Gas-phase photocatalytic oxidation of benzene over titanium dioxide loaded on Ce0.67Zr0.33O2

Abstract

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 TiO2 toward the decomposition of gaseous benzene in a batch reactor can be greatly enhanced by loading TiO2 on the surface of Ce0.67Zr0.33O2. In this work, we have investigated the loading amount of TiO2 on Ce0.67Zr0.33O2 in enhancing the photocatalytic activity of TiO2. This article reveals that the optimal loading amount of TiO2 on Ce0.67Zr0.33O2 for the degradation of gaseous benzene is 1% (wt). The prepared photocatalyst was characterized by Brunauer-Emmet Teller, X-ray diffraction, UV–vis diffuse reflectance, and X-ray photoelectron spectroscopy. The deposited titania was well dispersed in the Ce0.67Zr0.33O2 matrix. TiO2/Ce0.67Zr0.33O2 absorbs much more ultraviolet light than TiO2 in the ultraviolet light region. The binding energy values of Ti2p shift to lower value. TiO2/Ce0.67Zr0.33O2 demonstrates 1.5 times photocatalytic activity of that of pure TiO2. Based upon these observations, the mechanistic role of Ce0.67Zr0.33O2 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 absorption from 210 to 400 nm of TiO2/Ce0.67Zr0.33O2. © 2009 American Institute of Chemical Engineers Environ Prog, 2009