One-step synthesis of CoMoO4/graphene composites with enhanced electrochemical properties for supercapacitors

A facile hydrothermal method was provided for synthesis of the CoMoO4/graphene (CoMoO4/G) with the enhanced electrochemical properties for supercapacitor. The Co2+ ions were adsorbed on the graphene oxide by electrostatic interaction, followed by adding (NH4)6Mo7O24 and adjusting pH. The CoMoO4 nanoparticles were grown on the graphene sheet after hydrothermal reaction. The as-prepared CoMoO4/G composites possessed high surface/body ratios and large electroactive regions, which could facilitate easy accession of OH− ions and fast charge transport. As a result, CoMoO4/G composites achieved a specific capacitance about 394.5 F g−1 and a specific energy density around 54.8 Wh kg−1 calculated from the CV curve at 1 mV s−1, which was higher than that of pure-CoMoO4 (72.0 F g−1, 10.0 Wh Kg−1). Moreover, in comparison with pure-CoMoO4, the CoMoO4/G composites exhibited low electrochemical resistance, good rate capability and well cycle life.