Simultaneous Reduction of Graphene Oxide and Polyaniline: Doping-Assisted Formation of a Solid-State Charge-Transfer Complex

We report the formation of a solid-state charge-transfer complex upon simultaneous reduction of a graphene oxide–polyaniline (GO-PANI) composite consisting of GO sheets coated by a thin layer of PANI. The reduced R(GO-PANI) material exhibits an unprecedented donor–acceptor interaction at the interface between RGO sheets and the thin PANI layer coating. A conceptual explanation is proposed in which RGO plays a dual role as electron acceptor and as large counterion stabilizing an atypical intermediate oxidation state of PANI. Moreover, the donor–acceptor interactions are responsible for superior materials characteristics, such as excellent water dispersibility, high environmental (chemical and thermal) degradation stability, and enhanced electric conductivity as high as 2600 S/m. These results may enable further opportunities for the development of novel electroactive materials based on graphene and intrinsically conducting polymers and the fabrication of corresponding flexible electronic devices through traditional solution processing techniques.