Effect of graphene oxide on the properties of its composite with polyaniline.

Graphene oxide, a single layer of graphite oxide (GO), has been used to prepare graphene oxide/polyaniline (PANI) composite with improved electrochemical performance as supercapacitor electrode by in situ polymerization using a mild oxidant. The composites are synthesized under different mass ratios, using graphite as start material with two sizes: 12 500 and 500 mesh. The result shows that the morphology of the prepared composites is influenced dramatically by the different mass ratios. The composites are proposed to be combined through electrostatic interaction (doping process), hydrogen bonding, and pi-pi stacking interaction. The highest initial specific capacitances of 746 F g(-1) (12 500 mesh) and 627 F g(-1) (500 mesh) corresponding to the mass ratios 1:200 and 1:50 (graphene oxide/aniline) are obtained, compared to PANI of 216 F g(-1) at 200 mA g(-1) by charge-discharge analysis between 0.0 and 0.4 V. The improved capacitance retention of 73% (12 500 mesh) and 64% (500 mesh) after 500 cycles is obtained for the mass ratios 1:23 and 1:19 compared to PANI of 20%. The enhanced specific capacitance and cycling life implies a synergistic effect between two components. This study is of significance for developing new doped PANI materials for supercapacitors.