PdO nanoparticles decorated TiO2 film with enhanced photocatalytic and self-cleaning properties

Magnetron sputtering and gas aggregation source (GAS) approaches were combined for the preparation of columnar TiO2 structures decorated with PdO nanoparticles (NPs). The totally solvent-free synthesis approach provides good control of surface coverage, size, morphology, and stoichiometry of PdO NPs in comparison to wet chemical synthesis methods. X-ray photoelectron spectroscopy (XPS) analysis showed that the heat treatment led to the formation of a mixed oxide state PdO/PdO2 on the TiO2 layer. A steady equilibrium between PdO (oxidation by free and adsorbed center dot OH) and PdO2 (reduced by trapped photogenerated electrons) phases under UV irradiation seems to provide an efficient electron-hole pair separation. Such robust PdO-TiO2 thin films have a strong potential for use as photocatalytic and self-cleaning windows or similar out-door technical surfaces. (C) 2020 Elsevier Ltd. All rights reserved.