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).
