Sensitization of Pd loading for remarkably enhanced hydrogen sensing performance of 3DOM WO3

作者：Zhi-Hua Wang, Shuina Huang, Geling Men, Dong-Mei Han, Fu-Bo Gu · 发表于：Sensors and actuators. B, Chemical · 年份：2018 · DOI：10.1016/j.snb.2018.02.041 · 被引用次数：72 · 研究领域：Materials Science

Abstract Three-dimensionally ordered macroporous (3DOM) WO 3 materials were synthesized via colloidal crystal template method. Pd loading, aimed to improve the sensing performance of the sensor to hydrogen, was carried out by reducing Pd (II) centers. The obtained Pd-loaded 3DOM WO 3 samples were carefully characterized by XRD, Raman, SEM, TEM, XPS, UV–vis, Hall and the gas sensing properties targeting ppm level hydrogen were examined. The response of the Pd-loaded 3DOM WO 3 to 50 ppm H 2 is up to 382 at a low working temperature of 130 °C, which is approximately 225 times higher than that of the pure 3DOM WO 3 . Additionally, the sensor displays fast response (10 s) and recovery (50 s). More importantly, the Pd-loaded 3DOM WO 3 shows superior response to hydrogen with negligible response towards other interfering gases, indicating that the sensor exhibits excellent selectivity to hydrogen. Furthermore, the possible gas sensing mechanism based on the model of depletion layer is proposed to demonstrate that, both the structural defects and the sensitization exerted by Pd are responsible for the outstanding performance in hydrogen sensing.