阅读说明：本技术 一种用于宽范围全解水的镍钒双金属氢氧化物电极及其制备方法和应用 (Nickel-vanadium double metal hydroxide electrode for wide-range full-hydrolysis and preparation method and application thereof ) 是由 曹丽云 何丹阳 冯亮亮 黄剑锋 吴建鹏 李翠艳 刘倩倩 于 2019-11-05 设计创作，主要内容包括：本发明公开一种用于宽范围全解水的镍钒双金属氢氧化物电极及其制备方法和应用,1)泡沫镍预处理；2)将钒源、镍源、碱源均匀混合后溶解到水中,加入二甲基甲酰胺搅拌均匀得到溶液A；3)调节溶液A的pH值将处理的泡沫镍放入其中,并进行水热反应,经过洗涤并烘干,得到双金属氢氧化物电极；本发明采用水热法直接合成的最终样品,其反应过程简易、合成温度低、不需要大型的设备和苛刻的条件等特点,对环境友好、成本低,适合大规模生产；制备的镍钒双金属氢氧化物电极在碱性和中性条件下同时具有良好的全解水性能。(The invention discloses a nickel-vanadium double metal hydroxide electrode for wide-range full-hydrolysis and a preparation method and application thereof, 1) nickel foam pretreatment; 2) uniformly mixing a vanadium source, a nickel source and an alkali source, dissolving the mixture into water, adding dimethylformamide, and uniformly stirring to obtain a solution A; 3) adjusting the pH value of the solution A, putting the processed foamed nickel into the solution A, performing hydrothermal reaction, washing and drying to obtain a double-metal hydroxide electrode; the method adopts a hydrothermal method to directly synthesize a final sample, has the characteristics of simple reaction process, low synthesis temperature, no need of large-scale equipment and harsh conditions and the like, is environment-friendly, has low cost, and is suitable for large-scale production; the prepared nickel-vanadium double metal hydroxide electrode has good full-hydrolytic performance under alkaline and neutral conditions.)

1. A preparation method of a nickel-vanadium double metal hydroxide electrode for wide-range full-hydrolysis is characterized by comprising the following steps:

1) pretreating foamed nickel;

2) uniformly mixing 70-75 mg of vanadium source, 145-150 mg of nickel source and 80-85 mg of alkali source, dissolving into water, adding 1.5-2 mL of dimethylformamide, and uniformly stirring to obtain a solution A;

3) adjusting the pH value of the solution A to 4.3-4.7, pouring the solution A into a lining, putting the foamed nickel treated in the step 1) into the lining, and carrying out hydrothermal reaction at the temperature of 120-125 ℃ for 23-25 h;

4) and after the hydrothermal reaction is finished and cooled, taking out the product foamed nickel after the reaction, and washing and drying to obtain the nickel-vanadium double metal hydroxide electrode for wide-range full-hydrolysis.

2. The method of preparing a nickel vanadium double hydroxide electrode for wide range total hydrolysis according to claim 1, wherein: the step 1) of pretreating the foam nickel comprises the steps of ultrasonically cleaning 1cm multiplied by 5cm cut foam nickel in an acetone solution for 15-17 min, then pouring the foam nickel into 2-3 mol/L prepared hydrochloric acid for ultrasonically cleaning for 6-8 min, finally alternately washing with absolute ethyl alcohol and ultrapure water for 2-3 times, and then drying in vacuum at 27-29 ℃ for 12-14 h.

3. The method of preparing a nickel vanadium double hydroxide electrode for wide range total hydrolysis according to claim 1, wherein: the vanadium source, the nickel source and the alkali source added in the step 2) are respectively vanadium chloride, nickel chloride hexahydrate and urea, and the amounts of the vanadium source, the nickel source and the alkali source are respectively 70-75 mg, 145-150 mg and 80-85 mg.

4. The method of preparing a nickel vanadium double hydroxide electrode for wide range total hydrolysis according to claim 1, wherein: and 2) magnetic stirring is adopted in the stirring process in the step 2), and the stirring time is 20-25 min.

5. The method of preparing a nickel vanadium double hydroxide electrode for wide range total hydrolysis according to claim 1, wherein: and in the step 3), 2.5-3.5 mol/L ammonia water solution is adopted to adjust the pH value.

6. The method of preparing a nickel vanadium double hydroxide electrode for wide range total hydrolysis according to claim 1, wherein: and 3) reacting the solution A in the step 3) in a hydrothermal reaction kettle, wherein the filling ratio is 55-60%.

7. The method of preparing a nickel vanadium double hydroxide electrode for wide range total hydrolysis according to claim 1, wherein: and 4) alternately flushing the foamed nickel for 3-4 times by adopting ultrapure water and absolute ethyl alcohol in the washing process of the foamed nickel in the step 4).

