A new series of visible light-driven photocatalysis M2.5VMoO8 (M = Mg, Zn) crystallized in the orthorhombic crystal system were synthesized by a solid-state reaction method. The photophysical and photocatalytic properties of M2.5VMoO8 (M = Mg, Zn) under visible light irradiation were examined. It was found that efficient O-2 was evolved from aqueous AgNO3 solution dispersed with the M2.5VMoO8 (M = Mg, Zn) powder samples synthesized under visible light irradiation. The electronic band structures of M2.5VMoO8 (M = Mg, Zn) were discussed in regard to the corresponding photocatalytic properties. (C) 2004 Elsevier B.V. All rights reserved.