Difunctional CoMo / CoMoP-CF catalyst as well as preparation method and application thereof

Abstract

The invention relates to the technical field of electro-catalysis, and provides a bifunctional CoMo / CoMoP-CF catalyst as well as a preparation method and application thereof. Comprising the following steps: respectively carrying out ultrasonic cleaning on foamy copper by using acid, ethanol and deionized water to obtain pretreated foamy copper; the foamy copper serves as a cathode, a platinum sheet serves as an anode, mercury / mercuric oxide serves as a reference electrode, the foamy copper, the platinum sheet and the mercury / mercuric oxide are immersed in the first electrolyte, electro-deposition is conducted under the constant-voltage condition, and CoMo-CF is obtained; and immersing CoMo-CF serving as a cathode, a platinum sheet serving as an anode and mercury / mercuric oxide serving as a reference electrode into the second electrolyte, and carrying out electro-deposition under a constant voltage condition to obtain the CoMo / CoMoP-CF catalyst. The CoMo / CoMoP-CF catalyst prepared by the invention shows relatively low hydrogen evolution overpotential and excellent catalytic activity in electro-catalytic hydrogen evolution, also shows relatively low overpotential and excellent catalytic activity in glucose oxidation reaction, and is a bifunctional catalyst applied to electro-catalytic hydrogen evolution and glucose oxidation.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrocatalysis, and particularly relates to a bifunctional CoMo / CoMoP-CF catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] As a promising clean energy, hydrogen energy exhibits great application potential in the fields of energy conversion and efficient storage. The hydrogen production technology by electrolyzing water is considered as one of the key ways for large-scale hydrogen production in the future due to its green and efficient characteristics. However, the core challenge currently faced is to develop electrocatalysts with both high efficiency and high stability to ensure long-term reliability and economy in industrial applications. With the continuous growth of the global demand for clean energy, the development of efficient and stable electrocatalysts has become the key to promoting the development of hydrogen energy technology. In recent years, transition metal phosphides have attracted extensive attention in the field of electrocatalytic hydrogen evolution due to their excellent catalytic activity and stability. Especially molybdenum-based materials have become a hot research direction because of their rich reserves, low cost and excellent catalytic performance in the earth's crust. However, pure molybdenum-based materials still have certain limitations in catalytic activity and are difficult to meet the increasing industrial demands. Cobalt-based materials exhibit excellent catalytic performance in the electrocatalytic field due to their unique electronic structure and excellent conductivity. By compounding cobalt with molybdenum-based materials, it is expected to fully utilize the advantages of high catalytic activity of cobalt-based materials and high stability of molybdenum-based materials, thereby further improving the catalytic performance.

[0003] At present, to realize the industrial application of cobalt-molybdenum-based composite catalysts, a series of technical problems still need to be overcome. First, how to further improve the specific surface area and active site density of the catalyst by optimizing the preparation process and material structure; second, how to maintain the stability and activity of the catalyst in an alkaline environment is also a key challenge; traditional catalysts often inactivate active sites due to oxidation. Therefore, the development of a cobalt-molybdenum-based composite catalyst with a high specific surface area, excellent catalytic activity and excellent stability has become the key research direction at present. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a bifunctional CoMo / CoMoP-CF catalyst, a preparation method thereof, and an application thereof, aiming to solve the problems mentioned in the background art. The present invention prepares a CoMo / CoMoP-CF electrode on a conductive substrate (copper foam) by a secondary electrodeposition method. During the electrodeposition process, CoMo / CoMoP with a flocculent nanosphere structure grows in-situ on the conductive substrate, promoting the exposure of active sites and electron transfer.

[0005] In the first aspect, the present invention provides a preparation method of a bifunctional CoMo / CoMoP-CF catalyst, comprising the following steps:

[0006] Step S1: Ultrasonically clean the copper foam with acid, ethanol, and deionized water respectively to remove surface oxides and impurities, and obtain the pretreated copper foam.

[0007] Step S2: Use the copper foam as the cathode, the platinum sheet as the anode, and the mercury / mercuric oxide as the reference electrode, immerse them in the first electrolyte solution, and perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -2.0 to -1.0 V, and the time is 10 to 20 minutes. After rinsing with deionized water and drying, CoMo-CF is obtained.

[0008] Step S3: Use CoMo-CF as the cathode, the platinum sheet as the anode, and the mercury / mercuric oxide as the reference electrode, immerse them in the second electrolyte solution, and perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -2.0 to -1.0 V, and the time is 10 to 20 minutes. After rinsing with deionized water and drying, the CoMo / CoMoP-CF catalyst is obtained.

