We demonstrate that a desired oxidation state can be achieved by synthetic colloidal methods and the choice of characterization technique is crucial for determining the physicochemical properties that influence the photocatalytic activities. XPS studies showed that PtO2 was realized in this study, and the resultant crystalline PtO2-TiO2 prepared by subsequent hydrothermal treatment demonstrated activity for phenol degradation under simulated solar light irradiation. Preformed platinum based TiO2 ensures control over the oxidation state and the crystallite size of titania. The role of Pt-ox in the form of stable Pt4+ is elucidated as a mild recombination center, whereas the crystallite size of Pt in surfactant free Pt-0-TiO2 appears to be the overriding factor for attaining enhanced photocatalytic performance. (C) 2013 Elsevier B.V. All rights reserved.