title: The Origin of MoS2Significantly Influences Its Performance for the Hydrogen Evolution Reaction due to Differences in Phase Purity.
abstract: Molybdenum disulfide (MoS2) is at the forefront of materials research. It shows great promise for electrochemical applications, especially for hydrogen evolution reaction (HER) catalysis. There is a significant discrepancy in the literature on the reported catalytic activity for HER catalysis on MoS2. Here we test the electrochemical performance of MoS2obtained from seven sources and we show that these sources provide MoS2of various phase purity (2H and 3R, and their mixtures) and composition, which is responsible for their different electrochemical properties. The overpotentials for HER at -10 mA cm-2for MoS2from seven different sources range from -0.59 V to -0.78 V vs. reversible hydrogen electrode (RHE). This is of very high importance as with much interest in 2D-MoS2, the use of the top-down approach would usually involve the application of commercially available MoS2. These commercially available MoS2are rarely characterized for composition and phase purity. These key parameters are responsible for large variance of reported catalytic properties of MoS2.
authors.affiliation: Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
authors.forename: Xing Juan
authors.initials: XJ
authors.lastname: Chua
authors.affiliation: Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
authors.forename: Shu Min
authors.initials: SM
authors.lastname: Tan
authors.affiliation: Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
authors.forename: Xinyi
authors.initials: X
authors.lastname: Chia
authors.affiliation: Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technicka 5, 166 28, Prague 6, Czech Republic.
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Sofer
authors.affiliation: Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technicka 5, 166 28, Prague 6, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Luxa
authors.affiliation: Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
authors.forename: Martin
authors.identifier: http://orcid.org/0000-0001-5846-2951
authors.initials: M
authors.lastname: Pumera
keywords: electrocatalysis; hydrogen evolution reaction; molybdenum disulfide; phase purity; transition metal dichalcogenides