Deconvolution and quantification of defect types from the first order Raman spectra of graphene oxide derivatives

Abstract

The complete analysis of structural transformation and defects in a disordered structure like graphene oxide (GO) is very important as it will be supportive in fine-tuning of its intrinsic properties and further expanding their potential application in diverse fields. Herein, the first order Raman scattering has been employed to study the structural modifications and subsequently quantification of 0D and 1D defects in GO and thermally reduced GO (rGO). This study reveals that looking at the intensity ratios of graphitic (G) and defect (D) Raman peaks to estimate the defect density and to conclude the degree of reduction and quality of GO and rGO sheets provide an over or under estimation of results, because of presence of intermixed defects as it is inherent due to synthesis process. To overcome this, the integrated first order G & D-peak Raman intensities of GO and rGO annealed at different temperature with the intermixed defect density are analysed with the theoretical defect diagram to extract information about the defect contribution and nature of disorder over the structural evolution. This work provides new insight into the defect analysis using Raman scattering to identify defect type and defect density in GO and rGO and can be employed to analyse other 2D materials.