Hydrogen sensing in different hydrogen-carrying gases using composites of PdSnO2 and halloysite nanotubes

Abstract

In this work, we developed composites of palladium-decorated tin dioxide (PdSnO2) and halloysite nanotubes (HNTs) by adding different amounts of HNTs as additives into PdSnO2, and investigated how the different amounts of HNTs in the composites and the different hydrogen (H2) carrying gases (air and helium (He)) could affect the H2 sensing performance of such composites (PdSnO2-HNT). Through the sensing-performance characterization using H2 carried by air, it was found that PdSnO2 with an appropriate small amount of HNTs (i.e., 2 % of PdSnO2 mass) can improve the sensing performance with respect to limit of detection (LOD) and response/recovery time. Further, the optimal PdSnO2-HNT composite as a sensor was tested to detect H2 in He. The testing results indicated that the composite can detect H2 in He, but its performance parameters (i.e., the profile of calibration curve, LOD, and response time) are different from those of such a sensor in detecting H2 in air. Moreover, the 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 were 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.