Palladium and cerium oxide hollow strings of pearls for stable and wide-concentration-range hydrogen sensing at room temperature

Hydrogen (H2) sensing materials of palladium (Pd) adsorb H2 and form PdHx, however, the H2 adsorption saturation limits its detection range and stability. Here, Pd and cerium oxide hollow strings of pearls (Pd/CeO2 HSPs) have been synthesized for stable and wide-concentration-range H2 sensing via cross-linked carbon nanospheres template adsorbing Pd and Ce precursors, followed by annealing and reducing. Specifically, Pd/CeO2 HSPs are observed with HSP geometrical shapes, in which numerous holes are distributed over their surface. Beneficially, the Pd/CeO2 HSPs exhibit outstanding sensing response to 0.01–30 v/v% H2, and show high repeatability and stability upon repeated exposure to 1 v/v% H2 at room temperature (∼25 °C). The excellent sensing performance may be attributed to the synthetic effect that hollow and porous structure provides sufficiently permeable pathways and adsorption sites for H2 molecules, the SPs facilitate the transfer of electrons and CeO2 render Pd/CeO2 HSPs with high structural-stability by avoiding agglomeration of Pd particles. Practically, Pd/CeO2 HSPs sensor prototype has been simulated to detect H2 leakage with reliable H2 sensing. Palladium and cerium oxide hollow strings of pearls (Pd/CeO2 HSPs) have been developed for stable and wide-concentration-range hydrogen sensing at room temperature. [Display omitted] •Palladium and cerium oxide hollow strings of pearls (Pd/CeO2 HSPs) are developed.•The Pd/CeO2 HSPs exhibit stable and wide-detection-range hydrogen sensing.•Simulation for detecting hydrogen leakage is conducted with reliable sensing.