Boosting photocatalytic degradation of antibiotic wastewater by synergy effect of heterojunction and phosphorus doping

Phosphorus-doped g-C3N4/ZnIn2S4 (PCN/ZIS) heterojunction photocatalysts were constructed by solvothermal method. The physical and chemical properties were investigated with X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), etc. The degradation of antibiotic wastewater was used to investigate the photocatalytic activities of composites under visible-light irradiation. The 10% PCN/ZIS had the best pho-tocatalytic degradation performance for tetracycline with a photodegradation rate of 0.0874 min(-1), which is respectively about 2.9 and 52.0 times than that of pure ZIS and PCN. Meanwhile, it was concluded that the holes and center dot O-2(-) (superoxide radicals) play dominant roles in the photocatalytic reactions through radicals trapping experiments, while center dot OH (hydroxyl radicals) has a negative effect. In addition, 10%PCN/ZIS, with excellent stability and recyclability, also exhibited high photocatalytic activity for terramycin, chlortetracycline and ofloxacin. Overall, with the enhanced photocatalytic performance, PCN/ZIS could be potentially applied for photocatalytic degradation of antibiotic wastewater. (c) 2020 Elsevier Inc. All rights reserved.

Automated summary

The Phosphorus-doped g-C3N4/ZnIn2S4 (PCN/ZIS) heterojunction photocatalysts were constructed through solvothermal method, exhibiting excellent photocatalytic degradation performance, especially in treating tetracycline wastewater. Radical trapping experiments confirmed that holes and superoxide radicals played dominant roles in the photocatalytic reactions, while hydroxyl radicals had negative effects.