Fabrication and Characterization of rGO/Tin Oxide Nanocomposite using Hydrothermal Technique

Abstract

Tin Oxide is an important inorganic semiconductor material because of its unique properties such as electrical conductivity, high optical transparency and sensitivity to chemicals drawn considerable attention due to its broad applications in various fields such as gas sensors, dye sensitized solar cell, field emission and supercapacitors while graphene sheet which is 2D nonmaterial showing high carrier mobility at room temperature have further intensified interest in this material. Graphene sheet decorated with metal oxide nanoparticles can perform multiple roles including photocatalyst, adsorbent, lithium ion batteries (LIBs) and gas sensing characteristics. This thesis is based on synthesis of rGO/SnO nanocomposite via hydrothermal method with SnCl2 and graphene oxide (GO) as the precursors in hydrothermal process. The graphite flakes transformed into graphene oxide (GO) through oxidation by “Improved method” utilizing KMnO4 as an oxidizing agent. The GO and composite material were studied by characterization techniques such as X-ray diffraction (XRD), Atomic force microscopy (AFM), Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). It exhibited the dispersion of thermally unstable tetragonal crystalline structure SnO nanoparticles of size range (25-53nm) on graphene sheet. The resultant rGO/SnO composite obtained from different precursor solution ratio in hydrothermal process (SnCl2/GO= 1.1 mmol/1-3 mg) and graphene film were coated for electrical measurements on pre-coated interdigitated electrodes alumina substrate, annealed at 250 0C for 2 hrs. Significant change in the current-voltage (I-V) characteristic of bare graphene observed on adding SnO nanoparticles, current drops from mA to μA. The current measured in composite material increase with the increase of graphene concentration in composite material. Resistance of rGO/SnO composite material (Precursor ratio= 1.1 mmol/3 mg) decreased on raising temperature from 310 KΩ (25 oC) to 297 KΩ (200 oC).