Enhanced response of WO thin film through Ag loading towards room temperature hydrogen gas sensor.

This study investigates the enhancement of hydrogen gas-sensing performance by introducing silver (Ag) nanoparticles onto tungsten trioxide (WO) thin films. Herein, the WO thin films are deposited onto SiO/Si substrates using a sputtering technique and Ag nanoparticles are loaded onto the WO surface through a spin coating technique. To evaluate the sensing performance of a hydrogen gas, interdigitated titanium (Ti) electrodes are deposited onto the Ag:WO layer. Structural, chemical, and morphological analyses are conducted for both pristine WO and Ag:WO thin films, followed by the investigation of gas-sensing performance by varying hydrogen gas concentrations from 100 ppm to 300 ppm and operating temperatures between 30 °C and 300 °C. The obtained results demonstrate that Ag:WO thin films exhibit a notably enhanced response of 5.08% when exposed to a concentration of 100 ppm of hydrogen gas at room temperature, compared to the pristine WO of 3.40%. The fabricated Ag:WO sensor exhibits a response time of 3.0 s, a recovery time of 4.5 s, and also demonstrates excellent stability over 45 days period. Finally, with the superior sensitivity and fast response time, the fabricated Ti/Ag:WO/Ti hydrogen gas sensor test-device can be a potential for improvement of safety from both industrial and environmental perspectives.