Hollow CuCo2S4 nanorod and preparation method thereof
By preparing hollow CuCo2S4 nanorod electrocatalysts, the problems of high cost of precious metal catalysts and easy structure collapse are solved, and efficient and stable electrolytic hydrogen production process is achieved.
Patent Information
- Application Number
- CN202410077764.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-18
- Publication Date
- 2025-07-22
Smart Images
Figure CN120348978A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electrocatalysis, and particularly to a hollow CuCo2S4 nanorod and a preparation method thereof. Background Art
[0002] As a new energy source with zero emissions, hydrogen energy has attracted wide attention due to its high energy density, high calorific value, high efficiency and cleanliness. Electrolytic water for hydrogen production provides an effective method for producing green hydrogen. However, the anodic oxygen evolution reaction (OER) is a complex process involving four-electron transfer, with slow reaction kinetics and requiring a high overpotential to drive the process. The high cost and scarcity of existing noble metal catalysts (such as iridium, ruthenium, etc.) seriously hinder their industrial applications. Therefore, exploring inexpensive and efficient anodic OER electrocatalysts to improve the electrolytic water reaction is an urgent task.
[0003] Spinel-type metal sulfides have advantages such as high conductivity, a wide variety, and excellent electrochemical properties, making them ideal OER catalysts. However, during long-term OER reactions, due to high oxidation conditions, the catalyst structure usually collapses due to M-S bond reconstruction and oxidative corrosion, thereby reducing the OER catalytic activity. Moreover, the small specific surface area and few active sites of existing spinel-type metal sulfides are also not conducive to improving the catalytic performance during OER. Therefore, designing electrocatalysts with unique structures to increase the surface area of the catalyst is an important way to improve its electrocatalytic performance.
[0004] Therefore, a method for preparing an electrocatalyst with a simple preparation method, low cost, high efficiency, and a large specific surface area is needed. Summary of the Invention
[0005] In order to solve the above problems, the purpose of the present invention is to provide a hollow CuCo2S4 nanorod and a preparation method thereof. The CuCo2S4 material has a nanoscale size and a hollow structure, with a large specific surface area, many active sites, and high OER catalytic performance.
[0006] To achieve the above purpose, the present invention provides a preparation method for a hollow CuCo2S4 nanorod, which includes: mixing a cobalt salt and a precipitating agent in water, performing a hydrothermal reaction to obtain a cobalt precursor; adding the cobalt precursor to a sulfur source and performing a sulfidation reaction to obtain a sulfur cobalt compound; performing copper ion exchange on the sulfur cobalt compound, washing and drying to obtain the hollow CuCo2S4 nanorod.
[0007] In the above preparation method, the molar ratio of the cobalt salt to the precipitating agent can be 1-5:2-6.
[0008] In the above preparation method, the cobalt salt can be selected from soluble salts, such as cobalt chloride, etc.
[0009] In the above preparation method, the temperature of the hydrothermal reaction can be 120 - 150 °C, and the time of the hydrothermal reaction can be 10 - 12 h.
[0010] In some specific embodiments, the morphology of the cobalt precursor can be solid nanorods. The cobalt precursor can form Co4S3 solid nanorods through anion exchange with a sulfur source.
[0011] In the above preparation method, the sulfur source is used to sulfide the cobalt precursor. The sulfur source includes one or a combination of more than two of thioacetamide, L-cysteine, thiourea, and sodium sulfide.
[0012] In the above preparation method, the feeding ratio of the cobalt precursor to the sulfur source is 1 g : 0.07 - 0.3 mol, specifically it can be 1 g:0.07 mol, 1 g:0.08 mol, 1 g:0.09 mol, 1 g:0.10 mol, 1 g:0.15 mol, 1 g:0.20 mol, 1 g:0.25 mol, 1 g:0.30 mol and other specific values, as well as the ranges with any two of the above specific values as endpoints.
