Confinement synthesis of hierarchical ordered macro-/mesoporous TiO2 nanostructures with high crystallization for photodegradation

TiO2 hierarchical structures have attracted great research interests in last decades owing to their unique properties and wide applications. However, well-confined synthesis of hierarchical macro-/mesoporous TiO2 nanostructure still is a challenge. Herein, we report a facile synthesis of hierarchical ordered macro-/mesoporous TiO2 nanostructures through confinement self-assembly in three-dimensional (3D) periodic macroporous carbon scaffolds. Notably, the strong interaction between TiO2 frameworks and macroporous carbon scaffolds can re- strain the collapse of mesostructures during the heat treatment process, thus leading to the formation of high crystallized macro-/mesoporous TiO2. The resultant macro-/mesoporous TiO2 nanostructures possess a high surface area of 235 m(2) g(-1) and double interconnected pore structures, which are critically important for photocatalytic applications. The methylene blue degradation rate constants of the macro-/mesoporous TiO2 is 0.182 min(-1), which is almost 4 and 11 times higher than that of ordered mesoporous TiO2 (0.017 min(-1) ) and macroporous TiO2 (0.011 min(-1) ), respectively.