Preparation and Characterization of a Poly[Ni(salen)]/Multiwalled Carbon Nanotube Composite by<i>in Situ</i>Electropolymerization as a Capacitive Material

Abstract

A composite of poly[Ni(salen)] and multiwalled carbon nanotubes (MWCNTs) was synthesized by in situ electropolymerization. As-grown poly[Ni(salen)] filled gaps between MWCNTs and formed a ferroconcrete-like microstructure. It was found that the doping level and electrochemical reversibility of poly[Ni(salen)] were greatly improved because of the support of MWCNTs. Values of the charge diffusion transport coefficient estimated by cyclic voltammetry revealed the effect of the mass of poly[Ni(salen)] on the charge transport behavior of composites. Both the direct ohmic resistance and the alternating ohmic resistance of a composite with small mass ratios (0.29/1 and 0.63/1) were obviously lower than those of MWCNTs which was demonstrated by electrochemical impedance spectroscopy and galvanostatic charge/discharge tests. Galvanostatic charge/discharge tests also showed that the ability to store charge was improved significantly for composites by incorporating poly[Ni(salen)].