Preparation of a cerium/titanium composite with porous structure and enhanced visible light photocatalytic activity using beta-cyclodextrin polymer microspheres as the template

摘要

A porous Ce/TiO2 composite exhibiting high photocatalytic activity was successfully prepared by a sol-gel method using beta-cyclodextrin (beta-CD) polymer microspheres as the template. The structural and morphological characteristics of the prepared Ce/TiO2 composites were examined by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, low-temperature N-2 adsorption-desorption, thermogravimetry-differential thermal analysis, diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The characterization results revealed that after the calcination of as-prepared Ce/TiO2 at 500 A degrees C, it exhibits a porous structure with a TiO2 anatase phase. The photocatalytic performance of the as-prepared samples according to their different molar ratios was evaluated toward the degradation of rhodamine B (RhB). Compared to commercial TiO2, the porous Ce/TiO2 composite exhibited a higher photocatalytic activity under visible light irradiation at room temperature, with a photodegradation rate of up to 80% for RhB (5 mg L-1) within 60 min. Addition of beta-cyclodextrin polymer microspheres as the template not only renders a porous structure but also inhibits the crystal growth and anatase-to-rutile transformation of TiO2. Doping with Ce was hypothesized to decrease the radiative recombination of the photogenerated electrons and holes in TiO2, extending its light response to the visible region.