Electrochemical properties, optical modeling and electrocatalytic activity of pulse-electropolymerized ternary nanocomposite of poly (methylene blue) in aqueous solution

Abstract

This paper aims to investigate the relationship between surface morphology of poly (methylene blue) (PMB) films and pulse synthesis conditions. A simple and general strategy, namely in situ electropolymerization has been used for electrosynthesis of PMB on the Indium Tin Oxide (ITO) substrates by pulse galvanostatic method. The obtained surface analysis results revealed that the morphology and particle sizes of PMB strongly depended on the synthetic conditions. PMB nanoparticles with good electrochemical stability were obtained by optimization of synthetic conditions. Then, Ni (II) and Mn (II) ions were incorporated to electrode by immersion of the polymerically modified electrode in a stirred solution containing Ni and Mn ions to form Ni–Mn/PMB films. Furthermore, the experimental absorbance spectra of nanocomposite were compared with the results from the Maxwell-Garnett theory (MGT) and the value of energy, Eg, of composite obtained. Modified electrodes (Ni–Mn/poly methylene blue) were examined for their redox and electrocatalytic activities in the oxidation of methanol in alkaline solutions. The electrochemical results reveal that Ni–Mn/poly methylene blue modified electrode shows a significantly higher response for methanol oxidation in alkaline solution.