Photodegradation catalysts were prepared by doping MgF2 matrix with V2O5. Since V2O5 has a band-gap of 2.0 eV, it is a potentially visible light excitable semiconductor. However, because of the rapid recombination of electron-hole pairs, pure V2O5 is not active in photodegradation reaction of organic pollutants. The doping of V2O5 into MgF2 matrix retards the recombination of electron-hole pairs in catalysts and makes the catalysts active in visible light. A photon quantum efficiency of 3.2% at 578 nm was obtained over 9.1 mol%VOx/MgF2 for acetone degradation. An even higher photon quantum efficiency of 34.6% at 578 nm was obtained over 0.133%Pt/9.1%VOx/MgF2 (in mol) for acetone degradation. The VOx/MgF2 Catalysts and Pt-doped VOx/MgF2 catalysts were also proved to be active for the photodegradation of methanol, ethanol, and benzene. (C) 2008 Elsevier B.V. All rights reserved.