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

Abstract A facile hydrothermal method was provided for synthesis of the CoMoO 4 /graphene (CoMoO 4 /G) with the enhanced electrochemical properties for supercapacitor. The Co 2+ ions were adsorbed on the graphene oxide by electrostatic interaction, followed by adding (NH 4 ) 6 Mo 7 O 24 and adjusting pH. The CoMoO 4 nanoparticles were grown on the graphene sheet after hydrothermal reaction. The as-prepared CoMoO 4 /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, CoMoO 4 /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-CoMoO 4 (72.0 F g −1 , 10.0 Wh Kg −1 ). Moreover, in comparison with pure-CoMoO 4 , the CoMoO 4 /G composites exhibited low electrochemical resistance, good rate capability and well cycle life.