Conductive Polymer Nanosheets Generated from the Crystal Surface of an Organic Oxidant.

Morphology control of conductive polymers contributes to improving electrochemical properties based on their redox-active nature. In general, it is not easy to achieve simultaneous synthesis and morphology control of conductive polymers because of their low solubility and processability. Here the crystal surface of an organic oxidative agent is used for simultaneous synthesis and morphogenesis of the conductive polymer polypyrrole (PPy) under mild conditions. The oxidant crystal plays multiple roles, serving as the reaction field to supply the oxidative agent, the template for control of hierarchical morphology, and the source of dopant, with diffusion of the monomer vapor under low temperature and ambient pressure. A hollow plate-like morphology consisting of the PPy nanosheets was obtained from crystals of quinone derivatives through oxidative polymerization in high yield. The resultant PPy nanosheets showed improved conductivity without further doping and enhanced electrochemical properties as an active material of redox capacitors. The present approach using the crystal surface can be applied to a variety of polymerization systems.