CN112156788B

CN112156788B - A quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst and its preparation method and application

Info

Publication number: CN112156788B
Application number: CN202010740591.1A
Authority: CN
Inventors: 何捍卫; 张平; 刘晓峰
Original assignee: Central South University
Current assignee: Hunan Qiwei Hydrogen Energy Technology Co ltd
Priority date: 2020-07-28
Filing date: 2020-07-28
Publication date: 2021-11-12
Anticipated expiration: 2040-07-28
Also published as: CN112156788A

Abstract

The invention relates to a quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst and a preparation method and application thereof; belongs to the technical field of electrocatalysis water cracking. The catalyst comprises the following components in percentage by mass: 23-50% of Ni, 12-39% of Fe, 8-35% of W and 8-35% of Mo. The preparation method comprises the following steps: taking a conductive substrate with a clean surface as a cathode; taking a nickel plate as an anode; putting the cathode and the anode into an electrodeposition solution for electrodeposition to obtain the catalyst on the cathode; the electrodeposition solution contains soluble nickel salt, soluble ferrite, soluble tungstate, soluble molybdate and soluble additive. The catalyst designed and prepared by the invention has high-efficiency electrocatalysis performance at room temperature and high temperature. The invention has reasonable component design, simple and controllable preparation process and excellent product performance.

Description

Quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst and preparation method and application thereof

Technical Field

The invention relates to a quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution catalyst and a preparation method and application thereof; belongs to the technical field of electrocatalysis water cracking.

Background

Currently, water electrolysis technology is gaining extensive research interest in the production of clean, sustainable sources of hydrogen and energy, however, the Oxygen Evolution Reaction (OER) in water electrolysis processes typically involves a complex four electron transfer process, which makes the kinetics of the oxygen evolution reaction slow. Therefore, the development of the high-efficiency electrocatalyst has important significance for reducing the energy barrier and accelerating the OER reaction process. It is noteworthy that Ru/Ir based materials are the most suitable catalysts for OER. However, the practical application of Ru/Ir-based materials is greatly limited by the disadvantages of low storage capacity and high cost. Meanwhile, the research on the OER performance of the Ru/Ir-based electrocatalyst at high temperature is less. Therefore, it remains a challenge to develop a non-noble metal-based catalyst having high performance at both room temperature and high temperature.

At present, non-noble metal-based catalysts are widely studied and show good performance. Of these non-noble metal based catalysts, metal alloys have become ideal candidates for OER catalysts. Constructing metal alloys of different compositions is an effective way to improve the electrocatalytic properties, since combining different metals can improve their adsorption and conductivity properties. However, the electrocatalysts reported to date are mostly prepared in powder form, which necessarily requires the use of organic binders in attaching these powders. In general, a powder catalyst formed of an organic binder may cause a limited contact area between the catalyst and an electrolyte, thereby causing problems of limited electroactive sites and poor electrocatalytic activity. Worse still, the introduction of organic binders at high current densities may greatly reduce long-term durability. Therefore, it remains a great challenge to provide a simple and efficient method for synthesizing metal alloy electrocatalysts. Among the various synthetic methods, the electrochemical method is a simple and versatile method for preparing electrocatalysts with good performance. Electrodeposition, as an electrochemical process, can build binderless electrocatalysts directly on conductive substrates, which can provide abundant electroactive sites and reduce contact resistance. Although many metal alloys have been studied as electrocatalysts, much research into quaternary metal alloys and their electrocatalytic properties at high temperatures has been conducted.

Disclosure of Invention

The invention aims at the defects of the prior art; provides a quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst, a preparation method and application thereof. The binder-free quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst designed and prepared by the invention has high-efficiency electrocatalytic performance at room temperature and high temperature.

The invention relates to a quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst; the catalyst comprises the following components in percentage by mass:

23-50% of Ni, preferably 30-40% and more preferably 32-35%;

12-39% of Fe, preferably 18-25%, and more preferably 20-22%;

8-35% of W, preferably 10-20%, and more preferably 12-15%;

8 to 35% of Mo, preferably 10 to 20% and more preferably 12 to 15%.

As a preferred scheme, the binder-free quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst is disclosed; the catalyst is attached to a conductive substrate. As a further preferred scheme, the catalyst is attached to the conductive substrate and exists in a block shape and/or particles; wherein the surface of the block is concave-convex. As a further preferred embodiment; the block surface contains cracks and/or interstices. As a better technical scheme; a gap exists between at least two of the plurality of blocks.

The invention relates to a quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst; the binder is absent.

As a preferred scheme, the invention relates to a quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst; the conductive substrate is a mesh conductive material; as a further preferable scheme, the conductive substrate is a nickel mesh.

Preferably, the catalyst is obtained at 10 mA cm in 30 wt% potassium hydroxide solution at room temperature^-2The overpotential at the current density of (a) is 152 to 167 mV, preferably 152 mV, at 200 mA cm^-2The overpotential at the current density of (a) is 323 to 350 mV, preferably 323 mV.

