화학공학소재연구정보센터
Applied Surface Science, Vol.257, No.3, 756-761, 2010
Preparation of titania hollow spheres by catalyst-free hydrothermal method and their high thermal stabilities
TiO2 hollow spheres have been prepared by hydrothermal method using carbon spheres as hard templates based on template-directed deposition and calcination in order to remove templates. The morphology and structure of samples were systematically characterized by using various techniques, including XRD, zeta analyzer, SEM, TEM, DRS and FTIR. In this approach, the anatase phase was retained for temperatures up to 900 degrees C. Moreover, negative charged titania is deposited onto the negative charged surface of carbon spheres, which is proved by nanoparticle size analyzer. Therefore, a possible formation mechanism of TiO2 hollow spheres was proposed. TiO2 hollow spheres calcined at 550 degrees C exhibited the superior photocatalytic activity for the degradation of Rhodamine B, 2.9 times greater than that of Degussa P25. Furthermore, thermal stability of TiO2 hollow spheres was examined. Fortunately, we found that hollow structures could still be visible distinctly after calcining at 900 degrees C. Crown Copyright (C) 2010 Published by Elsevier B. V. All rights reserved.