[0009] Furthermore, in Step S1, the acid is 0.3 M dilute hydrochloric acid. Ultrasonically clean the copper foam with 0.3 M dilute hydrochloric acid, ethanol, and deionized water in sequence for 15 min.

[0010] Furthermore, in Step S2, the first electrolyte solution is Na2MoO4·2H2O, CoCl2·6H2O, H3BO3, Na2SO4, EDTA-2Na, and deionized water.

[0011] Furthermore, in the first electrolyte solution, in terms of molar amount, Na2MoO4·2H2O:CoCl2·6H2O:H3BO3:Na2SO4:EDTA-2Na = 0.02:0.12:0.2:0.1:0.05.

[0012] Furthermore, in Step S2, after rinsing three times with deionized water, dry in an oven for 6 h to obtain CoMo-CF.

[0013] Furthermore, in Step S3, the second electrolyte solution is Na2MoO4·2H2O, CoCl2·6H2O, H3BO3, Na2SO4, EDTA-2Na, NaH2PO2·H2O, and deionized water.

[0014] Furthermore, in the second electrolyte solution, in terms of molar amount, Na2MoO4·2H2O:CoCl2·6H2O:H3BO3:Na2SO4:EDTA-2Na:NaH2PO2·H2O = 0.02:0.12:0.2:0.1:0.05:0.094.

[0015] Further, in step S3, after rinsing with deionized water three times, it is dried in an oven for 6 h to obtain the CoMo / CoMoP-CF catalyst.

[0016] In a second aspect, the present invention also provides a bifunctional CoMo / CoMoP-CF catalyst, which has a flocculent nanosphere structure, and the nanospheres are interconnected to form a three-dimensional porous network structure.

[0017] In a third aspect, the present invention also provides an application of the bifunctional CoMo / CoMoP-CF catalyst in electrocatalytic hydrogen evolution and glucose oxidation.

[0018] The present invention has the following beneficial effects:

[0019] (1) The preparation method is simple, the process is easy to control, the period is short, the cost is low, the production efficiency is high, and it is suitable for industrial production. And it can keep the stability and activity of the catalyst in an alkaline environment, and the improvement of the corrosion resistance ensures the reliability of the CoMo / CoMoP-CF catalyst during long-term use. The prepared CoMo / CoMoP-CF catalyst shows a low hydrogen evolution overpotential and excellent catalytic activity in electrocatalytic hydrogen evolution, and also shows a low overpotential and excellent catalytic activity in the glucose oxidation reaction. It is a bifunctional catalyst applied to electrocatalytic hydrogen evolution and glucose oxidation. By replacing the traditional oxygen evolution reaction (OER) with the glucose oxidation reaction (GOR), through the generation of high-value-added products, not only the reaction efficiency is improved, but also the environmental friendliness is enhanced.

[0020] (2) The CoMo / CoMoP-CF catalyst prepared by the secondary electrodeposition method has a unique three-dimensional porous network structure, which is composed of interconnected flocculent nanospheres grown on the copper foam skeleton. In the electrocatalytic hydrogen evolution reaction, the three-dimensional porous network structure enables the electrolyte to fully infiltrate the catalyst surface and come into full contact with the active sites. The abundant pores provide an unobstructed channel for the generation and escape of hydrogen, effectively avoiding the adsorption and accumulation of hydrogen on the catalyst surface, thereby inhibiting the increase of the overpotential of the hydrogen evolution reaction and significantly improving the efficiency of the hydrogen evolution reaction. In the glucose oxidation reaction, the hierarchical pore system allows glucose molecules to rapidly diffuse into the catalyst interior and come into full contact with the active sites and react. The microscopic wrinkles and protrusions on the nanosphere surface further increase the adsorption capacity for glucose molecules and promote the reaction. Moreover, the generated products such as gluconic acid can quickly diffuse into the solution through the pores, avoiding the accumulation of products at the active sites and maintaining the continuous progress of the reaction, thus enhancing the catalytic activity and selectivity of the glucose oxidation reaction.

