Improved Solar-Powered Water-Splitting Performance of Bi4Ti3O12/TiO2 Composite with Synergistically Interacted Heterointerfaces Under Platinum Cocatalysis.

Abstract

Perovskite-phase Bi₄Ti₃O₁₂ (BTO) is recognized as a potential candidate for solar-powered water-splitting due to its special conduction-band and valence-band positions. However, due to its broadband defect and surface chemical inertness, it is difficult to obtain outstanding water-splitting performance under photoirradiation. Herein, a donor-acceptor system with synergistically interacted heterointerface is constructed by growing TiO₂ nanoparticles on BTO microspheres, and an internal high-speed electron transfer channel is established to improve the photoelectric property under the electronic interaction of surface Pt nanocatalyst. Due to the excellent broadband-light harvesting capacity, significantly accelerated photoexciton separation/transfer, and introduction of abundant active sites, it effectively hindered the photoexciton recombination, thereby ≈3093.16 µmol·g^-1·h^-1 of H₂O-to-H₂ rate (pH = 11) and 673.85 µmol·g^-1·h^-1 of H₂O-to-O₂ rate (pH = 4) are achieved under simulated sunlight irradiation, reaching ≈0.1062% of solar-to-exciton utilization efficiency, which obviously outperformed the majority of recently reported photocatalysts. After a process of PVDF-networked membrane, a stable water-splitting activity is maintained during 10 cycles (50 h) due to the reinforced organic-inorganic interface and convenient separation/recovery property. This study proposes a valuable strategy for improving the water-splitting performance of BTO-based photocatalyst.