VS-Ni3S2at-VO-CoMoO4 / CF heterojunction full-electrolysis water electric catalyst
VS-Ni3S2@VO-CoMoO4/CF electrocatalyst was prepared by hydrothermal-calcining method and electrodeposition method, and the problems of slow kinetics and high overpotential of the fully resolved hydroelectric catalyst were solved, and low-cost and efficient electrocatalytic performance was achieved. Suitable for large-scale applications.
Patent Information
- Application Number
- CN202411320269.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2025-01-07
AI Technical Summary
The existing fully decomposed hydroelectric catalysts have limitations in terms of slow kinetics and high overpotentiality, resulting in low hydrogen energy utilization efficiency and high cost of precious metal materials, which cannot be used on a large scale.
Heterojunction of oxygen-rich vacant CoMoO4 micron spheres and sulfur-rich vacant Ni3S2 nanosheets was prepared by hydrothermal-calcining method, and VS-Ni3S2@VO-CoMoO4/CF electrocatalyst was prepared by electrodeposition method to form a cross-linked network structure to improve activity site and catalytic properties.
The low overpotential and rapid reaction kinetics are achieved, and the HER, OER and full water-removing properties of the electrocatalyst are improved. When the current density reaches 10mA·cm-2, the overpotential is only 38~79mV and 169~218mV, and the voltage is only 1.46. ~1.49V, suitable for large-scale production and application.
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Figure CN119265614A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of semiconductor electrocatalysis, and specifically relates to a sulfur-rich Ni3S2 composite oxygen-rich CoMoO4 heterojunction complete water splitting electrocatalyst (V S -Ni3S2@V O -CoMoO4 / CF). Background Art
[0002] Hydrogen energy has become an ideal green energy candidate for solving energy crises and environmental pollution due to its high energy density, pollution-free and high calorific value of combustion. Water electrolysis is an ideal method for preparing high-purity hydrogen. However, the slow kinetics and high overpotential of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) greatly limit the energy conversion efficiency of overall water splitting. Therefore, it is urgent to explore a high-performance water electrolysis catalyst with low overpotential and fast reaction kinetics to overcome the high energy barrier. At present, although precious metal-based materials Pt / C show excellent HER activity and precious metal oxides such as IrO2 and RuO2 show good OER activity, they cannot be applied on a large scale due to their high cost and low abundance. Therefore, the development of low-cost and high-performance non-precious metal electrocatalysts for efficient hydrogen production is the key to the utilization and development of hydrogen energy.
[0003] Transition metal-based electrocatalysts (such as transition metal oxides, sulfides, carbides, phosphides, selenides, etc.) have potential high catalytic activity due to their low cost, high abundance, good stability and variable redox valence states. However, limited active sites and slow reaction kinetics lead to low energy conversion efficiency. Therefore, it is necessary to further improve the catalytic performance through appropriate modification strategies. Studies have shown that the combination of compounds with different work functions can not only give play to the advantages of each compound, but also construct a heterogeneous interface, form a built-in electric field at the heterogeneous interface, regulate the charge distribution, and improve the kinetics of the catalytic reaction. In addition, the introduction of oxygen vacancies is a very useful strategy to improve catalytic activity. Oxygen vacancies optimize the electronic structure of neighboring atoms, thereby reducing the decomposition energy barrier of reaction intermediates. Therefore, integrating oxygen vacancies into transition metal oxides can further optimize the local charge and improve the electrocatalytic activity. In addition, adjusting the nanostructure of high surface area catalysts is one of the effective ways to improve their atomic utilization. Among various nanostructures with controllable morphology, the three-dimensional flower-like structure has abundant catalytic sites, has anti-aggregation performance in violent reactions, and is also conducive to the timely escape of precipitated gases, thereby improving the utilization rate of catalytic sites. Therefore, the synergistic effect of the above strategies will greatly improve the catalytic performance of electrocatalysts. Based on this, the present invention adopts a hydrothermal-calcination method to prepare a V S -Ni3S2@V O -CoMoO4 heterojunction micro-flower ball full water splitting electrocatalyst (VS -Ni3S2@V O -CoMoO4 / CF), the electrocatalyst can efficiently catalyze the complete splitting of water and has broad practical application prospects. Summary of the invention
[0004] The present invention aims to provide a V having low cost, convenient scale preparation and broad application prospect. S -Ni3S2@V O -CoMoO4 / CF heterojunction full water splitting electrocatalyst. The present invention is achieved by the following technical solutions:
[0005] (1) Using Na2MoO4·2H2O and Co(NO3)2·6H2O as raw materials and ethanol as solvent, the oxygen-rich CoMoO4 microspheres (V) grown on CF were prepared by solvothermal treatment followed by annealing in an Ar / H2 atmosphere. O -CoMoO4 / CF);
[0006] (2) Saturated calomel, platinum wire and V O -CoMoO4 / CF was used as reference electrode, counter electrode and working electrode, with 1 mol·L -1 The electrolyte was a mixture of thiourea and nickel chloride of set concentration. Five cycles of electrodeposition were performed at a window voltage of -1.2 to 0.2 V, and then washed with deionized water and dried to obtain V S -Ni3S2@V O -CoMoO4 / CF electrocatalyst. The concentration of nickel chloride is 0.02-0.1 mol·L -1 .
