An Investigation into the Dynamic Photocatalytic Degradation of Organic Pollutants in Sunlight Exposure with ZnO Nanoparticles Synthesized Using a Green Approach

Currently, phytochemical approaches to metal oxide nanoparticles (NPs) are regarded as the most effective and environmentally benign option due to the varied roles in the formation of nanostructures. This study focused on synthesizing zinc oxide nanoparticles from Citron leaf extract. The synthesized samples were evaluated by XRD, FTIR, XPS, PL, UV-Vis, SEM with EDX, and HRTEM with EDX, respectively. As the leaf extract increases, the structure analysis shows that the ZnO NPs have the average size of the crystallites which decreases from 16.4 to 12.7 nm. The FT-IR study provides assurance about the contribution of various biomolecules to the sample surface and the formation of Zn–O bonding. SEM and HRTEM investigations revealed nanorod-shaped morphology with high particle homogeneity from the 20 mL ZnO NPs. Furthermore, surface chemical state analyses by XPS verified the accommodation of different oxygen-coordinated molecular species. The dye degradation rates of methylene orange and methylene violet organic dyes were found to be 99% and 98%, respectively. These outcomes were attained by using a bio nano-rod catalyst for 60 min under sun light irradiation. According to the findings, the photodegradation of MO dye solution by ZnO nanoparticles via an ecologically benign approach under favorable conditions was effective. Based on the present study, the application of bio-mediated ZnO NPs is suitable for aquatic environmental purification.