Titania nanopowders with co-doping of Zn(II) and Fe(III) were prepared through sol-gel processing. The photocatalytic activity was evaluated by the photocatalytic decomposition of phenol. The influence of some parameters such as pH, doping concentration on the activity was investigated. It was found that the photocatalytic activity of TiO2 was obviously enhanced by the co-doping. In addition, a mechanism was proposed in order to account for the enhanced activity. (C) 2002 Elsevier Science B.V. All rights reserved.