Size-controllable Synthesis of Hierarchically Structured Mesoporous Anatase TiO_2 Microspheres Covered With {001} Facet

摘要

Synthesis of anatase titanium dioxide (TiO_2) with both controllable size and high energy facets is technologically important for its application in photocatalysis, photoelectrochemical cell, and solar cells. Herein, we report a simple and fluorine free hydrothermal method to synthesize hierarchically nanostructured mesoporous anatase TiO_2 spheres (MATS) with controllable size, which covered with nearly 100% {001} facet. Mild H_2SO_4 was used as both a phase-inducer formation of anatase phase and a capping agent to promote oriented growth and formation of {001} facet. PVP acted as morphology control agent to prevent growing larger of the mesoporous anatase TiO_2 spheres (MATS) with ～600 nm in size. Detailed XRD and SEM studies suggested that formation of MTAS is a typical nucleation and growth process. The refining or reconstruction of TiO_2 crystal structure during growth resulted in mesoporous crystalline framework that exhibits enhanced photocatalytic degradation of rhodamine B.