As a preferred scheme, the binder-free quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst is disclosed; the resulting catalyst was at 10 mAcm in 30 wt% potassium hydroxide solution when the test temperature was 80 deg.C^-2The overpotential at the current density of (a) is 72-80 mV, preferably 72 mV, at 200 mAcm^-2The overpotential at the current density of (a) is 176-185 mV, preferably 176 mV.

The binder-free quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst is prepared by circulating 6000 circles of electrodes by cyclic voltammetry at room temperature (the voltage window reaches 200 mA cm in current density)^-2The same applies below) stable performance; at 80 ℃, the performance of the electrode is stable after 6000 cycles of cyclic voltammetry.

The invention relates to a preparation method of a quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst; the method comprises the following steps:

taking a conductive substrate with a clean surface as a cathode; taking a nickel plate as an anode; putting the cathode and the anode into an electrodeposition solution for electrodeposition to obtain the catalyst on the cathode;

the electrodeposition solution contains soluble nickel salt, soluble ferrite, soluble tungstate, soluble molybdate and soluble additive; the concentration of Ni in the electrodeposition solution is 80-120 g/L, Fe, the concentration of Ni in the electrodeposition solution is 30-50 g/L, W, the concentration of Ni in the electrodeposition solution is 20-40 g/L, Mo; the soluble additive consists of citric acid and ascorbic acid; wherein the concentration of citric acid is 20-40 g/L, and the concentration of ascorbic acid is 1-3 g/L.

During electrodeposition, the temperature is controlled at 25-35 deg.C, and the current density is 8-12 mA cm^-2。

The invention relates to a preparation method of a quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst; the conductive substrate is selected from a nickel mesh.

The surface-cleaned nickel mesh was prepared by the following scheme:

putting a nickel net in the mixed alkali solution; heating at 50-80 deg.C, preferably 60 deg.C for 10-50 min, preferably 30 min; then washing with water; after cleaning, soaking the fabric in 1-5 mol/L, preferably 3 mol/L hydrochloric acid solution for 10-40 min, preferably 20 min; after the nickel screen is soaked by hydrochloric acid, washing the nickel screen by using deionized water until the pH value of the washing liquor is greater than 6.8; and placing the washed nickel screen in an ethanol solution for later use. The mixed alkali solution contains 5-10 g/L NaOH and 10-20 g/L Na₂SiO₃、10-20 g/L Na₂CO₃And 20-40 g/L Na₃PO₄。

After the electrodeposition is finished, taking out the cathode with the catalyst; washing with deionized water, and drying at 30-60 deg.C, preferably 50 deg.C for 8-24 hr, preferably 12 hr.

The invention relates to the application of a quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst; the catalyst is used in the technical fields of electrocatalytic water cracking and the like.

Principles and advantages

The invention designs and prepares the quaternary Ni-Fe-W-Mo alloy high-efficiency oxygen evolution electrocatalyst for the first time; it has high efficiency at both room temperature and high temperature. The electrocatalyst is optimized, and the obtained electrode is at 10 mAcm in 30 wt% potassium hydroxide solution^-2Current density ofThe potential is 152 mV at 200 mAcm^-2The overpotential at the current density of (2) is 323 mV. All the above tests were carried out at room temperature.

The catalyst designed and prepared by the invention can be free of binder; and the electrocatalyst is far superior to the existing product.

The catalyst of the invention directly grows and is attached to the conductive substrate and exists in blocks and/or particles; wherein the surface of the block is concave-convex. The concave-convex surface and the surface of the catalyst in the granular form have rich active centers, so that the diffusion path of the product is short when the product is used, and the product has excellent electro-catalytic performance. Meanwhile, the surface of the blocky catalyst designed and prepared by the invention contains cracks and/or gaps; these gaps or cracks may provide more electroactive sites as an electrolyte reservoir.

The catalyst designed and prepared by the invention can be free of binder; the product performance is stable after 6000 cycles of cyclic voltammetry at room temperature or at higher temperatures (including 80 ℃).

In summary; the binder-free Ni-Fe-W-Mo alloy designed and prepared by the invention shows smaller overpotential and good stability at room temperature and high temperature. The excellent OER performance of Ni-Fe-W-Mo alloys can be attributed to a synergistic effect between the alloying of a particular component and its internal structure.

Drawings

FIG. 1 is a flow chart of the preparation process of the Ni-Fe-W-Mo alloy nanostructure of the invention.

FIG. 2 is an electron micrograph of a clean nickel screen and a product after deposition of a catalyst used in example 1 of the present invention and an analysis diagram of each element of the deposited catalyst; wherein (a) is an electron microscope image of the used clean nickel screen; (b) - (d) SEM image of Ni-Fe-W-Mo alloy nanostructure; (e) is an analysis chart of each element in the deposited catalyst;

FIG. 3 is a TEM image of the catalyst prepared in example 1 of the present invention, and a SAED result chart and an analysis chart of each element; wherein (a), (b) are TEM images, and (c) are SAED result images; (d) - (e) is an analysis chart of each element;

FIG. 4 is an XRD pattern and an XPS pattern of the catalyst prepared in example 1 of the present invention; wherein (a) is the XRD pattern of the catalyst; (b) is the full XPS spectrum of the catalyst. (c) High resolution XPS spectrum for Ni 2p, (d) high resolution XPS spectrum for Fe 2p, (e) high resolution XPS spectrum for W4 f, and (f) high resolution XPS spectrum for Mo3 d.

