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

A cobalt (Co)/graphene sheets (GRs) composite was synthesized via a one-pot chemical method. The composite shows high saturation magnetizations (M s ), 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 H 2 gas by hydrolysis of NaBH 4 solution. Effects of NaBH 4 initial concentration, the composite and reaction temperature on the H 2 generation rate were investigated. The H 2 generation rate is independent with the initial NaBH 4 concentration, increased with the reaction temperature increasing. The composite can be continuously used several times with about the same catalytic activity.