阅读说明：本技术 一种高效全解水电催化剂MoO2-CeOx/NF及其制备方法 (Efficient full-hydrolysis water catalyst MoO2-CeOx/NF and preparation method thereof ) 是由 漆小鹏 陈建 梁彤祥 曾金明 刘超 邓义群 蒋鸿辉 于 2021-06-09 设计创作，主要内容包括：一种高效全解水电催化剂MoO-2-CeO-x/NF及其制备方法。所述制备方法是通过将一定比例的钼酸铵、硝酸铈和乙酰胺,通过水热反应合成纳米锥前驱体；再经过氢气还原技术合成了MoO-2-CeO-x/NF的电催化剂材料。所述催化剂材料通过稀土氧化铈的界面调控作用,同时实现调控材料表面电子结构、调控表面氧空位浓度、在表面形成保护层提高材料循环稳定性三种作用,所得到的电催化剂具有优异的析氢析氧性能,并且具有良好的稳定性。(Efficient full-hydrolysis water catalyst MoO 2 ‑CeO x /NF and its preparation method. The preparation method comprises the steps of synthesizing a nanocone precursor by a hydrothermal reaction of ammonium molybdate, cerium nitrate and acetamide in a certain proportion; then MoO is synthesized by hydrogen reduction technology 2 ‑CeO x An electrocatalyst material of/NF. The catalyst material realizes three functions of regulating and controlling the surface electronic structure of the material, regulating and controlling the concentration of surface oxygen vacancies and forming a protective layer on the surface to improve the circulation stability of the material simultaneously through the interface regulation and control function of rare earth cerium oxide, and the obtained electrocatalyst has excellent hydrogen evolution and oxygen evolution performances and good stability.)

1. Efficient full-hydrolysis water catalyst MoO₂-CeO_xA process for the preparation of/NF, wherein x ═ 1.5 to 2, comprising the steps of:

(1) pretreating the porous nickel carrier for later use;

(2) weighing a certain amount of ammonium molybdate, cerium nitrate and acetamide, and adding water to mix uniformly to obtain a load solution;

(3) placing the pretreated porous nickel carrier obtained in the step (1) in the loading solution to enable the porous nickel carrier to be completely immersed in the loading solution, obtaining a nano conical precursor compounded on the porous nickel carrier through hydrothermal reaction, and washing and drying the nano conical precursor for later use;

(4) putting the dried porous nickel carrier compounded with the nano-cone-shaped precursor into a furnace, reacting at a certain temperature by a hydrogen reduction technology, and cooling to room temperature to obtain the high-efficiency full-hydrolysis hydro-electric catalyst MoO₂-CeO_x/NF。

2. The high-efficiency full-hydrolysis hydro-electrocatalyst MoO according to claim 1₂-CeO_xThe preparation method of/NF, wherein, in the step (1), the porous nickel carrier is foam nickel.

3. The high efficiency fully hydrolyzed hydro-electric catalyst MoO according to claim 1 or 2₂-CeO_xThe preparation method of/NF comprises the step (1) of sequentially placing the porous nickel carrier in dilute hydrochloric acid solution, absolute ethyl alcohol and deionized water for ultrasonic treatment and vacuum drying.

4. The high efficiency fully hydrolyzed hydro-electric catalyst MoO according to claim 1 or 2₂-CeO_xThe preparation method of/NF, wherein, in the step (2):

controlling the molar ratio of molybdenum element to cerium element in the ammonium molybdate and the cerium nitrate to be 5:1-40: 1;

controlling the molar ratio of acetamide to ammonium molybdate to be 2-8: 1.

5. The high efficiency fully hydrolyzed hydro-electric catalyst MoO according to claim 1 or 2₂-CeO_xThe method for preparing/NF, wherein, in the step (3), the hydrothermal reaction is controlledThe temperature is 150 ℃ and 240 ℃, and the reaction time is 6-32 h.

6. The high efficiency fully hydrolyzed hydro-electric catalyst MoO according to claim 1 or 2₂-CeO_xThe preparation method of/NF, wherein, in the step (4), the furnace tube furnace is adopted, and a porcelain boat containing the porous nickel carrier is placed in the center of the tube furnace.

7. The high efficiency fully hydrolyzed hydro-electric catalyst MoO according to claim 1 or 2₂-CeO_xThe method for producing NF, wherein in the step (4), H is controlled during the hydrogen reduction treatment₂The volume ratio of/Ar is 1: 4-12.