FIG. 5 is a LSV curve and overpotential plot for various cycle periods for the catalyst prepared in example 1 of the present invention; wherein (a) is the LSV curve of different electrocatalysts at 25 ℃ under different cycles, (b) is the overpotential diagram of the catalyst prepared in example 1 of the present invention at 25 ℃ under different cycle periods, and (c) is the LSV curve of the electrocatalysts at 80 ℃ under different cycles. (d) The overpotential pattern of the catalyst at 80 ℃ for different cycle periods.

The basic flow of the preparation process of the present invention can be seen from FIG. 1.

As can be seen from fig. 2a, the cleaned nickel mesh consisted of crossed wires and had a smooth and uniform surface. After electrodeposition, the surface of these crossing wires is transformed into a rough and uneven surface, as shown in fig. 2 b. As can be seen from the high resolution scanning electron microscope images of fig. 2b and 2d, the coating on the nickel mesh is bulk distributed during electrodeposition. The direct growth of the nanostructure on the conductive substrate is beneficial to providing rich active centers and ensuring that the diffusion path is short, thereby improving the electrocatalytic performance of the sample. In addition, there are significant gaps between these large coatings, which may provide more electroactive sites by acting as an electrolyte reservoir. Furthermore, the analysis of the mapping elements for the prepared samples is shown in fig. 2 e. It is apparent that the elements Ni, Fe, W and Mo are uniformly distributed in selected regions, which indicates the formation of solid solutions. The surface nanostructure and sample phase of the formed alloy coating were also analyzed by transmission electron microscopy.

It is apparent from the TEM image of fig. 3a that the coating scratched from the nickel mesh is large and thick. The high power TEM image in fig. 3b shows that the coating has a non-uniform edge structure. Furthermore, the Selected Area Electron Diffraction (SAED) plot in fig. 3c also shows the polycrystalline nature of the coatings produced. Fig. 3d shows a uniform distribution of the Ni, Fe, W and Mo elements, again confirming the main chemical composition of the coating.

As can be seen from fig. 4a, there is a distinct nickel phase present; meanwhile, no obvious Fe, W and Mo peaks exist in the XRD result. This indicates the presence of a nickel-based solid solution in the coating produced. FIG. 4b shows a full XPS spectrum of a Ni-Fe-W-Mo alloy, indicating that the Ni, Fe, W and Mo elements are predominantly present in the resulting coating. In FIG. 4c, the peak at about 852.0 ev corresponds to Ni⁰The peaks at about 855.9 ev and 858.4 ev represent Ni, respectively²⁺And Ni³⁺The existence of a state. The spectrum of Fe 2p in FIG. 4d shows three valence states, with peaks at 705.2 ev, 709.6 ev and 711.7 ev being associated with Fe⁰、Fe²⁺And Fe³⁺It is related. XPS spectra of W4 f are shown in FIG. 4e, where the peaks at 37.75 and 35.58 eV are from W2 p_7/2And W2 p_5/2. In FIG. 4f, the peaks at 235.66 ev and 232.53 ev are from Mo3d respectively_3/2And Mo3d_5/2。

FIG. 5 is an electro-catalytic performance detection map of the prepared Ni-Fe-W-Mo alloy tested under a three-electrode structure; wherein figure 5a shows a typical Linear Sweep Voltammetry (LSV) curve of an electrocatalyst obtained at room temperature. It is evident that the original nickel mesh has almost no OER activity. The result shows that the Ni-Fe-W-Mo alloy obviously improves the OER performance. Specifically, the Ni-Fe-W-Mo alloy only needs 152 mV of low overpotential to reach 10 mAcm^-2The current density of (1). When the current density is 200 mA cm^-2The overpotential of the Ni-Fe-W-Mo alloy is only 323 mV. Compared with Raney, the Ni-Fe-W-Mo alloy has better OER activity and shows huge application potential. In addition, long term OER stability was further confirmed by performing continuous cycling tests. As shown in fig. 5a, the LSV curve is clearly unchanged after 6000 cycles. Furthermore, FIG. 5b compares 200 mAcm after different cycles^-2Overpotential of (c), wherein during long-term testing the overpotential remains stable, again showing good long-term stability. The Ni-Fe-W-Mo alloy was also tested at 80 ℃ in view of the reported few studies of the OER performance of the electrocatalyst at high temperatures. FIG. 5c shows a typical electrocatalyst obtained at 80 deg.CProfile LSV curve. It is clear that the Ni-Fe-W-Mo alloy also exhibits better OER activity than Raney at 80 ℃. In particular a current density of 10 mA cm at 80 DEG C^-2When the alloy is used, the overpotential of the Ni-Fe-W-Mo alloy is only 72 mV. The Ni-Fe-W-Mo alloy is tested at 80 ℃ and 200 mA cm^-2Also the overpotential at high current density of (a) is only 176 mV, which also shows excellent OER activity. Similarly, FIG. 5c also measures long term OER stability at 80 ℃. As shown in FIG. 5c, there was clearly no change in the LSV curve after 6000 cycles at 80 ℃. In addition, FIG. 5d compares 200 mAcm after different cycles^-2Overpotential of time, wherein the overpotential remains stable in long term testing at 80 ℃. This again indicates good long-term stability at high temperatures.

