Reclaimable La: ZnO/PAN nanofiber catalyst for photodegradation of methyl paraoxon and its toxicological evaluation utilizing early life stages of zebra fish (Danio rerio)

In the present work, La: ZnO/PAN and ZnO/PAN nanofibers were designed and evaluated as a catalyst for the photodegradation of diethyl (4-nitrophenyl) phosphate (MP). The solid catalyst was characterized by various analytical techniques. Hexagonal and wurtzite crystal structure of the fabricated rod-shaped La-ZnO nanoparticles were substantiated from the XRD pattern. The catalytic activity of ZnO nanorods enhanced in the presence of La due to their surface plasmon resonance (SPR) effect. Real-time experiment carried out in the wastewater sample spiked with MP showed 100 %degradation efficiency at 150 min as quantified by HPLC. The product of degradation (4-nitrophenol) was directly converted to tertiary compound (p-amino phenol) eschewing the intermediate as attested by GC-MS analysis. Acute toxicity of MP was evaluated utilizing early stages of zebra fish and the degraded product was found to be less toxic for the aquatic living system.