8. The method of preparing a nickel vanadium double hydroxide electrode for wide range total hydrolysis according to claim 1, wherein: the drying temperature in the step 4) is 60-65 ℃, and the time is 5-7 h.

9. A nickel vanadium double hydroxide electrode for wide range total hydrolysis prepared according to the method of claims 1 to 8.

10. Use of a nickel vanadium double hydroxide electrode according to claim 9 for wide range total hydrolysis in hydrogen evolution reactions and oxygen evolution reactions under alkaline and neutral conditions.

Technical Field

The invention belongs to the field of electrocatalytic materials, and particularly relates to a nickel-vanadium double metal hydroxide electrode for wide-range full-water decomposition, and a preparation method and application thereof.

Background

The development of viable renewable energy sources is an inevitable problem in the scientific community due to the adverse effects of fossil fuels on the environment and human health. The combustion of fossil fuels produces large quantities of pollutant gases such as nitrogen oxides, carbon oxides, and sulfur oxides. For a long time, researchers have been working on finding renewable, clean, and carbon neutral energy sources to avoid catastrophic climate change. Hydrogen has the greatest energy density and can be burned to release energy without producing any harmful by-products. In fact, water is currently recognized as the most abundant resource that can be used to generate hydrogen by electrocatalytic or photocatalytic water splitting. In electrical systems, external electrical circuits typically provide energy to effect the splitting of water, including Hydrogen Evolution Reactions (HER) and Oxygen Evolution Reactions (OER). Noble metals or alloys, such as platinum (Pt), palladium (Pd), ruthenium (Ru) and iridium (Ir), have historically been the most effective water-splitting catalysts in acidic or alkaline electrolytes, but the abundance of these metals is low, and thus their long-term use is hindered by high cost. Therefore, a high efficiency electrocatalyst composed of earth-abundant materials is crucial for the development of water splitting devices. ^[1]

As a typical class of materials in the nickel oxide family, double metal hydroxides (LDHs) are a typical two-dimensional layered material, have unique physical and chemical properties, possess a high specific surface area and unique electronic properties, are considered as a very potential class of high-performance electrode materials, and have attracted a wide range of attention in the fields of electrocatalysis and energy storage. ^[2]In recent years, a new nickel-vanadium double metal hydroxide (NiV-LDH) has unique physical and chemical properties, and has good application prospects in energy conversion and electrochemical energy storage of super capacitors, secondary batteries, electrocatalysis and the like. At present, LDHs show excellent catalytic performance to anode OER under alkaline condition, and are gradually developed by regulating and controlling electronic structure, catalyst interface, morphology and the likeAn efficient alkaline full-hydrolysis hydro-catalyst is emitted, but the electrocatalytic HER and OER performances of full-hydrolysis under alkaline and neutral conditions are not reported.

[1]Faber M S,Jin S.Earth-abundant inorganic electrocatalysts andtheir nanostructures for energy conversion applications[J].Energy&Environmental Science,2014,7(11):3519-3542.

[2] The application of the layered double hydroxide in electrocatalysis [ J ] of ZhouClean, Shererigen, Wanglingjiang, chemical development, 2019,31(Z1):63-70.

Disclosure of Invention

The invention aims to provide a nickel-vanadium double metal hydroxide electrode for wide-range total hydrolysis, which has the advantages of simple preparation process, low cost and easily controlled process, and a preparation method and application thereof.

In order to achieve the above object, the present invention adopts the following technical solutions.

A preparation method of a nickel-vanadium double metal hydroxide electrode for wide-range full-water decomposition comprises the following steps:

1) pretreating foamed nickel;

2) uniformly mixing 70-75 mg of vanadium source, 145-150 mg of nickel source and 80-85 mg of alkali source, dissolving into water, adding 1.5-2 mL of dimethylformamide, and uniformly stirring to obtain a solution A;

3) adjusting the pH value of the solution A to 4.3-4.7, pouring the solution A into a lining, putting the foamed nickel treated in the step 1) into the lining, and carrying out hydrothermal reaction at the temperature of 120-125 ℃ for 23-25 h;

4) and after the hydrothermal reaction is finished and cooled, taking out the product foamed nickel after the reaction, and washing and drying to obtain the nickel-vanadium double metal hydroxide electrode for wide-range full-hydrolysis.

Further, the step 1) of pretreating the foam nickel comprises the steps of ultrasonically cleaning cut 1cm × 5cm foam nickel in an acetone solution for 15-17 min, then pouring the foam nickel into prepared 2-3 mol/L hydrochloric acid for ultrasonically cleaning for 6-8 min, finally alternately washing with absolute ethyl alcohol and ultrapure water for 2-3 times, and then drying in vacuum at 27-29 ℃ for 12-14 h.

