Investigation of the Electrocatalytic Effect of Polyaniline on the Redox Reaction of 2,5-Dimercapto-1,3,4-thiadiazole by Cyclic Voltammetry

Electrochemical polymerized polyaniline (PAn) film electrode was used to investigate the electrocatalytic effect of PAn on the electrochemical redox reaction of 2, 5-dimercapto-1,3,4-thiadiazole (DMcT). PAn film electrode was electrochemically treated or immersed in DMcT solution before it was scanned in 1. 0 mol/L HCl electrolyte. The cyclic voltammograms of PAn film electrode in 1. 0 mol/L HCl solution changed with the above treatment, implying the electrocatalytic effect of PAn on the redox reaction of DMcT. The formation of electron-donor-acceptor adducts through the interaction between thiol or disulfide groups of DMcT and amine or imine groups of PAn during the treatment was probably the reason of the catalysis. The electrochemical properties of the adduct were different from those of PAn and DMcT. The adduct possessed a higher electrochemical activity and a better electrochemical reversibility than DMcT or PAn used alone.