Detailed Description

The structural characterization of the products obtained in the examples and comparative examples of the present invention is carried out using the following apparatus and method:

and performing morphology and nanostructure characterization on the prepared sample by using a Scanning Electron Microscope (SEM) and a Transmission Electron Microscope (TEM). Furthermore, energy dispersive X-ray spectroscopy (EDS) is also used to characterize the elemental composition in the obtained samples. Meanwhile, the phase and surface states of the prepared sample were analyzed using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).

The apparatus and method used for electrochemical testing of the products obtained in the examples and comparative examples of the present invention are briefly as follows:

in this example, OER performance was tested at electrochemical workstation (CHI 660E) using 30 wt% potassium hydroxide solution as electrolyte. The prepared sample is directly used as a working electrode, and a Saturated Calomel Electrode (SCE) and a carbon rod are used as a reference electrode and a counter electrode. The OER polarization curve of the sample was tested at a scan rate of 2 mV/s. After electrochemical testing, all potentials were transformed into reversible hydrogen evolution electrodes (RHE). The formula for changing SCE to RHE is as follows:

E_vs.RHE= E_vs.SCE+0.242+0.059×pH-0.000791×（T-298.15）-iR_s，

in the formula E_vs.SCEAnd T, I and Rs are test potential, temperature, test current density andthe solution resistance. It is worth mentioning that the electrochemical tests were carried out at room temperature and at elevated temperature (80 ℃).

In addition, OER performance of commercial Raney nickel (Raney) was compared to that of the synthetic Ni-Fe-W-Mo alloy. The conditions for Raney testing OER performance are consistent with those for the Ni-Fe-W-Mo alloy designed and prepared in example 1.

Example 1

The preparation process is shown in figure 1. Before electrodeposition, 5 g/L NaOH and 20 g/L Na are used₂SiO₃、10 g /L Na₂CO₃And 40g/L Na₃PO₄Cleaning the nickel screen with the mixed alkali solution, heating at 60 ℃ for 30 min, then sequentially cleaning the treated nickel screen with tap water and deionized water, adding the cleaned nickel screen into a hydrochloric acid solution (3 mol/L) for 20 min, and washing the treated nickel screen with the deionized water until the pH value of the washing liquid after washing is 7. And putting the cleaned nickel screen into an ethanol solution for further treatment. Mixing 8 g of NiSO₄·6H₂O、3 g FeSO₄·7H₂O、2 g C₆H₈O₇·7H₂O, 0.1 g ascorbic acid, 2 g Na₂WO_4·2H₂O and 2 g Na₂MoO₄·2H₂O was mixed in 100 mL of deionized water to prepare an electrodeposition solution. The electrodeposition process is prepared in a double-electrode electrolytic cell by taking a nickel plate as an anode and the treated nickel screen as a cathode. In the electrodeposition process, the two dimensions are 2X 2 cm²The electrodes of (a) are immersed in the electrodeposition solution. The electrodeposition temperature was maintained at 30 ℃ and the current density was set at 10 mA cm^-2The electrodeposition time is 60 min, and the flow rate of 133 mL/min in the electrodeposition solution is kept by a peristaltic pump in the electrodeposition process. Finally, the prepared electrode was washed three times with deionized water and then dried at 50 ℃ for 12 hours. And (5) obtaining a product. The resulting electrode was at 10 mA cm in 30 wt% potassium hydroxide solution at room temperature^-2The overpotential at the current density of (2) is 160 mV at 200 mAcm^-2The overpotential at the current density of (2) is 340 mV. The resulting electrode was at 10 mA cm at 80 deg.C^-2The overpotential at the current density of (2) is 85 mV at 200 mA cm^-2Current density of 179 mV。

Example 2

The preparation process is shown in figure 1. Before electrodeposition, 5 g/L NaOH and 20 g/L Na are used₂SiO₃、10 g /L Na₂CO₃And 40g/L Na₃PO₄Cleaning the nickel screen with the mixed alkali solution, heating at 60 ℃ for 30 min, then sequentially cleaning the treated nickel screen with tap water and deionized water, adding the cleaned nickel screen into a hydrochloric acid solution (3 mol/L) for 20 min, and washing the treated nickel screen with the deionized water until the pH value of the washing liquid after washing is 7. And putting the cleaned nickel screen into an ethanol solution for further treatment. 12 g of NiSO₄·6H₂O、5 g FeSO₄·7H₂O、4 g C₆H₈O₇·7H₂O, 0.3 g ascorbic acid, 4g Na₂WO_4·2H₂O and 4g Na₂MoO₄·2H₂O was mixed in 100 mL of deionized water to prepare an electrodeposition solution. The electrodeposition process is prepared in a double-electrode electrolytic cell by taking a nickel plate as an anode and the treated nickel screen as a cathode. In the electrodeposition process, the two dimensions are 2X 2 cm²The electrodes of (a) are immersed in the electrodeposition solution. The electrodeposition temperature was maintained at 30 ℃ and the current density was set at 10 mA cm^-2The electrodeposition time is 60 min, and the flow rate of 133 mL/min in the electrodeposition solution is kept by a peristaltic pump in the electrodeposition process. Finally, the prepared electrode was washed three times with deionized water and then dried at 50 ℃ for 12 hours. And (5) obtaining a product. The resulting electrode was at 10 mA cm in 30 wt% potassium hydroxide solution at room temperature^-2Has an overpotential of 162 mV at 200 mAcm^-2The overpotential at current density of (2) is 348 mV. The resulting electrode was at 10 mA cm at 80 deg.C^-2At a current density of 79 mV at 200 mA cm^-2The overpotential at the current density of (2) is 179 mV.

