Fabrication of wide-detection-range H2 sensors with controllable saturation behavior using Au@Pd nanoparticle arrays.

Sensor saturation remains an obstacle to achieve reliable and quantitative detection of a specific gas at a high concentration. Herein, a new type of H2 sensor based on Au@Pd nanoparticle arrays (NAs) is demonstrated. While preserving a wide detection-range of 0.1–100% H2 concentrations, the Au@Pd NAs show a controllable saturation behavior depending on the Pd shell thickness. Mechanistically, this superior performance derives from the synergistic effect between the unique Au@Pd core–shell morphology and the rearrangement of Au@Pd nanoparticles during pre-conditioning. Our work represents a very promising strategy to design H2 sensors with enhanced performance at a high H2 concentration.