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.

Ionic solutions of two-dimensional materials

Nature Chemistry volume 9, pages 244–249 (2017)Cite this article

Subjects

Abstract

Strategies for forming liquid dispersions of nanomaterials typically focus on retarding reaggregation, for example via surface modification, as opposed to promoting the thermodynamically driven dissolution common for molecule-sized species. Here we demonstrate the true dissolution of a wide range of important 2D nanomaterials by forming layered material salts that spontaneously dissolve in polar solvents yielding ionic solutions. The benign dissolution advantageously maintains the morphology of the starting material, is stable against reaggregation and can achieve solutions containing exclusively individualized monolayers. Importantly, the charge on the anionic nanosheet solutes is reversible, enables targeted deposition over large areas via electroplating and can initiate novel self-assembly upon drying. Our findings thus reveal a unique solution-like behaviour for 2D materials that enables their scalable production and controlled manipulation.

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

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it

$39.95

Learn more

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Structure, dissolution and deposition of layered material salts.
Figure 2: The morphology of dissolved nanosheets.
Figure 3: Structure and self-assembly of dissolved nanosheets.
Figure 4: Electroplating a nanosheet solution.

References

  1. Nicolosi, V., Chowalla, M., Kanatzidis, M. G., Strano, M. S. & Coleman, J. N. Liquid exfoliation of layered materials. Science 340, 1226419 (2013).

    Article  Google Scholar 

  2. Ferrari, A. C. et al. Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems. Nanoscale 7, 4598–4810 (2015).

    Article  CAS  Google Scholar 

  3. Stankovich, S. et al. Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide. Carbon 45, 1558–1565 (2007).

    Article  CAS  Google Scholar 

  4. Hummelen, J. C. et al. Preparation and characterization of fulleroid and methanofullerene derivatives. J. Org. Chem. 60, 532–538 (1995).

    Article  CAS  Google Scholar 

  5. Sperling, R. A. & Parak, W. J. Surface modification, functionalization and bioconjugation of colloidal inorganic nanoparticles. Phil. Trans. R. Soc. A 368, 1333–1383 (2010).

    Article  CAS  Google Scholar 

  6. Zobel, M., Neder, R. B. & Kimber, S. A. Universal solvent restructuring induced by colloidal nanoparticles. Science 347, 292–294 (2015).

    Article  CAS  Google Scholar 

  7. Boles, M. A., Ling, D., Hyeon, T. & Talapin, D. V. The surface science of nanocrystals. Nat. Mat. 15, 141–153 (2016).

    Article  CAS  Google Scholar 

  8. Lotya, M. et al. Liquid phase production of graphene by exfoliation of graphite in surfactant/water solutions. J. Am. Chem. Soc. 131, 3611–3620 (2009).

    Article  CAS  Google Scholar 

  9. Paton, K. R. et al. Scalable production of large quantities of defect-free few-layer graphene by shear exfoliation in liquids. Nat. Mater. 13, 624–630 (2014).

    Article  CAS  Google Scholar 

  10. Shih, C. J. et al. Bi-and trilayer graphene solutions. Nat. Nanotech. 6, 439–445 (2011).

    Article  CAS  Google Scholar 

  11. Coleman, J. N. et al. Two-dimensional nanosheets produced by liquid exfoliation of layered materials. Science 331, 568–571 (2011).

    Article  CAS  Google Scholar 

  12. Huo, C., Yan, Z., Song, X. & Zeng, H. 2D materials via liquid exfoliation: a review on fabrication and applications. Sci. Bull. 60, 1994–2008 (2015).

    Article  CAS  Google Scholar 

  13. Ma, R. & Sasaki, T. Two-dimensional oxide and hydroxide nanosheets: controllable high-quality exfoliation, molecular assembly, and exploration of functionality. Acc. Chem. Res. 48, 136–143 (2015).

    Article  CAS  Google Scholar 

  14. Stöter, M., Rosenfeldt, S. & Breu, J. Tunable exfoliation of synthetic clays. Annu. Rev. Mater. Res. 45, 129–151 (2015).

    Article  Google Scholar 

  15. Batista, C. A. S., Larson, R. G. & Kotov, N. A. Nonadditivity of nanoparticle interactions. Science 350, 6257 (2015).

