Gas-Phase Photocatalytic Oxidation of Benzene over Titanium Dioxide Loaded on Ce_(0.67)Zr_(0.33)O_2

摘要

Increasing environmental pollution caused by the volatile organic compounds because of their toxicity is a matter of great concern; thus, it is crucial to develop processes that can destroy these compounds effectively. It has been found that the photocatalytic activity of TiO_2 toward the decomposition of gaseous benzene in a batch reactor can be greatly enhanced by loading TiO_2 on the surface of Ce_(0.67)Zr_(0.33)O_2. In this work, we have investigated the loading amount of TiO_2 on Ce_(0.67)Zr_(0.33)O_2 in enhancing the photocatalytic activity of TiO_2. This article reveals that the optimal loading amount of TiO_2 on Ce_(0.67)Zr_(0.33)O_2 for the degradation of gaseous benzene is 1% (wt). The prepared photocatalyst was characterized by Bruna-uer-Emmet Teller, X-ray diffraction, UV-vis diffuse reflectance, and X-ray photoelectron spectroscopy. The deposited titania was well dispersed in the Ce_(0.67)Zr_(0.33)O_2 matrix. TiO_2/Ce_(0.67)Zr_(0.33)O_2 absorbs much more ultraviolet light than TiO_2 in the ultraviolet light region. The binding energy values of Ti2p shift to lower value. TiO_2/Ce_(0.67)Zr_(0.33)O_2 demonstrates 1.5 times photocatalytic activity of that of pure TiO_2. Based upon these observations, the mechanistic role of Ce_(0.67)Zr_(0.33)O_2 in the photocatalytic oxidation reaction has been suggested. The suggested mechanism is electrons transfer, increase of the surface coverage of active oxygen species, and increase of the absorp-tion from 210 to 400 nm of TiO_2/Ce_(0.37)Zr_(0.33)O_2.