A series of metal (Pt, Ag, and Cu)-deposited TiO2 films with nanocrystalline structure was prepared. Compared with TiO2 film, the degradation efficiency of formic acid for the metal-deposited TiO2 films was significantly higher in both photocatalytic (PC) and photoelectrocatalytic (PEC) processes, the enhanced order in PC and PEC activity for the metal-deposited film is Pt-TiO2>Ag-TiO2>Cu-TiO2 However. the electrochemical dissolution of deposited metals (Ag, and Cu) on TiO2 film would be a technical problem in PEC processes, an alternate PC and PEC processes intermittently provide a positive approach to maintain deposited metals (Ag, and Cu) on the TiO2 films well (C) 2009 Elsevier B.V. All rights reserved.