[0007] Compared with the existing complete water splitting electrocatalyst, the V S -Ni3S2@V O -CoMoO4 / CF heterojunction electrocatalyst has the following advantages:
[0008] (1) The raw material reserves are abundant, the preparation process is simple, environmentally friendly, easy to scale production, and has broad application prospects.
[0009] (2) V prepared in the present invention S -Ni3S2@V O -CoMoO4 / CF heterojunction full water splitting electrocatalyst, the cross-linked network of sulfur-rich vacancies Ni3S2 formed by nanosheets grows closely on the surface of oxygen-rich vacancies CoMoO4 micron flower balls to form a heterojunction, and V O -CoMoO4 micron flower ball is composed of nanoparticles, V S -Ni3S2@V O-CoMoO4 heterojunction micro-flower balls are grown in situ on CF, which not only exposes more active sites but also facilitates the timely release of generated gases, thus giving it excellent HER, OER and overall water splitting performance. -1 In KOH electrolyte, the battery reaches 10 mA cm -2 At a current density of 1.3 Å, the overpotentials of electrocatalytic HER and OER are only 38-79 mV and 169-218 mV, respectively, and V S -Ni3S2@V O -Co, MoO4 / CF(+ / -) full water splitting system only requires a voltage of 1.46 to 1.49V. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 V prepared in Example 1 O -CoMoO4 / CF(a) and V S -Ni3S2@V O -SEM image of CoMoO4 / CF (b);
[0011] Figure 2 V prepared in Example 1 S -Ni3S2@V O - Transmission electron microscopy (a) and high-resolution transmission electron microscopy (b) images of CoMoO4 / CF electrocatalyst;
[0012] Figure 3 V prepared in Example 1 S -Ni3S2 / CF、V O -CoMoO4 / CF and V S -Ni3S2@V O -EPR spectrum of CoMoO4 / CF;
[0013] Figure 4 V prepared in Example 1 S -Ni3S2@V O -CoMoO4 / CF electrocatalyst at 1 mol·L -1 Performance diagram of electrocatalytic hydrogen evolution (a), oxygen evolution (b) and complete water splitting (c) in KOH solution;
[0014] Figure 5 V prepared in Example 2 S -Ni3S2@V O -CoMoO4 / CF electrocatalyst at 1 mol·L -1 Performance diagram of electrocatalytic hydrogen evolution (a), oxygen evolution (b) and complete water splitting (c) in KOH solution;
[0015] Figure 6V prepared in Example 3 S -Ni3S2@V O -CoMoO4 / CF electrocatalyst at 1 mol·L -1 Performance diagram of electrocatalytic hydrogen evolution (a), oxygen evolution (b) and complete water splitting (c) in KOH solution; DETAILED DESCRIPTION
[0016] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments. However, the accompanying drawings and specific embodiments are only used as examples and do not limit the scope of the present invention in any way.