[0021] (3) By adding H3BO3 during the electrodeposition process, H3BO3 significantly smoothens the surface of the catalyst, remarkably improves the surface morphology of the catalyst, and makes the distribution of nanoparticles more uniform and smooth. This characteristic not only increases the specific surface area and the density of active sites of the catalyst but also enhances the permeability of the electrolyte, facilitating the transport of reactants and products. The introduction of H3BO3 not only regulates the morphology of the catalyst but also significantly enhances the catalytic activity of the CoMo / CoMoP-CF catalyst in electrocatalytic hydrogen evolution (HER) and glucose oxidation (GOR) reactions. Especially at high current densities, the overpotential is lower, showing more excellent performance. This improvement makes the catalyst more competitive in industrial applications and can maintain efficient and stable catalytic performance under high-load conditions. The design concept of this bifunctional catalyst is to achieve efficient electrocatalytic performance by optimizing the microstructure and surface properties of the material to meet various application requirements. These characteristics enable the CoMo / CoMoP-CF catalyst to exhibit excellent bifunctional performance in electrocatalytic hydrogen evolution and glucose oxidation reactions, providing an efficient and stable solution for the hydrogen energy and green chemical industries.

[0022] (4) Through the synergistic effect of cobalt and molybdenum and the doping of phosphorus, the electronic structure and reaction path of the catalyst are further optimized, promoting the rapid transfer of electrons and significantly improving the overall catalytic efficiency. The introduction of cobalt effectively regulates the electronic structure of the molybdenum-based material, enhancing the hydrogen adsorption and dissociation ability, thereby improving the catalytic activity. The combination of cobalt and molybdenum-based materials and the introduction of phosphorus not only enhance the conductivity of the catalyst but also significantly improve its catalytic activity, making the catalyst show higher efficiency and stability in electrochemical reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The exemplary embodiments of the present invention can be more fully understood by referring to the following drawings:

[0024] Figure 1 Scanning electron microscope images of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3, and Example 1 of the present invention; wherein:

[0025] Figure 1 a in is the scanning electron microscope image of the CoMo-CF catalyst prepared in Comparative Example 1;

[0026] Figure 1 b in is the scanning electron microscope image of the CoMoP-CF catalyst prepared in Comparative Example 2;

[0027] Figure 1 c in is the scanning electron microscope image of the CoNi / CoMoP-CF catalyst prepared in Comparative Example 3;

[0028] Figure 1In this, d is the scanning electron microscope image of the CoMo / CoMoP-CF catalyst prepared in Example 1.

[0029] Figure 2 This is the LSV curve diagram of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 of the present invention under alkaline conditions; wherein:

[0030] Figure 2 In this, a is the LSV curve diagram of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 under alkaline conditions (1M KOH);

[0031] Figure 2 In this, b is the LSV curve diagram of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 under alkaline conditions (1M KOH + 0.1M C6H 12 O6);

[0032] Figure 2 In this, c is the LSV curve diagram of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 under alkaline conditions (1M KOH and 1M KOH + 0.1M C6H 12 O6).

[0033] Figure 3 This is the overpotential column chart of electrocatalytic hydrogen evolution (HER) and glucose oxidation (GOR) of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 of the present invention at a current density of 100 mA·cm -2 ; wherein:

[0034] Figure 3 In this, a is the overpotential column chart of electrocatalytic hydrogen evolution (HER) of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 at a current density of 100 mA·cm -2 ;

[0035] Figure 3 In this, b is the overpotential column chart of glucose oxidation (GOR) of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 at a current density of 100 mA·cm -2 ;

[0036] Figure 4 This is the impedance diagram of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 of the present invention; wherein:

[0037] Figure 4 In this, a is the hydrogen evolution impedance diagram of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 under alkaline conditions (1M KOH);

[0038] Figure 4 In this, b is the glucose oxidation impedance diagram of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 under alkaline conditions (1 M KOH + 0.1 M C6H 12 O6).

[0039] Figure 5 This is the double-layer capacitance diagram of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 of the present invention; wherein:

[0040] Figure 5 In this, a is the hydrogen evolution double-layer capacitance diagram of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 under alkaline conditions (1 M KOH);

[0041] Figure 5 In this, b is the glucose oxidation double-layer capacitance diagram of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 under alkaline conditions (1 M KOH + 0.1 M C6H 12 O6);

[0042] Figure 5 In this, c is the double-layer capacitance diagram of the catalysts prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 under alkaline conditions (1 M KOH and 1 M KOH + 0.1 M C6H 12 O6).

