Preparation method and application of Ni3S4-Yb2O3 / NF composite electrocatalyst
Patent Information
- Application Number
- CN202311590565.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-27
- Publication Date
- 2026-10-23
- Estimated Expiration
- 2043-11-27
AI Technical Summary
氧化镱Yb2O3不是本领域熟知的电催化析氧材料，自身电催化析氧性能差，多用于电催化析氢或者分解一些碳氢化合物
[0014]本发明提供的Ni3S4-Yb2O3/NF复合电催化剂在碱性电解液中具有优异的OER性能。OER的性能为在10mA/cm2的电流密度下表现出148mV的过电位，相比于Yb2O3/NF、Ni3S4/NF的过电位降低很多，证明了Yb2O3对Ni3S4的电催化析氧活性具有显著提高。
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Figure CN117737775B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrocatalyst preparation and application, specifically relating to a method for preparing and applying a Ni3S4-Yb2O3 / NF composite electrocatalyst. Technical Background
[0002] Faced with environmental degradation and an energy crisis, finding renewable energy sources to replace traditional fossil fuels is of paramount importance. Hydrogen energy, with its high energy density, sustainability, and zero emissions, is considered one of the most promising renewable energy sources. Among these, hydrogen production through water electrolysis is environmentally friendly. However, the oxygen evolution reaction (OER) process in water electrolysis is complex and affects the overall kinetic rate of water electrolysis.
[0003] Transition metals such as iron, cobalt, and nickel possess the advantages of abundance, multiple valence states, and high redox activity, making them candidate materials for OER electrocatalysts. Among them, transition metal sulfides contain abundant active sites and exhibit certain activity in both electrocatalytic hydrogen evolution and oxygen evolution reactions. Ytterbium oxide (Yb₂O₃) is not a well-known electrocatalytic oxygen evolution material in the field, exhibiting poor intrinsic performance and primarily used for electrocatalytic hydrogen evolution or the decomposition of some hydrocarbons. This invention, however, is the first to attempt to combine Yb₂O₃ with Ni₃S₄, discovering that this enhances the reaction with OH⁻. - The adsorption of the adsorption material lowers the H2O decomposition barrier and improves the electrocatalytic oxygen evolution activity of Ni3S4, but has a poor effect on improving the hydrogen evolution activity.
[0004] Therefore, the Ni3S4-Yb2O3 / NF composite electrocatalyst constructed in this invention improves the activity and stability of the electrocatalytic oxygen evolution reaction to a certain extent. Summary of the Invention
[0005] The purpose of this invention is to provide a method for preparing Ni3S4-Yb2O3 / NF composite electrocatalyst and its application, which is used to produce oxygen by electrolysis of water under alkaline conditions, and it has excellent OER performance.
[0006] The technical solution of the present invention: The present invention provides a Ni3S4-Yb2O3 / NF composite electrocatalyst, which is prepared by means of: synthesizing Ni3S4-Yb2O3 / NF composite electrocatalyst on nickel foam by hydrothermal method.
[0007] The specific preparation process is as follows:
[0008] Preparation of Ni3S4-Yb2O3 / NF composite electrocatalyst:
[0009] Nickel nitrate hexahydrate, thioacetamide, and ytterbium oxide were added to deionized water and mixed thoroughly. The fully mixed solution and nickel foam were transferred to a reactor and placed in an oven at 180°C for hydrothermal reaction for 18 hours. After the reaction was completed, the reactants were removed, washed with deionized water, and dried in a vacuum drying oven. The resulting catalyst was a Ni3S4-Yb2O3 / NF composite electrocatalyst.
[0010] The molar ratio of nickel nitrate hexahydrate to thioacetamide is 1:4, and the ratio of nickel foam to nickel nitrate hexahydrate is 6 cm⁻¹. 2 The ratio of ytterbium oxide to nickel nitrate hexahydrate is 0.2-0.25 mmol:1 mmol. Preferably, the molar ratio of ytterbium oxide to nickel nitrate hexahydrate is 0.2 mmol:1 mmol.
[0011] The hydrothermal reaction conditions are 180℃ for 18 hours. Ni3S4 cannot be synthesized under conditions lower or higher than these conditions, and the electrocatalytic oxygen evolution activity deteriorates.
[0012] This invention synthesizes a Ni3S4-Yb2O3 / NF composite electrocatalyst on nickel foam via a one-step hydrothermal method, resulting in a Ni3S4-Yb2O3 / NF composite electrocatalyst with optimal water electrolysis performance. This catalyst is then applied to the electrolysis of water to produce oxygen under alkaline conditions.
