Facile synthesis of sandwich-like polyaniline/boron-doped graphene nano hybrid for supercapacitors

The physicochemical property of chemically prepared graphene can be significantly changed due to the incorporating of heteroatoms into graphene. In this article, boron-doped graphene sheets are used as carbon substrates instead of graphene for loading polyaniline by in situ polymerization. Compared with the individual component and polyaniline/non-doped graphene, the sandwich-like polyaniline/boron-doped graphene exhibits remarkably enhanced electrochemical specific capacitance in both acid and alkaline electrolytes. In a three-electrode configuration, the hybrid has a specific capacitance about 406 F g−1 in 1 M H2SO4 and 318 F g−1 in 6 M KOH at 1 mV s−1. In the two-electrode system of a symmetric supercapacitor, this hybrid achieves a specific capacitance about 241 and 189 F g−1 at 0.5 A g−1 with a specific energy density around 19.9 and 30.1 Wh kg−1, in the acid and alkaline electrolytes, respectively. The as-obtained polyaniline/boron-doped graphene hybrid shows good rate performance. Notably, the obtained electrode materials exhibit long cycle stability in both acid and alkaline electrolytes (∼100% and 83% after 5000 cycles, respectively). The improved electrochemical performance of the hybrid is mainly attributed to the introduction of additional p-type carriers in carbon systems by boron-doping and the well combination of pseudocapacitive conducting polyaniline.