8. The high efficiency fully hydrolyzed hydro-electric catalyst MoO according to claim 1 or 2₂-CeO_xThe preparation method of/NF comprises the step (4), wherein the reaction temperature is 400-600 ℃ and the heat preservation time is 1-6h when the hydrogen reduction treatment is carried out.

9. The high-efficiency full-hydrolysis hydro-electrocatalyst MoO according to claim 1₂-CeO_xThe preparation method of/NF comprises the steps of washing with deionized water and drying at 30-70 ℃ for 6-15 h.

10. High-efficiency full-hydrolysis hydro-electric catalyst MoO prepared by the method of claims 1-9₂-CeO_xand/NF, wherein x is 1.5-2, characterized in that the catalyst is a heterojunction material of molybdenum oxide and cerium oxide.

Technical Field

The invention belongs to the field of new energy materials, and particularly relates to a high-efficiency full-hydrolysis water-power catalyst MoO₂-CeO_x/NF and its preparation method.

Background

With the development of society and the continuous promotion of industrialization process, the global energy demand is increased sharply. At present, the problem of environmental pollution and the shortage of energy are important factors for the urgent development of clean energy form, and the development of a clean, efficient and sustainable new energy system is a fundamental way to solve the increasingly severe energy crisis and environmental pollution in the world today. The hydrogen energy is used as a secondary energy with wide source, green and high efficiency, has the advantages of rich resources, cleanness, high efficiency, high energy density, environmental friendliness and the like, is an ideal renewable energy source, and will certainly become an important component of an energy system in the future. The production and utilization of hydrogen energy is critical to the mitigation of energy and environmental concerns and has attracted considerable attention by researchers. The electrolytic water and hydrogen-oxygen fuel cell is concerned by having unique advantages and application prospects in the preparation and utilization of hydrogen, and the popularization and application of hydrogen production by electrolytic water to consume renewable energy sources such as water and electricity, wind power and photovoltaic power generation with excessive structural property is an important way for optimizing energy consumption structures.

However, the hysteresis of the electrocatalytic reactions such as the oxygen evolution reaction, the hydrogen evolution reaction, and the oxygen reduction reaction, which are involved in the conventional energy conversion devices such as electrolysis water and fuel cells, is one of the important bottlenecks that restrict the development thereof, and the cause of the hysteresis is mainly due to the hysteresis of the catalyst performance. Although the traditional noble metal catalyst has better electrocatalytic performance, the high price and limited reserves thereof hinder the large-scale commercial production thereof and limit the development thereof in the electrocatalytic field. Therefore, the research and development of cheap, abundant and efficient non-noble metal catalysts to replace noble metal catalysts has become a hot area of research. Among them, a full hydrolysis catalyst capable of producing hydrogen and oxygen simultaneously is gaining wide attention.

In recent years, a great deal of research has been devoted to the development of low cost non-noble metal electrocatalysts, packagesIncluding transition metal carbides, sulfides, selenides, and oxide-substituted noble metal catalysts. Molybdenum dioxide (MoO), a potential molybdenum-based oxide to replace noble metal catalysts₂) It is a hot spot of research because of its good metal conductivity and chemical stability. The tetravalent molybdenum of the molybdenum dioxide can provide good metal indication characteristics in the catalytic reaction and has good activity at the fermi level. In addition, MoO₂Has high electron transfer rate, and Mo-O bond can be well dissociated to effectively adsorb and desorb the catalytic intermediate, thereby being beneficial to catalysis. But MoO alone₂HER activity exhibited in HER catalysis is not superior, and therefore, there is a need for an effective strategy to change the electronic environment on the surface of the catalyst, thereby exposing additional active sites during hydrogen evolution of the catalyst and further increasing the rate of electrocatalytic water decomposition.

