PNNL

Abstract

PdSnO2-based materials for efficient and reliable H2 sensing applications have been extensively explored and documented. Additionally, halloysite nanotubes (HNTs) with their unique porous structures, large surface areas, and hydrogen absorption capabilities have been recently reported as additives to H2 sensing materials (e.g., Fe3O4 and Pd) to enhance the H2 detection performance. It is of interest to investigate how HNTs as additives into PdSnO2 could affect H2 sensing performance. On the other hand, most of the reported H2 sensors employing PdSnO2 materials have been characterized under H2 gas carried by air. It is not clear whether PdSnO2-based sensors can be used to detect H2 in inert gases such as helium. In this work, we developed PdSnO2-HNT composites (PdSnO2 with different amounts of HNTs as additives) as H2 sensing materials, and investigated how different amounts of HNTs in composites and different carrying gases (air and helium) could affect the sensing performance of PdSnO2 based sensors. Through the sensor characterization using H2 carried by air, it was found that a relatively small amount of HNTs in PdSnO2 can improve the sensing performance. Further, using the optimal PdSnO2-HNT composite as a sensor, it was found that the PdSnO2-HNT composite can detect H2 in helium, but its performance in detecting H2 in He is different from that of such a sensor in detecting H2 in air. Moreover, the PdSnO2-HNT composite still presented better sensing performance than PdSnO2 without HNTs in detecting H2 in He. Possible reasons for the effects of HNT and H2-carrying gas on the sensing performance of PdSnO2-HNT-based sensors are discussed. We believe that this study provides valuable insights into the functionality and the adaptability of PdSnO2-HNT-based H2 sensors in diverse operational conditions.