[0043] Figure 6 This is the scanning electron microscope image of the catalysts prepared in Comparative Example 1, Comparative Example 2, Example 1, Comparative Example 4, Comparative Example 5 and Comparative Example 6 of the present invention; wherein:

[0044] Figure 6 In this, a is the scanning electron microscope image of the CoMo-CF catalyst prepared in Comparative Example 1;

[0045] Figure 6 In this, b is the scanning electron microscope image of the CoMoP-CF catalyst prepared in Comparative Example 2;

[0046] Figure 6 In this, c is the scanning electron microscope image of the CoMo / CoMoP-CF catalyst prepared in Example 1;

[0047] Figure 6 In this, d is the scanning electron microscope image of the CoMo-CF catalyst (without adding H3BO3) prepared in Comparative Example 4;

[0048] Figure 6 In this, e is the scanning electron microscope image of the CoMoP-CF catalyst (without adding H3BO3) prepared in Comparative Example 5;

[0049] Figure 6In this, f is the scanning electron microscope image of the CoMo / CoMoP-CF catalyst (without adding H3BO3) prepared in Comparative Example 6.

[0050] Figure 7 This is the LSV curve graph of the catalysts prepared in Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 4, Comparative Example 5 and Comparative Example 6 of the present invention under alkaline conditions (1M KOH).

[0051] Figure 8 This is the LSV curve graph of the catalysts prepared in Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 4, Comparative Example 5 and Comparative Example 6 of the present invention under alkaline conditions (1M KOH + 0.1M C6H 12 O6).

[0052] Figure 9 This is the stability (it) graph of the CoMo / CoMoP-CF catalyst prepared in Example 1 of the present invention at a current density of 100 mA·cm -2 -. Detailed implementation manners

[0053] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and do not limit the present invention.

[0055] The embodiments of the present invention provide a preparation method of a bifunctional CoMo / CoMoP-CF catalyst, including the following steps:

[0056] Step S1: Ultrasonically clean the copper foam with acid, ethanol and deionized water respectively to remove surface oxides and impurities, and obtain the pretreated copper foam;

[0057] Step S2: Immerse the copper foam as the cathode, the platinum sheet as the anode, and the mercury / mercuric oxide as the reference electrode into the first electrolyte solution, and perform electrodeposition under a constant voltage condition. The constant voltage of the electrodeposition is -2.0 to -1.0 V, and the time is 10 to 20 minutes. After rinsing with deionized water and drying, CoMo-CF is obtained;

[0058] Step S3: Use CoMo-CF as the cathode, a platinum sheet as the anode, and a mercury / mercuric oxide as the reference electrode. Immerse them in the second electrolyte and perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -2.0 to -1.0 V, and the time is 10 to 20 minutes. After rinsing with deionized water and drying, a CoMo / CoMoP-CF catalyst is obtained.

[0059] In some embodiments, in step S1, the acid is 0.3 M dilute hydrochloric acid. Ultrasonically clean the copper foam with 0.3 M dilute hydrochloric acid, ethanol, and deionized water for 15 min in sequence.

[0060] In some embodiments, in step S2, the first electrolyte is Na2MoO4·2H2O, CoCl2·6H2O, H3BO3, Na2SO4, EDTA-2Na, and deionized water.

[0061] In some embodiments, in the first electrolyte, in terms of molar amount, Na2MoO4·2H2O:CoCl2·6H2O:H3BO3:Na2SO4:EDTA-2Na = 0.02:0.12:0.2:0.1:0.05.

[0062] In some embodiments, in step S2, after rinsing three times with deionized water, dry in an oven for 6 h to obtain CoMo-CF.

[0063] In some embodiments, in step S3, the second electrolyte is Na2MoO4·2H2O, CoCl2·6H2O, H3BO3, Na2SO4, EDTA-2Na, NaH2PO2·H2O, and deionized water.

[0064] In some embodiments, in the second electrolyte, in terms of molar amount, Na2MoO4·2H2O:CoCl2·6H2O:H3BO3:Na2SO4:EDTA-2Na:NaH2PO2·H2O = 0.02:0.12:0.2:0.1:0.05:0.094.

[0065] In some embodiments, in step S3, after rinsing three times with deionized water, dry in an oven for 6 h to obtain the CoMo / CoMoP-CF catalyst.

[0066] In some embodiments, the present invention also provides a bifunctional CoMo / CoMoP-CF catalyst, which has a flocculent nanosphere structure, and the nanospheres are interconnected to form a three-dimensional porous network structure.

[0067] In some embodiments, the present invention also provides an application of the bifunctional CoMo / CoMoP-CF catalyst in electrocatalytic hydrogen evolution and glucose oxidation.

