In situ growth of single-stranded like poly (o-phenylenediamine) onto graphene for high performance supercapacitors

Herein, we present the first report on a new strategy to synthesize a kind of stereoregular poly (o-phenylenediamine) (PoPD)-graphene nanocomposite bound only by chemical bond via in situ growth of single-stranded like PoPD onto graphene for high performance supercapacitor. Firstly, aniline groups are grafted onto graphene oxide (GO) surface by diazotization reaction to prepare aniline functionalized graphene oxide (a-GO), and then o-phenylenediamine (oPD) monomers are polymerized on a-GO surface to form PoPD wrapped graphene oxide (a-GO/PoPD). Subsequently, the a-GO/PoPD are washed repeatedly to make the PoPD to anchor with aniline groups (GO-a-PoPD) to stay (due to the solubility of PoPD in aqueous solution), followed by reduction to obtain single-stranded like PoPD anchored graphene (r-GO-a-PoPD). Consequently, the r-GO-a-PoPD nanocomposite with special combining form and structure exhibits a high specific capacitance of 381 F g−1 in 1 M H2SO4 at 1 A g−1, and 230 F g−1 in 6 M KOH at 1 A g−1. Furthermore, the symmetric supercapacitor exhibits excellent stability, high energy density and power density. The achieved high electrochemical performance is ascribed to the stable connection of PoPD with graphene and the sufficient use of them, which provide high capacitance and stability.