Preparation method of laser-synthesized oxygen-vacancy tunable cobalt tetraoxide nitrogen-doped graphene

Abstract

The invention discloses a method for preparing laser-synthesized cobalt tetroxide nitrogen-doped graphene with adjustable oxygen vacancies. Graphite oxide is ultrasonically dispersed in absolute ethanol to form a 0.33mg / ml suspension, and 24ml of the suspension is added to 1.2ml 0.2M cobalt acetate solution, 0.5ml 30% NH 4 OH solution and 0.7ml deionized water, 80°C oil bath for 10h; pour the solution into the reaction kettle, and react for 3h at 150°C; then perform high-speed centrifugation at 12000-20000 rpm, and then wash repeatedly with deionized water for 3-4 After three times, the precipitate was obtained and freeze-dried; the sample and deionized water were mixed in a test tube with a mass ratio of 1:2 to 1:5, and under magnetic stirring, the solution was irradiated with nanosecond parallel pulse laser energy of 15 to 97 mJ for 5 to 5 25 min; centrifuge and freeze-dry to obtain oxygen vacancy-tunable tricobalt tetroxide nitrogen-doped graphene. The invention aims to adjust the concentration of oxygen vacancies in the composite system by adjusting the irradiation energy and time of the low-energy laser, and keep the structure of the composite system unchanged.

Description

technical field [0001] The invention belongs to the technical field of graphene preparation, in particular to a preparation method for hydrothermally synthesizing oxygen vacancy-adjustable tricobalt tetroxide composite nitrogen-doped graphene by using low-energy laser irradiation. Background technique [0002] Due to the increasingly serious energy crisis and environmental pollution caused by fossil fuels, people pay more and more attention to the development and utilization of renewable energy, which has led to widespread attention to the key technologies of renewable energy conversion and storage, including Fuel cells, metal-air batteries, electrolyzed water, etc., the electrochemical reactions involved include HER, OER and ORR. Due to the slow kinetics of these reactions, it is necessary to look for efficient and cheap electrocatalysts to replace the most active, but expensive and scarce noble metals (Pt, Ru, etc. and their oxides (IrO 2 , RuO 2 ) becomes particularly i...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the existing synthesis process cannot synthesize metal oxide composite nitrogen-doped graphene rich in oxygen vacancies at low temperature and low pressure and cannot effectively control the content of oxygen vacancies in the composite system. The irradiation energy and time of the energy laser can adjust the concentration of oxygen vacancies in the composite system and keep the structure of the composite system unchanged, and improve the OER / ORR catalytic performance of the material through the oxygen vacancies created on the surface and the Co-N-C bonds at the interface

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