 1, characterized in that, The rinsing described in steps S101 and S102 both include a first rinse and a second rinse: the washing solution for the first rinse includes anhydrous ethanol; the number of times the first rinse is performed is 2-4; the washing solution for the second rinse includes deionized water; the number of times the second rinse is performed is 2-4. In steps S101 and S102, the drying temperature is 60-80 ℃ and the drying time is 8-12 h.

9. A transition metal-corroded nickel-foamed rare earth oxide composite electrode material, characterized in that, The composite electrode material is prepared by the preparation method according to any one of claims 1 to 8, and the composite electrode material has a BET specific surface area of ​​45-120 m². 2 / g, electron transfer impedance R ct The Ω is as low as 1.8-8.5; the catalytic performance decay rate is less than 5% after 1000 h of continuous electrocatalytic cycling.

10. An application of the composite electrode material according to claim 9, characterized in that, The composite electrode material is used in electrocatalytic reactions.

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