Preparation method and application of rare earth doped vanadium disulfide electro-hydrogen evolution catalyst
By doping VS2 with rare earth elements to regulate its electronic structure and morphology, a highly efficient and stable rare earth-doped vanadium disulfide electrocatalyst for hydrogen production was prepared. This solved the conductivity and stability problems of existing catalysts in the process of hydrogen production by water electrolysis, and achieved low-cost and high-efficiency electrocatalytic hydrogen production.
Patent Information
- Application Number
- CN202511856342.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-10
- Publication Date
- 2026-03-20
AI Technical Summary
Existing transition metal sulfide catalysts suffer from poor conductivity, insufficient exposure of active sites, and structural instability during water electrolysis for hydrogen production, leading to rapid decay of catalytic activity and making it difficult to achieve efficient and low-cost electrocatalytic hydrogen production.
By doping vanadium disulfide (VS2) with rare earth elements, a rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst is formed. Its electronic structure and morphology are controlled to form a flower-like structure of stacked nanosheet arrays, thereby improving conductivity and exposure of active sites.
Rare earth-doped VS2 catalysts significantly improve the activity and stability of electrocatalytic hydrogen production, reduce overpotential, increase the efficiency of hydrogen production through water electrolysis, and are low in cost, making them suitable for new energy water electrolysis hydrogen production devices.
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Figure CN121700451A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of environmental protection material preparation technology, and more specifically, to a method for preparing and applying a rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst. Background Technology
[0002] With the continued growth of global energy demand, the overexploitation of fossil fuels has led to severe problems such as energy crises and environmental pollution. Hydrogen energy, as a clean and efficient secondary energy source, will become a key direction for energy transformation through its large-scale production and utilization. Currently, among the mainstream hydrogen production methods, gray hydrogen relies on fossil fuel reforming, emitting large amounts of greenhouse gases during production; while blue hydrogen achieves some emission reduction through carbon capture, it still remains highly dependent on fossil fuels. However, producing green hydrogen through water electrolysis is a highly promising hydrogen production method due to its environmentally friendly process, high product purity, and ability to directly couple renewable energy power to absorb grid waste and fluctuating electricity. The hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode are the core steps in the water electrolysis hydrogen production energy conversion process; however, the slow kinetics of these two half-reactions severely limit the overall efficiency of the reaction. Therefore, designing and synthesizing efficient catalysts is a key factor in promoting rapid reaction and achieving low-energy hydrogen production.
[0003] While traditional noble metal (such as Pt-based) catalysts possess excellent hydrogen evolution activity, their scarcity and high cost limit their large-scale application. Therefore, the search for highly active, low-cost non-noble metal hydrogen evolution catalysts has become a research focus. Transition metal sulfides, due to their unique electronic structure and tunable catalytic active sites, are considered potential candidates to replace noble metal catalysts. However, existing transition metal sulfides still have many shortcomings, such as poor conductivity, hindered electron transport affecting reaction rates, insufficient exposure of active sites, and susceptibility to structural reconstruction or corrosion in complex reaction systems, leading to rapid decay of their catalytic activity. Therefore, developing highly active, highly stable, and low-cost transition metal sulfide hydrogen evolution catalysts is of great significance for promoting large-scale hydrogen production and alleviating energy and environmental problems, and is a crucial direction urgently needing breakthroughs in the field of catalysis.
[0004] Transition metal sulfides possess various crystal phases, including 1T, 2H, and 3R. Studies have shown that the metallic 1T phase transition metal sulfides exhibit high conductivity, thus demonstrating higher activity in electrocatalytic hydrogen evolution reactions compared to other crystal structures. However, the 1T phase of materials such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2), which have been extensively studied, is an unstable thermodynamic structure, making its synthesis difficult. VS2, on the other hand, has a thermodynamically stable 1T phase with metallic properties, exhibiting high conductivity and abundant hydrogen evolution active sites, demonstrating excellent electrocatalytic hydrogen evolution activity. Rare earth elements possess unique electronic orbital structures; their incorporation into transition metal sulfides can alter the d-orbital electronic structure of the original catalyst, optimizing the adsorption energy of hydrogen atoms on its surface, thereby improving the electrocatalytic hydrogen evolution performance of the material. Therefore, improving the electrocatalytic hydrogen evolution activity of catalysts through rare earth element doping is currently one of the mainstream catalyst modification methods.
[0005] Therefore, there is an urgent need to design a method for preparing and applying a rare-earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst to solve the above problems. Summary of the Invention
[0006] The purpose of this invention is to provide a method for preparing and applying a rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst, so as to solve the problems mentioned in the background art.
