Plectranthus amboinicus leaf extract–assisted biosynthesis of ZnO nanoparticles and their photocatalytic activity

This article demonstrates the synthesis of ZnO nanoparticles (NPs) using leaf extract of Plectranthus amboinicus. The synthesized ZnO NPs were characterized by UV–vis spectroscopy, SEM, EDX, XRD, FTIR and photoluminescence spectroscopy. SEM study reveals that the biosynthesized ZnO NPs exhibits a rod shape structure with an average size of 88 nm. The UV–vis diffuse reflectance spectrum study indicates the band gap of biosynthesized ZnO NPs is 3.07 eV. Photocatalytic property of the ZnO NPs was investigated by photodegradation of methyl red (MR) under UV illumination. The photocatalytic performance of biosynthesized ZnO NPs was compared with hydrothermal synthesized ZnO NPs and P25. Results show that the biosynthesized ZnO NPs owing a superior photocatalytic activity towards degradation of MR.