[0068] Example 1:

[0069] (1) The copper foam was ultrasonically cleaned with 0.3 M dilute hydrochloric acid, ethanol, and deionized water for 15 min in sequence to remove surface oxides and impurities, and the pretreated copper foam was obtained;

[0070] (2) The copper foam was used as the cathode, the platinum sheet as the anode, and the mercury / mercuric oxide as the reference electrode, and they were immersed in the first electrolyte. The first electrolyte was 0.2 M Na2MoO4·2H2O, 0.12 M CoCl2·6H2O, 0.2 M H3BO3, 0.1 M Na2SO4, 0.05 M EDTA-2Na, and 50 mL deionized water. Electrochemical deposition was carried out under a constant voltage condition. The constant voltage for electrochemical deposition was -1.1 V and the time was 15 minutes. After rinsing three times with deionized water, it was dried in an oven for 6 h to obtain CoMo-CF;

[0071] (3) The CoMo-CF was used as the cathode, the platinum sheet as the anode, and the mercury / mercuric oxide as the reference electrode, and they were immersed in the second electrolyte. The second electrolyte was 0.2 M Na2MoO4·2H2O, 0.12 M CoCl2·6H2O, 0.2 M H3BO3, 0.1 M Na2SO4, 0.05 M EDTA-2Na, 0.094 M NaH2PO2·H2O, and 50 mL deionized water. Electrochemical deposition was carried out under a constant voltage condition. The constant voltage for electrochemical deposition was -1.1 V and the time was 15 minutes. After rinsing three times with deionized water, it was dried in an oven for 6 h to obtain the CoMo / CoMoP-CF catalyst.

[0072] Example 2:

[0073] (1) The copper foam was ultrasonically cleaned with 0.3 M dilute hydrochloric acid, ethanol, and deionized water for 15 min in sequence to remove surface oxides and impurities, and the pretreated copper foam was obtained;

[0074] (2) The copper foam was used as the cathode, the platinum sheet as the anode, and the mercury / mercuric oxide as the reference electrode, and they were immersed in the first electrolyte. The first electrolyte was 0.2 M Na2MoO4·2H2O, 0.12 M CoCl2·6H2O, 0.2 M H3BO3, 0.1 M Na2SO4, 0.05 M EDTA-2Na, and 50 mL deionized water. Electrochemical deposition was carried out under a constant voltage condition. The constant voltage for electrochemical deposition was -2.0 V and the time was 10 minutes. After rinsing three times with deionized water, it was dried in an oven for 6 h to obtain CoMo-CF;

[0075] (3) Using CoMo-CF as the cathode, a platinum sheet as the anode, and mercury / mercuric oxide as the reference electrode, immerse them in the second electrolyte. The second electrolyte is 0.2 M Na2MoO4·2H2O, 0.12 M CoCl2·6H2O, 0.2 M H3BO3, 0.1 M Na2SO4, 0.05 M EDTA-2Na, 0.094 M NaH2PO2·H2O, and 50 mL of deionized water. Perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -1.2 V, and the time is 10 minutes. After rinsing three times with deionized water, dry in an oven for 6 h to obtain the CoMo / CoMoP-CF catalyst.

[0076] Example 3:

[0077] (1) Ultrasonically clean the copper foam with 0.3 M dilute hydrochloric acid, ethanol, and deionized water successively for 15 min to remove surface oxides and impurities, obtaining the pretreated copper foam.

[0078] (2) Using the copper foam as the cathode, a platinum sheet as the anode, and mercury / mercuric oxide as the reference electrode, immerse them in the first electrolyte. The first electrolyte is 0.2 M Na2MoO4·2H2O, 0.12 M CoCl2·6H2O, 0.2 M H3BO3, 0.1 M Na2SO4, 0.05 M EDTA-2Na, and 50 mL of deionized water. Perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -1.0 V, and the time is 20 minutes. After rinsing three times with deionized water, dry in an oven for 6 h to obtain CoMo-CF.

[0079] (3) Using CoMo-CF as the cathode, a platinum sheet as the anode, and mercury / mercuric oxide as the reference electrode, immerse them in the second electrolyte. The second electrolyte is 0.2 M Na2MoO4·2H2O, 0.12 M CoCl2·6H2O, 0.2 M H3BO3, 0.1 M Na2SO4, 0.05 M EDTA-2Na, 0.094 M NaH2PO2·H2O, and 50 mL of deionized water. Perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -1.0 V, and the time is 20 minutes. After rinsing three times with deionized water, dry in an oven for 6 h to obtain the CoMo / CoMoP-CF catalyst.

[0080] Comparative Example 1:

[0081] (1) Ultrasonically clean the copper foam with 0.3 M dilute hydrochloric acid, ethanol, and deionized water successively for 15 min to remove surface oxides and impurities, obtaining the pretreated copper foam.

