Properties of electrochemically copolymerized aniline and melamine on functionalized multiwalled-carbon nanotube film electrodes

The electrochemical properties of polymerized aniline (PANI) and polymerized melamine (PMEL) that were electrochemical copolymerized (PANIMEL) on a glassy carbon electrode (GCE) that had been coated with functionalized multiwalled carbon nanotubes (fMWCNT) to form a PANIMEL/fMWCNT/GCE film electrode were studied, with an aim toward electrochemical energy storage (EES). A number of factors, such as the choice of working electrode, electrolyte, switching potential, applied scan rate, and type of fMWCNTs, were initially investigated and evaluated during the individual electrochemical polymerization of aniline and melamine via successive potential cycling. The electrochemical copolymerisation of aniline and melamine was then studied with an ideal monomeric ratio of 1:3 that gave an optimal ratio of the voltammetric peak current heights with distinguishable redox peak potentials. Variable scan rate cyclic voltammetry (CV) of the electrosynthesized copolymer film electrode confirmed the dominance of the surface-confined electron transfer process at the electrode. The electrochemical stability of the copolymer film electrode was also assessed and revealed a limited cyclability of the daughter polymeric melamine, which was hypothesized to be due to an excessive nitrogen content combined with a low porosity that led to a poor ion intercalation-deintercalation mechanism. Electrochemical impedance spectroscopy (EIS) was performed to evaluate the electrochemical performance of the copolymerized film electrode with other control electrodes. The corresponding EIS results suggested that the copolymerized film electrode was electrochemically superior to the PMEL/fMWCNT/GCE film electrode but was inferior to the PANI/fMWCNT/GCE film electrode.