A composite electroplating nickel-cobalt cathode hydrogen evolution catalyst and preparation method thereof

Abstract

The present invention discloses a composite electroplating nickel-cobalt cathode hydrogen evolution catalyst and a preparation method thereof, wherein a double-sided sandblasted nickel mesh degreased with alkali solution is pickled and washed with water, then immersed in electrolytes of different concentrations, electroplated for a period of time under a three-electrode system, and after the electroplating is completed, it is washed three times with deionized water and calcined at high temperature to obtain a hydrogen evolution electrode catalyst with multiple active sites. Through the above manner, the present invention discloses a composite electroplating nickel-cobalt cathode hydrogen evolution catalyst and a preparation method thereof, and adopts a composite electroplating nickel-cobalt alloy method to prepare an electrocatalyst material with multiple active sites, which can not only effectively reduce production costs, but also can utilize the nickel-cobalt electrolyte to play a pore-forming role to increase the specific surface area of ​​the catalyst material, thereby increasing the active point of the catalyst and improving the catalytic activity of the catalyst.

Description

Technical Field

[0001] The invention relates to the technical field of water electrolysis hydrogen evolution catalysts, and in particular to a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst and a preparation method thereof. Background Art

[0002] Renewable energy generation and water electrolysis to produce hydrogen are important links in energy storage, and are also an important and effective way to deal with the global energy and environmental crisis. Among them, water electrolysis to produce hydrogen includes two basic half reactions: cathode hydrogen evolution reaction (HER) and anode oxygen evolution reaction (OER).

[0003] At present, precious metals and their alloys have the best performance among hydrogen evolution electrocatalytic materials, but precious metals are scarce on the earth and are expensive. Therefore, the development and research of hydrogen evolution electrocatalytic materials that are efficient, stable, cheap, have high earth abundance and can be synthesized in large quantities has important theoretical significance and practical value. Summary of the invention

[0004] In order to solve the above technical problems, a technical solution adopted by the present invention is: Provided is a method for preparing a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst, the steps comprising: (1) degreasing the nickel mesh with alkaline solution, then placing the degreasing nickel mesh in an acid solution for ultrasonic treatment to complete pickling, and then washing the pickled nickel mesh with water to complete the pretreatment; (2) dissolving nickel chloride, cobalt chloride, boric acid and sodium hypophosphite hydrate in deionized water, and adjusting the pH to 3 with 1 mol / l sulfuric acid to prepare a nickel-cobalt electrolyte, wherein the concentrations of the components in the nickel-cobalt electrolyte are 0.5 mol / l nickel chloride, 0.5 mol / l cobalt chloride, 40 g / l boric acid and 0.2 mol / l sodium hypophosphite hydrate, respectively; (3) immersing the pretreated nickel mesh in a nickel-cobalt electrolyte and performing electroplating treatment under a three-electrode working system; (4) The nickel mesh after electroplating is placed in a muffle furnace for calcination to obtain a cathode hydrogen evolution electrode catalyst with multiple active sites to be used as an electrode in hydrogen production by electrolysis of water.

[0005] In a preferred embodiment of the present invention, in step (1), the nickel mesh is a nickel mesh woven from pure nickel wires sprayed with quartz sand on both sides.

[0006] In a preferred embodiment of the present invention, in step (1), the alkali solution is a sodium hydroxide solution with a concentration of 10%, the temperature of the alkali solution oil removal is 90° C., and the activation time is 1 hour.

[0007] In a preferred embodiment of the present invention, in step (1), the acid solution is a hydrochloric acid solution with a concentration of 0.1 mol / l.

[0008] In a preferred embodiment of the present invention, in step (1), the nickel mesh is ultrasonicated in an acid solution at room temperature for 30 minutes, and the ultrasonic power is 300W.

[0009] In a preferred embodiment of the present invention, in step (1), the pickled nickel mesh is washed three times with deionized water.

[0010] In a preferred embodiment of the present invention, in step (3), the reference electrode in the three-electrode working system is a silver-silver chloride electrode, the counter electrode is a platinum sheet electrode, and the working electrode is a pretreated nickel mesh.

