Sonochemical fabrication of morpho-genetic TiO₂ with hierarchical structures for photocatalyst

Titanium oxides (TiO₂) with hierarchical structures have been successfully replicated from biotemplate using a sonochemical method. The bio-templates, cedarwoods, were irradiated under ultrasonic waves in TiCl₄ 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.