Self-heated hydrogen gas sensors based on Pt-coated W 18O 49 nanowire networks with high sensitivity, good selectivity and low power consumption

Abstract

Self-heating effect can be applied to develop gas sensors avoiding use of external heaters. We report here a prototype self-heated hydrogen gas sensor based on Pt-coated W 18O 49 nanowire networks. Such a sensor has been shown to have promising performance, e.g., high sensitivity (able to detect down to 50 ppm of H 2), good selectivity (poor response to ethanol, CH 4, CO, and C 3H 8), and low power consumption of 30–60 mW at 6 V compatible to a portable device. Coaxial cable model and percolation theory are applied to explain the gas sensing effect of the Pt-coated W 18O 49 nanowire networks.