Self-heated hydrogen gas sensors based on Pt-coated W18O49 nanowire networks with high sensitivity, good selectivity and low power consumption

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 W18O49 nanowire networks. Such a sensor has been shown to have promising performance, e.g., high sensitivity (able to detect down to 50 ppm of H2), good selectivity (poor response to ethanol, CH4, CO, and C3H8), 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 W18O49 nanowire networks.