Syntheses, Li Insertion, and Photoactivity of Mesoporous Crystalline TiO₂

Ordered mesoporous rutile and anatase TiO 2 samples are prepared using mesoporous silica SBA‐15 as template and freshly synthesized titanium nitrate and titanium chloride solutions as precursors. The rutile material formed from the nitrate solution is monocrystalline and contains minimal amounts of Si with a Si:Ti ratio of 0.031(4), whereas the anatase material formed from the chloride solution comprises nanocrystals and contains a higher content of Si with a Si:Ti ratio of 0.18(3). It is found that control of temperature and selection of Ti‐containing precursor play important roles in determining the crystal phase and crystallinity. A possible formation mechanism of porous crystalline TiO 2 is suggested. Characterization of these porous materials is performed by XRD, HRTEM, and nitrogen adsorption/desorption. SBA‐15‐templated mesoporous rutile TiO 2 exhibits a higher Li ion insertion capability than KIT‐6‐templated TiO 2 due to its larger surface area. Likewise mesoporous anatase TiO 2 :SiO 2 composite has a better photoactivity than bulk TiO 2 or TiO 2 ‐loaded SBA‐15 for bleaching methylene blue.