Wide concentration range hydrogen sensor enabled by intense pulsed light treated PdAu alloy electrodes and Pd/MWCNT@PVP nanocomposite

Hydrogen (H 2 ) poses significant safety risks due to its high diffusivity, permeability, and flammability, particularly in confined environments. Therefore, reliable hydrogen gas sensors capable of detecting a wide concentration range are essential for safe hydrogen energy systems. Palladium (Pd), a widely used hydrogen catalyst and sensing material, suffers from structural instability and performance degradation at high hydrogen concentrations due to phase transitions. Herein, we report a wide-range hydrogen sensor enabled by PdAu alloy electrodes integrated with a Pd/MWCNT@PVP (PMP) nanocomposite sensing layer, fabricated via an intense pulsed light (IPL)-assisted process. The IPL treatment induces rapid photothermal reactions, enabling fast alloy formation and material processing while significantly reducing fabrication time and production cost. The H 2 sensor demonstrated high response, selectivity, and reproducibility across H 2 concentrations ranging from 10 ppm to 100% under ambient conditions with relative humidity (RH) values ranging from 4% to 85%. RH was controlled at 25°C. At high H 2 concentrations, it achieved rapid response/recovery times (t 90 = 3/8 s) at room temperature. Furthermore, the sensor exhibited oxygen-independent sensing behavior, highlighting its suitability for reliable H 2 detection in oxygen-deficient or explosion-prone environments. These results demonstrate that the proposed PdAu–PMP composite sensor, enabled by a synergistic dual sensing mechanism that integrates surface catalytic reactions and bulk hydrogen absorption, offers a highly reliable, scalable, and wide range solution for real-time hydrogen monitoring in advanced hydrogen energy systems.