Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Fabrication of Porous TiO2 Hollow Spheres and Their Application in Gas Sensing | Nanoscale Res Lett 2010 5 1437-1441 DOI s11671-010-9658-2 NANO EXPRESS Fabrication of Porous TiO2 Hollow Spheres and Their Application in Gas Sensing Gang Yang Peng Hu Yuebin Cao Fangli Yuan Ruifen Xu Received 31 March 2010 Accepted 19 May 2010 Published online 3 June 2010 The Author s 2010. This article is published with open access at Abstract In this work porous TiO2 hollow spheres with an average diameter of 100 nm and shell thickness of 20 nm were synthesized by a facile hydrothermal method with NH4HCO3 as the structure-directing agent and the formation mechanism for this porous hollow structure was proved to be the Ostwald ripening process by tracking the morphology of the products at different reaction stages. The product was characterized by SEM TEM XRD and BET analyses and the results show that the as-synthesized products are anatase phase with a high surface area up to m2 g. Gas-sensing investigation reveals that the product possesses sensitive response to methanal gas at 200 C due to its high surface area. Keywords Porous TiO2 Hollow sphere Hydrothermal synthesis Gas sensing Introduction In recent decades nanostructured materials have attracted much attention due to their special structure and excellent properties in optics electrics magnetics chemistry etc. 1-4 . In particular titanium dioxide TiO2 as an important IV-VI group semiconductor with a band gap of eV has been widely applied in chemical industry G. Yang R. Xu College of Materials Science and Engineering Beijing University of Chemical Technology 100029 Beijing China G. Yang P. Hu Y. Cao F. Yuan State Key Laboratory of Multi-phase Complex System Institute of Process Engineering Chinese Academy of Sciences 100190 Beijing China e-mail flyuan@ electronic industry environmental protection cosmetics industry medical science and so on 3-6 . In order to improve their performances nanostructured TiO2 with various structures including nanoparticles 7 .
