The influence of redox-treated Pt/TiO(2) photocatalysts on H(2) production is investigated. Catalyst characterizations are performed by TEM, XPS, XRD, BET, and UV-vis/DR spectroscopy techniques. In terms of production rate, the oxidation treatment shows higher reactivity than the reduction treatment. The reduction treatment allows the formation of metallic Pt(0), which more easily catalyzes the transition of TiO(2) from the anatase to the rutile phases. Reduction-treated Pt/TiO(2) photocatalysts have lower S(BET) values than oxidation-treated Pt/TiO(2) photocatalysts due to the higher percentage of TiO(2) in the rutile phase. Combining the results of XPS and optical analyses, PtO/TiO(2) shows a higher energy band gap than metallic Pt(0)/TiO(2), indicating that oxidation-treated Pt/TiO(2) is more capable of achieving water splitting for H(2) production. According to the results of this study, the oxidation treatment of Pt/TiO(2) photocatalysts can significantly enhance the reactivity of photocatalytic H(2) production because of their homogenous distribution, lower phase transition, higher S(BET), and higher energy band gap. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.