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.

  • Article
  • Published:

A silica sol–gel design strategy for nanostructured metallic materials

Abstract

Batteries, fuel cells and solar cells, among many other high-current-density devices, could benefit from the precise meso- to macroscopic structure control afforded by the silica sol–gel process. The porous materials made by silica sol–gel chemistry are typically insulators, however, which has restricted their application. Here we present a simple, yet highly versatile silica sol–gel process built around a multifunctional sol–gel precursor that is derived from the following: amino acids, hydroxy acids or peptides; a silicon alkoxide; and a metal acetate. This approach allows a wide range of biological functionalities and metals—including noble metals—to be combined into a library of sol–gel materials with a high degree of control over composition and structure. We demonstrate that the sol–gel process based on these precursors is compatible with block-copolymer self-assembly, colloidal crystal templating and the Stöber process. As a result of the exceptionally high metal content, these materials can be thermally processed to make porous nanocomposites with metallic percolation networks that have an electrical conductivity of over 1,000 S cm−1. This improves the electrical conductivity of porous silica sol–gel nanocomposites by three orders of magnitude over existing approaches, opening applications to high-current-density devices.

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

Access options

Buy this article

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

Figure 1: Synthesis of sol–gel precursor and sol–gel-derived thick films.
Figure 2: Structure control in sol–gel hybrids.
Figure 3: Structure analysis of porous pyrolysed palladium nanocomposites.
Figure 4: Electrical transport measurements on porous, pyrolysed, palladium-based films.

Similar content being viewed by others

References

  1. Brinker, C. J. & Scherer, G. W. Sol–Gel Science: The Physics and Chemistry of Sol–Gel Processing (Academic, 1990).

    Google Scholar 

  2. Iler, R. K. The Chemistry of Silica: Solubility, Polymerization, Colloid and Surface Properties, and Biochemistry (Wiley, 1979).

    Google Scholar 

  3. Aizenberg, J. et al. Skeleton of Euplectella sp.: Structural hierarchy from the nanoscale to the macroscale. Science 309, 275–278 (2005).

    Article  CAS  Google Scholar 

  4. Thimsen, E., Leformal, F., Graetzel, M. & Warren, S. C. Influence of plasmonic Au nanoparticles on the photoactivity of Fe2O3 electrodes for water splitting. Nano Lett. 11, 35–43 (2011).

    Article  CAS  Google Scholar 

  5. Warren, S. C. & Thimsen, E. Plasmonic solar water splitting. Energy Environ. Sci. 5, 5133–5146 (2012).

    CAS  Google Scholar 

  6. Atwater, H. A. & Polman, A. Plasmonics for improved photovoltaic devices. Nature Mater. 9, 205–213 (2010).

    Article  CAS  Google Scholar 

  7. Stöber, W., Fink, A. & Bohn, E. Controlled growth of monodisperse silica spheres in the micron size range. J. Colloid Interf. Sci. 26, 62–69 (1968).

    Article  Google Scholar 

  8. Yanagisawa, T., Shimizu, T., Kuroda, K. & Kato, C. Trimethylsilyl derivatives of alkyltrimethylammonium-kanemite complexes and their conversion to microporous silica materials. Bull. Chem. Soc. Jpn 63, 1535–1537 (1990).

    Article  CAS  Google Scholar 

  9. Kresge, C. T., Leonowicz, M. E., Roth, W. J., Vartuli, J. C. & Beck, J. S. Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism. Nature 359, 710–712 (1992).

    Article  CAS  Google Scholar 

  10. Templin, M. et al. Organically modified aluminosilicate mesostructures from block copolymer phases. Science 278, 1795–1798 (1997).

    Article  CAS  Google Scholar 

  11. Ryan, J. V. et al. Electronic connection to the interior of a mesoporous insulator with nanowires of crystalline RuO2 . Nature 406, 169–172 (2000).

