Synthesis and Characterization of Single‐Crystalline SnO2 Nanowires

Tin oxide (SnO2) nanowires were synthesized on oxidized silicon substrates by thermal evaporation of tin grains at 900°C in Ar flow at ambient pressure. Structural characterization using X‐ray diffraction and transmission electron microscopy shows that SnO2 nanowires have a single crystal tetragonal structure. Scanning electron microscopy observation demonstrates that SnO2 nanowires are 30–200 nm in diameter and several tens of micrometers in length. The surface vibration mode resulting from the nanosize effect at 565.1 cm−1 was found from the Fourier transform infrared spectrum. The formation of SnO2 nanowires follows a vapour‐solid (VS) growth mechanism. The gas sensing measurements indicate that SnO2 nanowire gas sensor obtains peak sensitivity at a low operating temperature of 150°C and shows reversible response to H2 gas (100–1000 ppm) at an operating temperature of RT‐300°C.