[0013] The technical effects achieved by this invention are:
[0014] The Ni3S4-Yb2O3 / NF composite electrocatalyst provided by this invention exhibits excellent OER performance in alkaline electrolytes. The OER performance is 10 mA / cm². 2 At a current density of 148 mV, it exhibits an overpotential of 148 mV, which is much lower than that of Yb2O3 / NF and Ni3S4 / NF, demonstrating that Yb2O3 significantly improves the electrocatalytic oxygen evolution activity of Ni3S4. Attached Figure Description
[0015] Figure 1 The images are XRD patterns of Embodiments 1-3 and Comparative Embodiments 1-3 of the present invention.
[0016] Figure 2 This is a SEM image of Ni3S4-Yb2O3 / NF-2 obtained in Example 1 of the present invention.
[0017] Figure 3 The graphs show the oxygen evolution polarization curves of Examples 1-3 and Comparative Examples 1-3 in 1.0M KOH solution.
[0018] Figure 4The above are Tafel slope curves of oxygen evolution in 1.0M KOH solution for Examples 1-3 and Comparative Examples 1-3 of the present invention. Detailed Implementation
[0019] The technical features of the present invention are further illustrated by the following examples, but the scope of protection of the present invention is not limited to the following embodiments.
[0020] Pretreatment of nickel foam: The nickel foam is immersed in hydrochloric acid solution, acetone solution, ethanol and ultrapure water respectively for ultrasonic treatment to clean surface impurities.
[0021] Preparation of Yb2O3: Dissolve 0.5g of ytterbium chloride in 10ml of deionized water and stir for 2h. Add 2g of urea after stirring for 20min. Transfer the well-stirred solution to a crucible and react in a muffle furnace at 600℃ for 4h. After the reaction is complete, wash 5 times with 20ml of deionized water and dry overnight in a drying oven at 60℃ to obtain Yb2O3.
[0022] The electrochemical oxygen evolution reaction (OER) uses a three-electrode system, with the working electrode having an area of 1 cm². 2 The Ni3S4-Yb2O3 / NF-2 composite electrocatalyst was used with a graphite rod electrode as the counter electrode and a Hg / HgO electrode as the reference electrode. The electrolyte was 1 mol / L KOH. Cyclic voltammetry (CV) activation was performed using a CV program. The OER test range was 0–0.8 V vs. RHE, with a scan rate of 100 mV / s, for 10 cycles until the electrode reached a stable state. After activation, the program was switched to a linear scan voltammetry program, with the OER test range being 0–1 V vs. RHE, and a scan rate of 5 mV / s. In the alkaline electrolyte, the electrocatalyst exhibited a flux density of 10 mA / cm². 2 At that time, the OER performance of the electrocatalyst was tested.
[0023] Example 1
[0024] Preparation of Ni3S4-Yb2O3 / NF-2 composite electrocatalyst
[0025] Dissolve 1 mmol nickel nitrate hexahydrate, 4 mmol thioacetamide, and 0.2 mmol ytterbium oxide in deionized water. Once dissolved and mixed thoroughly, combine the solution with nickel foam (6 cm). 2 The reactants were transferred to a high-pressure reactor lined with polytetrafluoroethylene and placed in an oven at 180°C for hydrothermal reaction for 18 hours. After the reaction was completed, the reactants were removed, washed with deionized water, and then dried under vacuum. The resulting catalyst was a Ni3S4-Yb2O3 / NF-2 composite electrocatalyst.
[0026] The OER performance of the Ni3S4-Yb2O3 / NF-2 composite electrocatalyst in Example 1 is 10 mA / cm². 2It exhibits an overpotential of 148mV at a current density.
[0027] from Figure 1 The XRD pattern shows that the Ni3S4-Yb2O3 / NF-2 composite electrocatalyst prepared in Example 1 only has diffraction peaks for Ni3S4 and nickel foam, indicating the successful preparation of the Ni3S4-Yb2O3 / NF-2 composite electrocatalyst. Meanwhile, from... Figure 2 SEM images show the cactus structure of Ni3S4 and the lamellar structure of Yb2O3.
[0028] Example 2
[0029] Compared with Example 1, the difference is that in the preparation of the Ni3S4-Yb2O3 / NF-2 composite electrocatalyst, the amount of ytterbium oxide is 0.15 mmol, resulting in Ni3S4-Yb2O3 / NF-1.
[0030] Example 2 Ni3S4-Yb2O3 / NF-1, OER performance is at 10 mA / cm 2 It exhibits an overpotential of 196 mV at a given current density.
