Mesh of ultrasmall Pd/Mg bimetallic nanowires as fast response wearable hydrogen sensors formed on filtration membrane

Abstract

This study demonstrates highly functional hydrogen (H2) sensors employing an ultrasmall bimetallic Pd/Mg nanowires mesh. The nanowires mesh is successfully made through the consecutive immobilization of ultrasmall Pd and Mg nanoparticles on a commercial filtration membrane. Specifically, a simple magnetron sputtering process enabled the mesh-type Pd/Mg nanowires with outstanding H2 gas sensing property at room temperature. The as-fabricated sensor can sufficiently detect H2 concentration from 10 to 40,000ppm, showing remarkable device stability, high response magnitude, and fast response time. Such high sensing performance of the Pd/Mg nanowire mesh is due to the increased surface-to-volume ratio and the confinement-induced suppression of the phase transition from Pd/H solid solution (α-phase) to Pd hydride (β-phase) of the sensing surface. Moreover, good selectivity, negligible humidity effect, and decreased response time at extremely bending state provide the possibility of wearable electronic applications. It will open up a new paradigm to manufacture bimetallic nanowire mesh simply and enable wearable H2 sensor for futuristic applications.