Construction of a novel OS/BiVO4 catalyst for enhancing the photocatalytic degradation performance of sulfonamide

Abstract

Exploiting of high-value-added environmental materials related to oily sludge (OS) is an important development direction for OS resource utilization. A series of OS/BiVO4 catalysts were synthesized by activation-pyrolysis and hydrothermal methods. Photocatalytic performance was estimated through sulfanilamide (SA) degradation (SA) under visible light irradiation. The OS/BiVO4–20% has the best photodegradation ability for SA. The degradation rate of SA was about 97.8% after six hours of visible light irradiation. The first-order kinetics degradation rate constants of OS/BiVO4–20% for SA is 8.3 times that of pure BiVO4. The radical quenching and ESR experiments reveal that the hole (h+) and hydroxyl radical (·OH) were the primary active species for SA photocatalytic degradation. The presence of OS and H2O2 can significantly improve the charge separation efficiency, and inhibit electron-hole complexes, thereby extending the lifetime of electron carriers and producing many active hydroxyl radicals and holes on the surface of catalyst particles. Due to the introduction of OS, OS/BiVO4 has good texture properties and high oxygen absorption content, which is also conducive to the photodegradation of SA. Fourier-transform infrared (FTIR), in combination with two-dimensional correlation spectroscopy (2D-COS), indicated that the C–N (1351 cm-1), CC (1450 cm-1), SO2–N (1116 or 1182 cm-1), and N–H (1636 cm-1) groups can change in turn during the catalytic degradation process. This work improves the surface properties of BiVO4 semiconductor materials by introducing OS, thereby increasing the photodegradation efficiency of BiVO4 catalysts against antibiotics, which provides valuable insights into the design of next-generation photocatalysts.