화학공학소재연구정보센터
Journal of Hazardous Materials, Vol.189, No.1-2, 329-335, 2011
Synthesis and photo-degradation application of WO3/TiO2 hollow spheres
A WO3/TiO2 composite, hollow-sphere photocatalyst with average diameter of 320 nm and shell thickness of 50 nm was successfully prepared using a template method. UV-vis diffuse reflectance spectra illustrated that the main absorption edges of the WO3/TiO2 hollow spheres were red-shifted compared to the TiO2 hollow spheres, indicating an extension of light absorption into the visible region of the composite photocatalyst. The WO3 and TiO2 phases were confirmed by X-ray diffraction analysis. BET isotherms revealed that the specific surface area and average pore diameter of the hollow spheres were 40.95 m(2)/g and 19 nm, respectively. Photocatalytic experiments indicate that 78% MB was degraded by WO3/TiO2 hollow spheres under visible light within 80 min. Under the same conditions, only 24% MB can be photodegraded by TiO2. The photocatalytic mineralization of MB, catalyzed by TiO2 and WO3/TiO2, proceeded at a significantly higher rate under UV irradiation than that under visible light, and more significant was the increase in the apparent rate constant with the WO3/TiO2 composite semiconductor material which was 3.2- and 3.5-fold higher than with the TiO2 material under both UV and visible light irradiation. The increased photocatalytic activity of the coupled nanocomposites was attributed to photoelectron/hole separation efficiency and the extension of the wavelength range of photoexcitation. (C) 2011 Elsevier B.V. All rights reserved.