Key Laboratory of Resource Chemistry of Nonferrous Metals, Ministry of Education, China, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
J Hazard Mater. 2011 May 15;189(1-2):329-35. doi: 10.1016/j.jhazmat.2011.02.038. Epub 2011 Feb 22.
A WO(3)/TiO(2) 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 WO(3)/TiO(2) hollow spheres were red-shifted compared to the TiO(2) hollow spheres, indicating an extension of light absorption into the visible region of the composite photocatalyst. The WO(3) and TiO(2) 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 WO(3)/TiO(2) hollow spheres under visible light within 80 min. Under the same conditions, only 24% MB can be photodegraded by TiO(2). The photocatalytic mineralization of MB, catalyzed by TiO(2) and WO(3)/TiO(2), 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 WO(3)/TiO(2) composite semiconductor material which was 3.2- and 3.5-fold higher than with the TiO(2) 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.
采用模板法成功制备了平均粒径为 320nm、壳厚 50nm 的 WO(3)/TiO(2)复合空心球光催化剂。UV-vis 漫反射光谱表明，WO(3)/TiO(2)空心球的主要吸收边缘相对于 TiO(2)空心球发生红移，表明复合光催化剂的光吸收扩展到可见光区域。X 射线衍射分析证实了 WO(3)和 TiO(2)相的存在。BET 等温线表明，空心球的比表面积和平均孔径分别为 40.95m(2)/g 和 19nm。光催化实验表明，WO(3)/TiO(2)空心球在可见光下 80min 内可降解 78%的 MB。在相同条件下，TiO(2)只能降解 24%的 MB。在紫外光照射下，TiO(2)和 WO(3)/TiO(2)催化的 MB 光催化矿化反应速率明显高于可见光照射下的反应速率，而在紫外光和可见光照射下，WO(3)/TiO(2)复合半导体材料的表观速率常数分别比 TiO(2)材料提高了 3.2 倍和 3.5 倍。耦合纳米复合材料光催化活性的提高归因于光电子/空穴分离效率和光激发波长范围的扩展。
