Phase control of hierarchically structured mesoporous anatase TiO2 microspheres covered with {001} facets

Abstract

The controlled synthesis of anatase titanium dioxide (TiO₂) with both high surface area and high energy facets is technologically important for its application in photocatalysis, photoelectrochemical cells, and solar cells. Here we report a simple and fluorine free hydrothermal method to synthesize hierarchically nanostructured mesoporous anatase TiO₂ spheres (MATS), which were covered with {001} facets. Mild H₂SO₄ was used as both a phase-inducer for the formation of the anatase phase and a capping agent to promote oriented growth and formation of {001} facets. Detailed XRD and SEM studies suggested that formation of MATS follows a typical nucleation and growth process. The refining or reconstruction of TiO₂ crystal structure during growth resulted in a mesoporous crystalline framework that exhibits enhanced adsorption and photocatalytic degradation of rhodamine B in comparison with that of commercial Degussa P25 TiO₂.