Preparation of palladium-doped mesoporous WO3 for hydrogen gas sensors

This study presents a hydrogen gas sensor using Pd-loaded mesoporous WO3 (Pd/M-WO3) as the sensing material. Pd/M-WO3 was synthesized through the hard-template method. The surface morphology, microstructure, and composition of Pd/M-WO3 were characterized through X-ray diffraction, transmission electron microscopy, energy-dispersive spectrometry, and the Brunner–Emmet–Teller model. Sensing responses using commercial WO3 powder and synthetic mesoporous WO3 (M-WO3) were compared with that using Pd/M-WO3 as the sensing materials for hydrogen sensors. Pd/M-WO3 exhibited the highest hydrogen sensing ability. Comparison of hydrogen sensing performances of WO3, M-WO3, and Pd/M-WO3 at room temperature showed that the sensing performance of M-WO3 is superior to that of commercial WO3 powder, but doping of M-WO3 with Pd can effectively improve the sensing efficiency (from 1.07 to 11.78). The Pd/M-WO3-based gas sensor exhibits promising hydrogen gas sensing characteristics, such as fast response, highly selective detection, good reproducibility, and extremely short recovery time (10 s). Therefore, this sensor is an ideal candidate for application in high-performance hydrogen gas sensing.