The increase in charge transfer rate can accelerate the performance of the electrocatalyst due to strong interactions between the different domains at the interface. Interface engineering is considered an effective method to design efficient electrocatalysts, since electrocatalytic reactions typically occur at the interface. Research shows that the heterojunction through interface engineering can promote electron transfer and influence the adsorption/desorption energy of active matter in electrocatalysis reaction, so as to regulate catalytic capacity. Moreover, the synergistic interaction of the two components may also be beneficial to further improve catalytic activity and stability of the heterostructure. Heterogeneous nanostructures show synergistically enhanced kinetics at different active center and electron reconstitution interfaces, superior to their single component electrocatalysts. Due to MoO₂It is difficult to exhibit better HER capacity and stability in acidic media, in order to solve MoO₂Huihui Zhao et al provides Mo source by Mo Foil (MF) and obtains MoO hydrothermally by using mixed solution of hydrogen peroxide and deionized water₂The mixture is subjected to hydrothermal and low-temperature phosphorization in sequence to obtain CoP-MoO with a heterogeneous interface₂a/MF nano-array. This "bottom-up" approach enables heterogeneous nanoarrays to be grown on MF without toleranceIs easy to fall off. CoP-MoO₂the/MF heterojunction maintains not only good HER performance and high stability in alkaline solutions, but also in acidic conditions. (H.ZHao, Z.Li, X.Dai, M.Cui, F.Nie, X.ZHang, Z.ren, Z.Yang, Y.gan, X.yin, Y.Wang, W.Song, heterogeneous structured CoP/MoO)₂on Mo foam as high-efficiency electrolytes for the hydrogen evolution reaction in the boundary acid and alkali medium, Journal of Materials Chemistry A, (2020) 6732-. As another example, Gance Yang et al applied the synthesis of POMOF to a self-sacrificial template of FeOOH matrix by in situ growth of phosphomolybdic acid and iron-based complexes ([email protected] Fe complexes), followed by low temperature phosphating to form MoO₂[email protected]。MoO₂Interfacial electron redistribution of-FeP @ C occurs at the interface, where electron accumulation on FeP favors H₂Optimization of O and H absorption energy, thereby improving HER activity, and MoO₂The accumulation of the upper cavities is beneficial to the absorption of biomass organic matters. The stronger synergistic effect of the nano heterostructure is greatly improved in the aspect of hydrogen evolution performance. (G.Yang, Y.Jiano, H.Yan, Y.Xie, A.Wu, X.Dong, D.Guo, C.Tian, H.Fu, Interfacial Engineering of MoO₂-FeP Heterojunction for Highly Efficient Hydrogen Evolution Coupled with Biomass Electrooxidation,Advanced Materials,32(2020)2000455.)。

The invention combines the excellent hydrogen evolution performance of molybdenum oxide and the excellent oxygen evolution performance of cerium oxide to obtain the electrocatalyst with high-efficiency full-electrolysis water performance, and simultaneously, the research of regulating and controlling the rearrangement of electrons at an interface, the oxygen vacancy concentration and the formation of a surface protection layer through the synergistic effect between heterojunction interfaces is very important, thereby having important significance for the development of the high-efficiency full-electrolysis water electrocatalyst.

Disclosure of Invention

In order to solve the technical problem, the invention provides an electrocatalyst MoO for efficient full water decomposition₂-CeO_xA process for the preparation of/NF, wherein x is 1.5-2, said process comprising the steps of:

(1) selecting a porous nickel carrier for pretreatment for later use;

(2) weighing a certain amount of ammonium molybdate, cerium nitrate and acetamide, and adding water to mix uniformly to obtain a load solution;

(3) placing the pretreated porous nickel carrier obtained in the step (1) in the loading solution to enable the porous nickel carrier to be completely immersed in the loading solution, obtaining a nano conical precursor compounded on the porous nickel carrier through hydrothermal reaction, and washing and drying the nano conical precursor for later use;

(4) completely putting the dried porous nickel carrier compounded with the nano cone-shaped precursor into a furnace, reacting at the temperature of 400-600 ℃ by using a hydrogen reduction technology, and cooling the furnace to room temperature to obtain the high-efficiency full-electrolysis hydro-electric catalyst MoO₂-CeO_x/NF。

Specifically, in the step (1), the porous nickel carrier is foamed nickel.

Specifically, in the step (1), the pretreatment step includes a step of sequentially placing the porous nickel carrier in a dilute hydrochloric acid solution, absolute ethyl alcohol and deionized water for ultrasonic treatment, and a step of vacuum drying at a low temperature.

Wherein the concentration of the dilute hydrochloric acid solution is preferably 3mol/L, and the ultrasonic treatment time in the dilute hydrochloric acid solution, the absolute ethyl alcohol and the deionized water is preferably controlled to be 15-25min (preferably 20min) respectively.

