Synergistic effect of ultrathin thickness and surface oxygen vacancies in high-efficiency Ti-mediated Bi2MoO6 for immense photocatalytic nitrofurantoin degradation and Cr(VI) reduction

Crystal defects have been broadly regarded to modulate the photoreactivity of semiconductors, mostly concerning the crystal and electronic structure of materials. On the other hand, oxygen defect-engineering is a fundamental approach to improve the photolysis activity of materials. Herein, an interactive hybrid intermediate strategy with oxygen defect-engineering was utilized to fabricate atomically-thin Ti-doped Bi2MoO6 nanosheets. Experimental results unveil that the well-engineered ultrathin Ti-doped Bi2MoO6 nanosheets tune the morphology, visible light absorption, local atomic and electronic band structure of Bi2MoO6. Importantly, the Ti doping hugely affects the BET specific surface area and porosity of Ti-Bi2MoO6 (72 m2 g(-1)) in contrast to bulk Bi2MoO6, which is 19 m(2) g(-1). Furthermore, the density functional theory calculations were carried out to explore the effect of Ti-doping on electronic band structure and the surface charge distribution in Ti-Bi2MoO6. It was found, rather than acting as a recombination center for photogenerated charge carriers, the defect caused by Ti doping mediated O vacancies in the crystal structure of Bi2MoO6, which favors the photogenerated charge carriers transfer and enhances the photocatalytic reactivity due to delocalized nature. With the advantages of atomically-thin structure Ti-Bi2MoO6 nanosheets, the synergistic effect of ultrathin thickness of Ti-Bi2MoO6 and oxygen vacancies has remarkably improved the photocatalytic activity towards the degradation of nitrofurantoin, and photoreduction of Cr(VI) in a highly acidic and alkaline medium. The present work opens a door for enhancing the photolysis performance of Bi2MoO6-based photocatalysts with excellent photolysis activity in the various environmental remediation processes.

Automated summary

Crystal defects play a significant role in modulating the photoreactivity of semiconductors, while oxygen defect-engineering is crucial for enhancing the photolysis activity of materials. In this study, atomically-thin Ti-doped Bi2MoO6 nanosheets were successfully fabricated using an interactive hybrid intermediate strategy with oxygen defect-engineering, showing improved photocatalytic activity towards environmental remediation processes. The synergistic effect of ultrathin thickness and oxygen vacancies in Ti-Bi2MoO6 significantly enhanced the photodegradation and photoreduction processes.