Significant improvement in TiO 2 photocatalytic activity through controllable ZrO 2 deposition.

ZrO 2 was deposited on anatase TiO 2 nanoparticles using 5-80 cycles of atomic layer deposition (ALD). The photocatalytic activity of all samples was evaluated based on the degradation of methylene blue (MB) solution under UV light. The TiO 2 sample with 45 cycles of ZrO 2 deposition (45c-Zr/TiO 2 , 1.1 wt% ZrO 2 ) was proved to be the most efficient catalyst with a degradation kinetic constant 10 times larger than that of the pure TiO 2 sample. All samples were characterized using inductively coupled plasma atomic emission spectroscopy (ICP-AES), nitrogen adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra analysis (UV-DRS), Raman and photoluminescence (PL) techniques. The high photocatalytic activity of 45c-Zr/TiO 2 can be attributed to stronger adsorption in the ultraviolet region and a reduction in the recombination rate of electron/hole pairs.