Specifically, in the step (2):

controlling the molar ratio of molybdenum element to cerium element in the ammonium molybdate and the cerium nitrate to be 5:1-40: 1;

controlling the molar ratio of acetamide to ammonium molybdate to be 2-8: 1.

And as for the amount of water in the supporting solution, it is preferable that the amount is sufficient to dissolve the above-mentioned substances for the purpose of dissolving ammonium molybdate, cerium nitrate and acetamide, and that the porous nickel support can be completely impregnated.

Specifically, in the step (3), the temperature of the hydrothermal reaction is controlled to be 150 ℃ and 240 ℃, and the reaction time is 6-32 h.

Specifically, in the step (4), the furnace tube furnace is a ceramic boat containing a porous nickel carrier and is placed in the center of the tube furnace.

Specifically, in the step (4), H is controlled during the hydrogen reduction treatment₂The volume ratio of/Ar is 1: 4-12.

Specifically, in the step (4), the reaction temperature is controlled to be 400-600 ℃ and the heat preservation time is 1-6h when the hydrogen reduction treatment is performed.

Specifically, in the step (3), the washing step is washing with deionized water, and the drying step is drying at 30-70 ℃ for 6-15 h.

The invention also discloses the high-efficiency full-hydrolysis water catalyst MoO prepared by the method₂-CeO_x/NF，Wherein x is 1.5-2, and the catalyst is a heterojunction material of molybdenum oxide and cerium oxide.

The invention has the following beneficial technical effects:

the invention relates to a high-efficiency full-hydrolysis water catalyst MoO₂-CeO_xthe/NF is that ammonium molybdate, cerium nitrate and acetamide in certain proportion are synthesized into a nanometer conical precursor through hydrothermal reaction; and then the heterojunction material of cerium oxide and molybdenum oxide with rich oxygen vacancies is obtained through hydrogen reduction treatment.

The catalyst is prepared by in-situ growing molybdenum-cerium-based precursor nanosheets on a porous nickel carrier, so that the intrinsic activity of the material is improved, and meanwhile, the active sites of the material are further increased; reducing the molybdenum-cerium-based precursor generated in situ into CeO by hydrogen reduction_xAnd MoO₂。

Formation of CeO_xAnd MoO₂The heterojunction of (2) realizes three functions of regulating and controlling the electronic structure on the surface of the material, regulating and controlling the concentration of oxygen vacancies on the surface and forming a protective layer on the surface to improve the circulation stability of the material simultaneously through the interface regulation and control function of the rare earth cerium oxide, and the obtained electrocatalyst has excellent hydrogen evolution and oxygen evolution performances and good stability.

Meanwhile, the preparation method of the whole catalyst is simple and feasible, and is suitable for industrial popularization.

Drawings

FIG. 1 is an SEM topography of pretreated nickel foam of example 1;

FIG. 2 is an SEM topography of a precursor prepared by hydrothermal reaction in example 1;

FIG. 3 shows the MoO production by reduction of hydrogen in example 1₂-CeO_xSEM topography of/NF;

FIG. 4 shows MoO obtained in example 1₂-CeO_x/NF MoO obtained in comparative example 1₂CeO prepared in/NF and comparative example 2_xXRD pattern of/NF;

FIG. 5 shows MoO obtained in example 1₂-CeO_xLSV, Tafel slope diagram and potential versus time diagram of/NF material;

FIG. 6 shows MoO obtained in example 1₂-CeO_xThe LSV curve of the total water splitting of the NF material;

FIG. 7 shows MoO obtained in example 1₂-CeO_xThe hydrogen evolution performance and the oxygen evolution performance of the/NF material are compared with those of other materials.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

The full hydrolysis water catalyst MoO described in this example₂-CeO_xThe preparation method of/NF comprises the following steps:

(1) cutting commercial foam nickel into the size of 10mm x 20mm, sequentially performing ultrasonic treatment in 3M dilute hydrochloric acid, absolute ethyl alcohol and deionized water for 25min, and then performing vacuum drying at 60 ℃ for 8h for later use, wherein an SEM (scanning electron microscope) morphology chart is shown in FIG. 1;

(2) weighing 1mmol of ammonium molybdate tetrahydrate, 0.4mmol of cerium nitrate hexahydrate and 4mmol of acetamide, adding 60ml of deionized water, and stirring for 30min to obtain a loading solution;

