Stabilize the oxygen vacancies in ZnO via altering local electronic structure by Co and Ni doping: A novel strategy for achieving durable visible light driven photo-Fenton degradation of chloramphenicol

Abstract

The build-up of antibiotics, harmful pollutants, and pharmaceutical products has led to the significant contamination of environmental water bodies. Hence, the advancement of oxidation methods such as light-induced photo-Fenton degradation has proven crucial for efficiently desolating these harmful pollutants. Herein, we report a novel photo Fenton catalyst, Co and Ni co-doped ZnO (Zn1-x-yCoxNiyO) nanorods (NRs) for enhanced photocatalytic degradation of chloramphenicol (CAP) under visible light irradiation. The NRs were synthesized via the ultrasonication-assisted solvothermal method. Among the different Co and Ni doping concentrations, Zn0.96Co0.03Ni0.01O NRs showed superior photodegradation efficiency of 94.2%. Here, •OH radicals were identified as predominant reactive oxygen species in photocatalytic degradation by electron spin resonance (ESR) analysis and scavenging assay. The effect of various environmental parameters such as nanoparticle dosage, CAP concentration, pH, and ions were investigated to understand the impact of these parameters on the degradation of CAP. Further, Zn0.96Co0.03Ni0.01O NRs were stable for six consecutive photodegradation cycles, which showed their excellent efficiency and reusability for prolonged usage. Photostability was further confirmed by XPS and XRD analysis of the used photocatalyst. Also, the photodegradation pathway of CAP was predicted by identifying the intermediate compounds via GC-MS analysis. This approach holds promise for the efficient visible-light-driven degradation of pharmaceutical pollutants including CAP and contributes to the advancement of sustainable water treatment technologies.