[0082] (2) Use copper foam as the cathode, a platinum sheet as the anode, and a mercury / mercuric oxide electrode as the reference electrode, and immerse them in the first electrolyte. The first electrolyte is 0.2 M Na2MoO4·2H2O, 0.12 M CoCl2·6H2O, 0.2 M H3BO3, 0.1 M Na2SO4, 0.05 M EDTA-2Na, and 50 mL of deionized water. Perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -1.1 V, and the time is 15 minutes. After rinsing three times with deionized water, dry in an oven at 6 h to obtain CoMo-CF.

[0083] Comparative Example 2:

[0084] (1) Ultrasonically clean copper foam with 0.3 M dilute hydrochloric acid, ethanol, and deionized water in sequence for 15 min to remove surface oxides and impurities, and obtain pretreated copper foam;

[0085] (2) Use copper foam as the cathode, a platinum sheet as the anode, and a mercury / mercuric oxide electrode as the reference electrode, and immerse them in the second electrolyte. The second electrolyte is 0.2 M Na2MoO4·2H2O, 0.12 M CoCl2·6H2O, 0.2 M H3BO3, 0.1 M Na2SO4, 0.05 M EDTA-2Na, 0.094 M NaH2PO2·H2O, and 50 mL of deionized water. Perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -1.2 V, and the time is 10 minutes. After rinsing three times with deionized water, dry in an oven at 6 h to obtain CoMoP-CF.

[0086] Comparative Example 3:

[0087] (1) Ultrasonically clean copper foam with 0.3 M dilute hydrochloric acid, ethanol, and deionized water in sequence for 15 min to remove surface oxides and impurities, and obtain pretreated copper foam;

[0088] (2) Use copper foam as the cathode, a platinum sheet as the anode, and a mercury / mercuric oxide electrode as the reference electrode, and immerse them in the third electrolyte. The third electrolyte is 0.2 M NiCl2·6H2O, 0.12 M CoCl2·6H2O, 0.2 M H3BO3, 0.1 M Na2SO4, 0.05 M EDTA-2Na, and 50 mL of deionized water. Perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -1.1 V, and the time is 15 minutes. After rinsing three times with deionized water, dry in an oven at 6 h to obtain CoNi-CF;

[0089] (3) Use CoNi-CF as the cathode, a platinum sheet as the anode, and mercury / mercuric oxide as the reference electrode, and immerse them in the second electrolyte. The second electrolyte is 0.2 M of Na2MoO4·2H2O, 0.12 M of CoCl2·6H2O, 0.2 M of H3BO3, 0.1 M of Na2SO4, 0.05 M of EDTA-2Na, 0.094 M of NaH2PO2·H2O, and 50 mL of deionized water. Perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -1.1 V, and the time is 15 minutes. After rinsing three times with deionized water, dry in an oven for 6 h to obtain the CoNi / CoMoP-CF catalyst.

[0090] Comparative Example 4:

[0091] Refer to Comparative Example 1, where 0.2 M of H3BO3 is not added to the first electrolyte, and the remaining preparation conditions are exactly the same as those in Comparative Example 1.

[0092] Comparative Example 5:

[0093] Refer to Comparative Example 2, where 0.2 M of H3BO3 is not added to the second electrolyte, and the remaining preparation conditions are exactly the same as those in Comparative Example 2.

[0094] Comparative Example 6:

[0095] Refer to Example 1, where 0.2 M of H3BO3 is not added to both electrolyte 1 and electrolyte 2, and the remaining preparation conditions are the same as those in Example 1.

[0096] Analysis of test results:

[0097] The scanning electron microscope images of Comparative Example 1 (CoMo-CF), Comparative Example 2 (CoMoP-CF), Comparative Example 3 (CoNi / CoMoP-CF), and Example 1 (CoMo / CoMoP-CF) are as Figure 1 shown. It can be seen that Example 1 ( Figure 1The CoMo / CoMoP-CF catalyst prepared in d) has a flocculent nanosphere structure, and the nanospheres are interconnected to form a three-dimensional porous network structure. In the electrocatalytic hydrogen evolution reaction, the three-dimensional porous network structure enables the electrolyte to fully infiltrate the catalyst surface and come into full contact with the active sites. The abundant pores provide unobstructed channels for the generation and escape of hydrogen, effectively avoiding the adsorption and accumulation of hydrogen on the catalyst surface, thereby inhibiting the increase in the overpotential of the hydrogen evolution reaction and significantly improving the efficiency of the hydrogen evolution reaction. In the glucose oxidation reaction, the hierarchical pore system allows glucose molecules to rapidly diffuse into the interior of the catalyst, come into full contact with the active sites and react. The microscopic wrinkles and protrusions on the surface of the nanospheres further increase the adsorption capacity for glucose molecules and promote the reaction. Moreover, the products such as gluconic acid generated can quickly diffuse into the solution through the pores, avoiding the accumulation of products at the active sites and maintaining the continuous progress of the reaction, enhancing the catalytic activity and selectivity of the glucose oxidation reaction; in contrast, Comparative Example 1( Figure 1 in a), Comparative Example 2( Figure 1 in b) and Comparative Example 3( Figure 1 in c) prepared catalysts have a relatively simple or loose structure and uneven pore distribution.

