Effects of palladium nanocrystal morphologies on hydrogen sensors based on palladium-graphene hydrid

In this work, we demonstrate the effects of palladium (Pd) nanocrystal morphologies on hydrogen (H₂) sensors based on Pd-graphene (Gr) hybrid nanomaterials. The Pd nanocrystal with different morphologies of nanocube, nanoporous and core-shell structures were synthesized in colloidal state by a chemical route in two-steps (seed-mediated growth) and then, simply reduced into graphene flakes by hydrazine in a simple one-step process. Resulting in H2 sensors based on Pd-graphene hybrid have such advantages of high sensitivity, good selectivity and stability. Especially, Pd nanoporous and Pt/Pd core-shell structures yield a fast response/recovery time and a large detectable range of H2 gas even at room temperature. The different H₂ response properties of various Pd morphologies in hybrid with graphene were investigated and emphasized in this work.