Facile and controllable preparation of mesoporous TiO2 using poly(ethylene glycol) as structure-directing agent and peroxotitanic acid as precursor

This work demonstrated that mesoporous TiO₂ (meso-TiO₂) with controllable mesoporous and crystalline structures can be facilely prepared by using poly (ethylene glycol) (PEG) as structure-directing (SD) agent and peroxotitanic acid (PTA) as precursor. Meso-TiO₂ with high specific surface area (157 m²?g^-1), pore volume (0.45 cm³?g^-1) and large mesopore size of 13.9 nm can be obtained after calcination at 450°C. Such meso-TiO₂ also shows relatively high thermal stability. BET surface area still reaches 114 m²?g^-1 after calcination at 550°C. In the synthesis and calcination process, PEG that plays multiple and important roles in delivering thermally stable and tunable mesoporous and crystalline structures shows to be a suitable low-cost SD agent for the controllable preparation of nanocrystalline meso-TiO₂. The photocatalytic activity tests show that both high surface area and bi-crystallinity of obtained meso-TiO₂ are important in enhancing the performance in photo-decomposing Rhodamine B in water.