Preparation of magnetic Co/graphene sheets composites and investigation on its catalytic activity for H2 generation

Abstract

A cobalt (Co)/graphene sheets (GRs) composite was synthesized via a one-pot chemical method. The composite shows high saturation magnetizations (Ms), which leads it to be conveniently separated from aqueous solution by an external magnetic field. Compared to the pure Co and some references, the catalytic activity of the as-obtained composite was significantly enhanced for the generation of H2 gas by hydrolysis of NaBH4 solution. Effects of NaBH4 initial concentration, the composite and reaction temperature on the H2 generation rate were investigated. The H2 generation rate is independent with the initial NaBH4 concentration, increased with the reaction temperature increasing. The composite can be continuously used several times with about the same catalytic activity.