Optimal Pt mesoporous layer modified nanocomposite film with highly sensitive detection of ethanol at low temperature

Abstract

Developing highly sensitive and selective gas sensing MOS materials with low working temperature is urgent to fabricate high-performance ethanol gas sensors. Herein, we report a Pt mesoporous layer modified multi-layer TiO2/SnO2 nanocomposite thin film for improving sensitivity and selectivity of detecting ethanol at a low temperature. The Pt mesoporous layer is prepared by simple sputtering techniques, which are completely compatible with the MEMS process. The characterization results show the Pt sputtering time of 30 s and the annealing temperature of 500℃ are the opening condition and forming condition of Pt mesoporous layer, respectively, which has the most mesoporous of 5–50 nm. Because the Pt mesoporous layer has copious mesoporous and there is an abundant Schottky barrier between Pt and TiO2, the thin film (optimal parameters: 30 s, 500℃) based sensor has the highest sensitivity to ethanol at 130 ℃ and its response is as high as 3.32 to 0.1 ppm of ethanol, so the thin film is regarded as the optimal Pt mesoporous layer. Thus, the Pt mesoporous layer on the multi-layer TiO2/SnO2 nanocomposite thin film prepared by sputtering techniques is a simple but effective method to largely improve the gas sensing properties of the nanocomposite film.