Synthesis of SnO2 nanowires forCO, CH4 and CH3OH gases sensing

Synthesis of one-dimensional nanostructures, such as nanowires, is of vigorous significance for achieving the desired properties and fabricating functional devices. In this work, we report the synthesis of tin oxide (SnO 2 ) nanowires on gold-catalyzed silicon substrate by carbothermal reduction process. SnO 2 nanowires were synthesized with SnO 2 and graphite powders as the source materials at atmospheric pressure and temperature of 900°C in the ambience of nitrogen (N 2 ) gas. First, the effect of source material ratio SnO 2 :C on growth of SnO 2 nanowires was studied. The structural, morphological and compositional properties of the samples were investigated by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. The scanning electron microscopy investigation reveals that uniform dense nanowires of SnO 2 (diameter ~127 nm and length ~40 µm) were synthesized with vapour–liquid–solid mechanism. Ultraviolet–visible spectra estimate that the optical band gap of the synthesized SnO 2 nanowires was 3.72 eV. Second, the gas sensing performance of synthesized SnO 2 nanowires was investigated by testing with carbon monoxide (CO), Methane (CH 4 ) and methanol (CH 3 OH) gases at different operating temperatures and concentrations. Results indicate that the synthesized SnO 2 nanowires are highly promising for gas sensing applications.