Different effects of cerium ions doping on properties of anatase and rutile TiO2

Pure and Ce4+ doped anatase and rutile TiO2 were prepared by hydrothermal methods and characterized by XRD, TEM, UV–vis diffusion spectroscopy, and XPS measurements. The photocatalytic reactivity of the catalysts was evaluated by the photodegradation of Rhodamine B (RB) under ultraviolet irradiation. The photocatalytic efficiency of the rutile sample doped with an appropriate amount of Ce4+ was enhanced while all Ce4+ doped anatase samples showed a much lower activity than pure anatase. The reasons were discussed