Example 3

The preparation process is shown in figure 1. Before electrodeposition, 5 g/L NaOH and 20 g/L Na are used₂SiO₃、10 g /L Na₂CO₃And 40g/L Na₃PO₄Cleaning nickel net with mixed alkali solution, heating at 60 deg.C for 30 min, and mixing with tap water and waterAnd sequentially cleaning the treated nickel screen by deionized water, adding the nickel screen into a hydrochloric acid solution (3 mol/L) for 20 min, and washing the treated nickel screen by the deionized water until the pH value of the washing liquid after washing is 7. And putting the cleaned nickel screen into an ethanol solution for further treatment. Mixing 10 g of NiSO₄·6H₂O、4 g FeSO₄·7H₂O、3 g C₆H₈O₇·7H₂O, 0.2 g ascorbic acid, 3 g Na₂WO_4·2H₂O and 3 g Na₂MoO₄·2H₂O was mixed in 100 mL of deionized water to prepare an electrodeposition solution. The electrodeposition process is prepared in a double-electrode electrolytic cell by taking a nickel plate as an anode and the treated nickel screen as a cathode. In the electrodeposition process, the two dimensions are 2X 2 cm²The electrodes of (a) are immersed in the electrodeposition solution. The electrodeposition temperature was maintained at 30 ℃ and the current density was set at 10 mA cm^-2The electrodeposition time is 60 min, and the flow rate of 133 mL/min in the electrodeposition solution is kept by a peristaltic pump in the electrodeposition process. Finally, the prepared electrode was washed three times with deionized water and then dried at 50 ℃ for 12 hours. And (5) obtaining a product. The resulting electrode was at 10 mA cm in 30 wt% potassium hydroxide solution at room temperature^-2The overpotential at the current density of (2) is 152 mV at 200 mA cm^-2The overpotential at the current density of (2) is 323 mV. The resulting electrode was at 10 mA cm at 80 deg.C^-2The overpotential at the current density of (a) is 72 mV at 200 mA cm^-2The overpotential at the current density of (2) is 176 mV.

Example 4

The preparation process is shown in figure 1. Before electrodeposition, 5 g/L NaOH and 20 g/L Na are used₂SiO₃、10 g /L Na₂CO₃And 40g/L Na₃PO₄Cleaning the nickel screen with the mixed alkali solution, heating at 60 ℃ for 30 min, then sequentially cleaning the treated nickel screen with tap water and deionized water, adding the cleaned nickel screen into a hydrochloric acid solution (3 mol/L) for 20 min, and washing the treated nickel screen with the deionized water until the pH value of the washing liquid after washing is 7. And putting the cleaned nickel screen into an ethanol solution for further treatment. Mixing 10 g of NiSO₄·6H₂O、4 g FeSO₄·7H₂O、3 g C₆H₈O₇·7H₂O, 0.2 g ascorbic acid, 3 g Na₂WO_4·2H₂O and 3 g Na₂MoO₄·2H₂O was mixed in 100 mL of deionized water to prepare an electrodeposition solution. The electrodeposition process is prepared in a double-electrode electrolytic cell by taking a nickel plate as an anode and the treated nickel screen as a cathode. In the electrodeposition process, the two dimensions are 2X 2 cm²The electrodes of (a) are immersed in the electrodeposition solution. The electrodeposition temperature was maintained at 30 ℃ and the current density was set at 10 mA cm^-2The electrodeposition time is 60 min, and the flow rate of 133 mL/min in the electrodeposition solution is kept by a peristaltic pump in the electrodeposition process. Finally, the prepared electrode was washed three times with deionized water and then dried at 50 ℃ for 24 hours. And (5) obtaining a product. The resulting electrode was at 10 mA cm in 30 wt% potassium hydroxide solution at room temperature^-2At a current density of 167 mV at 200 mA cm^-2The overpotential at the current density of (2) is 350 mV. The resulting electrode was at 10 mA cm at 80 deg.C^-2The overpotential at the current density of (a) is 80 mV at 200 mA cm^-2The overpotential at the current density of (a) is 185 mV.

