Synthesis of nanostructured silver particles using Citrus limetta peel extract for catalytic degradation of azo dyes through electron relay effect

Vartika Srivastava and Abhay Kumar Choubey

Abstract

Presently plant mediated synthesis of nanoparticles has attracted wide attention due to its low time consuming and eco-friendly nature. The current study reports the facile green synthesis of silver nanoparticles (AgNPs) using methanolic peel extract of Citrus limetta (Mosambi). The major advantage of using this process for the synthesis of silver nanoparticles (AgNPs) is an easy method of preparation. In this study, AgNPs were synthesised using Citrus limetta peel extract. The synthesised nanoparticles were further confirmed using UV–vis spectroscopy. The size and shape of nanoparticles were determined by x-ray diffraction (XRD), dynamic light scattering (DLS) and finally with transmission electron microscopy (TEM). The formation and stability of the reduced AgNPs in the resulting colloidal solution were monitored by analysing its zeta potential value through DLS study. The formation of nanoparticles was studied over a wide range of temperature and pH. The mean particle diameter of silver nanoparticles was calculated from the DLS and TEM analyses. TEM analysis exposed the spherical shape of the particles. Crystalline nature of the nanoparticles in the face-centred cubic structure was confirmed by the peaks which appeared in the XRD pattern corresponding to (111), (200), (220) and (311) planes. The catalytic activity of AgNPs was further examined through synergetic reduction approach for the degradation of azo dyes such as methylene blue (MB) and methyl orange (MO). The catalytic activity of nanoparticles was studied by analysing the absorbance maximum values of dyes with respect to time using UV–Visible spectrophotometer and is attributed to the electron relay effect. The efficiency of degradation was also determined using absorbance value obtained from UV–vis spectrophotometry data.