Superior triethylamine-sensing properties based on TiO2/SnO2 n-n heterojunction nanosheets directly grown on ceramic tubes

A highly sensitive and selective gas sensor towards triethylamine (TEA) has been successfully fabricated by designing n-n heterojunctions consisting of SnO2 nanosheets and TiO2 nanoparticles. The SnO2 nanosheets with the thickness about 15 nm were directly grown on Al2O3 ceramic tubes by a simple hydrothermal process. After the formation of n-n heterojunctions by employing PLD method, the TiO2 nanoparticle/SnO2 nanosheets heterojunctions exhibit high sensing properties to TEA gas. The as prepared ST3 (Sno(2)/TiO2 3000) sensor response could reach to 52.3 at relatively low temperature (260 degrees C) when exposed to 100 ppm TEA gas, which is much higher than that of pure SnO2 nanosheet sensor (-3@100 ppm TEA@320 degrees C). Compared with the pure SnO2 nanosheet sensor (S sensor), the depletion layer formed at the n-n heterojunctions interface in TiO2/SnO2 sensor can greatly increase the resistance in air and decrease the resistance in TEA gas. Due to the general working principle and controllable growth strategy, this work provides a way for developing the chemiresistive gas sensors. (C) 2016 Elsevier B.V. All rights reserved.