An enhancement in the photocatalytic activity of TiO_2 by the use of Pd: the question of layer sequence in the resulting hierarchical structure

摘要

TiO_2 and Pd-modified TiO_2 photocatalysts were prepared by sol-gel method. X-ray diffraction (XRD) data showed that the presence of Pd in TiO_2 catalyst decreases the crystalline size of TiO_2 and stabilizes anatase phase. The study of the photocatalytic activity of the films via Linear Sweep Voltametry (LSV) plots and antibacterial test against Escherichia coli ATCC 25922-a gram negative bacterium-showed that Pd increases the photocatalytic activity of the coatings. Besides, the sequence of layer deposition (TiO_2 and Pd-modified TiO_2) influences the photocatalytic properties. In other words, more photocatalytic activity is obtained when Pd-modified layer is deposited first.