Electrochemical behavior and multilayer films of the sandwich-type polyoxotungstate complex {K 10Co 4(H 2O) 2(PW 9O 34) 2}

Abstract

The electrochemical behavior of the sandwich-type polyoxotungstate complex of K 10Co 4(H 2O) 2(PW 9O 34) 2 (Co 4(PW 9) 2) was investigated by cyclic voltammetry in aqueous solutions. The polyoxoanion exhibits two successive redox peaks originating from the tungsten-oxo framework. The electrochemical behavior for the Co II species was not detected. Moreover, the multilayer films consisting of PEI and Co 4(PW 9) 2 were prepared by the layer-by-layer self-assembly method. The films were characterized by UV–vis spectroscopy, cyclic voltammetry and atomic force image. The films exhibit the electrochemical behavior of Co 4(PW 9) 2 polyoxoanion. Moreover, the films can catalyze the electrochemical reduction of NO 2 −. Electron transfer to Fe(CN) 6 3−/4− redox probe was also investigated.