Photocatalytic degradation of propyl paraben using green ZnO nanoparticles: reaction and kinetics

In the present work, an eco-friendly approach is used to synthesize ZnO nanoparticles (ZnO-NPs) for the removal of propyl paraben in the pharmaceutical industry. ZnO-NPs were prepared from aqueous lemon extract and characterized by different techniques such as XRD, FTIR and UV–Vis DRS spectroscopies, BET, SEM/EDS, and TGA. The crystallites exhibited a mean size of 49.5 nm measured via XRD and were highly pure, while SEM analyses confirmed their spherical or elliptical shape. The functional groups responsible for stabilizing and capping of ZnO-NPs were confirmed using FTIR analysis. UV–Vis DRS revealed that the optical bandgap of ZnO-NPs for direct and indirect transition was 3.17 and 3.04 eV, respectively. Synthesized ZnO-NPs were used to evaluate their possible reactivity through the parabens degradation employed for the fabrication of magnesium pidolate. ZnO-NPs photocatalyst was found to be highly active against propylparaben degradation with reaction efficiency ~ 80% after 120 min of reaction. Owing to the eco-friendly synthesis, and non-toxicity, ZnO-NPs synthesized from lemon extract can be exploited as potential candidates for environmental applications.