Abstract
Large-scale implementation of electrochemical water splitting for hydrogen evolution requires cheap and efficient catalysts to replace expensive platinum. However, catalysts that work well at high current densities with ultrafast intrinsic activities is still the central challenge for hydrogen evolution. An ideal case is to use single atoms on monolayer two-dimensional (2D) materials, which simplifies the system and in turn benefits the mechanism study, but is a grand challenge to synthesize. Here, we report a universal cold hydrogen plasma reduction method for synthesizing different single atoms sitting on 2D monolayers. In the case of molybdenum disulfide, we design and identify a type of active site, i.e., unsaturated Mo single atoms on cogenetic monolayer molybdenum disulfide. The catalyst shows exceptional intrinsic activity with a Tafel slope of 36.4 mV dec-1 in 0.5 M H2SO4 and superior performance at a high current density of 400 mA cm-2 with an overpotential of ∼260 mV, based on single flake microcell measurements. Theoretical studies indicate that coordinately unsaturated Mo single atoms sitting on molybdenum disulfide increase the bond strength between adsorbed hydrogen atoms and the substrates through hybridization, leading to fast hydrogen adsorption/desorption kinetics and superior hydrogen evolution activity. This work shines fresh light on preparing highly efficient electrocatalysts for water splitting and other electrochemical processes, as well as provides a general method to synthesize single atoms on two-dimensional monolayers.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.