[0017] Example 1
[0018] (1) Dissolve 1 mmol Na2MoO4·2H2O and 1 mmol Co(NO3)2·6H2O in 30 mL ethanol and place a 1×1 cm 2 The clean CF was immersed in the above solution, and the solution and the foamed copper were transferred to a 50 ml reactor. The reactor was sealed and kept at 180 ° C for 12 h, then cooled naturally to room temperature, and the product was washed several times with anhydrous ethanol and deionized water and dried, and then placed in a porcelain boat, which was placed in a tube furnace and annealed at 450 ° C for 2 h in an Ar / H2 atmosphere to obtain V O -CoMoO4 / CF, the SEM photo is attached Figure 1 a, which shows V O -CoMoO4 is in situ grown on CF, presenting a micron flower ball morphology, and the nanosheets of the flower ball are composed of nanoparticles.
[0019] (2) Saturated calomel, platinum wire and V O -CoMoO4 / CF was used as reference electrode, counter electrode and working electrode, with 1 mol·L -1 Thiourea and 0.05 mol·L -1 The nickel chloride mixed solution was used as the electrolyte, and the electrodeposition was performed for 5 cycles at a window voltage of -1.2 to 0.2 V, and then washed with deionized water and dried to obtain V S -Ni3S2@V O -CoMoO4 / CF heterojunction electrocatalyst. The SEM photo is attached. Figure 1 b, which shows V S -Ni3S2@V O -CoMoO4 / CF presents a micron flower ball morphology with a diameter of about 5μm, that is, the V O -CoMoO4 / CF retains the flower ball morphology, V S -Ni3S2 nanosheets grown on V O-CoMoO4 / CF surface, and these small nanosheets cross each other to form a large number of channels, which can not only expose more active sites, but also facilitate the timely release of generated gases and improve catalytic stability. Its transmission electron microscope and high-resolution transmission electron microscope photos are attached Figure 2 From the transmission electron microscope photo attached Figure 2 (a) The ultrathin Ni3S2 nanosheets surrounding the CoMoO4 nanoparticles can be seen more clearly; high-resolution transmission electron microscopy photo attached Figure 2 (b) clearly shows two different lattice fringes, with fringe spacing of 0.29nm and 0.33nm, which correspond to the (110) crystal plane of Ni3S2 and the (002) crystal plane of CoMoO4, respectively. Figure 3 ) can be seen in V S -Ni3S2@V O -CoMoO4 / CF samples contain abundant vacancies. The above results confirm that V S -Ni3S2@V O -CoMoO4 / CF heterojunction electrocatalyst was successfully prepared.
[0020] (3) Hg / HgO, platinum wire and the prepared V S -Ni3S2@V O -CoMoO4 / CF electrode was used as reference electrode, counter electrode and working electrode. -1 The HER, OER and overall water splitting performance of the prepared samples were measured in KOH electrolyte. The results are shown in the attached Figure 4 (a~c). Figure 4 (a) and (b) show that at 1 mol·L -1 In KOH electrolyte, 10 mA cm -2 Current density V S -Ni3S2@V O -CoMoO4 / CF catalytic HER and OER overpotentials are 38mV and 169mV, respectively. S -Ni3S2@V O -The full water splitting system with CoMoO4 / CF as cathode and anode only needs 1.46V voltage to reach 10mA·cm -2 of current density.
[0021] Example 2
[0022] (1) Prepare V according to the method of step (1) in Example 1 O -CoMoO4 / CF.
[0023] (2) Saturated calomel, platinum wire and V O-CoMoO4 / CF was used as reference electrode, counter electrode and working electrode, with 1 mol L -1 of thiourea and 0.02 mol L -1 Nickel chloride mixed solution was used as electrolyte, and electrodeposition was performed for 5 cycles at a window voltage of -1.2 to 0.2 V, and then washed with deionized water and dried to obtain V S -Ni3S2@V O -CoMoO4 / CF electrocatalyst.
[0024] (3) Hg / HgO, platinum wire and the prepared V S -Ni3S2@V O -CoMoO4 / CF electrode was used as reference electrode, counter electrode and working electrode. -1 The HER, OER and overall water splitting performance of the prepared samples were measured in KOH electrolyte. The results are shown in the attached Figure 5 (a~c). Figure 5 (a) and (b) show that at 1 mol·L -1 In KOH electrolyte, 10 mA cm -2 Current density V S -Ni3S2@V O -CoMoO4 / CF catalytic HER and OER overpotentials are 79mV and 218mV, respectively. S -Ni3S2@V O -The full water splitting system with CoMoO4 / CF as cathode and anode only needs 1.49V voltage to reach 10mA·cm -2 of current density.
