The activity of transition metal sulfides for the hydrogen evolution reaction (HER) can be increased by sulfur-enrichment of active metal-sulfide sites. In this report, we investigate the electrochemical sulfidation of atmospherically aged WS2 nanoarrays with respect to enhancing HER activity. In contrast to MoS2, it is found that sulfidation diminishes HER activity. Electrochemical and XPS experiments suggest the involvement of insoluble tungsten oxides in the altered HER and electron transfer properties. This demonstrates the strong dependence of the transition metal dichalcogenide (TMD) composition with the successful sulfur incorporation and subsequent HER activity.
Bibliographical note© 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/).
Funding: EPSRC (EP/L015749/1 and EP/G037116/1)).
- hydrogen evolution
- transition metal dichalcogenides
- tungsten disulfide