Sub-second and ppm-level Optical Sensing of Hydrogen Using Templated Control of Nano-hydride Geometry and Composition

TL;DR

This paper presents a rapid, highly sensitive optical hydrogen sensor using nano-engineered Pd alloy metasurfaces, achieving sub-second response times and ppm-level detection accuracy for safe hydrogen leak monitoring.

Contribution

The study introduces a novel nano-engineered Pd-alloy metasurface sensor with sub-second response and ppm-level detection, outperforming existing hydrogen sensing technologies.

Findings

Response time as low as 0.85 seconds at 1 mbar H₂

Detection limit of 2.5 ppm for hydrogen

Enhanced performance with Pd alloys containing Ag, Au, or Co

Abstract

The use of hydrogen as a clean and renewable alternative to fossil fuels requires a suite of flammability mitigating technologies, particularly robust sensors for hydrogen leak detection and concentration monitoring. To this end, we have developed a class of lightweight optical hydrogen sensors based on a metasurface of Pd nano-patchy particle arrays, which fulfills the increasing requirements of a safe hydrogen fuel sensing system with no risk of sparking. The structure of the optical sensor is readily nano-engineered to yield extraordinarily rapid response to hydrogen gas (<3 s at 1 mbar H$_{2}$) with a high degree of accuracy (<5%). By incorporating 20% Ag, Au or Co, the sensing performances of the Pd-alloy sensor are significantly enhanced, especially for the Pd$_{80}$Co$_{20}$ sensor whose optical response time at 1 mbar of H$_{2}$ is just ~0.85 s, while preserving the excellent accuracy (<2.5%), limit of detection (2.5 ppm), and robustness against aging, temperature, and interfering gases. The superior performance of our sensor places it among the fastest and most sensitive optical hydrogen sensors.