P/N co-doped microporous carbons from H3PO4-doped polyaniline by in situ activation for supercapacitors

P/N co-doped porous carbons have been synthesized by a simple method through direct carbonization of phosphoric acid doped polyaniline. The textural property and the surface chemistry have been investigated by nitrogen sorption and X-ray photoelectron spectra. P/N co-doped carbons exhibit typical microporous characters with a low surface area and a narrow pore size distribution. Interestingly, the concentration and the development of heteroatom-containing surface functionalities are strongly depended on the temperature of heat treatment. Cyclic voltammetry and galvanostatic charge-discharge tests have been used to investigate the capacitive performance of such microporous carbons, which exhibit high specific capacitance (154.4 F g(-1)) and excellent stability. The improved electrochemical performance is attributed to the combination of the co-doping of heteroatoms (P and N) and micropores generated by the in situ activation of phosphoric acid. (C) 2013 Elsevier Ltd. All rights reserved.