CN114684873A

CN114684873A - Nickel-indium layered double-metal hydroxide nanosheet catalyst and preparation method and application thereof

Info

Publication number: CN114684873A
Application number: CN202210504259.4A
Authority: CN
Inventors: 韩士奎; 尹婷婷; 许厚明
Original assignee: Hefei University of Technology
Current assignee: Hefei University of Technology
Priority date: 2022-05-10
Filing date: 2022-05-10
Publication date: 2022-07-01

Abstract

The invention belongs to the technical field of functional materials, and particularly relates to a nano nickel-indium layered double-metal hydroxide catalyst, a preparation method and application thereof, wherein the preparation method of the catalyst comprises the following steps: mixing nickel salt, indium salt, dimethylbenzene, a surfactant and oleic acid, and heating to obtain a reaction solution; under the condition of stirring, adding water into the reaction liquid to react to obtain a mixed material; and separating the mixed materials to obtain a solid product, and finally washing and drying the solid product to obtain the nano nickel-indium layered double metal hydroxide catalyst. The method adopts one-step synthesis of the nano nickel-indium layered double-metal hydroxide nanosheet catalyst, the preparation method is simple, the controllability is high, the prepared nickel-indium layered double-metal hydroxide nanosheet catalyst is stable in structure and stable in product performance, and compared with the catalytic efficiency of nickel-metal hydroxide nanosheets prepared without adding indium salt, the catalyst has higher catalytic activity and higher catalytic efficiency.

Description

Nickel-indium layered double-metal hydroxide nanosheet catalyst and preparation method and application thereof

Technical Field

The invention relates to the technical field of functional materials, in particular to a nickel-indium layered double-metal hydroxide nanosheet catalyst and a preparation method and application thereof.

Background

With the continuous use of fossil energy, two problems of energy exhaustion and environmental pollution are gradually faced. Hydrogen energy has a high combustion value and the combustion products are pollution-free water, electrocatalytic water splitting is one of the best ways to store solar energy. Therefore, many methods are used to prepare electrocatalysts having excellent properties. The distance between the layers of the layered double hydroxide structure is large, so that the electrolyte has a large electrochemical contact area. However, the layered spaces of the bulk layered double hydroxide are often stacked together, resulting in poor electron conductivity, poor electron transferability, and hindered active sites.

To overcome these problems, various strategies (e.g., peeling) are often employed to achieve high performance. Stripping can increase accessible active sites, regulate electronic effects, and adjust the surface properties of the electrocatalyst. For example, Hu et al reported the exfoliation of nickel-iron and nickel-cobalt layered double hydroxides into nanosheets in formamide solutions, with the resulting nanosheets being 4.5-fold enhanced over the bulk layered double hydroxides. However, the layered double hydroxide is usually stripped in a high boiling point solvent, which is costly and cumbersome.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a nickel-indium layered double-metal hydroxide nanosheet catalyst, and a preparation method and application thereof.

In order to achieve the purpose, the invention adopts the technical scheme that:

the invention discloses a preparation method of a nickel-indium layered double-metal hydroxide nanosheet catalyst, which comprises the following steps of: mixing nickel salt, indium salt, dimethylbenzene, a surfactant and oleic acid, and heating to dissolve solid raw materials to obtain a reaction solution; adding water into the reaction solution under the stirring condition, and continuously stirring for 6-8h to obtain a mixed material; and separating the mixed materials to obtain a solid product, and washing and drying the solid product in sequence to obtain the nano nickel-indium layered double metal hydroxide catalyst.

Preferably, the heating temperature is 110-130 ℃, and specifically, the heating temperature can be 110 ℃, 120 ℃ or 130 ℃. The nickel salt is nickel nitrate, nickel acetate or nickel sulfate; the indium salt is indium chloride or indium acetate; the surfactant is octadecene or oleylamine. The washing method comprises the steps of washing by adopting n-hexane or toluene, and then washing by adopting ethanol.

Electrochemical water splitting is considered as a key technology for sustainable and renewable energy conversion, storage and consumption. The process of splitting water can be divided into two sub-reactions, the cathodic Hydrogen Evolution Reaction (HER) and the anodic Oxygen Evolution Reaction (OER). In contrast to the relatively easy cathodic hydrogen evolution, anodic OER is a slow kinetic process in which 4 electrons participate in the formation of one oxygen molecule. Even in noble metal electrocatalysts (e.g. IrO)₂,RuO₂) In general, a large overpotential (-0.3V) is also required to overcome the kinetic barrier. The scarcity and expensive cost of expensive catalysts has severely hampered large-scale practical applications. Therefore, the complete decomposition of water by earth-rich materials instead of noble metals has attracted great interest in basic research and technology.

The invention also discloses the application of the nano nickel-indium layered double hydroxide catalyst in electrochemical water splitting to prepare hydrogen, in particular to the application of the catalyst in oxygen evolution reaction in electrochemical water splitting.