[0007] To achieve the above objectives, the present invention provides the following technical solution:
[0008] A method for preparing a rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst includes the following steps:
[0009] S1. Add ammonium metavanadate, ammonia and deionized water to a beaker and stir at room temperature for 15 minutes. After complete dissolution, a transparent reaction solution 1 is obtained.
[0010] S2. Add thioacetamide and polyvinylpyrrolidone to the reaction solution 1, and continue stirring at room temperature for 45 minutes to gradually change the solution from clear to black, thus obtaining reaction solution 2.
[0011] S3. Weigh out rare earth chlorides and dissolve them in deionized water to obtain reaction solution 3. The rare earth chlorides are selected from at least one of lanthanum chloride, cerium chloride, samarium chloride, europium chloride and gadolinium chloride.
[0012] S4. Transfer reaction solution 2 and reaction solution 3 to a hydrothermal reactor in sequence, seal the reactor, and heat it in a 140°C furnace for 10 hours. After the reaction is completed, cool the reactor to room temperature.
[0013] S5. Take out the cooled product, add ethanol for centrifugation and washing, discard the supernatant, repeat the washing three times to obtain the precipitate;
[0014] S6. Disperse the precipitate in ethanol and dry it in a drying oven at 75°C to obtain a powdered rare earth-doped VS2 electrochemical hydrogen evolution catalyst.
[0015] As a preferred technical solution of the present invention, the amount of rare earth chloride added is 0.5% to 5% based on the atomic molar ratio of rare earth elements to vanadium elements.
[0016] As a preferred embodiment of the present invention, the amount of polyvinylpyrrolidone used is 100-200 mg. The polyvinylpyrrolidone is used to regulate the surface energy of the product during the reaction process, thereby promoting the orderly stacking of the nanosheet array and forming a stable nanoflower-like structure.
[0017] As a preferred technical solution of the present invention, the rare earth-doped VS2 electrochemical hydrogen evolution catalyst has a 1T phase crystal structure, which has higher conductivity and more abundant electrocatalytic active sites compared with the 2H phase.
[0018] As a preferred technical solution of the present invention, the rare earth-doped VS2 electrochemical hydrogen evolution catalyst has a flower-like morphology formed by stacking nanosheet arrays, with a particle diameter of 2 to 6 μm. The introduction of rare earth elements changes the interaction between nanosheets, making the stacking arrangement more orderly.
[0019] As a preferred technical solution of the present invention, the rare earth elements are uniformly doped in the VS2 lattice, which can regulate the d orbital electronic structure of VS2, optimize the adsorption energy of hydrogen atoms on the catalyst surface, and improve its electrocatalytic hydrogen production activity and stability.
[0020] The present invention also provides a rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst, which exhibits a three-dimensional flower-like nanosheet array under a scanning electron microscope, and its X-ray diffraction pattern matches the diffraction peaks of standard VS2 without any impurity peaks.
[0021] As a preferred technical solution of the present invention, the catalyst exhibits a regular arrangement of nanosheets under a transmission electron microscope, and rare earth elements are uniformly distributed throughout the crystal lattice in X-ray energy dispersive spectroscopy (EDS) analysis.
[0022] This invention proposes a rare earth-doped vanadium disulfide electrochemical hydrogen production catalyst, which can be applied to hydrogen production through water electrolysis in the new energy sector.
[0023] The present invention also provides a method for producing hydrogen by electrolysis of water, which uses the rare earth-doped VS2 hydrogen evolution catalyst as the cathode catalyst and carries out the hydrogen evolution reaction in a standard three-electrode system, with a significantly lower overpotential than that of the undoped VS2 catalyst.
[0024] As a preferred embodiment of the present invention, the overpotential of the catalyst is not higher than 160mV when the current density is -10mA·cm⁻², and the overpotential of the catalyst is not higher than 240mV when the current density is -50mA·cm⁻².
[0025] Compared with existing technologies, this invention has the following advantages: By introducing rare earth elements into VS2, this invention achieves stable lattice doping, not only maintaining the 1T phase structure advantage of VS2 itself, but also further optimizing its electronic structure. The uniform distribution of rare earth elements changes the d-orbital electronic states, effectively improving the adsorption free energy of hydrogen atoms on the catalyst surface, thereby enhancing the electrocatalytic reaction kinetics and making the catalyst perform better in terms of conductivity and stability.
