With the recently-booming hydrogen (H2 ) economy by green H2 as the energy carriers and the newly-emerged exhaled diagnosis by human organ-metabolized H2 as a biomarker, H2 sensing is simultaneously required with fast response, low detection limit, and tolerant stability against humidity, switching, and poisoning. Here, reliable H2 sensing has been developed by utilizing indium oxide nanocubes decorated with palladium and gold nanodots (Pd-Au NDs/In2 O3 NCBs), which have been synthesized by combined hydrothermal reaction, annealing, and chemical bath deposition. As-prepared Pd-Au NDs/In2 O3 NCBs are observed with surface-enriched NDs and nanopores. Beneficially, Pd-Au NDs/In2 O3 NCBs show 300 ppb-low detection limit, 5 s-fast response to 500 ppm H2 , 75%RH-high humidity tolerance, and 56 days-long stability at 280 °C. Further, Pd-Au NDs/In2 O3 NCBs show excellent stability against switching sensing response, and are tolerant to H2 S poisoning even being exposed to 10 ppm H2 S at 280 °C. Such excellent H2 sensing may be attributed to the synergistic effect of the boosted Pd-Au NDs' spillover effect and interfacial electron transfer, increased adsorption sites over the porous NCBs' surface, and utilized Pd NDs' affinity with H2 and H2 S. Practically, Pd-Au NDs/In2 O3 NCBs are integrated into the H2 sensing device, which can reliably communicate with a smartphone.
Keywords: H2S poisoning; Pd and Au nanodots; porous In2O3 nanocubes; switching sensing response; tolerant stability.
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