Controllable synthesis of mesoporous F-TiO2 spheres for effective photocatalysis

An effective bottom-up synthesis strategy has been developed to prepare monodisperse mesoporous F-TiO2 spheres consisting of anatase nanocrystallites. The spherical morphology is derived from nonporous hydrous TiO2 spheres obtained from the direct precipitation of titanium alkoxides under the direction of dodecylamine (DDA) in water-containing ethanol-acetonitrile mixed solution, and a mesoporous structure is generated and stabilized by a subsequent solvothermal reaction in NH4F-contaning ethanol solution. After calcination, mesoporous F-TiO2 spheres with a diameter around 250 nm are fully crystallized with a large surface area of 132 m(2) g(-1), and a pore size of 8.5 nm. Ascribed to their accessible mesoporous structure, well-packed anatase nanocrystallites, excellent light harvesting property, and surface fluorination, the resulting mesoporous F-TiO2 spheres show enhanced light harvesting in the UV-Vis range as well as superior photocatalytic activity in dye degradation.