Biotemplated synthesis of high specific surface area copper-doped hollow spherical titania and its photocatalytic research for degradating chlorotetracycline

Copper-doped titania (Cu/TiO2) hollow microspheres were fabricated using the rape pollen as biotemplates via an improved sol-gel method and a followed calcinations process. In the fabricated process, a titanium(IV)-isopropoxide-based sol directly coated onto the surface of rape pollen. Subsequently, after calcinations, rape pollen was removed by high temperature and the hollow microsphere structure was retained. The average diameter of as-obtained hollow microspheres is 15-20 mu m and the thickness of shell is approximately 0.6 mu m. Knowing from XRD results, the main crystal phase of microspheres is anatase, coupled with rutile. The specific surface area varied between 141.80 m(2)/g and 172.51 m(2)/g. This hollow sphere photocatalysts with high specific surface area exhibited stronger absorption ability and higher photoactivity, stimulated by visible light. The degradation process of chlortetracycline (CTC) solution had been studied. The degradated results indicate that CTC could be effective degradated by fabricated hollow spherical materials. And the intermediate products formed in the photocatalytic process had been identified. (C) 2012 Elsevier B.V. All rights reserved.