V₂O₅/RGO/Pt nanocomposite on oxytetracycline degradation and pharmaceutical effluent detoxification

BACKGROUND: Antibiotics have been identified as significant pollutants owing to their adverse impact on the environment through the development of antibiotic-resistant bacteria. In a previous study, an e-waste-based reduced graphene oxide-V₂O₅-platinum (RGOV-Pt(1%)) nanocomposite was prepared and subsequently used for the photocatalytic degradation of oxytetracycline (OTC), a tetracycline group of antibiotics. RESULTS: This study aimed to assess the impact of additives such as H₂O₂, NaCl, Na₂CO₃, ethanol and persulfate on the photocatalytic degradation of OTC using RGOV-Pt(1%) nanocomposite. The results showed that the degradation efficiency decreased in the presence of NaCl and Na₂CO₃ owing to the electron–hole scavenging property of their anions. Low concentrations of H₂O₂ (up to 10 mmol L^–1) increased the OTC degradation efficiency, whereas high concentrations decreased the OTC degradation owing to the quenching of hydroxyl radicals. However, the presence of persulfate increased the OTC degradation efficiency owing to the formation of hydroxyl radicals. Furthermore, the OTC degradation pathway was elucidated using high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). The study was extended to real pharmaceutical effluent and the degradation efficiency was found to be less for real effluent (87%) in comparison with OTC (99%) in aqueous solution. CONCLUSION: RGOV-Pt(1%) photocatalyst effectively degraded OTC. An OTC degradation pathway was proposed based on the intermediates formed. The impact of additives was established. Effective real pharmaceutical effluent detoxification was observed. Thus the synthesized RGOV-Pt(1%) nanocomposite is a hopeful alternative for the removal of antibiotics in contaminated waters and sites.