    Google Scholar 

  16. Howard, C. A., Thompson, H., Wasse, J. C. & Skipper, N. T. Formation of giant solvation shells around fulleride anions in liquid ammonia. J. Am. Chem. Soc. 126, 13228–13229 (2004).

    Article  CAS  Google Scholar 

  17. Mezger, M. et al. Molecular layering of fluorinated ionic liquids at a charged sapphire (0001) surface. Science 322, 424–428 (2008).

    Article  CAS  Google Scholar 

  18. Burgess, J. Ions in Solution: Basic Principles of Chemical Interactions 2nd edn (Horwood, 1999).

  19. Joensen, P., Frindt, R. F. & Morrison, S. R. Single-layer MoS2 . Mater. Res. Bull. 21, 457–461 (1986).

    Article  CAS  Google Scholar 

  20. Eda, G. et al. Photoluminescence from chemically exfoliated MoS2 . Nano Lett. 11, 5111–5116 (2011).

    Article  CAS  Google Scholar 

  21. Lu, X. et al. Preparation of MoO3 QDs through combining intercalation and thermal exfoliation. J. Mat. Chem. C 4, 6720 (2016).

    Article  CAS  Google Scholar 

  22. Schaak, R. E. & Mallouk, T. E. Prying apart ruddlesden-popper phases: exfoliation into sheets and nanotubes for assembly of perovskite thin films. Chem. Mater. 12, 3427–3434 (2000).

    Article  CAS  Google Scholar 

  23. Sasaki, T., Watanabe, M., Hashizume, H., Yamada, H. & Nakazawa, H. Macromolecule-like aspects for a colloidal suspension of an exfoliated titanate. Pairwise association of nanosheets and dynamic reassembling process initiated from it. J. Am. Chem. Soc. 118, 8329–8335 (1996).

    Article  CAS  Google Scholar 

  24. Sposito, G. et al. Surface geochemistry of the clay minerals. Proc. Natl Acad. Sci. USA 96, 3358–3364 (1999).

    Article  CAS  Google Scholar 

  25. Dresselhaus, M. S. & Dresselhaus, G. Intercalation compounds of graphite. Adv. Phys. 51, 1–186 (2002).

    Article  CAS  Google Scholar 

  26. Fan, X. et al. Controlled exfoliation of MoS2 crystals into trilayer nanosheets. J. Am. Chem. Soc. 138, 5143–5149 (2016).

    Article  CAS  Google Scholar 

  27. Ding, Z., Viculis, L., Nakawatase, J. & Kaner, R. B. Intercalation and solution processing of bismuth telluride and bismuth selenide. Adv. Mater. 13, 797–800 (2001).

    Article  CAS  Google Scholar 

  28. Zeng, Z. et al. Single layer semiconducting nanosheets: high-yield preparation and device fabrication. Angew. Chem. Int. Ed. 50, 11093–11097 (2011).

    Article  CAS  Google Scholar 

  29. Vallés, C. et al. Solutions of negatively charged graphene sheets and ribbons. J. Am. Chem. Soc. 130, 15802–15804 (2008).

    Article  Google Scholar 

  30. Milner, E. M. et al. Structure and morphology of charged graphene platelets in solution by small-angle neutron scattering. J. Am. Chem. Soc. 134, 8302–8305 (2012).

    Article  CAS  Google Scholar 

  31. Huang, K. et al. Single layer nano graphene platelets derived from graphite nanofibres. Nanoscale 8, 8810 (2016).

    Article  CAS  Google Scholar 

  32. Pan, Z.-H. et al. Electronic structure of superconducting KC8 and nonsuperconducting LiC6 graphite intercalation compounds: evidence for a graphene-sheet-driven superconducting state. Phys. Rev. Lett. 106, 187002 (2011).

    Article  Google Scholar 

  33. Somoano, R. B., Hadek, V. & Rembaum, A. Alkali metal intercalates of molybdenum disulfide. J. Chem. Phys. 58, 697–701 (1973).

