Electrocatalytic evaluation of liquid phase deposited methylene blue/TiO2 hybrid films

Methylene blue (MB)/TiO2 hybrid thin films were prepared on glassy carbon (GC) electrode surface by the liquid phase deposition (LPD) process. The electrochemical measurements indicated that MB retained its electrochemical activity in the hybrid films. The linear dependence of the reduction peak current for MB upon the scan rate and linear relationship between the middle point potential of MB and pH revealed the surface-confined two-proton two-electron electrochemical characteristics of MB entrapped in hybrid LPD films. Although the electron transfer of K-3[Fe(CN)(6)] on GC surface was inhibited by TiO2 film, the catalytic reduction of K-3[Fe(CN)(6)] by MB was observed on the MB/TiO2 hybrid films. The electrocatalytic activity of hybrid films was also demonstrated as an artificial peroxiclase for the catalytic reduction of H2O2. (c) 2008 Elsevier B.V. All rights reserved.