Highly sensitive and selective room temperature alcohol gas sensors based on TeO2 nanowires

• The obtained TeO2 nanowires show a large surface-to-volume ratio.
• Growth process of TeO2 nanowires is dominated by vapour-solid growth mechanism.
• Sensitive and selective room temperature alcohol TeO2 nanowires gas sensor is demonstrated.

TeO2 nanowires were synthesized by thermal evaporation of Te powders in air at ambient pressure. The crystal structure, morphology, and alcohol sensing properties of TeO2 nanowires were investigated. Structural characterizations showed that TeO2 nanowires with a tetragonal structure were approximately 70–200 nm in diameter and several hundreds of micrometers to 2 mm in length. No Au nanoparticles were observed at any ends of TeO2 nanowires, revealing that the growth process was dominated by the vapour-solid growth mechanism. Gas sensing measurements indicated that TeO2 nanowires with an n-type conduction showed a quick and reversible response to ethanol gas at room temperature. The response increased in the order of methanol > ethanol > propanol under the same conditions as well as with increasing alcohol gas concentration. The results demonstrate the feasibility of using TeO2 nanowires for sensing alcohol gases.