Polyaniline nanowire-pillared graphene for supercapacitor electrode

A template-free method is presented to synthesize polyaniline nanowire-pillared graphene by melamine initiated nucleation. Polyaniline nanowire morphology was readily controlled by tailoring the amount of melamine. Polyaniline nanowires produced at optimized condition were vertically aligned on graphene sheets, and showed uniform diameter, length, and inter-nanowire spacing. The nanowire diameter was as small as ̃20 nm. The resultant specific capacitance of polyaniline nanowire-pillared graphene electrode was as high as 625 F/g. Electrochemical impedance test indicated that the as-synthesized structure significantly facilitated ion diffusion and exchange. The supercapacitor was very stable and more than 70% of capacitance was retained after 1000 cycles.