A Solid-State Carrier Transport-Prompted Z-Scheme BiVO4 Quantum Dots-Based Photocatalyst for Boosted Photocatalytic Degradation of Antibiotics

Monoclinic BiVO4 is extensively exploited in organic oxidation because of its appropriate valence band and remarkable catalytic activity. BiVO4 quantum dots not only have a high specific surface area and active sites for photocatalytic reactions, but can address the short carrier diffusion path problem. Herein, a Z-scheme BiVO4 quantum dots/reduced graphene oxide/g-C3N4 photocatalyst is constructed. Benefiting from the distinct BiVO4 quantum dots and layered g-C3N4 sheets, the photocatalytic compound possesses a considerable light capture capability and surface area. The established Z-scheme photocatalytic compound with a suitable electronic band structure and redox potential is integrated with a "synthesis and assembly" method. The sodium oleate surfactant plays an important role in the preparation of uniform BiVO4 quantum dots with a diameter of 3-6 nm. The optimized photocatalytic degradation experiments show that the ciprofloxacin and amoxicillin photocatalytic efficiencies are up to 92.2% and 70.7% in 1 h, respectively. It is shown that the improved photocatalytic activities involve in the prolonged lifetime of photogenerated electrons and fast carrier migration in the compound upon simulated sunlight exposure. Herein, a prospective stage for developing more Z-scheme heterojunctions with excellent photocatalytic properties for antibiotic wastewater treatment and reproducible solar capture in photochemical energy conversion is offered.