    Article  CAS  Google Scholar 

  12. Morris, C. A., Anderson, M. L., Stroud, R. M., Merzbacher, C. I. & Rolison, D. R. Silica sol as a nanoglue: Flexible synthesis of composite aerogels. Science 284, 622–624 (1999).

    Article  CAS  Google Scholar 

  13. Watcharotone, S. et al. Graphene-silica composite thin films as transparent conductors. Nano Lett. 7, 1888–1892 (2011).

    Article  Google Scholar 

  14. Wang, X., Zhi, L. & Mullen, K. Transparent, conductive graphene electrodes for dye-sensitized solar cells. Nano Lett. 8, 323–327 (2007).

    Article  Google Scholar 

  15. Kang, B. & Ceder, G. Battery materials for ultrafast charging and discharging. Nature 458, 190–193 (2009).

    Article  CAS  Google Scholar 

  16. Gasteiger, H. A., Kocha, S. S., Sompalli, B. & Wagner, F. T. Activity benchmarks and requirements for Pt, Pt-alloy, and non-Pt oxygen reduction catalysts for PEMFCs. Appl. Catal. B 56, 9–35 (2005).

    Article  CAS  Google Scholar 

  17. Mathias, M. F. et al. Two fuel cell cars in every garage? J. Electrochem. Soc. Interface 14, 24–35 (2005).

    CAS  Google Scholar 

  18. Aryanpour, M., Hoffmann, R. & DiSalvo, F. J. Tungsten-doped titanium dioxide in the rutile structure: Theoretical considerations. Chem. Mater. 21, 1627–1635 (2009).

    Article  CAS  Google Scholar 

  19. Rolison, D. R. Catalytic nanoarchitectures–the importance of nothing and the unimportance of periodicity. Science 299, 1698–1701 (2003).

    Article  CAS  Google Scholar 

  20. Terry, K. W., Lugmair, C. G. & Tilley, T. D. Tris(tert-butoxy)siloxy complexes as single-source precursors to homogeneous zirconia- and hafnia-silica materials. An alternative to the sol–gel method. J. Am. Chem. Soc. 119, 9745–9756 (1997).

    Article  CAS  Google Scholar 

  21. Rupp, W., Husing, N. & Schubert, U. Preparation of silica-titania xerogels and aerogels by sol–gel processing of new single-source precursors. J. Mater. Chem. 12, 2594–2596 (2002).

    Article  CAS  Google Scholar 

  22. Garcia, C., Zhang, Y. M., DiSalvo, F. & Wiesner, U. Mesoporous aluminosilicate materials with superparamagnetic γ-Fe2O3 particles embedded in the walls. Angew. Chem. Int. Ed. 42, 1526–1530 (2003).

    Article  CAS  Google Scholar 

  23. Luechinger, M., Kienhofer, A. & Pirngruber, G. D. Immobilized complexes of metals with amino acid ligands—a first step towards the development of new biomimetic catalysts. Chem. Mater. 18, 1330–1336 (2006).

    Article  CAS  Google Scholar 

  24. Schubert, U. Preparation of metal oxide or metal nanoparticles in silica via metal coordination to organofunctional trialkoxysilanes. Polym. Int. 58, 317–322 (2009).

    Article  CAS  Google Scholar 

  25. Cotton, F. A., Wilkinson, G., Murillo, C. A. & Bochmann, M. Advanced Inorganic Chemistry 6th edn (Wiley, 1999).

    Google Scholar 

  26. Schubert, U., Amberg-Schwab, S. & Breitscheidel, B. Metal complexes in inorganic matrixes. 4. Small metal particles in palladium–silica composites by sol–gel processing of metal complexes. Chem. Mater. 1, 576–578 (1989).

    Article  CAS  Google Scholar 

  27. Kakihana, M. & Yoshimura, M. Synthesis and characteristics of complex multicomponent oxides prepared by polymer complex method. Bull. Chem. Soc. Jpn 72, 1427–1443 (1999).

