Ultrathin fluorine-doped TiO2(B) nanosheets-anchored hierarchical cog wheel-shaped NH2-MIL-53(Al) for boosting photocatalytic activity

Abstract

Developing novel S-scheme systems with highly active solar-driven catalysts are of huge interest in degrading noxious antibiotics in a sustainable manner. Herein, fluorine (F)-doped TiO2(B) nanosheets-modified gear-shaped NH2-MIL-53(Al) were first fabricated for tetracycline degradation. Benefiting from the synergy among the incorporated F species, well-matched band structure, and built-in electric field, the optimized nanohybrid attains an impressive degradation rate (94.6 %) and TOC mineralization efficiency (71.4 %). Moreover, the addition of external interferential ions, such as Cu2+ or NO3− nearly have no influence on the photoactivity. A probable degradation pathway was proposed on the basis of the calculated Fuki indexes and prime intermediates identified by a high-performance liquid chromatography-mass spectrometer. On NH2-MIL-53(Al)/F-TiO2(B) interfaces, the migration of electrons from F-TiO2(B) to NH2-MIL-53(Al) via intense electronic interactions contribute to a S-scheme mode, which is conductive to facilitating rapid spatial charge separation, superior visible light utilization, and populated exposed active sites with high potentials. This study paves new avenues to an atomic-scale interfacial engineering of S-scheme heterojunctions for efficient water purification.