title: Enhanced hydrogen evolution catalysis from chemically exfoliated metallic MoS2 nanosheets.
abstract: Promising catalytic activity from molybdenum disulfide (MoS2) in the hydrogen evolution reaction (HER) is attributed to active sites located along the edges of its two-dimensional layered crystal structure, but its performance is currently limited by the density and reactivity of active sites, poor electrical transport, and inefficient electrical contact to the catalyst. Here we report dramatically enhanced HER catalysis (an electrocatalytic current density of 10 mA/cm(2) at a low overpotential of -187 mV vs RHE and a Tafel slope of 43 mV/decade) from metallic nanosheets of 1T-MoS2 chemically exfoliated via lithium intercalation from semiconducting 2H-MoS2 nanostructures grown directly on graphite. Structural characterization and electrochemical studies confirmed that the nanosheets of the metallic MoS2 polymorph exhibit facile electrode kinetics and low-loss electrical transport and possess a proliferated density of catalytic active sites. These distinct and previously unexploited features of 1T-MoS2 make these metallic nanosheets a highly competitive earth-abundant HER catalyst.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Lukowski
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Daniel
authors.forename: Fei
authors.initials: F
authors.lastname: Meng
authors.forename: Audrey
authors.initials: A
authors.lastname: Forticaux
authors.forename: Linsen
authors.initials: L
authors.lastname: Li
authors.forename: Song
authors.initials: S
authors.lastname: Jin
mesh_terms: D002384:Catalysis; D004220:Disulfides / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D008982:Molybdenum / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D004220:Disulfides; D006859:Hydrogen; D008982:Molybdenum; C082964:molybdenum disulfide