Method for catalytic reduction of graphene oxide

Abstract

The invention provides a method for catalytic reduction of graphene oxide. The method comprises the following steps: firstly, adding a metal salt solution into a graphene oxide water solution based on a salting-out effect of the graphene oxide to form a cotton-like suspended substance; adding NH3BH3 and catalyzing hydrolysis of the NH3BH3 by utilizing reduced metal particles at room temperature so as to release nascent hydrogen atoms with high reducibility on the surface of the graphene oxide; reducing the graphene oxide by utilizing the hydrogen atoms; and finally removing the metal particles by means of acid washing to obtain graphene. The method disclosed by the invention is used for reducing the graphene oxide without using compounds such as hydrazine hydrate, derivatives of the hydrazine hydrate, hydrogen iodide and the like with high toxicity, high volatility and high corrosivity as a reducing agent and has the characteristics of being environment-friendly and safe; compared with a metal powder / hydrochloric acid reduction system, the method is relatively high in reduction efficiency; meanwhile, the method can be implemented at room temperature, the reaction condition is mild and generation of defects of the graphene during reduction is reduced.

Description

technical field [0001] The invention relates to the technical field of nanomaterial preparation, in particular to a method for catalytically reducing graphene oxide. Background technique [0002] Graphene has excellent electrical conductivity, extremely high strength and good light transmission, and its appearance is expected to trigger a revolution in semiconductors and other fields. At present, there are many methods for preparing graphene, including mechanical separation method, chemical redox method, epitaxial growth method, chemical vapor deposition (CVD) and so on. The chemical redox method is to oxidize and exfoliate natural flake graphite in an aqueous solution to obtain graphene oxide, and then add a reducing agent to remove the oxidation functional group of graphene oxide to obtain reduced graphene oxide (graphene). Compared with several other methods, the chemical redox method has the advantages of simple process and low cost. [0003] Graphene oxide can be synt...

AI Technical Summary

Problems solved by technology

Prior to the present invention, previous work mainly used hydrazine hydrate and its derivatives as reducing agents to reduce graphene oxide, but hydrazine hydrate and its derivatives are highly toxic and volatile, and cannot be used on a large scale , and the reduced graphene will be doped with many nitrogen atoms, which will affect the physical and chemical properties of graphene

There is also research on the use of hydrogen iodide / acetic acid mixed system to reduce graphene oxide, but hydrogen iodide is extremely corrosive, which limits the use of this method

Sodium borohydride (NaBH 4 ), ascorbic acid (VC), etc. are used as reducing agents to reduce graphene oxide, but these reactions require heating, high energy consumption, and easy to increase the defects of graphene

Recently, there are also studies on the use of hydrogen atoms produced by the reaction of Fe, Zn, Al and other metal powders with hydrochloric acid to reduce graphene oxide, but the hydrophobic metal powder particles are larger (200nm ~ 10um) compatible with hydrophilic graphene oxide. Poor performance, the hydrogen atoms generated on the metal surface are easy to combine to form hydrogen gas, it is difficult to reduce graphene oxide, so the reduction efficiency is very low (5-30%)

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