A new visible-light-driven photocatalyst Sm2InNbO7 crystallized in a cubic system with the space group Fd3m was synthesized by a solid-state reaction method. Sm2InNbO7 showed high activities for photocatalytic H-2 evolution from CH3OH aqueous solution and for photocatalytic O-2 evolution from AgNO3 aqueous solution under visible-light irradiation, which was even better than that of InNbO4, a well-known visible-light-driven photocatalyst. Density functional theory (DFT) calculation indicated that strong dispersion from the hybridized In 5s and 5p orbitals at the bottom of the conduction band (CB) was considered to contribute to the high activity of photocatalyst Sm2InNbO7. (C) 2009 Elsevier B.V. All rights reserved.