Insight into Photocatalytic Degradation of Amoxicillin by Biofabricated Granular Zinc Oxide Nanoparticle: Mechanism, Optimization and Toxicity Evaluation

Amoxicillin trihydrate (AMX) is an antibiotic drug and their metabolism in aqueous phase produce adverse effects on environmental standards and human health. Present research discloses the remediation of AMX antibiotic by photocatalytic degradation using fabricated zinc oxide nanoparticles (ZnONPs). Zinc oxide behaves as an excellent n-type semiconducting material for its high band gap (similar to 3.37 eV). In this investigation, the ZnONPs were synthesized biologically using banana peels extract as both reducing and capping agent. The effects of peel extract, precursor concentration and pH on ZnONPs synthesis were investigated and optimized using response surface methodology (RSM). Moreover, the synthesised nanoparticle was characterised by UV-Vis, FESEM-EDX, TEM, XRD, dynamic light scattering (DLS) and FTIR. The characteristics properties give confirmation about the spherical shape, crystalline nature of the synthesized nanoparticle. Results revealed that over 90% of AMX can be photocatalytically degraded in 120 min irradiation under UV-B irradiation. The rate of degradation of AMX was better agreed with the pseudo-second-order kinetics. The thermodynamics of the antibiotic degradation revealed that reactions were exothermic and spontaneous nature. Additionally, effective efficacy of antibiotic residues have been tested against E. coli bacteria and poor efficiency against bacteria was recorded. Finally, it can be suggested that the ZnONPs could be an effective semiconductor towards degradation of AMX from wastewater. Graphic abstract