In order to increase the effectiveness of water splitting by TiO2 photocatalysts, the effects of the Pt deposition method and the Pt concentration on the hydrogen production rate of Pt-deposited TiO2 were studied. Among the methods used in this study, the formaidehyde method resulted in the highest rate of H-2 production. The amount of Pt on TiO2 had to be optimized to obtain the highest rate of H2 production. The Pt particles on the Pt-deposited TiO2 prepared by the present method were too small or too thin to be observed by transmission electron microscopy. (c) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.