Compared with the prior art, the invention has the beneficial effects that: the method adopts one-step synthesis of the nano nickel-indium layered double-metal hydroxide nanosheet catalyst, the preparation method is simple, the controllability is high, the prepared nickel-indium layered double-metal hydroxide nanosheet catalyst is stable in structure and stable in product performance, and compared with the catalytic efficiency of nickel-metal hydroxide nanosheets prepared without adding indium salt, the catalyst has higher catalytic activity and higher catalytic efficiency.

Drawings

Fig. 1 is a TEM characterization photograph of a nickel indium layered double metal hydroxide nanosheet catalyst prepared in accordance with the present invention;

fig. 2 is an XRD pattern of a layered double metal hydroxide nanosheet catalyst of nickel indium prepared in accordance with the present invention;

FIG. 3 is a linear sweep voltammogram of different catalysts;

FIG. 4 is a graph of the corresponding Tafel slopes for different catalysts in electrocatalysis;

Detailed Description

The above and further features and advantages of the present invention are described in more detail below with reference to the accompanying drawings.

Example 1

A preparation method of a nickel-indium layered double-metal hydroxide nanosheet catalyst comprises the following steps:

s1: adding 48mg of nickel nitrate, 22mg of indium chloride, 15mL of dimethylbenzene, 1mL of oleylamine and 2mL of oleic acid into a three-necked flask, magnetically stirring, and heating at 120 ℃ to obtain a reaction solution;

s2: adding 5ml of deionized water into the reaction solution, and continuing to react for 7 hours to obtain a mixed material; (ii) a

S3: and separating the mixed materials to obtain a solid product, washing the solid product by using normal hexane and ethanol in sequence, and finally drying to obtain the layered nickel-indium bimetal hydroxide nanosheet catalyst, which is recorded as Niln-LDH.

Comparative example

The comparative example differs from example 1 in that no indium chloride was added in step S1, the other processes are the same as in example 1, and the product prepared is denoted as Ni-LDH.

TEM characterization was performed on the nickel indium layered double hydroxide nanosheet catalyst obtained in example 1, and the characterization results are shown in fig. 1. It is apparent from fig. 1 that the nickel indium layered double metal hydroxide nanosheets are platelet-layered.

Fig. 2 is an XRD pattern of the nickel-indium layered double metal hydroxide nanosheets, from which it can be seen that, in comparison with the card, the line of the nickel-indium layered double metal hydroxide nanosheets is shifted a little to the left as seen from the nickel hydroxide, because of the shift caused by the incorporation of a small amount of indium ions into the nickel hydroxide, the characteristic peak of indium in the peak is not so obvious, and because of the use of a very small amount of indium chloride, the peak is not so obvious due to the too small amount.

FIGS. 3 and 4 show Niln-LDH, Ni-LDH and Commercial ruthenium oxide (Commercial RuO), respectively₂) The linear sweep voltammogram of the Bare glassy carbon electrode (Bare GC) and the corresponding tafel slope chart show that the Niln-LDH has the most excellent properties.

It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Claims

1. A preparation method of a nano nickel-indium layered double metal hydroxide catalyst is characterized by comprising the following steps: mixing nickel salt, indium salt, dimethylbenzene, a surfactant and oleic acid, and heating to obtain a reaction solution; adding water into the reaction solution under the stirring condition, and continuously stirring for 6-8h to obtain a mixed material; and separating the mixed materials to obtain a solid product, and washing and drying the solid product in sequence to obtain the nano nickel-indium layered double metal hydroxide catalyst.

2. The method for preparing a layered double hydroxide catalyst of nano nickel indium as claimed in claim 1, wherein the method comprises the following steps: the nickel salt is nickel nitrate, nickel acetate or nickel sulfate.

3. The method for preparing a layered double hydroxide catalyst of nano nickel indium as claimed in claim 1, wherein the method comprises the following steps: the indium salt is indium chloride or indium acetate.

4. The method for preparing a layered double hydroxide catalyst of nano nickel indium as claimed in claim 1, wherein the method comprises the following steps: the surfactant is octadecene or oleylamine.

5. The method for preparing a layered double hydroxide catalyst of nano nickel indium as claimed in claim 1, wherein the method comprises the following steps: the heating temperature is 110-130 ℃.

6. The method for preparing a layered double hydroxide catalyst of nano nickel indium as claimed in claim 1, wherein the method comprises the following steps: the washing method comprises the steps of firstly washing by using normal hexane or toluene and then washing by using ethanol.

7. The layered double hydroxide catalyst of nano nickel indium prepared by the preparation method as set forth in any one of claims 1 to 6.

8. The nano-nickel indium layered double hydroxide catalyst as claimed in claim 7 is used for electrochemical water splitting to produce hydrogen.