Photocatalytic water splitting properties of BaCeO3 were investigated experimentally and theoretically. Photocatalytic evaluation results showed that H-2 and O-2 evolved from aqueous solutions containing CH3OH and AgNO3 sacrificial reagents, respectively, and overall water splitting was achieved with the aid of RuO2-loading under ultraviolet light irradiation. Density function theory calculation indicated that the valence band of BaCeO3 was mainly composed of O 2p orbitals, while the conduction band was dominantly constructed by Ce 4f orbitals. (C) 2007 Published by Elsevier B.V.