[0026] In terms of material morphology, the rare-earth-doped VS2 prepared in this invention exhibits a three-dimensional flower-like structure formed by the stacking of nanosheet arrays, with uniform particle size and orderly arrangement. Compared with undoped VS2, the introduction of rare-earth elements enhances the interaction between nanosheets, resulting in a more regular morphology and higher exposure of active sites, thereby providing more effective reaction interfaces for the hydrogen evolution reaction.
[0027] In terms of electrochemical performance, the rare-earth-doped VS2 catalyst of this invention exhibits significantly better hydrogen evolution activity than pure VS2. At a current density of -10 mA·cm⁻², its overpotential is below 160 mV, and at -50 mA·cm⁻², the overpotential does not exceed 240 mV, significantly reducing energy consumption. This catalyst has a simple preparation process, low cost, and promising application prospects, and can be widely used in new energy technology fields such as water electrolysis for hydrogen production. Attached Figure Description
[0028] To more clearly illustrate the technical solution of the present invention, the accompanying drawings required for the example description are briefly introduced below.
[0029] Figure 1 Technical roadmap for preparing pure VS2 and rare earth-doped VS2 electrochemical hydrogen evolution catalysts.
[0030] Figure 2 X-ray diffraction (XRD) patterns of pure VS2 and VS2 electrochemical hydrogen evolution catalysts doped with different proportions of rare earth Ce.
[0031] Figure 3 Scanning electron microscope (SEM) images of pure VS2 and rare earth Ce-doped VS2 electrochemical hydrogen evolution catalysts.
[0032] Figure 4 X-ray energy dispersive spectroscopy (EDS) of rare earth Ce-doped VS2 electrochemical hydrogen evolution catalyst.
[0033] Figure 5Transmission electron microscopy (TEM) images of pure VS2 and rare earth Ce-doped VS2 electrochemical hydrogen evolution catalysts.
[0034] Figure 6 Electrochemical hydrogen evolution performance of pure VS2 and VS2 catalysts doped with different proportions of rare earth Ce.
[0035] Figure 7 XRD patterns of pure VS2 and VS2 electrochemical hydrogen evolution catalysts doped with different rare earth elements. Detailed Implementation
[0036] The following will refer to the appendices in the embodiments of the present invention. Figure 1 The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the embodiments described below 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 are within the scope of protection of the present invention. In order to provide a clearer explanation and description of the technical solutions and implementation methods of the present invention, specific examples of preferred implementations of the technical solutions of the present invention are introduced below.
[0037] A method for preparing a rare-earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst, such as... Figure 1 As shown,
[0038] 1. Add 0.334g of ammonium metavanadate, 2mL of ammonia water and 30mL of deionized water to a beaker, and stir at room temperature for 15min until the ammonium metavanadate is completely dissolved;
[0039] 2. Weigh 1.5g of thioacetamide and 100mg of polyvinylpyrrolidone and add them to the reaction solution from step 1. Stir at room temperature for 45 minutes until the solution turns black.
[0040] 3. Prepare an aqueous solution of rare earth elements according to the atomic weight ratio of rare earth elements to vanadium elements;
[0041] 4. Transfer the solution after stirring in step 2 above to a 50mL hydrothermal reactor;
[0042] 5. Add the rare earth element aqueous solution prepared in step 3 to the hydrothermal reactor;
[0043] 6. Transfer the reactor to a preheated furnace at 140°C and maintain this temperature for 10 hours;
[0044] 7. After the reaction is complete and the mixture has cooled to room temperature, open the reactor and remove the reaction liquid.
[0045] 8. Add ethanol to the reaction solution in step 7, centrifuge and wash, discard the supernatant, repeat three times, and then dry the sample at 75°C to obtain powdered rare earth-doped VS2 catalyst.
[0046] 9. Except for steps three and five, the remaining steps are the same, and pure VS2 is prepared.
[0047] Material characterization:
[0048] X-ray diffraction analysis was performed on the prepared pure VS2 and powdered rare earth-doped VS2 electrochemical hydrogen evolution catalysts, and the results are as follows: Figure 2 As shown in the figure, the peaks of pure VS2 and Ce-doped VS2 (Ce-VS2) are sharp and have high intensity, indicating high crystallinity. All powder samples exhibited distinct characteristic peaks at 2θ = 15.4°, 35.7°, 45.2°, 57.1°, 58.3°, 59.6°, and 69.3°, corresponding to crystal planes (hkl) of (001), (011), (012), (110), (103), (111), and (201), respectively. These peaks are consistent with the standard PDF card ICDD / PDFNo. 01-089-1640 for VS2 and show no impurity peaks, indicating high-quality synthesis of VS2. With increasing rare earth element doping ratio, the peak intensity of the XRD pattern decreased, the half-maximum width increased slightly, and the peaks shifted slightly to the right, indicating that the incorporation of rare earth elements affects the interplanar spacing and crystallinity of VS2.
