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

Abstract

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 restrain 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 m2 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.