Graphene meshes decorated with palladium nanoparticles for hydrogen detection

We fabricated flexible and transparent hydrogen gas sensors based on a palladium-decorated graphene mesh. Electron microscopy analysis confirmed that ∼2–3 nm diameter Pd nanoparticles were uniformly dispersed on the graphene mesh surfaces. The sensors were highly transparent with an average optical transmission of  >90% to visible light and they exhibited good electrical stability with a resistance change of 1.5% under a tensile strain of 1.1% in a cyclic bending-unbending test. Compared with graphene-based sensors, the graphene mesh sensors exhibited a faster response to hydrogen gas with sensitivity as high as ∼5% at a low concentration of 10 ppm H₂/air, even at room temperature. The enhanced H₂ detection characteristic of the graphene mesh sensors is attributed to the existence of edges. (paper)