Sonochemical fabrication of morpho-genetic TiO<inf>2</inf> with hierarchical structures for photocatalyst

Abstract

Titanium oxides (TiO2) with hierarchical structures have been successfully replicated from biotemplate using a sonochemical method. The biotemplates, cedarwoods, were irradiated under ultrasonic waves in TiCl 4 solutions and then calcined at temperatures between 450 and 600 °C. The fine replications of the biotemplates in TiO2 down to nanometer's level were verified using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The photocatalytic activities were assessed by measuring the percentage degradation of methylene blue using UV-vis spectroscopy. The calcination temperature has a strong effect on the structural replication and photocatalytic activity of the replicas. It appears that the calcination temperature of 450 °C results in the best structural replication with the highest surface area of 54.8 m2 g-1, and thus has the best photocatalytic properties. This method provides a simple, efficient, and versatile technique for fabricating TiO2 with hierarchical structures, and it has the potential to be applied to other systems for producing functional hierarchical materials for chemical sensor and nanodevices. © Springer Science+Business Media B.V. 2009.