[0013] In the above preparation method, it can be that a cobalt salt is added to a sulfur source solution for a sulfidation reaction. The concentration of the sulfur source solution can be 0.05 - 0.15 mol / L.
[0014] In the above preparation method, the temperature of the sulfidation reaction can be 160 - 180 °C, for example, it can be 160 °C, 165 °C, 170 °C, 175 °C, 180 °C and other specific values, as well as the ranges with any two of the above specific values as endpoints.
[0015] In the above preparation method, the time of the hydrothermal reaction can be 10 - 12 h, for example, it can be 10 h, 11 h, 12 h and other specific values, as well as the ranges with any two of the above specific values as endpoints.
[0016] In the above preparation method, the sulfur cobalt compound obtained from the sulfidation reaction is generally Co4S3, specifically it can be Co4S3 nanorods. The length of the Co4S3 nanorods can be 3 μm - 5 μm, and the diameter can be 200 nm - 400 nm.
[0017] In the above preparation method, the copper ion exchange process can introduce copper ions into the sulfur cobalt compound to induce the formation of a hollow nanorod structure, making the final product have a larger specific surface area, thereby exposing more active sites and accelerating the reaction kinetics.
[0018] In the above preparation method, the temperature of the copper ion exchange can be 160 - 180 °C, for example, it can be specific values such as 160 °C, 165 °C, 170 °C, 175 °C, 180 °C, etc., and ranges with any two of the above specific values as endpoints.
[0019] In the above preparation method, the time of the copper ion exchange can be 10 - 12 h, for example, it can be specific values such as 10 h, 11 h, 12 h, etc., and ranges with any two of the above specific values as endpoints.
[0020] In the above preparation method, the process of the copper ion exchange can specifically include: mixing the sulfur cobalt compound with a solution of a copper salt; wherein, the concentration of the solution of the copper salt is 0.01 - 0.03 mol / L, for example, it can be specific values such as 0.01 mol / L, 0.015 mol / L, 0.02 mol / L, 0.025 mol / L, 0.03 mol / L, etc., and ranges with any two of the above specific values as endpoints. The copper salt can be a soluble salt, such as copper nitrate, etc.
[0021] In the above preparation method, the feeding ratio of the sulfur cobalt compound to the copper salt can be 1 g: 2 - 9 mmol, specifically, it can be specific values such as 1 g: 2 mmol, 1 g: 3 mmol, 1 g: 4 mmol, 1 g: 5 mmol, 1 g: 6 mmol, 1 g: 7 mmol, 1 g: 8 mmol, 1 g: 9 mmol, etc., and ranges with any two of the above specific values as endpoints.
[0022] The present invention also provides a hollow CuCo₂S₄ nanorod, which is prepared by the above preparation method. In some specific embodiments, the diameter of the hollow CuCo₂S₄ nanorod is 200 - 400 nm, and the length of the hollow CuCo₂S₄ nanorod is 3 - 5 μm. The specific surface area of the hollow CuCo₂S₄ nanorod is 180 - 210 cm 2 mg -1 。
[0023] In some specific embodiments, the hollow CuCo₂S₄ nanorod may have a spinel structure.
[0024] In the above preparation method, a cobalt precursor with a solid structure is made through a hydrothermal reaction, and the cobalt precursor forms Co₄S₃ with sulfide ions through an anion structure; Co₄S₃ forms a hollow CuCo₂S₄ with a spinel structure through cation exchange with the copper salt cation. The above preparation method uses inexpensive and easily available transition metal salts as raw materials, and prepares a hollow CuCo₂S₄ nanorod electrocatalyst through a continuous anion / cation exchange strategy. The preparation method is simple and the conditions are mild.