(3) transferring the obtained load solution into a reaction kettle, adding the foamed nickel treated in the step (1), sealing, and then putting into a 200 ℃ drying oven for reaction for 14 hours; when the reaction kettle is cooled to room temperature, taking out the foamed nickel, washing with deionized water for 3 times, putting into a 45 ℃ oven, and drying for 8 hours to obtain a precursor, wherein an SEM appearance diagram of the precursor is shown in FIG. 2;

(4) putting the dried foam nickel compounded with the nanometer cone-shaped precursor into a tube furnace, reacting at 500 ℃ by using a hydrogen reduction technology, preserving the temperature for 2 hours, and cooling the tube furnace to room temperature to obtain the high-efficiency full-hydrolysis hydro-electric catalyst MoO₂-CeO_xThe SEM topography is shown in figure 3, and the XRD pattern is shown in figure 4.

As shown in fig. 1, it can be seen from (1) in fig. 1 that the three-dimensional net-like NF scaffold has a smooth surface, and it can be seen from (2) in fig. 1 that it has small protrusions thereon, which facilitates the adhesion of the material.

As shown in fig. 2, it can be seen from (1) in fig. 2 that irregular precursors of pyramidal structures grow on the surface of the precursor, and it can be seen from (2) in fig. 2 that these irregular precursors of pyramidal structures are formed by aggregation of nanospheres and particles, and the length thereof is about 1.1 μm.

As shown in fig. 3, it can be seen from (1) in fig. 3 that the morphology and size of the irregular vertebral structure after hydrogen reduction substantially correspond to those of the prepared precursor. Such irregular vertebral structures have extremely high stability and large specific surface area, and therefore can increase the material-electrolyte contact area, and can also expose additional edge active sites, which can lead to enhanced catalytic activity; as can be seen from comparison of fig. 3 (2) and fig. 2(2), irregular tapered nanospheres formed due to aggregation of particles disappear after the thermal annealing process after hydrogen reduction. This observation may be attributed to the tendency of the particles to amorphize and the rearrangement of electrons, which results in close packing of the nanoparticles to form a protective film.

As shown in FIG. 4, it can be seen that the material prepared in example 1 contains CeO_x、MoO₂And Ni. Wherein, MoO₂And CeO_xFrom the product after hydrogen reduction, Ni is the substrate foam nickel, the MoO₂And CeO_xMainly the irregular vertebral structure.

MoO obtained in this example₂-CeO_xThe LSV and Tafel slope graphs and the current density-time relationship graph of the/NF material under the alkaline condition are shown in the attached figure 5; wherein the content of the first and second substances,

FIG. 5 (1) is a LSV graph of hydrogen evolution of the material, from which it can be seen that the hydrogen evolution performance of the material is 26mV at 10 mA/cm;

FIG. 5 (2) is a Tafel slope diagram converted from the LSV diagram of hydrogen evolution of the material, from which it can be seen that the Tafel slope of hydrogen evolution of the material is 52 mA/dec;

in FIG. 5 (3) is the hydrogen evolution cycle of the material, which can be seen at 10mA/cm²The current density can be kept for 95h without obvious change, so that the hydrogen evolution catalyst has good hydrogen evolution cycle performance;

FIG. 5 (4) is the LSV diagram of oxygen evolution of the material, from which it can be seen that the oxygen evolution performance of the material is 100mA/cm²272mV at the time of (1);

FIG. 5 (5) is a Tafel slope diagram converted from the LSV diagram of oxygen evolution of the material, from which it can be seen that the Tafel slope of the oxygen evolution of the material is 33.92 mA/dec;

FIG. 5 (6) shows the oxygen evolution cycle of the material, which is shown to be at 100mA/cm²The current density can be kept for 58h without obvious change, so that the oxygen evolution cycle performance is good.

FIG. 6 shows MoO₂-CeO_xThe total water splitting curve of the/NF material can be seen from the figure, and is 10mA cm^-2And 20mA cm^-2In the presence of oxygen, MoO₂-CeO_x/NF//MoO₂-CeO_xThe electrolysis voltage of/NF is as low as 1.397V and 1.47V respectively.