[0011] In a preferred embodiment of the present invention, in step (3), the electroplating time is 300-900s.

[0012] In a preferred embodiment of the present invention, in step (4), the calcination temperature is 350°C-400°C, and the calcination time is 1 hour.

[0013] A composite electroplated nickel-cobalt cathode hydrogen evolution catalyst is prepared by any of the above methods and is used as an electrode in the electrolysis of water to produce hydrogen.

[0014] The beneficial effects of the present invention are: the electrocatalyst material with multiple active sites is prepared by the composite electroplating nickel-cobalt alloy method, which can not only effectively reduce the production cost, but also utilize the nickel-cobalt electrolyte to play a pore-forming role to increase the specific surface area of ​​the catalyst material, thereby increasing the active point of the catalyst and improving the catalytic activity of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which: Figure 1 is a metallographic microscope spectrum of the water electrolysis catalyst after electroplating under alkaline conditions obtained in Example 1 of the present invention; Figure 2 is the hydrogen evolution performance curve of the water electrolysis catalyst after electroplating under alkaline conditions obtained in Example 1 of the present invention; Figure 3 It is the oxygen evolution performance curve of the water electrolysis catalyst after electroplating under alkaline conditions obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] See also Figure 1-3 , the embodiment of the present invention includes: A method for preparing a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst comprises the following steps: (1) The nickel mesh is degreased with alkaline solution, and then the degreased nickel mesh is pre-treated by acid washing and water washing.

[0018] Further preferably, the nickel mesh is a nickel mesh woven from pure nickel wires sprayed with quartz sand on both sides, and is cut into a size of 1*1 cm and a thickness of 1 mm.

[0019] More preferably, the alkali solution is a sodium hydroxide solution with a concentration of 10%, the temperature of the alkali solution for oil removal is 90° C., and the activation time is 1 hour.

[0020] More preferably, the pickling is performed using a 0.1 M hydrochloric acid solution and ultrasonication is performed at room temperature for 30 minutes, with the ultrasonic power being 300 W.

[0021] (2) Immerse the pretreated nickel mesh in a nickel-cobalt electrolyte with a certain ratio and perform electroplating for 300-900 seconds under a three-electrode working system.

[0022] Further preferably, nickel chloride, cobalt chloride, boric acid and sodium hypophosphite hydrate are dissolved in deionized water, and the pH is adjusted to 3 with 1M sulfuric acid to prepare a nickel-cobalt electrolyte, wherein the concentrations of the components in the nickel-cobalt electrolyte are 0.5 mol / l nickel chloride, 0.5 mol / l cobalt chloride, 40 g / l boric acid and 0.2 mol / l sodium hypophosphite hydrate, respectively.

[0023] Among them, when sodium hypophosphite hydrate is used as a modifying component for electroplating, good electrochemical properties of the catalyst can be guaranteed without using precious metals.

[0024] Further preferably, the electroplating conditions are 70 ml of nickel-cobalt electrolyte, a three-electrode working system, reference electrode: silver-silver chloride electrode, counter electrode: 1 cm * 1 cm platinum sheet electrode, working electrode: 1 cm * 1 cm pretreated nickel mesh, working mode: it curve, and current sensitivity is 1e-005.

[0025] (3) The nickel mesh after electroplating is placed in a muffle furnace for calcination to obtain a cathode hydrogen evolution electrode catalyst with multiple active sites, which can be used as an electrode in hydrogen production by electrolysis of water.

[0026] More preferably, the calcination temperature is 350-400° C. and the calcination time is 1 hour. Example

[0027] A double-sided sandblasted nickel mesh cut into 1*1cm was immersed in a 10% NaOH solution and heated at 90℃ in a water bath for 1h. The nickel mesh was taken out and rinsed with clean water for 3 times. Then, the nickel mesh was placed in a 0.1M hydrochloric acid solution and ultrasonicated at room temperature for 0.5h. The nickel mesh was taken out and rinsed with clean water for 3 times for use. 70ml of nickel-cobalt electrolyte was prepared, and a constant potential of -0.8V was maintained for electroplating for 300s in a three-electrode system with the nickel mesh as the working electrode. After the electroplating, the nickel mesh was rinsed with ultrapure water, and then placed in a muffle furnace and calcined at 350℃ for 1h to obtain a double-sided sandblasted electrode catalyst.

