Catalytic Reduction of Organic Dyes with Green Synthesized Silver Nanoparticles using Aloe vera Leaf Extract

Abstract

In this present study, we report a facile, cost-effective and non-toxic method of synthesis of silver nanoparticles using 4mM silver nitrate and aqueous leaf extract of Aloe vera as reducing and capping agent in presence of 25% ammonia solution. Then these green synthesized nanoparticles are used as catalysts for the degradation of organic dyes. The synthesized silver nanoparticles (AVSNPs) were characterized using different techniques like UV-Visible spectroscopy, Fourier infrared spectroscopy (FTIR), Dynamic light scattering (DLS), X-ray diffraction (XRD), Field emission-scanning electron microscopy (FESEM) and Energy Dispersive X-Ray Spectroscopy (EDAX). Further, the nanoparticles were seen to degrade organic dyes which were visibly seen and also recorded in UV-Visible Spectrometer. The initial synthesis of silver nanoparticles is confirmed by a peak at 417nm. The nanoparticles were found to be spherical in shape with an average size ranging between 11-23 nm. XRD analysis confirmed the formation of silver nanoparticles of crystalline nature and a face-centered cubic (fcc) lattice and FTIR analysis showed the involvement of the biomolecules in the reduction of silver to form silver nanoparticles and the EDAX confirmed the presence of silver nanoparticles. The green synthesized nanoparticles catalyze the degradation of different organic dyes in a very short period of time. The green synthesized silver nanoparticles were seen to show excellent activity in catalyzing the degradation of organic dyes in an aqueous medium in the presence of the electron donor sodium borohydride (NaBH 4 ). Keywords:  Aloe vera, catalysis, dye reduction, green synthesis, NaBH4, organic dyes, silver nanoparticles