Example 2

The full hydrolysis water catalyst MoO described in this example₂-CeO_x-0.2/NF preparation process comprising the steps of:

(1) cutting commercial foam nickel into the size of 10mm x 20mm, sequentially performing ultrasonic treatment in 3M dilute hydrochloric acid, absolute ethyl alcohol and deionized water for 25min, and then performing vacuum drying at 60 ℃ for 8h for later use;

(2) weighing 1mmol of ammonium molybdate tetrahydrate, 0.2mmol of cerium nitrate hexahydrate and 4mmol of acetamide, adding 60ml of deionized water, and stirring for 30min to obtain a loading solution;

(3) transferring the obtained load solution into a reaction kettle, adding the previously treated foamed nickel, sealing, and placing into a 200 ℃ drying oven for reaction for 14 hours; when the reaction kettle is cooled to room temperature, taking out the foamed nickel, washing with deionized water for 3 times, and putting into a 45 ℃ oven for drying for 8 hours to obtain a precursor;

(4) putting the dried foam nickel compounded with the nanometer cone-shaped precursor into a tube furnace, reacting at 500 ℃ by using a hydrogen reduction technology, preserving the temperature for 2 hours, and cooling the tube furnace to room temperature to obtain the high-efficiency full-hydrolysis hydro-electric catalyst MoO₂-CeO_x-0.2/NF。

The electrocatalytic material obtained in the example was determined to have a current density of 10mA/cm²Then, the hydrogen evolution overpotential was measured to be 35mV under the alkaline condition, the Tafel slope was 55.75mV/dec, and the constant 10mA/cm was used²Under the current density, the voltage can still keep stable after 95 hours; measuring that the oxygen evolution overpotential is 296mV and the Tafel slope is 39.87 mV/dec; at the same time, the constant current is 10mA/cm²Under the current density, the voltage can still keep stable after 58 h;

example 3

The full hydrolysis water catalyst MoO described in this example₂-CeO_x-0.6/NF preparation method, comprising the following steps:

(1) cutting commercial foam nickel into the size of 10mm x 20mm, sequentially performing ultrasonic treatment in 3M dilute hydrochloric acid, absolute ethyl alcohol and deionized water for 25min, and then performing vacuum drying at 60 ℃ for 8h for later use;

(2) weighing 1mmol of ammonium molybdate tetrahydrate, 0.6mmol of cerium nitrate hexahydrate and 4mmol of acetamide, adding 60ml of deionized water, and stirring for 30min to obtain a loading solution;

(3) transferring the obtained load solution into a reaction kettle, adding the previously treated foamed nickel, sealing, and placing into a 200 ℃ drying oven for reaction for 14 hours; when the reaction kettle is cooled to room temperature, taking out the foamed nickel, washing with deionized water for 3 times, and putting into a 45 ℃ oven for drying for 8 hours to obtain a precursor;

(4) putting the dried foam nickel compounded with the nanometer cone-shaped precursor into a tube furnace, reacting at 500 ℃ by using a hydrogen reduction technology, preserving the temperature for 2 hours, and cooling the tube furnace to room temperature to obtain the high-efficiency full-hydrolysis hydro-electric catalyst MoO₂-CeO_x-0.6/NF。

The electrocatalytic material obtained in the example was determined to have a current density of 10mA/cm²When the hydrogen evolution overpotential is measured under alkaline conditions to be 46mV, the Tafel slope is 75.32mV/dec, and the constant value is 10mA/cm²Under the current density, the voltage can still keep stable after 95 hours; measuring the oxygen evolution overpotential to be 320mV and the Tafel slope to be 69.47 mV/dec; at the same time, the constant current is 10mA/cm²Under the current density, the voltage can still keep stable after 58 h;

comparative example 1

The material of the comparative example was a material without cerium nitrate (noted as MoO)₂/NF) and the specific preparation process comprises the following steps:

(1) cutting commercial foam nickel into the size of 10mm x 20mm, sequentially performing ultrasonic treatment in 3M dilute hydrochloric acid, absolute ethyl alcohol and deionized water for 25min, and then performing vacuum drying at 60 ℃ for 8h for later use;

(2) weighing 1mmol of ammonium molybdate tetrahydrate and 4mmol of acetamide, adding 60ml of deionized water, and stirring for 30min to obtain a loading solution;

(3) transferring the obtained load solution into a reaction kettle, adding the previously treated foamed nickel, sealing, and placing into a 200 ℃ drying oven for reaction for 14 hours; when the reaction kettle is cooled to room temperature, taking out the foamed nickel, washing with deionized water for 3 times, and putting into a 45 ℃ oven for drying for 8 hours to obtain a precursor;

(4) putting the dried foam nickel compounded with the nano-cone-shaped precursor into a tube furnace, reacting at 500 ℃ by using a hydrogen reduction technology, preserving the temperature for 2 hours, cooling the tube furnace to room temperature, and finally obtaining the MoO of the comparative example 1₂/NF electrocatalytic material.