[0028] During the test, a three-electrode system was selected, using Hg / HgO as the reference electrode, a platinum electrode as the counter electrode, and an electrode catalyst as the working electrode. Water electrolysis was performed to produce hydrogen under the condition of 1 mol / L KOH, and the current density was 300 mA / cm 2 The overpotential for hydrogen evolution is 669 mV and the overpotential for oxygen evolution is 828 mV. Example

[0029] A double-sided sandblasted nickel mesh cut into 1*1cm was immersed in a 10% NaOH solution and heated at 90℃ in a water bath for 1h. The nickel mesh was taken out and rinsed with clean water for 3 times. Then, the nickel mesh was placed in a 0.1M hydrochloric acid solution and ultrasonicated at room temperature for 0.5h. The nickel mesh was taken out and rinsed with clean water for 3 times for use. 70ml of nickel-cobalt electrolyte was prepared, and in a three-electrode system with the nickel mesh as the working electrode, a constant potential of -1V was maintained for electroplating for 300s. After the electroplating, the nickel mesh was rinsed with ultrapure water, and then placed in a muffle furnace and calcined at 350℃ for 1h to obtain a double-sided sandblasted electrode catalyst.

[0030] During the test, a three-electrode system was selected, using Hg / HgO as the reference electrode, a platinum electrode as the counter electrode, and an electrode catalyst as the working electrode. Water electrolysis was performed to produce hydrogen under the condition of 1 mol / L KOH, and the current density was 300 mA / cm 2 The overpotential for hydrogen evolution is 697 mV and the overpotential for oxygen evolution is 904 mV. Example

[0031] A double-sided sandblasted nickel mesh cut into 1*1cm was immersed in a 10% NaOH solution and heated at 90℃ in a water bath for 1h. The nickel mesh was taken out and rinsed with clean water for 3 times. Then, the nickel mesh was placed in a 0.1M hydrochloric acid solution and ultrasonicated at room temperature for 0.5h. The nickel mesh was taken out and rinsed with clean water for 3 times for use. 70ml of nickel-cobalt electrolyte was prepared, and in a three-electrode system with the nickel mesh as the working electrode, a constant potential of -1V was maintained for 900s. After the electroplating, the nickel mesh was rinsed with ultrapure water, and then placed in a muffle furnace and calcined at 350℃ for 1h to obtain a double-sided sandblasted electrode catalyst.

[0032] During the test, a three-electrode system was selected, using Hg / HgO as the reference electrode, a platinum electrode as the counter electrode, and an electrode catalyst as the working electrode. Water electrolysis was performed to produce hydrogen under the condition of 1 mol / L KOH, and the current density was 300 mA / cm 2 The overpotential for hydrogen evolution is 674 mV and the overpotential for oxygen evolution is 815 mV. Example

[0033] A double-sided sandblasted nickel mesh cut into 1*1cm was immersed in a 10% NaOH solution and heated at 90℃ in a water bath for 1h. The nickel mesh was taken out and rinsed with clean water for 3 times. Then, the nickel mesh was placed in a 0.1M hydrochloric acid solution and ultrasonicated at room temperature for 0.5h. The nickel mesh was taken out and rinsed with clean water for 3 times for use. 70ml of nickel-cobalt electrolyte was prepared, and in a three-electrode system with the nickel mesh as the working electrode, a constant potential of -1V was maintained for electroplating for 300s. After the electroplating, the nickel mesh was rinsed with ultrapure water, and then placed in a muffle furnace and calcined at 400℃ for 1h to obtain a double-sided sandblasted electrode catalyst after calcination.

[0034] During the test, a three-electrode system was selected, using Hg / HgO as the reference electrode, a platinum electrode as the counter electrode, and an electrode catalyst as the working electrode. Water electrolysis was performed to produce hydrogen under the condition of 1 mol / L KOH, and the current density was 300 mA / cm 2 The overpotential for hydrogen evolution is 678 mV and the overpotential for oxygen evolution is 825 mV.

