Synthesis and Application of a Fe 3 O 4 /Ag 3 PO 4 /g-C 3 N 4 Magnetic Composite Photocatalyst for Sulfonamide Antibiotics Degradation

In this study, a novel Fe 3 O 4 /Ag 3 PO 4 /g-C 3 N 4 magnetic composite photocatalyst was successfully synthesized, tailored specifically for the visible light-driven photocatalytic degradation of sulfonamide antibiotics, more precisely, sulfamethazine (SMZ). To analyze the fabricated samples, characterization techniques such as X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), photoluminescence spectroscopy (PL), and UV-vis diffuse reflectance spectra (UV-vis) were systematically employed. The composite showcased efficient visible-light absorption and charge separation, with its peak photocatalytic performance recorded at a solution pH value of 6.0. Significantly, the Fe 3 O 4 /Ag 3 PO 4 /g-C 3 N 4 magnetic composite photocatalyst displayed excellent stability and recyclability, consistently maintaining a high degradation efficiency of over 97% even after five consecutive cycles. Further experimentation with radical scavengers confirmed a significant decrease in photocatalytic activity, establishing that superoxide radicals (•O 2 − ) and photo-generated holes (h + ) are the primary active species during the degradation of SMZ. Overall, it provides a crucial understanding regarding the photocatalytic decomposition of sulfonamide antibiotics using magnetic composite photocatalysts. It also emphasizes the promising potential of the Fe 3 O 4 /Ag 3 PO 4 /g-C 3 N 4 composite for tangible applications in environmental remediation.