Magnetic fluorinated mesoporous g-C3N4 for photocatalytic degradation of amoxicillin: Transformation mechanism and toxicity assessment

Abstract

A novel fluorinated graphitic carbon nitride photocatalyst with magnetic properties was synthesized by a facile hydrothermal method and used for degradation of amoxicillin (AMX) in water. Compared to the bulk g-C3N4, magnetic fluorinated Fe3O4/g-C3N4 (FeGF) with a high specific surface area (243 m2 g−1) and easy separation from aqueous solution by magnet, led to improved photocatalytic activity in terms of AMX removal and mineralization as well as detoxification of the solution. The results showed that in comparison with a 500 W visible lamp, using a UV lamp (10 W) was considerably more effective for AMX removal, its mineralization and detoxification of the solution. Based on the measurement of accurate mass of the transformation products and their main fragments, a degradation pathway for AMX was proposed. The peak intensities of most transformation products (TPs) generated by using modified photocatalyst under UV light (UV/FeGF2) process were significantly lower than those generated by using pristine g-C3N4, suggesting that UV/FeGF2 process produced a higher extent of mineralization and a lower accumulation of transformation by-products. Based on the use of inexpensive precursor and modifier, simple preparation, good photocatalytic activity and low energy consumption, the proposed method can guide the development of low-cost and high-performance photocatalysts.