Electropolymerization of graphene oxide/polyaniline composite for high-performance supercapacitor

Highlights: ► The graphene oxide/polyaniline (GO/PANI) composite was prepared by the one-step electrochemical co-deposition. ► A specific capacitance of 1136.4 F g−1 for GO/PANI composites was achieved. ► GO sheets could improve the crystallization by providing surface sites for the well-dispersed deposition of PANI. ► A three dimensional (both layered and fibrous) structure providing better accessibility for ions was achieved. ► Different contents of GO during the synthesis process influenced the capacitance. -- Abstract: The graphene oxide/polyaniline (GO/PANI) composite was prepared by the one-step electrochemical co-deposition method. The different mass concentrations of GO were utilized to improve the electrochemical performances. Scanning electron microscope and transmission electron microscope images showed that PANI nanofibers not only were coated on the surface but also intercalated into GO sheets. The maximum specific capacitance of the GO/PANI composite achieved 1136.4 F g−1 with a GO concentration of 10 mg L−1 at a scan rate of 1 mV s−1, which is almost two-fold higher than that of PANI (484.5 F g−1). The GO/PANI composite also showed a good cycling stability, retaining over 89% of its initial capacitance after 1000 cycles. High electrochemical performances were attributed to increasing active sites for the deposition of PANI provided by large surface areas of GO sheets and the synergistic effect between GO and PANI, shortening the ion diffusion paths. Results indicate that the GO/PANI composites can be developed as excellent electrode materials of high-performance supercapacitor by a versatile, effective and environment-friendly method