Optimization of Chemiresistive Hydrogen Sensor Device Using a Film of Platinum-supported Tungsten Oxide

Hydrogen has a very wide explosive range, making fire hazards a serious concern. Therefore, conventional spot-type sensors are insufficient for ensuring the safety of hydrogen energy systems, and it is necessary to introduce multi-point sensor systems with more densely distributed sensors. This paper addresses a chemiresistive hydrogen sensor device using a thin film of platinum-supported tungsten oxide to realize an efficient multi-point hydrogen detection system. The hydrogen-sensitive film was prepared by a sol-gel method and immobilized on various interdigital electrodes on a glass substrate. The sensor devices were fabricated under various fabrication conditions, and the responses were evaluated for determining the optimal fabrication conditions. Then, the performances required for the practical applications, such as sensitivity and reproducibility, were verified. Experimental results revealed excellent response of the hydrogen sensor device and electrical properties such as resistance dependent on the film thickness. From several results, it was also concluded that the catalytic activity of the Pt electrode itself is one of the important factors for obtaining good hydrogen response.