[0025] The present invention also provides an electrocatalyst, which comprises the above-mentioned hollow CuCo2S4 nanorods or is made of the hollow CuCo2S4 nanorods. The hollow CuCo2S4 nanorods provided by the present invention have a nanoscale size and a hollow structure, with a relatively high specific surface area, which can provide a large number of active sites and exhibit relatively high reaction activity in reaction processes such as OER. For example, in a three-electrode system, the OER overpotential of the above-mentioned CuCo2S4 material at a current density of 10 mA cm -2 is 220 mV; when the CuCo2S4 material is applied to the electrolysis of water reaction in a two-electrode system, only 1.55 V is required to reach a current density of 10 mA cm -2 .
[0026] The beneficial effects of the present invention include:
[0027] 1. The CuCo2S4 material provided by the present invention has a nanoscale size and a hollow structure. On the one hand, it can increase the specific surface area of the material, improve the conductivity, enhance the inherent catalytic activity, and increase the electrochemically active surface area, thereby providing favorable kinetic conditions for reducing the OER reaction overpotential; on the other hand, the hollow structure can also expand the contact area between the electrolyte / reactant, promote the diffusion / penetration process of the electrolyte / reactant-electrode, and enhance the charge transfer ability. The preparation method provided by the present invention can improve the activity and stability of the spinel-type metal sulfide electrocatalyst in the oxygen evolution reaction by constructing a hollow nanorod structure in the spinel-type metal sulfide, thereby obtaining an inexpensive and high-performance electrocatalyst for water electrolysis reaction.
[0028] 2. The CuCo2S4 material provided by the present invention contains both Cu and Co. Through the synergistic effect and interfacial electron interaction between Cu and Co, the electron transfer and charge distribution of CuCo2S4 can be significantly improved, which is beneficial to optimizing the adsorption / desorption process of reaction intermediates (such as O*, OH*, OOH*, etc.), thereby promoting the progress of the OER and the electrolysis of water reaction, and enabling it to have good electrocatalytic performance under alkaline conditions. Description of the Drawings
[0029] Figure 1 SEM image of the Co nanorod precursor prepared in step (1) of Example 1. It can be seen from Figure 1 this that the product has a nanorod structure.
[0030] Figure 2a Selected area electron diffraction pattern of Co4S3 prepared in step (2) of Example 1.
[0031] Figure 2b SEM image of Co4S3 prepared in step (2) of Example 1.
[0032] Figure 3 SEM image of the CuCo2S4 electrocatalyst prepared in Example 1.
[0033] Figure 4 XRD pattern of the CuCo2S4 electrocatalyst prepared in Example 1.
[0034] Figure 5 LSV graph of the OER performance of the CuCo2S4 electrocatalyst prepared in Example 1 under a three - electrode system.
[0035] Figure 6 LSV graph of the water electrolysis performance of the CuCo2S4 electrocatalyst prepared in Example 1 under a two - electrode system.
[0036] Figure 7 Cyclic stability graph of the water electrolysis performance of the CuCo2S4 electrocatalyst prepared in Example 1 under a two - electrode system. Detailed implementation manners
[0037] For a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the technical solutions of the present invention are described in detail below, but it should not be construed as a limitation on the implementable scope of the present invention.
[0038] Tables 1 and 2 show the sources of raw materials and equipment used in the examples and comparative examples:
[0039] Table 1 Main experimental reagents
[0040] Reagent Name Chemical Formula Purity Manufacturer Copper Nitrate <![CDATA[Cu(NO2)2·3H2O]]> AR Macklin Biochemical Co., Ltd. Cobalt Chloride <![CDATA[CoCl2·6H2O]]> AR Macklin Biochemical Co., Ltd. Thioacetamide <![CDATA[CH3CSNH2]]> AR Macklin Biochemical Co., Ltd. Urea <![CDATA[CO(NH2)2]]> AR Macklin Biochemical Co., Ltd. Potassium Hydroxide KOH AR Macklin Biochemical Co., Ltd. Nafion <![CDATA[C9HF 17 O5S]]> 5wt% Macklin Biochemical Co., Ltd. Absolute Ethanol <![CDATA[C2H5OH]]> AR Macklin Biochemical Co., Ltd. Graphite Powder C SP Macklin Biochemical Co., Ltd.
