PHOTOCATALYTIC DEGRADATION OF ORGANIC POLLUTANTS VIA METAL-OXIDE NANOSTRUCTURES

Abstract

Increasing contamination of freshwater by persistent organic pollutants calls for efficient and eco-friendly treatment methods. This study explores photocatalytic degradation of organic dyes using metal-oxide nanostructures (TiO₂, ZnO, Fe₂O₃) synthesized via sol-gel and hydrothermal techniques. Characterization by SEM, FTIR, XRD, and UV-Vis confirmed well-dispersed nanostructures with favorable structural and optical properties. Under UV and visible light, significant degradation of dyes like methylene blue, Rhodamine B, and methyl orange was observed. Photocatalytic efficiency was tested across catalyst dosage, dye concentration, pH, and light conditions. Kinetic analysis indicated pseudo-second-order behavior, suggesting surface chemisorption as the key degradation mechanism. Reusability tests showed catalyst stability over multiple cycles. These results demonstrate the potential of green-synthesized metal-oxide nanostructures as sustainable catalysts for effective wastewater treatment.