    Article  CAS  Google Scholar 

  34. Picco, L. M. et al. Breaking the speed limit with atomic force microscopy. Nanotechnology 18, 044030 (2006).

    Article  Google Scholar 

  35. Zeng, Z., Tan, C., Huang, X., Bao, S. & Zhang, H. Growth of noble metal nanoparticles on single-layer TiS2 and TaS2 nanosheets for hydrogen evolution reaction. Energy Environ. Sci. 7, 797 (2014).

    Article  CAS  Google Scholar 

  36. Lui, C. H., Liu, L., Mak, K. F., Flynn, G. W. & Heinz, T. F. Ultraflat graphene. Nature 462, 339–341 (2009).

    Article  CAS  Google Scholar 

  37. Tonndorf, P. et al. Photoluminescence emission and Raman response of monolayer MoS2, MoSe2, and WSe2 . Opt. Express 21, 4908–4916 (2013).

    Article  CAS  Google Scholar 

  38. Yoon, G. et al. Factors affecting the exfoliation of graphite intercalation compounds for graphene synthesis. Chem. Mater. 27, 2067–2073 (2015).

    Article  CAS  Google Scholar 

  39. Payton, O. D. et al. Experimental observation of contact mode cantilever dynamics with nanosecond resolution. Rev. Sci. Instrum. 82, 043704 (2011).

    Article  CAS  Google Scholar 

  40. Kodera, N., Yamamoto, D., Ishikawa, R. & Ando, T. Video imaging of walking myosin V by high-speed atomic force microscopy. Nature 468, 72–76 (2010).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

This publication was funded, in part, by the Engineering & Physical Sciences Research Council (EPSRC). L.P. & O.D.P. thank the Royal Academy of Engineering for funding the development of the HS-AFM and the NSQI Low Noise Lab for hosting the HS-AFM. We thank Martial Duchamp for his valuable assistance with the ‘PICO’ TEM at the Ernst–Ruska Research Centre. The authors are grateful to Milo Shaffer & Paul McMillan for helpful and supportive discussions.

Author information

Authors and Affiliations

  1. Department of Physics & Astronomy, University College London, London, WC1E 6BT, UK

    Patrick L. Cullen, Kathleen M. Cox, Mohammed K. Bin Subhan, David J. Buckley, Neal T. Skipper & Christopher A. Howard

  2. Interface Analysis Centre, H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK

    Loren Picco & Oliver D. Payton

  3. Department of Chemistry, University College London, London, WC1E 6BT, UK

    David J. Buckley & Thomas S. Miller

  4. Cambridge Graphene Centre, 9 JJ Thomson Avenue, Cambridge, CB3 0FA, UK

    Stephen A. Hodge

  5. Institute of Materials, École polytechnique fédérale de Lausanne, Lausanne, CH-1015, Switzerland

    Vasiliki Tileli

Authors
  1. Patrick L. Cullen
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Kathleen M. Cox
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Mohammed K. Bin Subhan
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Loren Picco
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Oliver D. Payton
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. David J. Buckley
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Thomas S. Miller
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Stephen A. Hodge
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Neal T. Skipper
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Vasiliki Tileli
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Christopher A. Howard
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

C.A.H. and P.L.C. conceived the project. P.L.C., V.T., M.K.B.S., K.M.C. and C.A.H. made the intercalated compounds and solutions. M.K.B.S., K.M.C., P.L.C. & C.A.H. carried out X-ray analysis. L.P., O.D.P., P.L.C., K.M.C. and C.A.H. performed and analysed the AFM measurements. L.P. wrote the automated HS-AFM platelet detection and step height measurement algorithms. V.T. performed S/TEM and contributed to the analysis of the results. C.A.H. carried out the electroplating and Raman experiment. C.A.H. directed the study and wrote the paper. All authors discussed and developed the science and commented on the manuscript.

Corresponding author

Correspondence to Christopher A. Howard.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 13917 kb)

Supplementary movie

Supplementary movie 1 (MP4 14021 kb)

Rights and permissions

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Cullen, P., Cox, K., Bin Subhan, M. et al. Ionic solutions of two-dimensional materials. Nature Chem 9, 244–249 (2017). https://doi.org/10.1038/nchem.2650

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nchem.2650

This article is cited by

Search

Advanced 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