[0041] Table 2 Main experimental reagents
[0042] Instrument Name Model Manufacturer Forced Air Drying Oven DHG-9030A Shanghai Yiheng Scientific Instrument Co., Ltd. Electronic Balance BSA2243 Sartorius Co., Ltd. Electrochemical Workstation CHI 760E Shanghai Chenhua Instrument Co., Ltd. Scanning Electron Microscope Sigma 300 ZEISS, Germany X-ray Powder Diffractometer X’Pert PRO MPD Spectris Pte, Netherlands Electron Paramagnetic Resonance Spectrometer Bruker EMXPlus Bruker, USA Inductively Coupled Plasma Spectrometer PerkinElmer 8300 PerkinElmer, USA Specific Surface and Porosity Analyzer ASAP 2460 Micromeritics, USA Tube Furnace SLG1100 Shanghai Shengli Testing Instrument Co., Ltd. Glassy Carbon Electrode Diameter 0.5cm Tianjin Aida Hengsheng Technology Development Co., Ltd.
[0043] Evaluation and analysis method: All electrochemical measurements were carried out at room temperature using a Chenhua workstation (CHI760E) and a standard three - electrode system. The glassy carbon electrode loaded with the catalyst was used as the working electrode, the carbon rod as the counter electrode, the Hg / HgO electrode as the reference electrode, and the electrolyte was 1M KOH aqueous solution. Preparation of the glassy carbon electrode sample: Weigh 4mg of the catalyst and 0.8mg of acetylene black, dissolve them in a mixed solution of 360mL of ultrapure water, 120mL of absolute ethanol, and 20μL of Nafion, and ultrasonicate for 2h to obtain a uniformly dispersed slurry; Use a pipette to transfer a certain amount of the slurry and drop it on the glassy carbon electrode, and let it dry naturally for standby. The OER catalytic performance of the catalyst was tested in 1M KOH at a scan rate of 2mV / s.
[0044] Example 1
[0045] This embodiment provides a CuCo2S4 electrocatalyst, and its preparation method includes:
[0046] (1) Dissolve 5 mmol of cobalt chloride and 5 mmol of urea in 60 mL of deionized water respectively, stir for 20 min to form a mixed solution, transfer it to a 100 mL polytetrafluoroethylene hydrothermal reactor, and react at 120 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash, and vacuum dry at 50 °C for 4 h to obtain the Co nanorod precursor, and the product is denoted as Co precursor.
[0047] (2) Add 0.40 g of the Co precursor to a 0.1 mol / L thioacetamide solution (60 mL) for sulfidation treatment, and react at 180 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash with ethanol and deionized water, and vacuum dry at 50 °C for 4 h to obtain Co4S3 nanorods.
[0048] (3) Add 0.17 g of Co4S3 nanorods to a 0.02 mol / L copper nitrate solution (50 mL), stir to form a uniform suspension, transfer it to a 100 mL / polytetrafluoroethylene hydrothermal reactor, and react at 180 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash with ethanol and deionized water, and vacuum dry at 50 °C for 4 h to obtain hollow CuCo2S4 nanorods.
[0049] Figure 1 is the SEM image of the Co nanorod precursor prepared in step (1) of this embodiment. From Figure 1 it can be seen that the product has a nanorod structure.
[0050] Figure 2a is the selected area electron diffraction pattern of Co4S3 prepared in step (2) of this embodiment. Figure 2a The diffraction spots of (311), (400), (440), (531), (551) and (800) in Figure 2b are consistent with the standard card of Co4S3 (JCPDS No.02-1338). Perform morphology characterization on Co4S3, and the SEM results are as
[0051] Figure 3 shown. It can be seen that the Co4S3 catalyst maintains a nanorod structure, and the surface of the nanorods is covered with irregular particles. Perform elemental analysis on Co4S3, and it is measured that there are two elements, Co and S, in the sample, and the atomic ratio of the two elements is about 4:3. The above results prove that the product of step (2) is Co4S3 nanorods.
