Influence of reduced graphene oxide on structural, optical, thermal and dielectric properties of SnO2 nanoparticles

Abstract

The present work has been carried out with the aim to synthesize tin oxide decorated reduce graphene oxide nanocomposite (SnO2/RGO-Nc) via in-situ synthesis process and the influence of RGO loading on structural, optical, thermal and dielectric properties of SnO2 has been discussed. The XRD, FESEM coupled with EDX elemental mapping, TEM, FTIR, Raman and XPS results reveal that the SnO2 nanoparticles have been successfully incorporated onto the RGO sheets. The reduction in the energy gap of the composite sample as compared to SnO2 measured from the Tauc’s relation can be attributed to strong coupling between RGO and SnO2 NPs. Thermogravimetric analysis (TGA) shows improved thermal stability of the SnO2/RGO-Nc. From the dielectric measurements, it is observed that the dielectric constant and dielectric loss decreases as frequency of applied field increases. AC conductivity of all samples increases as applied frequency increases which follows Jonscher’s power law. All composite samples show better conductivity as compared to SnO2. This is due to the formation of continuous conductive pathway between SnO2 and RGO sheets. Further high dielectric constant, low loss and high ac conductivity have been observed at optimum loading of RGO in SnO2/RGO2-Nc as compared to other composite samples which is due the percolation effects. The impedance analysis exhibits only one semicircle for SnO2 and SnO2/RGO composite which suggests that the involvement of grain boundaries dominated over the grain contribution.