Morphology control of conductive polymers contributes to improvinge lectrochemical properties based on their redox-active nature.I ng eneral, it is not easy to achieves imultaneous synthesis and morphologyc ontrol of conductive polymers because of their low solubility and processability.H ere the crystal surfaceo fa no rganic oxidativea gent is used for simultaneous synthesis and morphogenesis of the conductive polymerp olypyrrole (PPy) under mild conditions. The oxidant crystal plays multiple roles, serving as the reactionfield to supply the oxidative agent, the template forcontrol of hierarchical morphology, and the source of dopant, with diffusion of the monomer vapor under low temperature and ambientp ressure. Ah ollow plate-like morphologyc onsisting of the PPy nanosheets was obtained from crystalso fq uinone derivatives through oxidative polymerization in high yield. The resultant PPy nanosheets showedi mproved conductivity without furtherd oping and enhanced electrochemical properties as an active materialo f redox capacitors. The present approach using the crystal surface can be applied to avariety of polymerizationsystems.The designa nd synthesiso fp olymers and macromolecules have been studied on the molecular scale for the development of functional materials. [1] On al arger scale, the morphologyo f functional materials contributes to enhancing their properties. [2] Conductive polymers with a p-conjugated backbone have av ariety of applications based on their photochemical, electronic,a nd electrochemical properties. [3] When conductive polymers are applied to charge-storage devices owing to their redox-active nature, the morphologies from the nanometer to the micrometer scale affect the electrochemical properties. [4] The nanoscale morphologies contribute to an increase in the specific surfacea rea. In addition, sufficient interspace on the sub-micrometer scale is necessary for the diffusion of electrolytes. However,i ti sn ot easy to control the hierarchical morphologies of conductive polymers because of their low solubility and processability,o riginating from the rigid p-conjugated chain. New rational and versatile approaches are required to achieve the simultaneous synthesis and morphogenesis. In the presentw ork, the surface of an organic oxidant crystal induced formation of ah ollow plate consisting of the PPy nanosheets upon diffusion of the monomer vapor.T he organic oxidant crystal plays an important role for the simultaneous synthesis and morphogenesis throughas olvent-and metal-free route under mild conditions. Chemical oxidative polymerization in the liquid phase is used to for morphology control of conductive polymers. [5] Improvede lectrochemical properties can be achieved by morphologyc ontrolu sing templates and additive molecules. [6] For example, PPy nanowires and hollow nanorods were synthesized by using surfactant templates. The resultant PPy showed enhanced electrochemical properties as an active material of redox capacitors. [4a-c, 6] PPy nanosheets were synthesized in the...