[0051] Figure 3 is the SEM image of the hollow CuCo2S4 nanorods prepared in this embodiment. It can be seen from the figure that the catalyst has a hollow nanorod structure with a diameter of about 250 nm, which is beneficial to increasing the contact area between the catalyst and the electrolyte and promoting the reaction.
[0052] Figure 4 XRD pattern of the hollow CuCo2S4 nanorods prepared in this example. Its diffraction peaks match the crystal planes of spinel-type CuCo2S4, indicating the successful preparation of the hollow CuCo2S4 nanorod electrocatalyst.
[0053] Example 2
[0054] This example provides a CuCo2S4 electrocatalyst, and its preparation method includes:
[0055] (1) Dissolve 5 mmol of cobalt chloride and 5 mmol of urea in 60 mL of deionized water respectively, stir for 20 min to form a mixed solution, transfer it to a 100 mL polytetrafluoroethylene hydrothermal reaction kettle, and react at 120 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash, and dry in vacuum at 50 °C for 4 h to obtain the Co nanorod precursor, and the product is denoted as Co precursor.
[0056] (2) Add 0.40 g of the Co precursor to a 0.05 mol / L thioacetamide solution (60 mL) for sulfidation treatment, and react at 180 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash with ethanol and deionized water, and dry in vacuum at 50 °C for 4 h to obtain Co4S3 nanorods.
[0057] (3) Add 0.17 g of Co4S3 nanorods to a 0.02 mol / L copper nitrate solution (50 mL), stir to form a uniform suspension, transfer it to a 100 mL polytetrafluoroethylene hydrothermal reaction kettle, and react at 180 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash with ethanol and deionized water, and dry in vacuum at 50 °C for 4 h to obtain hollow CuCo2S4 nanorods.
[0058] Example 3
[0059] This example provides a CuCo2S4 electrocatalyst, and its preparation method includes:
[0060] (1) Dissolve 5 mmol of cobalt chloride and 5 mmol of urea in 60 mL of deionized water respectively, stir for 20 min to form a mixed solution, transfer it to a 100 mL polytetrafluoroethylene hydrothermal reaction kettle, and react at 120 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash, and dry in vacuum at 50 °C for 4 h to obtain the Co nanorod precursor, and the product is denoted as Co precursor.
[0061] (2) Add 0.40 g of the Co precursor to a 0.15 mol / L thioacetamide solution (60 mL) for sulfidation treatment, and react at 180 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash with ethanol and deionized water, and dry in vacuum at 50 °C for 4 h to obtain Co4S3 nanorods.
[0062] (3) Add 0.17 g of Co4S3 nanorods to 0.02 mol / L copper nitrate solution (50 mL), stir to form a uniform suspension, transfer it to a 100 mL polytetrafluoroethylene hydrothermal reactor, and react at 180 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash with ethanol and deionized water, and dry in vacuum at 50 °C for 4 h to obtain hollow CuCo2S4 nanorods.
[0063] Example 4
[0064] This example provides a CuCo2S4 electrocatalyst, and its preparation method includes:
[0065] (1) Dissolve 5 mmol of cobalt chloride and 5 mmol of urea in 60 mL of deionized water respectively, stir for 20 min to form a mixed solution, transfer it to a 100 mL polytetrafluoroethylene hydrothermal reactor, and react at 120 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash, and dry in vacuum at 50 °C for 4 h to obtain a Co nanorod precursor, and the product is denoted as Co precursor.
[0066] (2) Add 0.40 g of Co precursor to 0.1 mol / L thioacetamide solution (60 mL) for sulfidation treatment, and react at 180 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash with ethanol and deionized water, and dry in vacuum at 50 °C for 4 h to obtain Co4S3 nanorods.
