Hydrogen Gas Sensors Using Palladium Nanogaps on an Elastomeric Substrate.

Abstract

With the recent reillumination of the hydrogen economy around the world, the demand for H₂ sensors is expected to increase rapidly. Due to safety issues caused by the highly flammable and explosive character of hydrogen gas (H₂ ), it is imperative to develop the sensors that can quickly and sensitively detect H₂ leaks. For the development of H₂ sensors, Pd-based materials have been extensively used due to the high affinity of Pd metal for H₂ . Among Pd-based H₂ sensors, Pd nanogap-based sensors have been extensively investigated because these sensors can operate in an on-off manner, which enables them to have improved sensing capabilities, including high sensitivity, rapid response, short recovery time, and good reliability. Importantly, significant advances in H₂ -sensing performance have been achieved by simply using an elastomeric substrate to form Pd nanogaps. Herein, the progress and advanced approaches achieved over the last decade for Pd nanogap-based H₂ sensors supported on elastomeric substrates are reviewed, with a focus on strategies to reduce detection limits and increase reliability, sensitivity, and stability.