Two-dimensional Aluminum Oxide Nanosheets Decorated with Palladium Oxide Nanodots for Highly Stable and Selective Hydrogen Sensing

Hydrogen (H-2) sensing materials such as semiconductor metal oxides may suffer from poor long-term stability against humidity and unsatisfactory selectivity against other interfering gases. To address the above issues, highly stable and selective H-2 sensing built with palladium oxide nanodots decorating aluminum oxide nanosheets (PdO NDs//Al2O3 NSs) has been achieved via combined template synthesis, photochemical deposition, and oxidation. Typically, the PdO NDs//Al2O3 NSs are observed with thin NSs (approximate to 17 nm thick) decorated with nanodots (approximate to 3.3 nm in diameter). Beneficially, the sensor prototypes built with PdO NDs//Al2O3 NSs show excellent long-term stability for 278 days, high selectivity against interfering gases, and outstanding stability against humidity at 300 degrees C. Remarkably, the sensor prototypes enable detection of a wide-range of 20 ppm - 6 V/V% H-2, and the response and recovery times are approximate to 5 and 16 s to 1 V/V% H-2, respectively. Theoretically, the heterojunctions of PdO NDs-Al2O3 NSs with a large specific surface ratio and Al2O3 NSs as the support exhibit excellent stability and selective H-2 sensing. Practically, a sensing device integrated with the PdO NDs//Al2O3 NSs sensor prototype is simulated for detecting H-2 with reliable sensing response.

Automated summary

A hydrogen sensing prototype with high stability and selectivity has been achieved by combining template synthesis, photochemical deposition, and oxidation. The sensor shows excellent long-term stability, high selectivity against interfering gases, and outstanding stability against humidity at 300 degrees C. It is capable of detecting hydrogen in a wide range of concentrations.