    Article  CAS  Google Scholar 

  28. Lenaerts, P. et al. The films of highly luminescent lanthanide complexes covalently linked to an organic–inorganic hybrid material via 2-substituted imidazo[4,5-f]-1,10-phenanthroline groups. Chem. Mater. 17, 5194–5201 (2005).

    Article  CAS  Google Scholar 

  29. Sanchez, C., Lebeau, B., Chaput, F. & Boilot, J-P. Optical properties of functional hybrid organic–inorganic nanocomposites. Adv. Mater. 15, 1969–1994 (2003).

    Article  CAS  Google Scholar 

  30. Schubert, U., Huesing, N. & Lorenz, A. Hybrid inorganic–organic materials by sol–gel processing of organofunctional metal alkoxides. Chem. Mater. 7, 2010–2027 (1995).

    Article  CAS  Google Scholar 

  31. Callebaut, C., Krust, B., Jacotot, E. & Hovanessian, A. G. T-cell activation antigen, CΔ26, as a cofactor for entry of HIV in CΔ4+ cells. Science 262, 2045–2050 (1993).

    Article  CAS  Google Scholar 

  32. Dong, D., Jiang, S., Men, Y., Ji, X. & Jiang, B. Nanostructured hybrid organic–inorganic lanthanide complex films produced in situ via a sol–gel approach. Adv. Mater. 12, 646–649 (2000).

    Article  CAS  Google Scholar 

  33. Merbach, A. E. & Tóth, É. The Chemistry of Contrast Agents in Medical Magnetic Resonance Imaging (Wiley, 2001).

    Google Scholar 

  34. Jiang, S. P. A review of wet impregnation—an alternative method for the fabrication of high performance and nano-structured electrodes of solid oxide fuel cells. Mater. Sci. Eng. A-Struct. 418, 199–210 (2006).

    Article  Google Scholar 

  35. Pike, G. E. & Seager, C. H. Electrical properties and conduction mechanisms of Ru-based thick-film (cermet) resistors. J. Appl. Phys. 48, 5152–5169 (1977).

    Article  CAS  Google Scholar 

  36. Van der Pauw, L. J. A method of measuring specific resistivity and Hall effect of discs of arbitrary shape. Phil. Res. Rep. 13, 1–9 (1958).

    Google Scholar 

  37. Abeles, B., Sheng, P., Coutts, M. D. & Arie, Y. Structural and electrical properties of granular metal films. Adv. Phys. 24, 407–461 (1975).

    Article  CAS  Google Scholar 

  38. Terrill, R. H. et al. Monolayers in three dimensions: NMR, SAXS, thermal, and electron hopping studies of alkanethiol stabilized gold clusters. J. Am. Chem. Soc. 117, 12537–12548 (1995).

    Article  CAS  Google Scholar 

  39. Zabet-Khosousi, A. & Dhirani, A-A. Charge transport in nanoparticle assemblies. Chem. Rev. 108, 4072–4124 (2008).

    Article  CAS  Google Scholar 

  40. Joo, S. H. et al. Thermally stable Pt/mesoporous silica core-shell nanocatalysts for high-temperature reactions. Nature Mater. 8, 126–131 (2009).

    Article  CAS  Google Scholar 

  41. Warren, S. C. et al. Ordered mesoporous materials from metal nanoparticle-block copolymer self-assembly. Science 320, 1748–1752 (2008).

    Article  CAS  Google Scholar 

  42. Raney, M. Method of producing finely-divided nickel. US patent 1,628,190 (1927).

  43. Erlebacher, J., Aziz, M. J., Karma, A., Dimitrov, N. & Sieradzki, K. Evolution of nanoporosity in dealloying. Nature 410, 450–453 (2001).

    Article  CAS  Google Scholar 

  44. Sandler, J. et al. Development of a dispersion process for carbon nanotubes in an epoxy matrix and the resulting electrical properties. Polymer 40, 5967–5971 (1999).