[0035] The results show that the activated composite electroplated nickel-cobalt cathode hydrogen evolution catalyst has excellent HER performance, and the hydrogen evolution performance is optimal when electroplating at -0.8V constant potential for 300s and calcining at 350℃ for 1h. The hydrogen evolution ability is significantly better than that of traditional nickel mesh.

[0036] The beneficial effects of the composite electroplated nickel-cobalt cathode hydrogen evolution catalyst and the preparation method thereof of the present invention are: 1. The electrocatalyst material with multiple active sites is prepared by the composite electroplating nickel-cobalt alloy method. On the one hand, since the raw materials for preparing the catalyst are widely available and inexpensive, the production cost can be effectively reduced; on the other hand, the nickel-cobalt electrolyte can play a certain pore-forming role in the catalyst preparation process to increase the specific surface area of ​​the catalyst material, thereby increasing the active points of the catalyst and improving the catalytic activity of the catalyst; 2. It can be applied to substrates of different shapes and materials, has strong versatility, and the prepared electrodes can obtain amorphous and nanocrystalline coatings, which effectively improves the catalytic activity of the catalyst.

[0037] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst, characterized in that the steps include: (1) degreasing the nickel mesh with alkaline solution, then placing the degreasing nickel mesh in an acid solution for ultrasonic treatment to complete pickling, and then washing the pickled nickel mesh with water to complete the pretreatment; (2) dissolving nickel chloride, cobalt chloride, boric acid and sodium hypophosphite hydrate in deionized water, and adjusting the pH to 3 with 1 mol / l sulfuric acid to prepare a nickel-cobalt electrolyte, wherein the concentrations of the components in the nickel-cobalt electrolyte are 0.5 mol / l nickel chloride, 0.5 mol / l cobalt chloride, 40 g / l boric acid and 0.2 mol / l sodium hypophosphite hydrate, respectively; (3) immersing the pretreated nickel mesh in a nickel-cobalt electrolyte and performing electroplating treatment under a three-electrode working system; (4) The nickel mesh after electroplating is placed in a muffle furnace for calcination to obtain a cathode hydrogen evolution electrode catalyst with multiple active sites to be used as an electrode in hydrogen production by electrolysis of water.

2. The method for preparing a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst according to claim 1, characterized in that: In step (1), the nickel mesh is a nickel mesh woven from pure nickel wires sprayed with quartz sand on both sides.

3. The method for preparing a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst according to claim 1, characterized in that: In step (1), the alkali solution is a sodium hydroxide solution with a concentration of 10%, the temperature of the alkali solution for oil removal is 90° C., and the activation time is 1 hour.

4. The method for preparing a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst according to claim 1, characterized in that: In step (1), the acid solution is a hydrochloric acid solution with a concentration of 0.1 mol / l.

5. The method for preparing a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst according to claim 1, characterized in that: In step (1), the nickel mesh is ultrasonicated in an acid solution at room temperature for 30 minutes at an ultrasonic power of 300 W.

6. The method for preparing a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst according to claim 1, characterized in that: In step (1), the pickled nickel mesh is washed three times with deionized water.

7. The method for preparing a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst according to claim 1, characterized in that: In step (3), the reference electrode in the three-electrode working system is a silver-silver chloride electrode, the counter electrode is a platinum sheet electrode, and the working electrode is a pretreated nickel mesh.

8. The method for preparing a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst according to claim 1, characterized in that: In step (3), the electroplating time is 300-900s.

9. The method for preparing a composite electroplated nickel-cobalt cathode hydrogen evolution catalyst according to claim 1, characterized in that: In step (4), the calcination temperature is 350°C-400°C, and the calcination time is 1 hour.

10. A composite electroplated nickel-cobalt cathode hydrogen evolution catalyst, characterized in that: The electrode is prepared by any method of claims 1-7 and used as an electrode in the electrolysis of water to produce hydrogen.

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