Preparation method of cobalt vanadium duplex-metal hydroxide nanosheet as catalyst in electrolysis of water for oxygen evolution

Abstract

The invention relates to a preparation method of a cobalt vanadium duplex-metal hydroxide nanosheet as a catalyst in electrolysis of water for oxygen evolution. The preparation method includes the steps that cobalt chloride hexahydrate, vanadium chloride and hexamethylenetetramine are simultaneously added into deionized water to obtain a solution A; the solution A is poured into a reaction still and then sealed, the reaction still is placed in an outer kettle, and then the outer kettle is placed in a homogeneous reactor for a reaction; after the reaction is completed, the reaction still is naturally cooled to room temperature, and a product obtained after the reaction is alternately washed with water and alcohol, collected and dried under vacuum to obtain the CoV-LDH nanosheet. A one-stephydrothermal method is adopted, the synthesis temperature is low, the yield is high, no post-treatment is needed, and the environment is protected. The prepared CoV-LDH is a two-dimensional nanosheetwhich is beneficial to free ion in and out, full contact of an electrolyte and the CoV-LDH nanosheet is facilitated, more active sites can be exposed, and correspondingly the electrochemical performance can be improved. In addition, the chemical composition of the product is uniform, the purity is high, the morphology is uniform, the nanosheet can show excellent electrochemical performance when used as an electrode material in electrolysis of water, and at the current density of 10mA / cm<2>, the overpotential is about 280 mV.

Description

Technical field [0001] The invention belongs to the technical field of electrocatalysts, and specifically relates to a preparation method of a cobalt-vanadium double metal hydroxide nanosheet electrolysis water oxygen evolution catalyst. Background technique [0002] Hydrogen energy is a clean, efficient, and pollution-free energy source, and because of its high energy density, it is widely used as an energy carrier. Splitting water into hydrogen and oxygen is considered one of the most promising strategies for producing hydrogen. The electrochemical oxygen evolution reaction (OER) is a process that determines the efficiency of water splitting. OER is a multi-step, four-electron, slow kinetic reaction and requires a higher overpotential process. Designing an efficient OER catalyst can improve reaction kinetics and reduce overvoltage. Noble metal oxide (IrO 2 And RuO 2 ) Are considered the most effective OER catalysts for water splitting, but they are scarce and expensive. Rec...

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Problems solved by technology

Hydrothermal Synthesis of Nanorods and Nanowires of Mg / AlLayered Double Hydroxides. Zhao et al. used the hydrothermal method to synthesize LDH nanowires at 190°C. The product was regular and well dispersed. However, this method had a high temperature and high energy consumption. and has a certain risk

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