Enhancing photocatalytic activities of titanium dioxide via well-dispersed copper nanoparticles.

The modification of titanium dioxide (TiO2) using noble metal nanoparticles is considered as a promising technique to make electrode with outstanding photocatalytic performance. In this paper, self-organized anodic TiO2 nanotube arrays were decorated with well-distributed small Cu nanoparticles through a novel technique that combines magnetron sputtering and thermal dewetting. The obtained nanocomposite catalyst exhibited 4-fold increase in the photodegradation rate of methylene blue aqueous solution under solar light irradiation than anatase TiO2 prepared with same anodization conditions. The enhanced photocatalytic activity was attributed to the synergistic effect of Schottky barrier and Surface plasmon resonance. The influence of post annealing process, sputtering time and thermal dewetting temperature on photocatalytic performance was studied and the optimal preparation conditions were proposed. The results of this study may provide a new strategy to improve photocatalytic efficiency of TiO2 without using high-cost noble metals.