Impact Electrochemistry of Layered Transition Metal Dichalcogenides

Chee Shan Lim, Shu Min Tan, Zdeněk Sofer, Martin Pumera

Research output: Contribution to journalArticlepeer-review

45 Citations (Scopus)


Layered transition metal dichalcogenides (TMDs) exhibit paramount importance in the electrocatalysis of the hydrogen evolution reaction. It is crucial to determine the size of the electrocatalytic particles as well as to establish their electrocatalytic activity, which occurs at the edges of these particles. Here, we show that individual TMD (MoS2, MoSe2, WS2, or WSe2; in general MX2) nanoparticles impacting an electrode surface provide well-defined current "spikes" in both the cathodic and anodic regions. These spikes originate from direct oxidation of the nanoparticles (from M4+ to M6+) at the anodic region and from the electrocatalytic currents generated upon hydrogen evolution in the cathodic region. The positive correlation between the frequency of the impacts and the concentration of TMD nanoparticles is also demonstrated here, enabling determination of the concentration of TMD nanoparticles in colloidal form. In addition, the size of individual TMD nanoparticles can be evaluated using the charge passed during every spike. The capability of detecting both the "indirect" catalytic effect of an impacting TMD nanoparticle as well as "direct" oxidation indicates that the frequency of impacts in both the "indirect" and "direct" scenarios are comparable. This suggests that all TMD nanoparticles, which are electrochemically oxidizable (thus capable of donating electrons to electrodes), are also capable of catalyzing the hydrogen reduction reaction. (Figure Presented).

Original languageEnglish
Pages (from-to)8474-8483
Number of pages10
JournalACS Nano
Issue number8
Publication statusPublished - 2015 Aug 25

Bibliographical note

Publisher Copyright:
© 2015 American Chemical Society.

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)


Dive into the research topics of 'Impact Electrochemistry of Layered Transition Metal Dichalcogenides'. Together they form a unique fingerprint.

Cite this