HLaNb2O7 photocatalyst was prepared by the proton exchange reaction of KLaNb2O7 With diluted acid. The layered perovskite KLaNb2O7 has been successfully synthesized by the polymerized complex method. The product was characterized by X-ray diffraction, ultraviolet-visible spectra, scan electron microscope, TG-DSC, specific surface area, and FTIR. The layered perovskite KLaNb2O7 was formed at a lower calcination temperature (1000 degrees C, 6 h) by the polymerized complex method than a solid-state reaction method (1150 degrees C, 24 h). Photocatalytic decomposition of water to produce hydrogen under UV irradiation with methanol as electron donor was studied over layered perovskite HLaNb2O7 photocatalysts. The HLaNb2O7 photocatalyst prepared by the polymerized complex method showed much higher activity than that prepared by conventional solid-state reaction method. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.