Magnetic CoOx@C-Reduced graphene oxide composite with catalytic activity towards hydrogen generation

Abstract

Cobalt-containing magnetic core-shell structures are alternative catalysts with better catalytic performance for hydrogen evolution. In this study, a facile route is adopted to fabricate a CoOx@carbon-reduced graphene oxide composite containing Co nanoparticle cores, carbon shells, and reduced graphene oxide. During hydrogen generation through the catalytic hydrolysis of NaBH4 and NH3BH3, the surface of CoOx cores provides active catalytic sites, and the carbon shells protect the CoOx cores from aggregating into gigantic cobalt oxide granules. The magnetism of CoOx anchored onto reduced graphene oxide sheets achieves effectively a momentum transfer assisted by a motional external magnetic field. In a batch reactor, the composite exhibits a higher catalytic activity in a self-stirring mode than that in a magneton-stirring mode. This simple and efficient synthesis strategy is highly promising for the next development of both facile hydrogen generation and core-shell composite functional materials.