Spatially Separated Bifunctional Cocatalysts Decorated on Hollow-Structured TiO for Enhanced Photocatalytic Hydrogen Generation.

Efficient charge separation can promote photocatalysis of semiconductors. Herein, a hollow-structured TiO sphere decorated with spatially separated bifunctional cocatalysts was designed, which exhibited enhanced photocatalytic hydrogen generation. Ultrasmall-sized MO (M = Pd, Co, Ni, or Cu) nanoparticles (NPs) were first introduced into a zeolite via confinement synthesis, and then, hollow TiO was fabricated by using the zeolite as a sacrificial template forming MO@TiO. Finally, Pt NPs were decorated on the outer shell, giving rise to MO@TiO@Pt, in which the MO NPs and Pt NPs acted as hole capturers and electron sinks, respectively. Thanks to the enhanced light harvesting of the hollow structure and improved charge separation induced by the smaller-sized cocatalysts as well as spatially separated bifunctional cocatalysts, the as-prepared PdO@TiO@Pt catalyst exhibited a superior photocatalytic hydrogen-generation property (0.45 mmol h). This work demonstrates the advantage of the spatially separated bifunctional cocatalysts in enhancing the photocatalytic properties of semiconductors.