Highly selective hydrogen sensing of Pt-loaded WO<inf>3</inf>synthesized by hydrothermal/impregnation methods

Abstract

Unloaded and 0.25-1.0 wt% Pt-loaded WO3nanoparticles were synthesized by hydrothermal method using sodium tungstate dihydrate and sodium chloride as precursors in an acidic condition and impregnated using platinum acetylacetonate. Pt-loaded WO3films on an Al2O3substrate with interdigitated Au electrodes were prepared by spin-coating technique. The response of WO3sensors with different Pt-loading concentrations was tested towards 0.01-1.0 vol% of H2in air as a function of operating temperature (200-350 °C). The 1.0 wt% Pt-loaded WO3sensing film showed the highest response of ∼2.16 × 104to 1.0 vol% H2at 250 °C. Therefore, an operating temperature of 250 °C was optimal for H2detection. The responses of 1.0 wt% Pt-loaded WO3sensing film to other flammable gases, including C2H5OH, C2H4and CO, were considerably less, demonstrating Pt-loaded WO3sensing film to be highly selective to H2. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.