A modified composite film electrode of polyoxometalate/carbon nanotubes and its electrocatalytic reduction

Keggin-type polyoxometalate (H4SiMo12O40) and carbon nanotubes (CNTs) coated by poly(allylamine hydrochloride) (PAH) were alternately deposited on glassy carbon (GC) electrodes by an electrochemical growth method in acidic aqueous solution. The preparation of the film electrode was simple and convenient. Thus-prepared multilayer films and the electrochemical behavior of the composite film modified electrode were characterized by UV-vis spectroscopy and cyclic voltammetry. It was shown that the multilayer films are uniform and stable. The resulting multilayer film modified electrode behaves as an electrochemical sensor because of its low overpotential for the catalytic reduction of S2O8 (2-) and NO2 (-) in acidic aqueous solution.