[0049] The surface morphology and structure of the prepared pure VS2 and Ce-VS2 catalysts were analyzed under a scanning electron microscope, and the obtained SEM images are shown below. Figure 3 As shown. Figure 3 (a) and (b) are pure VS2 morphology images magnified 500x and 10,000x, respectively; (c) and (d) are Ce-VS2 morphology images magnified 500x and 10,000x, respectively. Figure 3 As shown in (a) and (b), the pure VS2 morphology is a nanoflower-like material formed by the stacking of nanosheet arrays, with uniform particle size and a diameter of approximately 4 μm. Figure 3 As shown in (c) and (d), after the rare earth element Ce is added, the surface morphology of VS2 is still a flower-like structure formed by the stacking of nanosheet arrays, and the flower-like structure is more obvious. This is because the rare earth element changes the interaction between VS2 nanosheets, thereby changing the stacking mode of the nanosheet array and making the nanosheets more ordered.
[0050] EDS energy dispersive spectroscopy analysis of Ce-VS2 catalyst as follows Figure 4As shown in the figure, V and S elements are completely and uniformly distributed in the Ce-VS2 catalyst, and Ce is also uniformly distributed in VS2. Combined with the changes in the XRD pattern after doping, it can be proved that Ce element is incorporated into the VS2 lattice, demonstrating the successful synthesis of Ce-doped VS2 electrochemical hydrogen evolution catalyst.
[0051] The pure VS2 and Ce-VS2 electrochemical hydrogen evolution catalysts were characterized using transmission electron microscopy, and the results are as follows: Figure 5 As shown. Compared to Figure 5 (a) shows the pure VS2, Figure 5 Ce-VS2 in (b) exhibits a more regular nanosheet arrangement structure, consistent with the results obtained from the SEM image, further demonstrating that rare earth elements have the effect of regulating the stacking mode between nanosheets, thereby improving the overall morphology of the catalyst.
[0052] Using the prepared pure VS2 and Ce-VS2 in different proportions as catalysts, the electrochemical hydrogen evolution performance was tested on a CHI760E electrochemical workstation using a standard three-electrode system. The linear sweep voltammetry (LSV) results are shown below. Figure 6 As shown in the figure, the overpotentials of the pure VS2 catalyst at current densities of -10, -50, and -100 mA cm⁻² are 233, 298, and 349 mV, respectively. A series of catalysts doped with Ce all exhibited higher electrocatalytic hydrogen evolution performance than pure VS2, demonstrating that rare earth elements significantly enhance the electrocatalytic hydrogen evolution performance of VS2. When the Ce doping ratio is 1.5%, VS2 exhibits the best electrocatalytic hydrogen evolution performance, with overpotentials of 150, 238, and 302 mV at current densities of -10, -50, and -100 mA cm⁻², respectively.
[0053] Based on the successful preparation of Ce-VS2 catalysts with different proportions, rare earth elements La, Sm, Eu, and Gd were incorporated into VS2 at a ratio of 1.5% using the same method as in the Ce-doped VS2 experiment. The obtained XRD patterns are shown below. Figure 7 As shown in the figure, the XRD patterns of this series of rare earth-doped VS2 catalysts are similar to those of pure VS2, with peaks appearing at approximately the same positions. The overall peak shape is relatively sharp, and almost no impurity peaks appear, indicating that these catalysts have good crystallinity. Among them, the XRD pattern of the Eu-doped VS2 catalyst has a relatively broad peak shape, indicating that the grain size of VS2 has changed under the influence of Eu.
[0054] The rare-earth-doped VS2 electrocatalyst for hydrogen evolution prepared by the above method is a stable powder product exhibiting a three-dimensional flower-like nanosheet array structure. XRD and SEM characterization showed that its characteristic peaks were consistent with standard VS2, and its morphology was regular and free of impurity peaks, demonstrating the high crystallinity and structural integrity of the sample. Combined EDS and TEM analysis revealed that rare-earth elements were uniformly doped into the VS2 lattice, altering the d-orbital electronic state distribution and thus optimizing the adsorption free energy of hydrogen atoms on the catalyst surface. This modulation of the electronic structure effectively enhances the activity and kinetics of electrocatalytic hydrogen production, resulting in superior long-term stability and conductivity.