Example 5

The preparation process is shown in figure 1. Before electrodeposition, 5 g/L NaOH and 20 g/L Na are used₂SiO₃、10 g /L Na₂CO₃And 40g/L Na₃PO₄Cleaning the nickel screen with the mixed alkali solution, heating at 60 ℃ for 30 min, then sequentially cleaning the treated nickel screen with tap water and deionized water, adding the cleaned nickel screen into a hydrochloric acid solution (3 mol/L) for 20 min, and washing the treated nickel screen with the deionized water until the pH value of the washing liquid after washing is 7. And putting the cleaned nickel screen into an ethanol solution for further treatment. Mixing 10 g of NiSO₄·6H₂O、4 g FeSO₄·7H₂O、3 g C₆H₈O₇·7H₂O, 0.2 g ascorbic acid, 3 g Na₂WO_4·2H₂O and 3 g Na₂MoO₄·2H₂O was mixed in 100 mL of deionized water to prepare an electrodeposition solution. The electrodeposition process is prepared in a double-electrode electrolytic cell by taking a nickel plate as an anode and the treated nickel screen as a cathode. In thatTwo dimensions of 2X 2 cm in the electrodeposition process²The electrodes of (a) are immersed in the electrodeposition solution. The electrodeposition temperature was maintained at 30 ℃ and the current density was set at 10 mA cm^-2The electrodeposition time is 60 min, and the flow rate of 133 mL/min in the electrodeposition solution is kept by a peristaltic pump in the electrodeposition process. Finally, the prepared electrode was washed three times with deionized water and then dried at 50 ℃ for 8 hours. And (5) obtaining a product. The resulting electrode was at 10 mA cm in 30 wt% potassium hydroxide solution at room temperature^-2At a current density of 165 mV at 200 mA cm^-2Has an overpotential of 347 mV at the current density of (1). The resulting electrode was at 10 mA cm at 80 deg.C^-2The overpotential at the current density of (2) is 78 mV at 200 mA cm^-2The overpotential at the current density of (2) is 183 mV.

Comparative example 1

The preparation process is shown in figure 1. Before electrodeposition, 5 g/L NaOH and 20 g/L Na are used₂SiO₃、10 g /L Na₂CO₃And 40g/L Na₃PO₄Cleaning the nickel screen with the mixed alkali solution, heating at 60 ℃ for 30 min, then sequentially cleaning the treated nickel screen with tap water and deionized water, adding the cleaned nickel screen into a hydrochloric acid solution (3 mol/L) for 20 min, and washing the treated nickel screen with the deionized water until the pH value of the washing liquid after washing is 7. And putting the cleaned nickel screen into an ethanol solution for further treatment. 30 g of NiSO₄·6H₂O、15 g FeSO₄·7H₂O、15 g C₆H₈O₇·7H₂O, 2 g ascorbic acid were mixed in 100 mL deionized water to prepare an electrodeposition solution. The electrodeposition process is prepared in a double-electrode electrolytic cell by taking a nickel plate as an anode and the treated nickel screen as a cathode. In the electrodeposition process, the two dimensions are 2X 2 cm²The electrodes of (a) are immersed in the electrodeposition solution. The electrodeposition temperature was maintained at 30 ℃ and the current density was set at 10 mA cm^-2The electrodeposition time is 60 min, and the flow rate of 133 mL/min in the electrodeposition solution is kept by a peristaltic pump in the electrodeposition process. Finally, the prepared electrode was washed three times with deionized water and then dried at 50 ℃ for 12 hours. And (5) obtaining a product. The resulting electrode was immersed in a 30 wt% potassium hydroxide solution at room temperatureAt 10 mA cm^-2At a current density of 294 mV at 200 mA cm^-2The overpotential of (2) is 496 mV. The obtained electrode had a thickness of 10 mAcm at 80 deg.C^-2The overpotential at the current density of (2) is 147 mV at 200 mA cm^-2The overpotential at the current density of (2) was 246 mV.

Comparative example 2

The preparation process is shown in figure 1. Before electrodeposition, 5 g/L NaOH and 20 g/L Na are used₂SiO₃、10 g /L Na₂CO₃And 40g/L Na₃PO₄Cleaning the nickel screen with the mixed alkali solution, heating at 60 ℃ for 30 min, then sequentially cleaning the treated nickel screen with tap water and deionized water, adding the cleaned nickel screen into a hydrochloric acid solution (3 mol/L) for 20 min, and washing the treated nickel screen with the deionized water until the pH value of the washing liquid after washing is 7. And putting the cleaned nickel screen into an ethanol solution for further treatment. 5 g of NiSO₄·6H₂O、2 g FeSO₄·7H₂O、1 g C₆H₈O₇·7H₂O、1 g Na₂WO_4·2H₂O was mixed in 100 mL of deionized water to prepare an electrodeposition solution. The electrodeposition process is prepared in a double-electrode electrolytic cell by taking a nickel plate as an anode and the treated nickel screen as a cathode. In the electrodeposition process, the two dimensions are 2X 2 cm²The electrodes of (a) are immersed in the electrodeposition solution. The electrodeposition temperature was maintained at 30 ℃ and the current density was set at 10 mA cm^-2The electrodeposition time is 60 min, and the flow rate of 133 mL/min in the electrodeposition solution is kept by a peristaltic pump in the electrodeposition process. Finally, the prepared electrode was washed three times with deionized water and then dried at 50 ℃ for 12 hours. And (5) obtaining a product. The resulting electrode was at 10 mA cm in 30 wt% potassium hydroxide solution at room temperature^-2The overpotential at the current density of (a) is 327 mV at 200 mA cm^-2The overpotential at the current density of (1) is 568 mV. The resulting electrode was at 10 mA cm at 80 deg.C^-2The overpotential at the current density of (1) is 156 mV at 200 mA cm^-2The overpotential at the current density of (2) was 274 mV.

