Economical and green synthesis of graphene and carbon quantum dots from agricultural waste

Abstract

In this study, we aimed to develop simple, efficient, economic and sustainable approach for synthesis of carbon based quantum dots from agricultural waste. Sugarcane bagasse is one of the major solid agricultural waste and through its utility a novel strategy is evolved which makes a good sense both environmentally and economically. Herein, graphene quantum dots have been synthesized by chemical cutting from graphene oxide, while chemical oxidation followed by exfoliation method was used to form carbon quantum dots. The manufactured carbon based quantum dots were structurally characterised by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). The quantum dots were optically characterised by UV–vis spectroscopy, Fluorescence microscopy and Photoluminescence spectroscopy. SEM and TEM analysis indicated size, shape and monodispersed nature of carbon based quantum dots along with structural information about graphene oxide and sugarcane bagasse. The presence of large amount of oxygenous functionality was confirmed by FT-IR spectra and UV–vis spectroscopy. The optical properties reveal the bright blue luminescent nature of carbon quantum dots and graphene quantum dots with a produced yield of 25.7% and 12.54% respectively.