Comparative example 2

This comparative exampleThe material is the material without ammonium molybdate tetrahydrate (noted as CeO)_x/NF) and the specific preparation process comprises the following steps:

cutting commercial foam nickel into the size of 10mm x 20mm, sequentially performing ultrasonic treatment in 3M dilute hydrochloric acid, absolute ethyl alcohol and deionized water for 25min, and then performing vacuum drying at 60 ℃ for 8h for later use;

(2) weighing 0.4mmol of cerium nitrate hexahydrate and 4mmol of acetamide, adding 60ml of deionized water, and stirring for 30min to obtain a loading solution;

(3) transferring the obtained load solution into a reaction kettle, adding the previously treated foamed nickel, sealing, and placing into a 200 ℃ drying oven for reaction for 14 hours; when the reaction kettle is cooled to room temperature, taking out the foamed nickel, washing with deionized water for 3 times, and putting into a 45 ℃ oven for drying for 8 hours to obtain a precursor;

(4) putting the dried foam nickel compounded with the nanometer cone-shaped precursor into a tube furnace, reacting at 500 ℃ by using a hydrogen reduction technology, preserving the temperature for 2 hours, cooling the tube furnace to room temperature, and finally obtaining CeO_xthe/NF comparative scheme electrocatalytic materials.

Catalytic materials (noted as MoO) from example 1, respectively₂-CeO_xNF), material prepared in comparative example 1 without cerium nitrate (noted as MoO)₂NF), comparative example 2, the material prepared without ammonium molybdate tetrahydrate (noted CeO_x/NF), and pure nickel foam (noted NF), commercial platinum carbon (noted Pt/C)/commercial ruthenium oxide (noted RuO)₂) The performance difference comparison was performed and the results are shown in FIG. 7.

FIG. 7 (1) is a comparison between the hydrogen evolution performance of the materials, and it can be seen that pure Nickel Foam (NF) has the worst performance because it is the matrix material and its hydrogen evolution performance is negligible; comparative example 1 preparation of a material without added cerium nitrate (noted as MoO)₂NF), comparative example 2, the material prepared without ammonium molybdate tetrahydrate (noted CeO_xNF) and commercial Pt-C (Pt/C) at 10mA/cm²The values of the time intervals are 52mV, 196mV and 27mV respectively.

FIG. 7 (2) shows Tafel slope corresponding to the data in FIG. 7 (1)As can be seen from the graph, the material prepared in comparative example 1 without adding cerium nitrate (noted as MoO)₂NF), comparative example 2, the material prepared without ammonium molybdate tetrahydrate (noted CeO_xNF) and commercial platinum carbon (Pt/C) have Tafel slopes of 64.84mV/dec, 208.04mV/dec, and 52.95mV/dec, respectively.

FIG. 7 (3) is a comparison between the oxygen evolution performance of the materials, and it can be seen that the pure Nickel Foam (NF) has the worst performance, because the nickel foam is the matrix material, and the oxygen evolution performance of the nickel foam is negligible; comparative example 1 preparation of a material without added cerium nitrate (noted as MoO)₂NF), comparative example 2, the material prepared without ammonium molybdate tetrahydrate (noted CeO_x/NF) and commercial ruthenium oxide (RuO)₂) At 100mA/cm²At times 428mV, 474mV and 393mV respectively.

FIG. 7 (4) shows the Tafel slope corresponding to the data in FIG. 7 (3), and it can be seen that the material prepared in comparative example 1 without cerium nitrate (denoted as MoO)₂NF), comparative example 2, the material prepared without ammonium molybdate tetrahydrate (noted CeO_x/NF) and commercial ruthenium oxide (RuO)₂) The Tafel slopes of (a) were 146.34mV/dec, 160.98mV/dec, and 90.97mV/dec, respectively.

Therefore, the catalyst material has excellent hydrogen evolution performance and oxygen evolution performance and has electrocatalysis performance of high-efficiency full water decomposition performance.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.