In situ synthesis and catalytic application of reduced graphene oxide supported cobalt nanowires

Controlled synthesis of magnetic nanocomposite with outstanding catalytic performances is a promising strategy in catalyst industry. We proposed a novel concept for fabrication of reduced graphene oxide supported cobalt nanowires (RGO/Co-NWs) nanocomposite as high-efficient magnetic catalyst. Unlike the majority of experiments necessitating harsh synthesis conditions such as high-pressure, high temperature and expensive template, here the RGO/Co-NWs were successfully prepared in aqueous solution under mild conditions with the assistance of external magnetic field. The synthetic process was facile and external magnetic force was adopted to induce the unidirectional self-assembly of cobalt crystals on graphene oxide to form RGO/Co-NWs. The possible formation mechanism laid on the fact that the dipole magnetic moments of the nanoparticles were aligned along the magnetic induction lines with the external magnetic field direction resulting in the formation of nanowires elongating in the direction of the magnetization axis. Simultaneously, a series of controlled reactions were conducted to illuminate the effect of graphene oxide, external magnetic field and PVP on the morphology and size of RGO/Co-NWs in the present approach. More importantly, the nanocomposite exhibited a high catalytic performance towards ammonia borane. Hence the novel nanocomposite holds a great potential for technological applications such as catalyst industry. (C) 2018 Elsevier B.V. All rights reserved.