Enhancement of Electrochemical Capacitance of Carbon Nanotubes by Polythionine Modification

Thionine molecules have been electropolymerized onto different types of carbon nanotubes (CNT) using a cyclic voltammetry scanning technology, including multi‐walled carbon nanotubes, single‐walled carbon nanotubes and aligned carbon nanotubes. Results indicate that such prepared nanocomposites have combined the intrinsic faradic capacitance of polythionine with the double layer capacitance of polythionine‐CNT, and thus the polythionine modification obviously enhanced the CNT capacitance. Especially the carboxyl group modified multi‐walled carbon nanotubes, which have made their nanotube tips opened, allowed much more electropolymerization cycles and then obtained a most significant increment in capacitance than the other three ones.