Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Spontaneous doping of the basal plane of MoS2 single layers through oxygen substitution under ambient conditions

Abstract

The chemical inertness of the defect-free basal plane confers environmental stability to MoS2 single layers, but it also limits their chemical versatility and catalytic activity. The stability of pristine MoS2 basal plane against oxidation under ambient conditions is a widely accepted assumption however, here we report single-atom-level structural investigations that reveal that oxygen atoms spontaneously incorporate into the basal plane of MoS2 single layers during ambient exposure. The use of scanning tunnelling microscopy reveals a slow oxygen-substitution reaction, during which individual sulfur atoms are replaced one by one by oxygen, giving rise to solid-solution-type 2D MoS2−xOx crystals. Oxygen substitution sites present all over the basal plane act as single-atom reaction centres, substantially increasing the catalytic activity of the entire MoS2 basal plane for the electrochemical H2 evolution reaction.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Fig. 1: 2D MoS2−xOx solid solution crystals by ambient oxidation of MoS2.
Fig. 2: Stability of 2D MoSe2 basal plane under ambient conditions.
Fig. 3: Energetics and kinetics of O substitution in the MoS2 and MoSe2 basal plane.
Fig. 4: Reduction of 2D MoS2−xOx to pristine MoS2.
Fig. 5: Catalytic activity of 2D MoS2−xOx for hydrogen evolution.

Data availability

The data supporting the findings of this study are available within the Article and its Supplementary Information files. All other relevant source data are available from the corresponding author upon request.

References

  1. Liu, L. et al. Graphene oxidation: thickness-dependent etching and strong chemical doping. Nano Lett. 8, 1965–1970 (2008).

    CAS  Article  Google Scholar 

  2. Luo, Z. et al. Thickness-dependent reversible hydrogenation of graphene layers. ACS Nano 3, 1781–1788 (2009).

    CAS  Article  Google Scholar 

  3. Chhowalla, M. et al. The chemistry of two-dimensional layered transition metal dichalcogenide nanosheets. Nat. Chem. 5, 263–275 (2013).

    Article  Google Scholar 

  4. Jaramillo, T. F. et al. Identification of active edge sites for electrochemical H2 evolution from MoS2 nanocatalysts. Science 317, 100–102 (2007).

    CAS  Article  Google Scholar 

  5. Lauritsen, J. V. et al. Hydrodesulfurization reaction pathways on MoS2 nanoclusters revealed by scanning tunneling microscopy. J. Catal. 224, 94–160 (2004).

    CAS  Article  Google Scholar 

  6. Lauritsen, J. V. et al. Size-dependent structure of MoS2 nanocrystals. Nat. Nanotech. 2, 53–58 (2007).

    CAS  Article  Google Scholar 

  7. Dreyer, D. R., Park, S., Bielawski, C. W. & Ruoff, R. S. The chemistry of graphene oxide. Chem. Soc. Rev. 39, 228–240 (2010).

    CAS  Article  Google Scholar 

  8. Mirabelli, G. et al. Air sensitivity of MoS2, MoSe2, MoTe2, HfS2, HfSe2. J. Appl. Phys. 120, 125102 (2016).

    Article  Google Scholar 

  9. Yue, R. et al. HfSe2 films: 2D transition metal dichalcogenides grown by molecular beam epitaxy. ACS Nano 9, 474–480 (2015).

    CAS  Article  Google Scholar 

  10. Lee, C. H. et al. Tungsten ditelluride: a layered semimetal. Sci. Rep. 5, 10013 (2015).

    CAS  Article  Google Scholar 

  11. Li, Y., Zhou, Z., Zhang, S. & Chen, Z. MoS2 nanoribbons: high stability and unusual electronic and magnetic properties. J. Am. Chem. Soc. 130, 16739–16744 (2008).

    CAS  Article  Google Scholar 

  12. Grønborg, S. S. et al. Synthesis of epitaxial single-layer MoS2 on Au(111). Langmuir 31, 9700–9706 (2015).

    Article  Google Scholar 

  13. Gao, J. et al. Aging of transition metal dichalcogenide monolayers. ACS Nano 10, 2628–2635 (2016).

    CAS  Article  Google Scholar 

  14. Longo, R. C. et al. Intrinsic air stability mechanisms of two-dimensional transition metal dichalcogenide surfaces: basal plane versus edge oxidation. 2D Mater. 4, 025050 (2017).

    Article  Google Scholar 

  15. Martincova, J., Otyepka, M. & Lazar, P. Is single layer MoS2 stable in the air? Chem. Eur. J. 23, 13233–13239 (2017).

    CAS  Article  Google Scholar 

  16. Santosh, K. C., Longo, R. C., Wallace, R. M. & Cho, K. Surface oxidation energetics and kinetics on MoS2 monolayer. J. Appl. Phys. 117, 135301 (2015).

