摘要
The development of promising materials for effective visible-light-driven photodegradation of emerging pollutants for environmental sustainability is an urgent issue. In this study, a type-II g-C 3 N 4 (g-CN)/NH 2 -modified MIL-125 (Ti) (MOF) nanocomposite was fabricated, and then linked with Schottky Ti 3 C 2 (MXene) for the visible-light-responsive photodegradation of diclofenac (DCF), a commonly found pharmaceutical contaminant in an aquatic environment, under different environmental conditions. The electron microscopic results indicate that the g-CN can be well-deposited onto the disc-type MOF and then coated onto MXene to form a ternary system. The UV–vis spectra confirm the reduced electron-hole recombination rate of g-CN/MOF/MXene, leading to the enhancement of photodegradation of DCF under visible light irradiation. The rate constant for 10 mg L -1 DCF photodegradation is 0.038 min −1 over 0.5 g L -1 photocatalyst at the optimal pH of 5. The scavenger experimental results corroborate the type-II-based Schottky heterojunction mechanism. Electrons can be transferred from g-CN to NH 2 -MIL-125, while holes can migrate from MOF to generate O 2 [rad]− radicals for DCF photodegradation. Moreover, MXene acts as the reservoir for electrons to reduce the electron-hole pair recombination rate. The developed photocatalyst exhibits superior photoactivity and can be recycled for at least 5 cycles. Results demonstrate superiority of g-CN/MOF/MXene photocatalysts for efficient photodegradation of DCF and antibiotics, enabling development of MOF/MXene-based photocatalysts for wastewater treatment.