Effect of metal doping into Ce_(0.5)Zr_(0.5)O_2 on photocatalytic activity of TiO_2/Ce_(0.45)Zr_(0.45)M_(0.1)O_X (M = Y, La, Mn)

摘要

The paper demonstrates that the photocatalytic activity of TiO_2 towards the decomposition of gaseous benzene in a batch reactor can be greatly improved by loading TiO_2 on the surface of CeO_2-ZrO_2. The research investigates the effects of three metals doping into Ce_(0.5)Zr_(0.5)O_2 on photocatalytic activity of TiO_2/Ce_(0.45)Zr_(0.45)M_(0.1)O_X (M = Y, La, Mn). The prepared photocatalysts were characterized by BET, XRD, UV-vis diffuse reflectance and XPS analyses. BET surface area of TiO_2/Ce_(0.45)Zr_(0.45)M_(0.1)O_X (M = Y, La, Mn) is smaller than that of Ce_(0.5)Zr_(0.5)O_2. XRD results reveal that the deposited titania is highly dispersed as in the CeO_2-ZrO_2 matrix, doping M in the CeO_2-ZrO_2 lattice causes the changing of lattice space and the diffraction peaks shift to higher 2θ position. Among these four catalysts, the band gap value of TiO_2/Ce_(0.45)Zr_(0.45)La_(0.1)O_X is the lowest. The binding energy value of Ti 2p_(3/2) of four catalysts transfers to a lower value. The order of photocatalytic activity is TiO_2/Ce_(0.45)Zr_(0.45)La_(0.1)O_X >TiO_2/Ce_(0.45)Zr_(0.45)Y_(0.1)O_X >TiO_2/Ce_(0.45)Zr_(0.45)Mn_(0.1)O_X >TiO_2/Ce_(0.5)Zr_(0.5)O_2 >TiO_2. The proposed mechanism is of electron transfer and the stronger absorption in the region 210-400 nm.