Room Temperature-Built Gas Sensors from Green Carbon Derivative: A Comparative Study between Pristine SnO₂ and GO-SnO₂ Nanocomposite

Room temperature-built gas sensors were fabricated from graphene oxide (GO), pristine and doped SnO2 nanostructures. The as-synthesized green carbon derivative (GO) nanomaterials were prepared from waste plastic precursor using Modified Hummer’s methodology. Pristine SnO2 and GO-SnO2 nanocomposite were synthesized employing a wet synthesis technique known as co-precipitation. The as-prepared nanoparticles were investigated for structural crystallographic and morphological features using X-ray diffractometry (XRD) and Transmission electron microscopy (TEM) analytical techniques. High-angle annular dark field (HAADF) and elemental quantifications of the nanopowders were investigated with the Energy dispersive X-ray spectroscopy (EDX). Textural features were determined with the assistance of Brunauer-Emmett-Teller (BET) analyzer. Thermogravimetric analysis (TGA) was performed to ascertain the material stability and degradability of the synthetic materials. Functional group and bond structure analysis was conducted using Fourier-transform infrared (FTIR) spectroscopy. Gas sensor devices were tested for responses towards CH4, H2, LPG, and CO2 gases at 20 ppm concentrations of each. GO-SnO2 nanocomposite sensing device showed optimal detection response towards the respective analyte gases with values of 5.00, 5.08, 4.90 and 3.41 respectively. The prepared nanocomposite showed stability and selectivity towards the target gases in an order of magnitude of H2 > CH4 > LPG > CO2. The optimal gas sensor device’s dynamic gas sensing response was ascribed to the GO doping effect which relatively increased its surface area (46.48 m² g^-1) and adsorption sites.