Green synthesis of ZnO nanoparticles by using Calotropis procera leaves for the photodegradation of methyl orange

Abstract

A facile, innovative and inexpensive green route has been demonstrated for the formation of ZnO nanoparticles by biogenic method using aqueous leaf extract of Calotropis procera which acts as a reducing and stabilizing agent. The as prepared ZnO nanoparticles were characterized by a host of different techniques such as X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM) and fourier transform infrared spectroscopy (FT-IR). The XRD pattern confesses that ZnO nanoparticles associate to hexagonal wurtzite structure. The DRS absorption spectrum shows an absorption edge at 397 nm corresponds to the ground excitonic peak of ZnO nanoparticles and the band gap is found to be 3.1 eV. The FT-IR spectra indicate the presence of hydroxyl groups, aldehydes, amines, ketones, and carboxylic acids which are responsible for biochemical reaction. TEM images shows that the particles of ZnO have spherical shape with size ranging from 15 to 25 nm. ZnO nanoparticles were subjected to photocatalytic application for the degradation of methyl orange under UV light. The photodegradation efficiency of MO was found to be 81% within 100 min under UV light, such an excellent activity is obtained by biogenic ZnO NPs.