Conducting MoS2 Nanosheets as Catalysts for Hydrogen Evolution Reaction

• Published in: Nano letters Vol. 13; no. 12; pp. 6222 - 6227
• Main Authors: Voiry, Damien, Salehi, Maryam, Silva, Rafael, Fujita, Takeshi, Chen, Mingwei, Asefa, Tewodros, Shenoy, Vivek B, Eda, Goki, Chhowalla, Manish
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 11.12.2013
• Subjects: Catalysis; Catalytic methods; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Disulfides - chemistry; Electric Conductivity; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Hydrogen - chemistry; Materials science; Methods of nanofabrication; Molybdenum - chemistry; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanostructures - chemistry; Nanotubes; Nanotubes, Carbon - chemistry; Physics; Surface Properties; Layered materials; MoS2; chemical exfoliation; layered transition metal dichalcogenide; hydrogen evolution reaction; Electrical conductivity; Nanosheet; Catalysts; Active site; Carbon nanotubes; Oxidation; Catalyst activity; Nanostructured materials
• ISSN: 1530-6984; 1530-6992; 1530-6992
• DOI: 10.1021/nl403661s

We report chemically exfoliated MoS2 nanosheets with a very high concentration of metallic 1T phase using a solvent free intercalation method. After removing the excess of negative charges from the surface of the nanosheets, highly conducting 1T phase MoS2 nanosheets exhibit excellent catalytic activity toward the evolution of hydrogen with a notably low Tafel slope of 40 mV/dec. By partially oxidizing MoS2, we found that the activity of 2H MoS2 is significantly reduced after oxidation, consistent with edge oxidation. On the other hand, 1T MoS2 remains unaffected after oxidation, suggesting that edges of the nanosheets are not the main active sites. The importance of electrical conductivity of the two phases on the hydrogen evolution reaction activity has been further confirmed by using carbon nanotubes to increase the conductivity of 2H MoS2.