[0055] The rare-earth-doped VS2 catalyst can be stored and used independently, and can also be directly applied as a cathode catalyst in water electrolysis devices. Under a standard three-electrode system, this catalyst exhibits significantly better hydrogen evolution performance than undoped VS2, especially at a current density of -10 mA·cm⁻², where its overpotential is below 160 mV, and at -50 mA·cm⁻², the overpotential is no higher than 240 mV, far superior to the control sample. These results clearly demonstrate that rare-earth doping significantly modifies the structure and electronic properties of VS2, effectively reducing the hydrogen evolution reaction energy barrier and improving the efficiency of hydrogen production through water electrolysis.
[0056] The contents not described in detail in this description are existing technologies known to those skilled in the art. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst, characterized in that, Includes the following steps: S1. Add ammonium metavanadate, ammonia and deionized water to a beaker and stir at room temperature for 15 minutes. After complete dissolution, a transparent reaction solution 1 is obtained. S2. Add thioacetamide and polyvinylpyrrolidone to the reaction solution 1, and continue stirring at room temperature for 45 minutes to gradually change the solution from clear to black, thus obtaining reaction solution 2. S3. Weigh out rare earth chlorides and dissolve them in deionized water to obtain reaction solution 3. The rare earth chlorides are selected from at least one of lanthanum chloride, cerium chloride, samarium chloride, europium chloride and gadolinium chloride. S4. Transfer reaction solution 2 and reaction solution 3 to a hydrothermal reactor in sequence, seal the reactor, and heat it in a 140°C furnace for 10 hours. After the reaction is completed, cool the reactor to room temperature. S5. Take out the cooled product, add ethanol for centrifugation and washing, discard the supernatant, repeat the washing three times to obtain the precipitate; S6. Disperse the precipitate in ethanol and dry it in a drying oven at 75°C to obtain a powdered rare earth-doped VS2 electrochemical hydrogen evolution catalyst.
2. The method for preparing a rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst according to claim 1, characterized in that, The amount of rare earth chloride added is 0.5% to 5% based on the atomic molar ratio of rare earth elements to vanadium elements.
3. The method for preparing a rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst according to claim 1, characterized in that, The amount of polyvinylpyrrolidone used is 100-200 mg. During the reaction, the polyvinylpyrrolidone is used to regulate the surface energy of the product, thereby promoting the orderly stacking of the nanosheet array and forming a stable nanoflower-like structure.
4. The method for preparing a rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst according to claim 1, characterized in that, The rare earth-doped VS2 electrocatalyst has a 1T phase crystal structure, which has higher conductivity and more abundant electrocatalytic active sites compared to the 2H phase.
5. The method for preparing a rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst according to claim 1, characterized in that, The rare earth-doped VS2 electrochemical hydrogen evolution catalyst has a flower-like morphology formed by stacking nanosheets, with a particle diameter of 2-6 μm. The introduction of rare earth elements changes the interaction between the nanosheets, making the stacking arrangement more orderly.
6. The method for preparing a rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst according to claim 1, characterized in that, The rare earth elements are uniformly doped in the VS2 lattice, which can regulate the d-orbital electronic structure of VS2, optimize the adsorption energy of hydrogen atoms on the catalyst surface, and improve its electrocatalytic hydrogen production activity and stability.
7. A rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst, prepared by the method according to any one of claims 1-6, wherein the catalyst exhibits a three-dimensional flower-like nanosheet array under a scanning electron microscope, and its X-ray diffraction pattern matches the diffraction peaks of standard VS2 without any impurity peaks. The catalyst also exhibits a regular arrangement of nanosheets under a transmission electron microscope, and X-ray energy dispersive spectroscopy (EDS) analysis shows that rare earth elements are uniformly distributed throughout the crystal lattice.
8. The rare earth-doped vanadium disulfide electrochemical hydrogen evolution catalyst according to claim 7, characterized in that, It is used in the production of hydrogen through water electrolysis in the new energy sector.
9. A method for producing hydrogen by electrolysis of water, characterized in that, Using the rare earth-doped VS2 electrochemical hydrogen evolution catalyst according to any one of claims 7 or 8 as the cathode catalyst, and carrying out the hydrogen evolution reaction in a standard three-electrode system, the overpotential is significantly lower than that of the undoped VS2 catalyst.
10. The method for producing hydrogen by water electrolysis according to claim 9, characterized in that, At a current density of -10 mA·cm⁻², the overpotential of the catalyst is not higher than 160 mV, and at a current density of -50 mA·cm⁻², the overpotential of the catalyst is not higher than 240 mV.