Comparative example 3

The preparation process is shown in figure 1. Electric powerBefore deposition, 5 g/L NaOH and 20 g/L Na are used₂SiO₃、10 g /L Na₂CO₃And 40g/L Na₃PO₄Cleaning the nickel screen with the mixed alkali solution, heating at 60 ℃ for 30 min, then sequentially cleaning the treated nickel screen with tap water and deionized water, adding the cleaned nickel screen into a hydrochloric acid solution (3 mol/L) for 20 min, and washing the treated nickel screen with the deionized water until the pH value of the washing liquid after washing is 7. And putting the cleaned nickel screen into an ethanol solution for further treatment. Mixing 10 g of NiSO₄·6H₂O、4 g FeSO₄·7H₂O、3 g C₆H₈O₇·7H₂O, 0.2 g ascorbic acid, 3 g Na₂MO_4·2H₂O was mixed in 100 mL of deionized water to prepare an electrodeposition solution. The electrodeposition process is prepared in a double-electrode electrolytic cell by taking a nickel plate as an anode and the treated nickel screen as a cathode. In the electrodeposition process, the two dimensions are 2X 2 cm²The electrodes of (a) are immersed in the electrodeposition solution. The electrodeposition temperature was maintained at 30 ℃ and the current density was set at 10 mA cm^-2The electrodeposition time is 60 min, and the flow rate of 133 mL/min in the electrodeposition solution is kept by a peristaltic pump in the electrodeposition process. Finally, the prepared electrode was washed three times with deionized water and then dried at 50 ℃ for 12 hours. And (5) obtaining a product. The resulting electrode was at 10 mA cm in 30 wt% potassium hydroxide solution at room temperature^-2The overpotential at the current density of (2) is 190 mV at 200 mA cm^-2The overpotential at the current density of (2) is 398 mV. The resulting electrode was at 10 mA cm at 80 deg.C^-2The overpotential at the current density of (2) is 98 mV at 200 mA cm^-2The overpotential at the current density of (2) was 225 mV.

Comparative example 4

The preparation process is shown in figure 1. Before electrodeposition, 5 g/L NaOH and 20 g/L Na are used₂SiO₃、10 g /L Na₂CO₃And 40g/L Na₃PO₄Cleaning the nickel screen with the mixed alkali solution, heating at 60 ℃ for 30 min, then sequentially cleaning the treated nickel screen with tap water and deionized water, adding the cleaned nickel screen into a hydrochloric acid solution (3 mol/L) for 20 min, and washing the treated nickel screen with the deionized water until the pH value of the washing liquid after washing is 7. Medicine for treating acute respiratory syndromeThe cleaned nickel screen is put into an ethanol solution for further treatment. Mixing 10 g of NiSO₄·6H₂O、4 g FeSO₄·7H₂O、3 g C₆H₈O₇·7H₂O, 0.2 g ascorbic acid, 3 g Na₂MO_4·2H₂O and 3 g Na₂WO_4·2H₂O was mixed in 100 mL of deionized water to prepare an electrodeposition solution. The electrodeposition process is prepared in a double-electrode electrolytic cell by taking a nickel plate as an anode and the treated nickel screen as a cathode. In the electrodeposition process, the two dimensions are 2X 2 cm²The electrodes of (a) are immersed in the electrodeposition solution. The electrodeposition temperature was maintained at 30 ℃ and the current density was set at 10 mA cm^-2The electrodeposition time is 60 min, and the flow rate of 133 mL/min in the electrodeposition solution is kept by a peristaltic pump in the electrodeposition process. Finally, the prepared electrode was washed three times with deionized water and then dried at 50 ℃ for 50 hours. And (5) obtaining a product. The resulting electrode was at 10 mA cm in 30 wt% potassium hydroxide solution at room temperature^-2The overpotential at the current density of (2) is 200 mV at 200 mA cm^-2The overpotential at the current density of (2) is 396 mV. The resulting electrode was at 10 mA cm at 80 deg.C^-2The overpotential at the current density of (1) is 102 mV at 200 mA cm^-2The overpotential at the current density of (2) is 240 mV.

