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

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 CoO_x@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 CoO_x cores provides active catalytic sites, and the carbon shells protect the CoO_x cores from aggregating into gigantic cobalt oxide granules. The magnetism of CoO_x 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.