    Article  CAS  Google Scholar 

  45. Sandler, J. K. W., Kirk, J. E., Kinloch, I. A., Shaffer, M. S. P. & Windle, A. H. Ultra-low electrical percolation threshold in carbon-nanotube-epoxy composites. Polymer 44, 5893–5899 (2003).

    Article  CAS  Google Scholar 

  46. Kinoshita, K. Particle size effects for oxygen reduction on highly dispersed platinum in acid electrolytes. J. Electrochem. Soc. 137, 845–848 (1990).

    Article  CAS  Google Scholar 

  47. Pantea, D., Darmstadt, H., Kaliaguine, S., Sümmchen, L. & Roy, C. Electrical conductivity of thermal carbon blacks: Influence of surface chemistry. Carbon 39, 1147–1158 (2001).

    Article  CAS  Google Scholar 

  48. Becerril, H. A. et al. Evaluation of solution-processed reduced graphene oxide films as transparent conductors. ACS Nano 2, 463–470 (2008).

    Article  CAS  Google Scholar 

  49. Attard, G. S. et al. Mesoporous platinum films from lyotropic liquid crystalline phases. Science 278, 838–840 (1997).

    Article  CAS  Google Scholar 

  50. Yamauchi, Y., Yokoshima, T., Momma, T., Osaka, T. & Kuroda, K. Fabrication of magnetic mesostructured nickel–cobalt alloys from lyotropic liquid crystalline media by electroless deposition. J. Mater. Chem. 14, 2935–2940 (2004).

    Article  CAS  Google Scholar 

  51. Carrette, L., Friedrich, K. A. & Stimming, U. Fuel cells: Principles, types, fuels, and applications. ChemPhysChem 1, 162–193 (2000).

    Article  CAS  Google Scholar 

  52. Avnir, D., Braun, S., Lev, O. & Ottolenghi, M. Enzymes and other proteins entrapped in sol–gel materials. Chem. Mater. 6, 1605–1614 (1994).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

The authors acknowledge support of this research by the DOE (DE-FG02-03ER46072) and the NSF through single investigator awards (DMR-0605856 and DMR-1104773). We further acknowledge use of facilities of the Cornell Center for Materials Research (CCMR) with financial support from the Materials Research Science and Engineering Center programme of the National Science Foundation (cooperative agreement DMR 0520404). X-ray diffraction at the Cornell High Energy Synchrotron Source (CHESS) is supported by the National Science Foundation under award DMR-0225180. S.C.W. acknowledges support from the EPA STAR fellowship programme. We thank Debra Rolison for helpful discussions.

Author information

Authors and Affiliations

Authors

Contributions

S.C.W. designed the sol–gel chemistry and carried out most experiments and data analysis. M.R.P. and S.C.W. synthesized the sol–gel precursors and hybrid films. A.M.A. and S.C.W. synthesized the block-copolymer hybrids. M.K. carried out colloidal crystal templating. E.H. and T.S. synthesized Stöber-type particles. A.A.B. and S.C.W. carried out EDX. S.C.W. carried out electrical conductivity measurements. H.A. etched silica. H.S. and J.W. carried out Raman measurements. Z.L., A.M.A. and S.C.W. prepared and analysed the block-copolymer hybrids. J.S. and S.C.W. synthesized the block copolymers. U.W-Z. and J.W.Z. carried out solid-state NMR measurements. S.C.W. and U.W. wrote the manuscript and all authors contributed to revisions. M.G., F.J.D. and U.W. supervised the research.

Corresponding author

Correspondence to Ulrich Wiesner.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 1390 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Warren, S., Perkins, M., Adams, A. et al. A silica sol–gel design strategy for nanostructured metallic materials. Nature Mater 11, 460–467 (2012). https://doi.org/10.1038/nmat3274

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nmat3274

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