[0067] (3) Add 0.17 g of Co4S3 nanorods to 0.01 mol / L copper nitrate solution (50 mL), stir to form a uniform suspension, transfer it to a 100 mL polytetrafluoroethylene hydrothermal reactor, and react at 180 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash with ethanol and deionized water, and dry in vacuum at 50 °C for 4 h to obtain hollow CuCo2S4 nanorods.
[0068] Example 5
[0069] This example provides a CuCo2S4 electrocatalyst, and its preparation method includes:
[0070] (1) Dissolve 5 mmol of cobalt chloride and 5 mmol of urea in 60 mL of deionized water respectively, stir for 20 min to form a mixed solution, transfer it to a 100 mL polytetrafluoroethylene hydrothermal reactor, and react at 120 °C for 12 h. After the reaction is completed and cooled to room temperature, centrifuge and wash, and dry in vacuum at 50 °C for 4 h to obtain a Co nanorod precursor, and the product is denoted as Co precursor.
[0071] (2) 0.40 g of Co precursor was added to 0.1 mol / L thioacetamide solution (60 mL) for sulfidation treatment, and the reaction was carried out at 180 °C for 12 h. After the reaction was completed and cooled to room temperature, it was centrifugally washed with ethanol and deionized water, and vacuum dried at 50 °C for 4 h to obtain Co4S3 nanorods.
[0072] (3) 0.17 g of Co4S3 nanorods was added to 0.03 mol / L copper nitrate solution (50 mL), stirred to form a uniform suspension, transferred to a 100 mL polytetrafluoroethylene hydrothermal reaction kettle, and the reaction was carried out at 180 °C for 12 h. After the reaction was completed and cooled to room temperature, it was centrifugally washed with ethanol and deionized water, and vacuum dried at 50 °C for 4 h to obtain hollow CuCo2S4 nanorods.
[0073] Comparative Example 1
[0074] This comparative example provides a cobalt precursor, and its preparation method includes:
[0075] (1) 5 mmol of cobalt chloride and 5 mmol of urea were respectively dissolved in 60 mL of deionized water, stirred for 20 min to form a mixed solution, transferred to a 100 mL polytetrafluoroethylene hydrothermal reaction kettle, and the reaction was carried out at 120 °C for 12 h. After the reaction was completed and cooled to room temperature, it was centrifugally washed and vacuum dried at 50 °C for 4 h to obtain a Co nanorod precursor, and the product was denoted as Co precursor.
[0076] Comparative Example 2
[0077] This comparative example provides a Co4S3 catalyst, and its preparation method includes:
[0078] (1) 5 mmol of cobalt chloride and 5 mmol of urea were respectively dissolved in 60 mL of deionized water, stirred for 20 min to form a mixed solution, transferred to a 100 mL polytetrafluoroethylene hydrothermal reaction kettle, and the reaction was carried out at 120 °C for 12 h. After the reaction was completed and cooled to room temperature, it was centrifugally washed and vacuum dried at 50 °C for 4 h to obtain a Co nanorod precursor, and the product was denoted as Co precursor.
[0079] (2) 0.40 g of Co precursor was added to 0.1 mol / L thioacetamide solution (60 mL) for sulfidation treatment, and the reaction was carried out at 180 °C for 12 h. After the reaction was completed and cooled to room temperature, it was centrifugally washed with ethanol and deionized water, and vacuum dried at 50 °C for 4 h to obtain Co4S3 nanorods.
[0080] The products prepared in the examples and comparative examples of the present invention were used as catalysts in electrocatalytic reactions.
[0081] In a three - electrode system, the prepared catalyst was used as the working electrode, the Hg / HgO electrode and the carbon rod were used as the reference electrode and the counter electrode respectively, and 1 M KOH (pH = 14) was used as the electrolyte. The linear sweep voltammetry (LSV) was adopted to test the OER performance of the prepared electrocatalyst at a scan rate of 5 mV s -1 −1. In a two - electrode system, the prepared catalyst was assembled into an electrolytic cell as the anode, and its water electrolysis performance was tested in 1 M KOH. The LSV curve was tested at a scan rate of 5 mV s -1 −1.