Further, the vanadium source, the nickel source and the alkali source added in the step 2) are respectively vanadium chloride, nickel chloride hexahydrate and urea, and the amounts of the vanadium source, the nickel source and the alkali source are respectively 70-75 mg, 145-150 mg and 80-85 mg.

Further, magnetic stirring is adopted in the stirring process in the step 2), and the stirring time is 20-25 min.

Further, in the step 3), 2.5-3.5 mol/L ammonia water solution is adopted to adjust the pH value.

Further, the solution A in the step 3) reacts in a hydrothermal reaction kettle, and the filling ratio is 55-60%.

Further, the washing process of the foamed nickel in the step 4) adopts ultrapure water and absolute ethyl alcohol to alternately wash for 3-4 times.

Further, the drying temperature in the step 4) is 60-65 ℃, and the time is 5-7 h.

An application of Ni-V bimetal hydroxide electrode for wide-range full-hydrolytic reaction in hydrogen evolution reaction and oxygen evolution reaction under alkaline and neutral conditions.

Compared with the prior art, the method has the following specific beneficial effects:

1) the method adopts a final sample directly synthesized by a one-step hydrothermal method, has the characteristics of simple reaction process, low synthesis temperature, no need of large-scale equipment and harsh conditions and the like, is environment-friendly and low in cost, and is suitable for large-scale production.

2) In the invention, a small amount of dimethylformamide is introduced to regulate and control reaction solvent water, and the induction effect of the dimethylformamide is fully utilized by strictly controlling the volume between the two, the proportion of the nickel source, the vanadium source and the alkali source, the reaction filling ratio, the reaction time, the reaction temperature and other parameters, so that the control of the nickel-vanadium double metal hydroxide is realized.

3) The dimethylformamide plays a key role in the synthesis of the NiV-LDH/NF catalyst electrode for wide-range full-hydrolysis, and when the water is replaced by equal amounts of ethanol, glycol and acetone, the electrode with the structure and the performance cannot be synthesized.

4) The material of the invention shows good electrochemical activity when applied on electrocatalysts HER and OER. The NiV-LDH/NF electrodes of the invention were subjected to full-hydrolysis electrocatalytic tests in alkaline (pH 14) and neutral (pH 7) solutions, respectively. The catalytic test is carried out in an alkaline environment, and when the current density reaches 100mA/cm ²The HER and OER overpotentials required were 354mV and 360mV, respectively. The catalyst is tested in a neutral environment, and when the current density reaches 10mA/cm ²The required overpotentials for HER and OER were 503mV and 650mV, respectively. The result shows that the NiV-LDH/NF electrode has good full-hydrolytic performance under the conditions of high current density, alkalinity and neutrality.

Drawings

FIG. 1 is an X-ray diffraction (XRD) pattern of NiV-LDH/NF electrocatalyst prepared in example 1 of the present invention

FIG. 2 is a Scanning Electron Microscope (SEM) micrograph of NiV-LDH/NF electrocatalyst prepared according to example 1 of the present invention

FIG. 3 is a high magnification Scanning Electron Microscope (SEM) photograph of NiV-LDH/NF electrocatalyst prepared in example 1 of the present invention

FIG. 4 is a low power Transmission Electron Microscope (TEM) photograph of NiV-LDH/NF electrocatalyst prepared in example 1 of the present invention

FIG. 5 is a high-power Transmission Electron Microscope (TEM) photograph of NiV-LDH/NF electrocatalyst prepared in example 1 of the present invention

FIG. 6 is a graph of hydrogen production performance (HER) of Linear Sweep Voltammetry (LSV) curves under alkaline conditions for NiV-LDH/NF electrocatalyst prepared in example 1 of the present invention

FIG. 7 is a graph of oxygen evolution performance (OER) of Linear Sweep Voltammetry (LSV) curves under alkaline conditions for NiV-LDH/NF electrocatalyst prepared in example 1 of the present invention

FIG. 8 is a graph of oxygen evolution performance (HER) of Linear Sweep Voltammetry (LSV) curves under neutral conditions for NiV-LDH/NF electrocatalyst prepared in example 1 of the present invention

FIG. 9 is a graph of oxygen evolution performance (OER) of Linear Sweep Voltammetry (LSV) curves under neutral conditions for NiV-LDH/NF electrocatalyst prepared in example 1 of the present invention

Detailed Description

The present invention will be described in further detail with reference to the following examples, which are not intended to limit the invention thereto.