[0098] The LSV curves of Comparative Example 1 (CoMo-CF), Comparative Example 2 (CoMoP-CF), Comparative Example 3 (CoNi / CoMoP-CF) and Example 1 (CoMo / CoMoP-CF) under alkaline conditions (1 M KOH, 1 M KOH + 0.1 M C6H12O6) are as Figure 2 shown. It can be seen that compared with Comparative Examples 1-3, the CoMo / CoMoP-CF catalyst prepared in Example 1 shows a lower hydrogen evolution overpotential, glucose oxidation overpotential and higher current density in the alkaline electrolyte.

[0099] The overpotential columns of electrocatalytic hydrogen evolution (HER) and glucose oxidation (GOR) of Comparative Example 1 (CoMo-CF), Comparative Example 2 (CoMoP-CF), Comparative Example 3 (CoNi / CoMoP-CF) and Example 1 (CoMo / CoMoP-CF) at a current density of 100 mA·cm -2 are as Figure 3 shown. It can be seen that compared with Comparative Examples 1-3, the CoMo / CoMoP-CF catalyst prepared in Example 1 shows a lower hydrogen evolution overpotential, glucose oxidation overpotential and higher catalytic activity in the alkaline electrolyte.

[0100] The impedances of Comparative Example 1 (CoMo-CF), Comparative Example 2 (CoMoP-CF), Comparative Example 3 (CoNi / CoMoP-CF) and Example 1 (CoMo / CoMoP-CF) are asFigure 4 As shown, it can be seen that the CoMo / CoMoP-CF catalyst prepared in Example 1 has the smallest impedance, indicating that it has a faster electron transfer rate and higher conductivity. This is mainly attributed to its unique three-dimensional porous network structure and the synergistic effect of cobalt and molybdenum, which effectively promote the rapid transfer of electrons and the uniform distribution of charges, thus reducing the overall impedance.

[0101] The double-layer capacitances (C dl ) of Comparative Example 1 (CoMo-CF), Comparative Example 2 (CoMoP-CF), Comparative Example 3 (CoNi / CoMoP-CF), and Example 1 (CoMo / CoMoP-CF) are as Figure 5 shown. It can be seen that the CoMo / CoMoP-CF catalyst prepared in Example 1 exhibits significantly higher double-layer capacitance, indicating that it has a larger electrochemically active surface area.

[0102] The scanning electron microscope images of Comparative Example 1 (CoMo-CF), Comparative Example 2 (CoMoP-CF), Example 1 (CoMo / CoMoP-CF), Comparative Example 4 (CoMo-CF without adding H3BO3), Comparative Example 5 (CoMoP-CF without adding H3BO3), and Comparative Example 6 (CoMo / CoMoP-CF without adding H3BO3) are as Figure 6 shown. It can be seen that compared with the catalysts prepared without adding H3BO3 in Comparative Example 4 ( Figure 6 d), Comparative Example 5 ( Figure 6 e), and Comparative Example 6 ( Figure 6 f), the catalysts prepared with the addition of H3BO3 in Comparative Example 1 ( Figure 6 a), Comparative Example 2 ( Figure 6 b), and Example 1 ( Figure 6 c) have smoother and more uniform morphologies; and the CoMo / CoMoP-CF catalyst prepared in Example 1, due to its unique three-dimensional porous network structure and the smooth and uniform distribution of nanoparticles after adding H3BO3, these characteristics effectively increase the contact area of its electrode / electrolyte interface, thus enhancing the electrochemically active surface area.

