Nanowire TiO2 thin films were successfullyprepared on Ti metal substrates by hydrothermal treatment ofcalcined Ti foils in 10 MNaOH. The nanowire TiO2 thin filmsexhibited much larger surface area and higher photoelectrochemicalperformance than the TiO2 thin films prepared on Timetal substrates by the calcination of Ti foil. These nanowirefilms were shown to act as an efficient photoanodes for thephotoelectrochemical water splitting reaction.