[0025] Example 3
[0026] (1) Prepare V according to the method of step (1) in Example 1 O -CoMoO4 / CF.
[0027] (2) Saturated calomel, platinum wire and V O -CoMoO4 / CF was used as reference electrode, counter electrode and working electrode, with 1 mol L -1 of thiourea and 0.1 mol L -1 Nickel chloride mixed solution was used as electrolyte, and electrodeposition was performed for 5 cycles at a window voltage of -1.2 to 0.2 V, and then washed with deionized water and dried to obtain V S -Ni3S2@V O -CoMoO4 / CF electrocatalyst.
[0028] (3) Hg / HgO, platinum wire and the prepared V S -Ni3S2@VO -CoMoO4 / CF electrode was used as reference electrode, counter electrode and working electrode. -1 The HER, OER and overall water splitting performance of the prepared samples were measured in KOH electrolyte. The results are shown in the attached Figure 6 (a~c). Figure 6 (a) and (b) show that at 1 mol·L -1 In KOH electrolyte, 10 mA cm -2 Current density V S -Ni3S2@V O -CoMoO4 / CF catalytic HER and OER overpotentials are 49mV and 194mV, respectively. S -Ni3S2@V O -The full water splitting system with CoMoO4 / CF as cathode and anode only needs 1.48V voltage to reach 10mA·cm -2 of current density.
[0029] The above experimental results confirm that V was successfully prepared by hydrothermal-calcination combined with electrodeposition. S -Ni3S2@V O -CoMoO4 / CF electrocatalyst, and the electrocatalyst exhibits excellent electrocatalytic HER, OER and overall water splitting performance in alkaline electrolyte.
Claims
1. A V S -Ni3S2@V O -CoMoO4 / CF heterojunction full water splitting electrocatalyst, characterized in that: V S -Ni3S2@V O -CoMoO4 micron flower balls are in situ grown on copper foam (CF). The oxygen-rich vacancy CoMoO4 micron flower balls are composed of nanoparticles. Ultra-thin sulfur-rich vacancy Ni3S2 nanosheets grow closely and evenly on the oxygen-rich vacancy CoMoO4 micron flower balls, forming a unique V S -Ni3S2@V O -CoMoO4 heterojunction micro-flower ball electrocatalyst (V S -Ni3S2@V O -CoMoO4 / CF), which is prepared by the following steps: (1) Using Na2MoO4·2H2O and Co(NO3)2·6H2O as raw materials and ethanol as solvent, the oxygen-rich CoMoO4 microspheres (V) grown on CF were prepared by solvothermal treatment followed by annealing in an Ar / H2 atmosphere. O -CoMoO4 / CF); (2) Saturated calomel, platinum wire and V O -CoMoO4 / CF was used as reference electrode, counter electrode and working electrode, with 1 molL -1 The electrolyte was a mixture of thiourea and nickel chloride of set concentration. Five cycles of electrodeposition were performed at a window voltage of -1.2 to 0.2 V, and then washed with deionized water and dried to obtain V S -Ni3S2@V O -CoMoO4 / CF electrocatalyst.
2. As claimed in claim 1, a V S -Ni3S2@V O -CoMoO4 / CF heterojunction full water splitting electrocatalyst, characterized in that: The concentration of nickel chloride in step (2) is 0.02 to 0.1 mol·L -1 .
3. As claimed in claim 1, a V S -Ni3S2@V O -CoMoO4 / CF heterojunction full water splitting electrocatalyst, characterized in that: The catalyst has excellent electrocatalytic HER, OER and overall water splitting performance. -1 In KOH electrolyte, the battery reaches 10 mA cm -2 At the current density, the overpotential of electrocatalytic HER is 38-79 mV, the overpotential of electrocatalytic OER is 169-218 mV, and V S -Ni3S2@V O -The voltage of the CoMoO4 / CF(+ / -) full water splitting system only requires 1.46~1.49V.