    Article  Google Scholar 

  17. Rao, R., Islam, A. E., Campbell, P. E., Vogel, E. M. & Marujama, B. In situ thermal oxidation kinetics in few layer MoS2. 2D Mater. 4, 025058 (2017).

    Article  Google Scholar 

  18. Bonde, J., Moses, P. G., Jaramillo, T. F., Norskov, J. K. & Chorkendorff, I. Hydrogen evolution on nano-particulate transition metal sulfides. Faraday Discuss. 140, 219–223 (2009).

    Article  Google Scholar 

  19. Angelica, A. et al. HfO2 on UV–O3 exposed transition metal dichalcogenides: interfacial reactions study. 2D Mater. 2, 014004 (2015).

    Article  Google Scholar 

  20. Walter, T. N., Kwok, F., Simchi, H., Aldosari, H. M. & Mohney, S. E. Oxidation and oxidative vapor-phase etching of few-layer MoS2. J. Vac. Sci. Technol. 35, 021203 (2017).

    Article  Google Scholar 

  21. Jaehyun, J. et al. Improved growth behavior of atomic-layer-deposited high-k dielectrics on multilayer MoS2 by oxygen plasma pretreatment. ACS Appl. Mater. Inter. 5, 4739–4744 (2013).

    Article  Google Scholar 

  22. Pingli, Q. et al. In situ growth of double-layer MoO3/MoS2 film from MoS2 for hole-transport layers in organic solar cell. J. Mater. Chem. A 2, 2742–2756 (2014).

    Article  Google Scholar 

  23. Voiry, D. et al. Conducting MoS2 nanosheets as catalysts for hydrogen evolution reaction. Nano. Lett. 13, 6222 (2013).

    CAS  Article  Google Scholar 

  24. Juanfeng, X. et al. Controllable disorder engineering in oxygen-incorporated MoS2 ultrathin nanosheets for efficient hydrogen evolution. J. Am. Chem. Soc. 135, 17881–17888 (2013).

    Article  Google Scholar 

  25. Liu, X. et al. Insight into the structure and energy of Mo27SxOy clusters. RSC Adv. 7, 9513–9520 (2017).

    CAS  Article  Google Scholar 

  26. Shu, H., Li, Y., Niu, X. & Wang, J. Greatly enhanced optical absorption of a defective MoS2 monolayer through oxygen passivation. ACS Appl. Mater. Interfaces 8, 13150–13156 (2016).

    CAS  Article  Google Scholar 

  27. Magda, G. Z. et al. Exfoliation of large-area transition metal chalcogenide single layers. Sci. Rep. 5, 14714 (2015).

    CAS  Article  Google Scholar 

  28. inhua, H. et al. Exploring atomic defects in molybdenum disulphide monolayers. Nat. Commun. 6, 6293 (2015).

    Article  Google Scholar 

  29. Krivanek, O. L. et al. Atom-by-atom structural and chemical analysis by annular dark field electron microscopy. Nature 464, 571–574 (2010).

    CAS  Article  Google Scholar 

  30. Komsa, H. P. et al. Two-dimensional transition metal dichalcogenides under electron irradiation: defect production and doping. Phys. Rev. Lett. 109, 035503 (2012).

    Article  Google Scholar 

  31. Vancsó, P. et al. The intrinsic defect structure of exfoliated MoS2 single layers revealed by scanning tunneling microscopy. Sci. Rep. 6, 29726 (2016).

    Article  Google Scholar 

  32. Nagl, C., Haller, O., Platzgummer, E., Scmid, M. & Varga, P. Submonolayer growth of Pb on Cu (111): surface alloying and de-alloying. Surf. Sci. 321, 237–248 (1994).

    CAS  Article  Google Scholar 

  33. Li, Z. et al. Spontaneous doping of two-dimensional NaCl films with Cr atoms: aggregation and electronic structure. Nanocale 7, 2366 (2015).

    CAS  Google Scholar 

  34. Bampoulis, P. et al. Defect dominated charge transport and Fermi level pinning in MoS2/metal contacts. ACS Appl. Mater. Interfaces 9, 19278–19286 (2017).

    CAS  Article  Google Scholar 

  35. Chow, P. K. et al. Defect induced photoluminescence in monolayer semiconducting transition metal dichalcogenides. ACS Nano 9, 1520–1527 (2015).

    CAS  Article  Google Scholar 

  36. Tongay, S. et al. Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged and free excitons. Sci. Rep. 3, 2657 (2013).

    Article  Google Scholar 

  37. Lince, J. R. Mo2−xOx solid solutions in thin films produced by rf-sputter-deposition. J. Mater. Res. 5, 218–222 (1990).

    CAS  Article  Google Scholar 

  38. Lince, J. R., Hilton, M. R. & Bommannavar, A. S. Oxygen substitution in sputter deposited MoS2 films studied by extended X-ray absorption fine-structure, X-ray photoelectron spectroscopy and X-ray diffraction. Surf. Coat. Technol. 43–44, 640–651 (1990).

