Study of Gasochromic Pt-decorated WO₃ thin films synthesized via the Sol-Gel Route

¹ Assistant Professor, Sahyadri College of Engineering and Management
² Professor, IIST, Thrivandrum

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Abstract

Metal Oxide-based Chemi-resistive sensors for hydrogen gas detection utilize microheaters, posing a risk of explosion due to electric sparks, as hydrogen concentrations above 4% are highly flammable. Gasochromic sensors, on the other hand, are safe as they can detect target gases based on changes in optical transmittance at room temperature. The transmittance of synthesized films changes reversibly when the target gas is alternatively purged and stopped. In the proposed work, noble metal-doped WO₃ thin films are synthesized via the sol-gel route followed by spin coating. UV-VIS-NIR transmittance spectra for the samples were measured at room temperature by alternatively exposing the samples to 4% Hydrogen and synthetic air. The results show that gasochromic sensing can be enhanced by increasing the doping concentration to 2wt%. The better sensing could be linked to the fine dispersal of the Pt nanoparticles on WO₃ thin films, facilitating the adsorption and hydrogenation of molecular hydrogen.