Comparative example 5

The preparation process is shown in figure 1. Before electrodeposition, 5 g/L NaOH and 20 g/L Na are used₂SiO₃、10 g /L Na₂CO₃And 40g/L Na₃PO₄Cleaning the nickel screen with the mixed alkali solution, heating at 60 ℃ for 30 min, then sequentially cleaning the treated nickel screen with tap water and deionized water, adding the cleaned nickel screen into a hydrochloric acid solution (3 mol/L) for 20 min, and washing the treated nickel screen with the deionized water until the pH value of the washing liquid after washing is 7. And putting the cleaned nickel screen into an ethanol solution for further treatment. Mixing 10 g of NiSO₄·6H₂O、4 g FeSO₄·7H₂O、3 g C₆H₈O₇·7H₂O, 0.2 g ascorbic acid, 3 g Na₂MO_4·2H₂O and 3 g Na₂WO_4·2H₂O was mixed in 100 mL of deionized water to prepare an electrodeposition solution. The electrodeposition process is prepared in a double-electrode electrolytic cell by taking a nickel plate as an anode and the treated nickel screen as a cathode. In the electrodeposition process, the two dimensions are 2X 2 cm²The electrodes of (a) are immersed in the electrodeposition solution. The electrodeposition temperature was maintained at 60 ℃ and the current density was set at 10 mA cm^-2The electrodeposition time is 120 min, and the flow rate of 500 mL/min in the electrodeposition solution is kept by a peristaltic pump in the electrodeposition process. Finally, the prepared electrode was washed three times with deionized water and then dried at 50 ℃ for 12 hours. And (5) obtaining a product. The resulting electrode was at 10 mA cm in 30 wt% potassium hydroxide solution at room temperature^-2The current density of (a) is 187 mV at 200 mAcm^-2The overpotential at the current density of (1) is 389 mV. The resulting electrode was at 10 mA cm at 80 deg.C^-2The overpotential at the current density of (1) is 99 mV at 200 mA cm^-2The overpotential at the current density of (2) is 237 mV.

Claims

1. a quaternary Ni-Fe-W-Mo alloy oxygen evolution electrocatalyst, is characterized in that: described catalyzer comprises following component in mass percent:

Ni 23~50%;

Fe 12~39%;

W 8~35%;

Mo 8~35%;

The catalyst is prepared by the following steps:

The conductive substrate with clean surface is used as the cathode; the nickel plate is used as the anode; the cathode and the anode are placed in the electrodeposition solution for electrodeposition, and the catalyst is obtained on the cathode;

The electrodeposition solution contains soluble nickel salt, soluble ferrous salt, soluble tungstate, soluble molybdate, and soluble additives; the concentration of Ni in the electrodeposition solution is 80-120 g/L, and the concentration of Fe is 30-50 g/L, the concentration of W is 20-40 g/L, the concentration of Mo is 20-40 g/L; the soluble additive is composed of citric acid and ascorbic acid; wherein the concentration of citric acid is 20-40 g /L, the concentration of ascorbic acid is 1-3 g/L;

During electrodeposition, the control temperature is 25-35°C, and the current density is 8-12 mA/cm ² ;

After the electrodeposition was completed, the cathode with the catalyst was taken out; washed with deionized water and dried at 30-60 °C for 8-24 h.

2 . The quaternary Ni-Fe-W-Mo alloy oxygen evolution electrocatalyst according to claim 1 , wherein the catalyst is attached to the conductive substrate. 3 .

3. a kind of quaternary Ni-Fe-W-Mo alloy oxygen evolution electrocatalyst according to claim 2; It is characterized in that: described catalyzer is attached on conductive substrate and exists in block and/or particle; Wherein block The surface of the object is concave and convex.

4. A quaternary Ni-Fe-W-Mo alloy oxygen evolution electrocatalyst according to claim 3; characterized in that: the surface of the block contains cracks and/or gaps.

5 . The quaternary Ni-Fe-W-Mo alloy oxygen evolution electrocatalyst according to claim 1 , wherein the catalyst does not contain a binder. 6 .

6 . The quaternary Ni-Fe-W-Mo alloy oxygen evolution electrocatalyst according to claim 1 , wherein the conductive substrate is a reticulated conductive material. 7 .

7. a kind of quaternary Ni-Fe-W-Mo alloy oxygen evolution electrocatalyst according to claim 1; It is characterized in that: at room temperature, in the potassium hydroxide solution of 30 wt%, gained catalyst is at 10 mA/ The overpotentials at the current density of cm ² are 152~167 mV, and the overpotentials at the current density of 200 mA/cm ² are 323~350 mV;

When the test temperature was 80 °C, in 30 wt% potassium hydroxide solution, the obtained catalyst exhibited an overpotential of 72–80 mV at a current density of 10 mA/cm and ²⁰⁰ mA/cm at a current density of ²⁰⁰ mA/cm. The overpotential is 176~185 mV.

8. a kind of quaternary Ni-Fe-W-Mo alloy oxygen evolution electrocatalyst according to claim 1; It is characterized in that:

The conductive substrate is selected from nickel mesh;

Surface-cleaned nickel meshes were prepared by the following protocol:

Put the nickel mesh in the mixed alkali solution; heat it at 50-80 ℃ for 10-50 min; then wash it with water; after washing, soak it in 1-5mol/L hydrochloric acid solution for 10-40 min; after soaking in hydrochloric acid, the nickel mesh is used Washing with deionization until the pH value of the washing solution is greater than 6.8; the washed nickel mesh is placed in an ethanol solution for standby use; the mixed alkali solution contains 5-10 g/L NaOH, 10-20 g/LNa ₂ SiO ₃ , 10- 20 g/L Na ₂ CO ₃ and 20-40 g/L Na ₃ PO ₄ .

9. The application of a quaternary Ni-Fe-W-Mo alloy oxygen evolution electrocatalyst according to any one of claims 1-7; characterized in that: the catalyst is used in the technical field of electrocatalytic water splitting.