Hollow Bi4Ti3O12/TiO2 nanocakes for photocatalytic hydrogen generation

We prepared Bi4Ti3O12/TiO2 hollow nanocakes via a metal-organic framework (MOF)-derived calcination strategy to achieve enhanced photocatalytic hydrogen generation compared to TiO2 hollow nanocakes. The photocatalytic hydrogen generation performance of Bi4Ti3O12/TiO2 hollow nanocakes was optimized by altering the concentration of precursor solution. Further research was performed to investigate the mechanism of improvement in the photocatalytic properties and to compare the photocatalytic and photoelectrochemical properties of Bi4Ti3O12/TiO2 with different structures and compositions. Owing to the structural advantages, the enhanced specific surface area of the as-prepared hollow nanocakes with more exposed active sites can improve the light-harvesting efficiency. More importantly, the type II heterojunction developed between Bi4Ti3O12 and TiO2 can not only enlarge the photo-response range, but can also efficiently promote the separation and suppress the recombination of photogenerated charge carriers. The integrated merits of hollow nanocake-like structure and type II heterojunction endow the enhanced photocatalytic water splitting efficiency. This work provides a reliable strategy for the design and fabrication of high-efficiency photocatalytic reaction systems.