In-situ polymerization growth of polyaniline nanowire arrays on graphene foam for high specific capacitance supercapacitor electrode

Graphene foam (GF) was fabricated by chemical vapor deposition using nickel foam as the template and the GF was activated by concentrated nitric acid. Polyaniline nanowire arrays (PANI NWAs) were grown on the surface of GF by in-situ polymerization to obtain the PANI NWAs/GF composite. The morphologies and structures of GF and PANI NWAs/GF composite were characterized by scanning electron microscopy, transmission electron microscopy and Raman analysis, respectively. The integration between GF and PANI NWAs shows a synergistic effect. GF provides electrically conductive channels for the PANI NWAs anchored on it, and PANI NWAs with small diameters provide high pseudocapacitance and enhanced electrode specific surface area. The electrode exhibits a high specific capacitance 870 F g(-1) at 1 A g(-1). Moreover, the electrodes possess an excellent cycle life with 80% capacitance retention after 1000 cycles at 6 A g(-1).