Degradation of benzene on Zr-doped TiO2 photocatalysts with a bimodal pore size distribution

Zr-doped TiO2 was prepared from TiOSO4 and ZrOCO3 by a co-precipitation method using NH3 center dot H2O as the precipitation agent. The Zr-doped TiO2 was characterized by X-ray diffraction (XRD), low temperature N-2 adsorption-desorption measurement, and UV-Vis diffuse reflectance spectroscopy technology. Appropriate amounts of ZrO2 addition can greatly improve the TiO2 microstructure properties and its photocatalytic activities. In addition, polyethylene glycol (PEG) was used as a surfactant for templating the pore structure of samples. A bimodal pore structure can be controlled using PEG6000 and PEG20000 surfactants simultaneously during the preparation. The rate constant of benzene degradation over the Zr-doped TiO2 linearly decreases with the increase of photocatalytic reaction temperature and decreases in a polynomial relation with the benzene concentration. Moreover, it increases approximately linearly with the increase of the illumination intensity or area.