Hydrogen-evolving photoanode of TiO2 nanoparticles film deposited by a femtosecond laser

TiO2 nanoparticles (NPs) were deposited on Ti foil by fs-PLD at room temperature under different chamber pressure from high vacuum (~10-6 mbar) to oxygen pressure (0.1 mbar, 1 mbar). The present work focuses on investigating the effects of deposition conditions on crystalline phase, morphology and photoelectrochemical properties of the resulting TiO2 NPs-assembled films electrode. The results show that the morphology of the sample obtained in 1 mbar shows the sparser nanoagglomerates than that of TiO2 NPs deposited under vacuum or in 0.1 mbar. Moreover, TiO2 NPs films with pure rutile phase and the thickness of less than 400 nm exhibited the higher photocurrent densities and the greater charge carrier densities. Combined with the analysis of the photovoltage, it can be deduced that the optimal deposition condition for better PEC performance of TiO2 NPs films produced by fs-PLD is the higher chamber pressure (1 mbar) and longer deposition time (3 h).