    Article  Google Scholar 

  39. Fleischauer, P. D. & Lince, J. R. A comparison of oxidation and oxygen substitution in MoS2 solid film lubricants. Tribol. Int. 32, 627–636 (1999).

    CAS  Article  Google Scholar 

  40. Benoist, L. et al. X-ray photoelectron spectroscopy characterization of amorphous molybdenum oxysulfide thin films. Thin Solid Films 258, 110–114 (1995).

    CAS  Article  Google Scholar 

  41. Sung, H. S. et al. Bandgap widening of phase quilted, 2D MoS2 by oxidative intercalation. Adv. Mater. 27, 3152–3158 (2015).

    Article  Google Scholar 

  42. Henkelman, G., Uberuaga, B. P. & Jónsson, H. A climbing image nudged elastic band method for finding saddle points and minimum energy paths. J. Chem. Phys. 113, 9901–9904 (2000).

    CAS  Article  Google Scholar 

  43. Nan, H. et al. Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding. ACS Nano 8, 5738–5745 (2014).

    CAS  Article  Google Scholar 

  44. Hong, L. et al. Activating and optimizing MoS2 basal planes for hydrogen evolution through the formation of strained sulphur vacancies. Nat. Mater. 15, 48–53 (2016).

    Article  Google Scholar 

  45. Xia, Z. Hydrogen evolution guiding principles. Nat. Energy 1, 16155 (2016).

    Article  Google Scholar 

  46. Jiao, Y., Zheng, Y., Davey, K. & Qiao, S. Z. Activity origin and catalyst design principles for electrocatalytic hydrogen evolution on hetero-atom-doped graphene. Nat. Energy 1, 16130 (2016).

    CAS  Article  Google Scholar 

  47. Yang, N., Zheng, X., Li, L., Li, J. & Wei, Z. Influence of phosphorus configuration on electronic structure and oxygen reduction reactions of phosphorus-doped graphene. J. Phys. Chem. C 121, 19321 (2017).

    CAS  Article  Google Scholar 

  48. Komsa, H. P., Berseneva, N., Krashenninikov, A. & Nieminen, R. M. Charged point defects in the flatland: accurate formation energy calculations in two-dimensional materials. Phys. Rev. X 4, 031044 (2014).

    Google Scholar 

  49. Su, Y., Gao, S., Lei, F. & Xie, Y. Atomically-thin two-dimensional sheets for understanding active sites in catalysis. Chem. Soc. Rev. 44, 623–636 (2015).

    Article  Google Scholar 

  50. Qiao, B. et al. Single-atom catalysis of CO oxidation using Pt1/FeOx. Nat. Chem. 3, 634–641 (2011).

    CAS  Article  Google Scholar 

Download references

Acknowledgements

This work was performed in the framework of a NanoFab2D ERC starting grant, H2020 Graphene Core2 project no. 785219 and the Korea Hungary Joint Laboratory for Nanosciences. L.T. acknowledges OTKA grant K108753 and the ‘Lendület’ programme. The work was also supported by a VEKOP-2.3.2-16-2016-00011 grant, supported by the European Structural and Investment Funds. Z.I.P. and P.B.S. acknowledge financial support from the Ministry of Education and Science of the Russian Federation in the framework of the Increase Competitiveness Program of NUST ‘MISIS’ (no. K2-2017-001). Z.I.P. and P.B.S. acknowledge the supercomputer cluster provided by the Materials Modelling and Development Laboratory at NUST “MISIS” (supported via a grant from the Ministry of Education and Science of the Russian Federation no. 14.Y26.31.0005), and the Information Technology Centre of Novosibirsk State University for providing access to the cluster computational resources. Z.I.P. acknowledges the financial support of the Russian Scientific Foundation according to research project no. 18-73-10135 for stability calculations. P.V. acknowledges the Plateforme Technologique de Calcul Intensif (PTCI), which was supported by the FRS-FNRS under convention no. 2.5020.11. P.B.S. acknowledges financial support from the RFBR, via research project no. 16-32-60138 mol_а_dk. The authors thank J. S. Pap for useful discussions on electrochemistry.

Author information

Authors and Affiliations

Authors

Contributions

L.T. conceived and designed the experiments. J.P. and G.Z.M. prepared the samples and performed the STM measurements. T.O. performed the chemical reduction and electrocatalytic experiments. Z.I.P., P.V. and P.B.S. performed theoretical calculations. G.D. and G.Z.M. conducted Raman and photoluminescence investigations. L.T., P.B.S. and C.H. supervised the project. L.T. wrote the paper. All authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to Levente Tapasztó.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary information

Supplementary Figures 1–15, Supplementary Methods, Supplementary Characterization

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Pető, J., Ollár, T., Vancsó, P. et al. Spontaneous doping of the basal plane of MoS2 single layers through oxygen substitution under ambient conditions. Nature Chem 10, 1246–1251 (2018). https://doi.org/10.1038/s41557-018-0136-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41557-018-0136-2

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing