Preparation method and application of carbon nanotube-wound s-doped se-vacancy type niSe2 electrocatalyst
By preparing a carbon nanotube-wound S-doped Se vacancy-type NiSe2 electrocatalyst, the problems of insufficient active sites and slow reaction kinetics in non-noble metal catalysts in OER were solved, achieving high-efficiency OER performance and outperforming the stability of commercial noble metal catalysts.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2026-03-24
AI Technical Summary
Existing non-precious metal-based catalysts have insufficient active sites and slow reaction kinetics in the oxygen evolution reaction (OER), which limits their application in the field of water electrolysis.
A carbon nanotube-wound S-doped Se vacancy-type NiSe2 electrocatalyst was prepared by a combination of hydrothermal and solid-state heat treatment. Ni(OH)2 nanosheet precursor was prepared by hydrothermal reaction, followed by winding S-doped NiSe2 and introducing Se vacancies under an inert atmosphere.
It improves the OER activity of the catalyst under alkaline conditions and has better stability than commercial noble metal catalysts.
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Figure CN119265612B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of catalytic materials, and particularly relates to a preparation method and application of a carbon nanotube-wrapped S-doped Se-vacancy type NiSe2 electrocatalyst. BACKGROUND
[0002] With the rapid growth of population and the development of industry, the global energy demand is rapidly growing, stimulating social energy consumption and increasing environmental burden. Global energy supply and the resulting environmental problems are prompting researchers to seek renewable, clean and alternative energy to replace the gradually exhausted and heavily polluting fossil fuels. At present, sustainable green energy includes solar energy, tidal energy, wind energy, water energy and hydrogen energy, etc. Among them, hydrogen, which is abundant on earth, has a high energy density and is considered to be the most promising alternative to traditional energy.
[0003] Unfortunately, due to the slow kinetics characteristics of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), especially the huge energy barrier caused by the four-step proton-coupled electron transfer of OER, an effective catalyst is needed to narrow the gap between the theoretical potential and the actual required potential. Therefore, the catalyst plays a key role in designing efficient processes and systems, which can maximize the value of raw materials to meet energy demand and achieve the goal of large-scale hydrogen production for future sustainable energy and industry.
[0004] Nowadays, non-noble metal-based catalysts have the highest cost performance, and more and more people are committed to developing transition metal-based electrocatalysts, which mainly include transition metal oxides, phosphides, sulfides, selenides and nitrides, etc. By a series of reasonable means such as doping heteroatoms, constructing heterojunction interfaces and introducing defects or vacancies, etc. to optimize the electrocatalytic performance, many transition metal-based electrocatalysts have been developed, which have comparable catalytic activity to noble metal-based catalysts. However, although the above research has achieved remarkable results, non-noble metal catalysts are still limited by insufficient active sites and slow reaction kinetics, which affects their application in the field of water electrolysis. SUMMARY
[0005] In view of the above problems, the application provides a preparation method of a carbon nanotube-wrapped S-doped Se-vacancy type NiSe2 electrocatalyst. The electrocatalyst material involved in the application is prepared by a combination of hydrothermal and solid-state heat treatment methods. The steps include first preparing a carbon nanotube-loaded Ni(OH)2 nanosheet precursor by hydrothermal reaction, then obtaining a carbon nanotube-wrapped S-doped NiSe2 electrocatalyst by hydrothermal reaction, and finally introducing Se vacancies under inert atmosphere by heat treatment.
[0006] The technical solution adopted by the application is as follows:
[0007] (1) carbon nanotubes, nickel salt, urotropin and citrate, polyvinylpyrrolidone are dissolved in a deionized water / ethanol mixed solution, mixed uniformly, hydrothermal reaction is carried out at a specific temperature for a certain time, after reaction, centrifugation, washing and drying are carried out, and carbon nanotube loaded Ni(OH)2 nanosheet precursor is obtained;
[0008] (2) the precursor in S1 is dispersed in an aqueous solution containing a sulfur source and a selenium source, then transferred to a high-pressure hydrothermal kettle, and reacted at a suitable temperature and time, then centrifuged, washed and dried to obtain a carbon nanotube-wrapped S-doped NiSe2 electrocatalyst;
[0009] (3) the powder obtained in S2 is calcined under an inert atmosphere by setting a suitable heating rate, calcination temperature and calcination time to obtain a carbon nanotube-wrapped S-doped Se-vacancy type NiSe2 electrocatalyst.
[0010] In step (1), the nickel salt includes but is not limited to one or more of nickel nitrate, nickel sulfate, nickel chloride and nickel acetate, etc., and the concentration is 5-50 mmol / L -1 ; the hydrothermal temperature is 90-150℃; and the hydrothermal time is 5-12h.
[0011] In step (2), the sulfur source includes but is not limited to sodium thiosulfate, sodium sulfite, thiourea, sodium sulfide, thioacetamide, etc.; the selenium source includes but is not limited to sodium selenate, sodium hydroselenide, selenourea, sodium selenite, sodium selenide, etc.; the concentration of the sulfur source is 10-100 mmol / L -1 ; the concentration of the selenium source is 10-100 mmol / L -1 ; the hydrothermal temperature is 100-200℃; and the hydrothermal time is 10-48h.
[0012] In step (3), the inert atmosphere includes nitrogen, argon and helium; the heating rate is 1-20℃ / min -1 ; the target temperature is 250-450℃; and the holding time is 0.5-6h.
[0013] Another aspect of the present application provides a carbon nanotube-wrapped S-doped Se-vacancy type NiSe2 electrocatalyst prepared by the above preparation method.
[0014] The present application also provides the application of the above carbon nanotube-wrapped S-doped Se-vacancy type NiSe2 electrocatalyst in water electrolysis or metal-air battery.
[0015] The present application has the following beneficial effects compared with the prior art:
[0016] The stability of the OER activity of the carbon nanotube-wrapped S-doped Se-vacancy type NiSe2 electrocatalyst under alkaline conditions is better than that of a commercial noble metal catalyst. BRIEF DESCRIPTION OF DRAWINGS
[0017] In order to more clearly illustrate the embodiments of the present application, the drawings involved in the embodiments will be briefly introduced as follows.
[0018] Figure 1 XRD patterns of the samples prepared for Example 1, Comparative Example 1 and Comparative Example 2.
[0019] Figure 2 SEM images of the samples prepared for Example 1 (Figure c), Comparative Example 1 (Figure b) and Comparative Example 2 (Figure a).
[0020] Figure 3 OER performance LSV curves of Example 2.
[0021] Figure 4 Full water electrolysis LSV curves and stability curves of Example 2. DETAILED DESCRIPTION
[0022] The present application will be described in detail below with reference to the embodiments, but the embodiments of the present application are not limited thereto. It is obvious that the embodiments described below are only partial embodiments of the present application, and other similar embodiments obtained by those skilled in the art without creative effort fall within the protection scope of the present application.
[0023] Example 1:
[0024] (1) 40 mg of PVP was added to a mixed solution of 10 ml of ethanol and 40 ml of water, and after dissolution, 40 mg of carbon nanotubes was added and ultrasonically dispersed for 2 hours. Nickel nitrate (0.3 mmol, 0.0872 g) was added and stirred for 5 min. Urotropine (0.5 mmol, 0.0701 g) and sodium citrate (0.05 mmol, 0.0147 g) were added and stirred for 10 min. Hydrothermal reaction was carried out at 90°C for 6 h, and then cooled to room temperature. Centrifugation (ethanol washing for 3 times, 10000 r / 10 min), and vacuum drying at 70°C for 12 h.
[0025] (2) 30 mg of the above product was added to 20 ml of water, stirred for 3 h, and ultrasonically dispersed for 2 h. 60 mg of sodium thiosulfate was added and ultrasonically dissolved until all the solids were dissolved. The above solution was purged with nitrogen for 30 min. 1.5 ml of sodium hydroselenide was added dropwise. The autoclave was heated at 150°C for 36 h, and then cooled to room temperature. Centrifugation, water washing for 3 times, and ethanol washing for 3 times. Vacuum drying at 80°C for 12 h to obtain S-NiSe2 / CNTs.
[0026] (3) The above sample was placed in a tube furnace and heat treated at 450°C for 0.5 h under nitrogen atmosphere, with a heating rate of 10°C min -1, cooled to room temperature to obtain black powder (S-NiSe2-V Se / CNTs).
[0027] Example 2
[0028] In this example, the prepared material was dispersed in ethanol to form a dispersion liquid, and the dispersion liquid was coated on carbon cloth. The electrolyte was 1M KOH aqueous solution.
[0029] Comparative Example 1
[0030] In this example, the experiment was the same as that of Example 1, except that the heat treatment in step (3) was not performed.
[0031] Comparative Example 2
[0032] In this example, the experiment was the same as that of Comparative Example 1, except that sodium thiosulfate was not added in the hydrothermal process.
[0033] Figure 1 XRD patterns of the samples prepared in Example 1, Comparative Example 1 and Comparative Example 2.
[0034] Figure 2 SEM images of the samples prepared in Example 1 (Figure c), Comparative Example 1 (Figure b) and Comparative Example 2 (Figure a).
[0035] Figure 3 LSV curve of OER performance of Example 2.
[0036] Figure 4 Full water electrolysis LSV curve and stability curve of Example 2.
[0037] It should be noted that the above examples are only for further illustrating the content of the present application, and should not be understood as limiting the present application. Any modification or replacement of the method, step or condition of the present application without departing from the spirit and essence of the present application shall fall within the scope of the present application.
Claims
1. A carbon nanotube-wound S-doped Se vacancy-type NiSe2 electrocatalyst, characterized in that: The catalyst contains intertwined carbon nanotubes that form an integrated conductive network.
2. A carbon nanotube-wound S-doped Se vacancy-type NiSe2 electrocatalyst, characterized in that: The catalyst NiSe2 is doped with S atoms.
3. A carbon nanotube-wound S-doped Se vacancy-type NiSe2 electrocatalyst, characterized in that: The catalyst NiSe2 contains abundant Se vacancies.
4. A method for preparing the carbon nanotube-wound S-doped Se vacancy-type NiSe2 electrocatalyst according to claim 1, 2, or 3, characterized in that... Includes the following steps: S1: Carbon nanotubes, nickel salt, hexamethylenetetramine, citrate, and polyvinylpyrrolidone were dissolved in a deionized water / ethanol mixed solution, mixed evenly, and hydrothermally reacted at 90-150℃ for 5-12 hours. After the reaction, the precursor of carbon nanotube-supported Ni(OH)2 nanosheets was obtained by centrifugation, washing, and drying. S2: The precursor described in S1 is dispersed in an aqueous solution containing a sulfur source and a selenium source, and hydrothermally reacted at 100-200°C for 10-48 hours. Then, it is centrifuged, washed, and dried to obtain a carbon nanotube-wound S-doped NiSe2 electrocatalyst. S3: The powder obtained in S2 is subjected to an inert atmosphere at 1–20 °C for min. -1 Heating to 250–450℃ and holding for 0.5–6 hours yields a carbon nanotube-wound S-doped Se vacancy-type NiSe2 electrocatalyst.
5. The preparation method according to claim 4, characterized in that: In step S1, the nickel salt includes one or more of nickel nitrate, nickel sulfate, nickel chloride, and nickel acetate, with a concentration of 5–50 mmol / L. -1 .
6. The preparation method according to claim 4, characterized in that: In step S2, the sulfur source includes sodium thiosulfate, sodium sulfite, thiourea, sodium sulfide, and thioacetamide; the selenium source includes sodium selenate, sodium selenide, selenourea, sodium selenite, and sodium selenide; the concentration of the sulfur source is 10–100 mmol / L. -1 The selenium source concentration is 10–100 mmol / L. -1 .
7. The preparation method according to claim 4, characterized in that: In step S3, the inert atmosphere includes nitrogen, argon, and helium.
8. The carbon nanotube-wound S-doped Se vacancy-type NiSe2 electrocatalyst prepared by the preparation method according to any one of claims 4-7.
9. The application of the carbon nanotube-wound S-doped Se vacancy-type NiSe2 electrocatalyst according to claim 8 in water electrolysis and metal-air batteries.