This study compares the photocatalytic (PC) and photoelectrocatalytic (PEC) oxidation of glucose by Pt-TiO2 films under similar conditions. The overall oxidation efficiency of the PEG process was better than the PC process, for both TiO2 and Pt-TiO2 films. The Pt deposits enhanced the PEC oxidation efficiency of glucose at low cathodic (-0.1 V) and low anodic potential bias (+0.1 V). As the applied anodic bias was increased to >+0.5 V, the undoped-TiO2 films outperformed their Pt-TiO2 counterparts. This suggests that in the studied systems, at an anodic bias of >+0.5 V. more holes were available for the oxidation of glucose on the surface of TiO2 compared to Pt-TiO2 films. In the PEC systems, above a certain applied bias, Pt deposits may have a detrimental effect on the performance of a PEG system because the Pt deposits could merely block the surface of TiO2 (particularly at the highest Pt loadings). Lower measured photocurrents from Pt-TiO2 films compared to undoped-TiO2 and a decrease in the photocurrent as the Pt loading increased corroborate this postulation. (C) 2010 Elsevier B.V. All rights reserved.