[0031] Example 3
[0032] Compared with Example 1, the difference is that ytterbium oxide was 0.25 mmol in the preparation of the Ni3S4-Yb2O3 / NF-2 composite electrocatalyst, resulting in Ni3S4-Yb2O3 / NF-3.
[0033] Example 3: The OER performance of Ni3S4-Yb2O3 / NF-3 is 10 mA / cm. 2 It exhibits an overpotential of 304 mV at a given current density.
[0034] Comparative Example 1
[0035] Compared with Example 1, the difference is that ytterbium oxide and nickel foam are not added during the hydrothermal preparation of the Ni3S4-Yb2O3 / NF-2 composite electrocatalyst, thus obtaining Ni3S4.
[0036] The OER performance of Ni3S4 obtained in Comparative Example 1 is as follows: at 10 mA / cm 2 It exhibits an overpotential of 1135mV at a given current density.
[0037] Comparative Example 2
[0038] Compared with Example 1, the difference is that ytterbium oxide was not added during the hydrothermal preparation of the Ni3S4-Yb2O3 / NF-2 composite electrocatalyst, resulting in Ni3S4 / NF.
[0039] The OER performance of Ni3S4 / NF obtained in Comparative Example 2 is as follows: at 10 mA / cm 2 It exhibits an overpotential of 309 mV at a given current density.
[0040] Comparative Example 3
[0041] The difference compared to Example 1 is that ytterbium oxide was prepared by dropping ytterbium oxide onto nickel foam to prepare Yb2O3 / NF.
[0042] The OER performance of Yb2O3 / NF obtained in Comparative Example 3 is as follows: at 10 mA / cm 2 It exhibits an overpotential of 350mV at a given current density.
[0043] The comparison of OER performance between Examples 1-3 and Comparative Examples 1-3 shows that the Ni3S4-Yb2O3 / NF composite electrocatalyst has excellent OER performance in alkaline electrolyte, and Yb2O3 significantly enhances the electrocatalytic oxygen evolution activity of Ni3S4.
[0044] The HER performance of Examples 1-3 and Comparative Examples 1-3 was further investigated. The HER test range was 0-0.8V vs. RHE, and the scan rate was 5mV / s.
[0045] In an alkaline electrolyte (1M KOH), the electrocatalyst operates at -10 mA / cm². 2 The HER performance overpotential of the Ni3S4-Yb2O3 / NF-2 electrocatalyst prepared in Example 1 was -231 mV; the HER performance overpotential of the Ni3S4-Yb2O3 / NF-1 electrocatalyst prepared in Example 2 was -248 mV; the HER performance overpotential of the Ni3S4-Yb2O3 / NF-3 electrocatalyst prepared in Example 3 was -257 mV; the HER performance overpotential of the Ni3S4 electrocatalyst prepared in Comparative Example 1 was -822 mV; the HER performance overpotential of the Ni3S4 / NF electrocatalyst prepared in Comparative Example 2 was -240 mV; and the HER performance overpotential of the Yb2O3 / NF electrocatalyst prepared in Comparative Example 3 was -267 mV. It is evident that Yb2O3 did not significantly improve the electrocatalytic hydrogen evolution activity of Ni3S4 in terms of HER performance.
Claims
1. A method for preparing a Ni3S4-Yb2O3 / NF composite electrocatalyst, characterized in that, The specific steps of the preparation method are as follows: Soluble nickel salt, sulfur source and Yb2O3 were added to deionized water and mixed evenly. The mixed solution and foamed nickel were transferred to a reactor and placed in an oven at 180 °C for hydrothermal reaction for 18 h. After the reaction was completed, the reactants were taken out, washed with deionized water and then dried under vacuum. The catalyst obtained was Ni3S4-Yb2O3 / NF composite electrocatalyst. The soluble nickel salt is nickel nitrate hexahydrate; the sulfur source is thioacetamide; the molar ratio of soluble nickel salt to sulfur source is 1:4; and the ratio of Yb2O3 to soluble nickel salt is 0.15-0.20 mmol:1 mmol.
2. The preparation method of the Ni3S4-Yb2O3 / NF composite electrocatalyst according to claim 1, characterized in that: The ratio of nickel foam to soluble nickel salt is 6cm. 2 1 mmol.
3. The preparation method of the Ni3S4-Yb2O3 / NF composite electrocatalyst according to claim 1, characterized in that, The ratio of Yb₂O₃ to soluble nickel salt is 0.20 mmol: 1 mmol.
4. The application of a Ni3S4-Yb2O3 / NF composite electrocatalyst prepared according to any one of claims 1-3, characterized in that, The Ni3S4-Yb2O3 / NF composite electrocatalyst is used for electrocatalytic oxygen evolution under alkaline conditions.