Size‐Dependent Enhancement of Electrocatalytic Oxygen‐Reduction and Hydrogen‐Evolution Performance of MoS2 Particles. Issue 36 (19th July 2013)

• Record Type: Journal Article
• Authors: Wang, Tanyuan; Gao, Dongliang; Zhuo, Junqiao; Zhu, Zhiwei; Papakonstantinou, Pagona; Li, Yan; Li, Meixian
• Is Part Of: Chemistry. Volume 19:Issue 36(2013)
• Page Start: 11939
• Page End: 11948
• Publication Date: 2013-07-19
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201301406
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>MoS₂ particles with different size distributions were prepared by simple ultrasonication of bulk MoS₂ followed by gradient centrifugation. Relative to the inert microscale MoS₂, nanoscale MoS₂ showed significantly improved catalytic activity toward the oxygen‐reduction reaction (ORR) and hydrogen‐evolution reaction (HER). The decrease in particle size was accompanied by an increase in catalytic activity. Particles with a size of around 2 nm exhibited the best dual ORR and HER performance with a four‐electron ORR process and an HER onset potential of −0.16 V versus the standard hydrogen electrode (SHE). This is the first investigation on the size‐dependent effect of the ORR activity of MoS₂, and a four‐electron transfer route was found. The exposed abundant Mo edges of the MoS₂ nanoparticles were proven to be responsible for the high ORR catalytic activity, whereas the origin of the improved HER activity of the nanoparticles was attributed to the plentiful exposed S edges. This newly discovered process provides a simple protocol to produce inexpensive highly active MoS₂ catalysts that could easily be scaled up. Hence, it opens up possibilities for wide applications of MoS₂ nanoparticles in the fields of energy conversion and storage.</p> </abstract>