[0082] Figure 5 Figure 8 shows the LSV curve of the OER performance of the hollow CuCo2S4 nanorods prepared in Example 1 of the present invention in a three - electrode system. As Figure 5 shown, the OER overpotential at a current density of 10 mA cm -2 −2 was 220 mV, indicating its good OER catalytic activity. In the three - electrode system, the OER overpotential of Comparative Example 1 was 330 mV at a current density of 10 mA cm -2 −2, and the OER overpotential of Comparative Example 2 was 270 mV at a current density of 10 mA cm -2 −2.
[0083] Figure 6 Figure 9 Figure 7 shows the LSV diagram and the cyclic stability diagram of the water electrolysis performance of the hollow CuCo2S4 nanorods prepared in Example 1 of the present invention in a two - electrode system. As can be seen from Figure 6 Figure 9 Figure 7 , when applied to the water electrolysis reaction, only 1.55 V was required to reach a current density of 10 mA cm -2 −2, which confirmed that using the hollow CuCo2S4 nanorods as the anode electrode exhibited excellent water electrolysis catalytic activity. When continuously electrolyzed for more than 38 h, its current density remained basically unchanged, indicating its superior cyclic stability. The present invention prepared a hollow CuCo2S4 nanorod electrocatalyst by a continuous anion / cation exchange method and applied it to the electrocatalytic reaction. In the present invention, cobalt and copper were used as metal salt precursors, which had wide raw material sources and good conductivity. Moreover, the preparation method of the present invention was simple and the conditions were mild, and it had excellent electrocatalytic performance under alkaline conditions.
Claims
1. A preparation method of hollow CuCo₂S₄ nanorods, the preparation method comprising: Mixing a cobalt salt and a precipitant in water and performing a hydrothermal reaction to obtain a cobalt precursor; Adding the cobalt precursor to a sulfur source and performing a sulfidation reaction to obtain a sulfur cobalt compound; Performing copper ion exchange on the sulfur cobalt compound, washing and drying to obtain the hollow CuCo₂S₄ nanorods.
2. The preparation method according to claim 1, wherein, The molar ratio of the cobalt salt to the precipitant is 1-5:2-6.
3. The preparation method according to claim 1, wherein The precipitant includes urea.
4. The preparation method according to claim 1, wherein The temperature of the hydrothermal reaction is 120-150 °C, and the time of the hydrothermal reaction is 10-12 h.
5. The preparation method according to claim 1, wherein The sulfur source includes one or a combination of two or more of thioacetamide, L-cysteine, thiourea, and sodium sulfide.
6. The preparation method according to claim 1, wherein, The feeding ratio of the cobalt precursor to the sulfur source is 1 g:0.07-0.3 mol.
7. The preparation method according to claim 1, wherein, The temperature of the sulfidation reaction is 160-180 °C, and the time of the hydrothermal reaction is 10-12 h.
8. The preparation method according to claim 1, wherein The temperature of the copper ion exchange is 160-180 °C, and the time of the copper ion exchange is 10-12 h.
9. The preparation method according to claim 1, wherein, The process of the copper ion exchange includes: mixing the sulfur cobalt compound with a solution of a copper salt; the concentration of the solution of the copper salt is preferably 0.01-0.03 mol / L.
10. The preparation method according to claim 9, wherein, The feeding ratio of the sulfur cobalt compound to the copper salt is 1 g:2-9 mmol.
11. A hollow CuCo₂S₄ nanorod, which is prepared by the preparation method according to any one of claims 1-10; Preferably, the diameter of the hollow CuCo₂S₄ nanorod is 200 nm-400 nm, and the length of the hollow CuCo₂S₄ nanorod is 3 μm-5 μm.
12. An electrocatalyst, which comprises the hollow CuCo₂S₄ nanorod according to claim 11 or is made of the hollow CuCo₂S₄ nanorod according to claim 11.