[0103] The LSV curves of Example 1 (CoMo / CoMoP-CF), Comparative Example 1 (CoMo-CF), Comparative Example 2 (CoMoP-CF), Comparative Example 4 (CoMo-CF without adding H3BO3), Comparative Example 5 (CoMoP-CF without adding H3BO3), and Comparative Example 6 (CoMo / CoMoP-CF without adding H3BO3) under alkaline conditions (1 M KOH) are as Figure 7As shown, it can be seen that compared with the catalysts prepared in Comparative Examples 4-6 (without adding H3BO3), the catalysts prepared in Example 1 and Comparative Examples 2-3 (adding H3BO3) exhibit lower hydrogen evolution overpotential in alkaline electrolyte.

[0104] The LSV curves of Example 1 (CoMo / CoMoP-CF), Comparative Example 1 (CoMo-CF), Comparative Example 2 (CoMoP-CF), Comparative Example 4 (CoMo-CF without adding H3BO3), Comparative Example 5 (CoMoP-CF without adding H3BO3), and Comparative Example 6 (CoMo / CoMoP-CF without adding H3BO3) under alkaline conditions (1M KOH + 0.1M C6H 12 O6) are as Figure 8 shown. It can be seen that compared with the catalysts prepared in Comparative Examples 4-6 (without adding H3BO3), the catalysts prepared in Example 1 and Comparative Examples 2-3 (adding H3BO3) exhibit lower glucose oxidation overpotential in alkaline electrolyte.

[0105] The stability (it) of Example 1 (CoMo / CoMoP-CF) at a current density of 100 mA·cm -2 is as Figure 9 shown. It can be seen that there is not much difference in the LSV curve of the CoMo / CoMoP-CF catalyst prepared in Example 1 after 100 h, and its stability is excellent.

[0106] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a bifunctional CoMo / CoMoP-CF catalyst, characterized in that: It includes the following steps: Step S1: Ultrasonically clean the copper foam with acid, ethanol, and deionized water respectively to remove surface oxides and impurities, and obtain the pretreated copper foam. Step S2: Use the copper foam as the cathode, the platinum sheet as the anode, and the mercury / mercuric oxide as the reference electrode, immerse them in the first electrolyte, and perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -2.0 to -1.0 V, and the time is 10 to 20 minutes. After rinsing with deionized water and drying, obtain CoMo-CF. Step S3: Use CoMo-CF as the cathode, the platinum sheet as the anode, and the mercury / mercuric oxide as the reference electrode, immerse them in the second electrolyte, and perform electrodeposition under a constant voltage condition. The constant voltage for electrodeposition is -2.0 to -1.0 V, and the time is 10 to 20 minutes. After rinsing with deionized water and drying, obtain the CoMo / CoMoP-CF catalyst.

2. The preparation method according to claim 1, characterized in that: In step S1, the acid is 0.3 M dilute hydrochloric acid. Ultrasonically clean the copper foam with 0.3 M dilute hydrochloric acid, ethanol, and deionized water in sequence for 15 min each.

3. The preparation method according to claim 1, characterized in that: In step S2, the first electrolyte is Na2MoO4·2H2O, CoCl2·6H2O, H3BO3, Na2SO4, EDTA-2Na, and deionized water.

4. The preparation method according to claim 3, characterized in that: In the first electrolyte, in terms of the number of moles, Na2MoO4·2H2O:CoCl2·6H2O:H3BO3:Na2SO4:EDTA-2Na = 0.02:0.12:0.2:0.1:0.

05.

5. The preparation method according to claim 1, wherein: In step S2, after rinsing three times with deionized water, dry in an oven for 6 h to obtain CoMo-CF.

6. The preparation method according to claim 1, characterized in that: In step S3, the second electrolyte is Na2MoO4·2H2O, CoCl2·6H2O, H3BO3, Na2SO4, EDTA-2Na, NaH2PO2·H2O, and deionized water.

7. The preparation method according to claim 6, characterized in that: In the second electrolyte, in terms of the number of moles, Na2MoO4·2H2O:CoCl2·6H2O:H3BO3:Na2SO4:EDTA-2Na:NaH2PO2·H2O = 0.02:0.12:0.2:0.1:0.05:0.

094.

8. The preparation method according to claim 1, wherein: In step S3, after rinsing three times with deionized water, dry in an oven for 6 h to obtain the CoMo / CoMoP-CF catalyst.

9. A bifunctional CoMo / CoMoP-CF catalyst, which is prepared by the preparation method according to any one of claims 1 to 8, and is characterized in that: It has a flocculent nanosphere structure, and the nanospheres are interconnected to form a three-dimensional porous network structure.

10. Application of a bifunctional CoMo / CoMoP-CF catalyst in electrocatalytic hydrogen evolution and glucose oxidation.

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