Synthesis of gold nanoparticles by cotton peels aqueous extract and their catalytic efficiency for the degradation of dyes and antioxidant activity

Abstract

In this study, the authors synthesised gold nanoparticles (Au NPs) by a green approach using an aqueous extract of empty cotton boll peels (ECBPs) which was rapid, simple and inexpensive eco-friendly method compared to chemical and physical methods. The ECBP aqueous extract played a vital role in the reduction of Au+3 ions into Au NPs which was further confirmed by analytical characterisation. The phase purity and crystallinity of Au NPs were confirmed by X-ray diffraction analysis. The characteristic functional groups of synthesised Au NPs were identified by Fourier transform infrared analysis. The surface morphology and topography of Au NPs were studied by scanning electron microscopy and transmission electron microscopy analysis. Size with dispersion stability of Au NPs was determined by dynamic light scattering and zeta potential studies. In this study, the authors performed a catalytic activity of Au NPs using different pollutant organic dyes such as methylene blue and methyl orange. It also showed good antioxidant activity compared to standard ascorbic acid by using the standard 1,1-diphenyl-2-picryl-hydrazil method. Hence, this study concluded that ECBP mediated Au NPs could act as a promising material for degradation of dyes and antioxidant activity.