Enhancing performances of a resistivity-type hydrogen sensor based on Pd/SnO₂/RGO nanocomposites

Palladium/tin oxide/reduced graphene oxide (Pd/SnO₂/RGO) nanocomposites with Pd and SnO₂ crystalline nanoparticles of high density and uniformity coated on RGO have been synthesized by a two-step reduction process. A novel hydrogen (H₂) sensor based on Pd/SnO₂/RGO nanocomposites was fabricated by placing Pd/SnO₂/RGO nanocomposites onto a pair of gold electrodes. The Pd/SnO₂/RGO nanocomposite-based sensor exhibited higher responses than Pd/RGO to H₂ because the introduction of SnO₂ nanoparticles enhances H₂ adsorption and forms a P-N junction with RGO. The sensor shows a high response of 55% to 10 000 ppm H₂, and a low detection limit, fast response, good selectivity and repeatability due to a combination effect of the Pd and SnO₂ nanoparticles. The studies provide a novel strategy for great potential applications of graphene-based gas sensors.