A heterostructured SrTiO3/TiO2 nanotube (NT) array film was successfully fabricated through the conversion of a highly ordered TiO2 NT film by a hydrothermal method. As the hydrothermal reaction proceeded, an increasing amount of TiO2 in the film was converted into SrTiO3 nanoparticles, and the SrTiO3/TiO2 nanotube wall thickness gradually increased. As compared with the TiO2 NT film, the SrTiO3/TiO2 composite film presented a higher separation efficiency of the photogenerated electron-hole pairs and a higher photo-to-current conversion efficiency. The heterostructured SrTiO3/TiO2 film prepared by 1 h hydrothermal reaction exhibited the best photoelectrochemical performance. The film as a photoanode could make the potential of 403 stainless steel in a 0.5 M NaCl solution decreased by 480 mV under illumination, showing a good photocathodic protection effect. The results demonstrated that the formation of the composite structure played an important role in the separation of photogenerated electrons and holes. (C) 2014 Elsevier Ltd. All rights reserved.