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.

Photo-illuminated diamond as a solid-state source of solvated electrons in water for nitrogen reduction

Abstract

The photocatalytic reduction of N2 to NH3 is typically hampered by poor binding of N2 to catalytic materials and by the very high energy of the intermediates involved in this reaction. Solvated electrons directly introduced into the reactant solution can provide an alternative pathway to overcome such limitations. Here we demonstrate that illuminated hydrogen-terminated diamond yields facile electron emission into water, thus inducing reduction of N2 to NH3 at ambient temperature and pressure. Transient absorption measurements at 632 nm reveal the presence of solvated electrons adjacent to the diamond after photoexcitation. Experiments using inexpensive synthetic diamond samples and diamond powder show that photocatalytic activity is strongly dependent on the surface termination and correlates with the production of solvated electrons. The use of diamond to eject electrons into a reactant liquid represents a new paradigm for photocatalytic reduction, bringing electrons directly to reactants without requiring molecular adsorption to the surface.

Your institute does not have access to this article

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.

Figure 1: Electronic energy-level diagram of diamond.
Figure 2: Detection of solvated electrons produced by photoexcitation of diamond in water.
Figure 3: Ammonia yields from photochemical reduction of N2 at diamond surfaces.
Figure 4: The influence of excitation wavelength and surface termination on N2 photoreduction activity.
Figure 5: Comparison of experimental spectra obtained after N2 photoreduction on diamond with calculated infrared spectra of specific NH3 isotopes.

References

  1. Swain, G. M. & Ramesham, R. The electrochemical activity of boron-doped polycrystalline diamond thin film electrodes. Anal. Chem. 65, 345–351 (1993).

    CAS  Article  Google Scholar 

  2. Martin, H. B., Argoitia, A., Landau, U., Anderson, A. B. & Angus, J. C. Hydrogen and oxygen evolution on boron-doped diamond electrodes. J. Electrochem. Soc. 143, L133–L136 (1996).

    CAS  Article  Google Scholar 

  3. Himpsel, F. J., Knapp, J. A., Vanvechten, J. A. & Eastman, D. E. Quantum photoyield of diamond(111) - stable negative-affinity emitter. Phys. Rev. B 20, 624–627 (1979).

    CAS  Article  Google Scholar 

  4. Takeuchi, D. et al. Direct observation of negative electron affinity in hydrogen-terminated diamond surfaces. Appl. Phys. Lett. 86, 823–825 (2005).

    Article  Google Scholar 

  5. Van der Weide, J. et al. Negative-electron-affinity effects on the diamond (100) surface. Phys. Rev. B 50, 5803–5806 (1994).

    CAS  Article  Google Scholar 

  6. Bandis, C. & Pate, B. Photoelectric emission from negative-electron-affinity diamond (111) surfaces: Exciton breakup versus conduction-band emission. Phys. Rev. B 52, 12056–12071 (1995).

    CAS  Article  Google Scholar 

  7. Bandis, C. & Pate, B. Electron emission due to exciton breakup from negative electron affinity diamond. Phys. Rev. Lett. 74, 777–780 (1995).

    CAS  Article  Google Scholar 

  8. Takeuchi, D., Nebel, C. E. & Yamasaki, S. Surface defect states analysis on diamond by photoelectron emission yield experiments. Diamond Relat. Mater. 16, 823–825 (2007).

    CAS  Article  Google Scholar 

  9. Ristein, J., Stein, W. & Ley, L. Defect spectroscopy and determination of the electron diffusion length in single crystal diamond by total photoelectron yield spectroscopy. Phys. Rev. Lett. 78, 1803–1806 (1997).

    CAS  Article  Google Scholar 

  10. Pleskov, Y. V. in Diamond and Diamond-Like Film Applications (eds Giellise, P. J., Ivanov-Omskii, V. I., Popovici, G. & Prelas, M.) (Technomic, 1998).

    Google Scholar 

  11. Boonma, L., Yano, T., Tryk, D., Hashimoto, K. & Fujishima, A. Observation of photocurrent from band-gap excitation of semiconducting p-type diamond thin film electrodes. J. Electrochem. Soc. 144, L142–L145 (1997).

    CAS  Article  Google Scholar 

  12. Krohn, C. E., Antoniewicz, P. R. & Thompson, J. C. Energetics for photoemission of electrons into NH3 and H2O. Surf. Sci. 101, 241–250 (1980).

    CAS  Article  Google Scholar 

  13. Trasatti, S. The absolute electrode potential: An explanatory note. Pure Appl. Chem. 58, 955–966 (1986).

    CAS  Article  Google Scholar 

  14. Jang, D. M. et al. Nanodiamonds as photocatalysts for reduction of water and graphene oxide. Chem. Commun. 48, 696–698 (2012).

    CAS  Article  Google Scholar 

  15. Tennakone, K., Wickramanayake, S., Fernando, C. A. N., Ileperuma, O. A. & Punchihewa, S. Photocatalytic nitrogen reduction using visible light. J. Chem. Soc.; Chem. Commun. 14, 1078–1080 (1987).

    Article  Google Scholar 

  16. Vettraino, M., Trudeau, M., Lo, A., Schurko, R. & Antonelli, D. Room-temperature ammonia formation from dinitrogen on a reduced mesoporous titanium oxide surface with metallic properties. J. Am. Chem. Soc. 124, 9567–9573 (2002).

    CAS  Article  Google Scholar 

  17. Schrauzer, G. N. & Guth, T. D. Photocatalytic reactions. 1. Photolysis of water and photoreduction of nitrogen on titanium dioxide. J. Am. Chem. Soc. 99, 7189–7193 (1977).

    CAS  Article  Google Scholar 

  18. Miyama, H., Fujii, N. & Nagae, Y. Heterogeneous photocatalytic synthesis of ammonia from water and nitrogen. Chem. Phys. Lett. 74, 523–524 (1980).

    CAS  Article  Google Scholar 

  19. Leigh, G. J. Chemistry: Fixing nitrogen any which way. Science 279, 506–507 (1998).

    CAS  Article  Google Scholar 

  20. Ranjit, K., Varadarajan, T. & Viswanathan, B. Photocatalytic reduction of dinitrogen to ammonia over noble-metal-loaded TiO2 . J. Photochem. Photobiol. A 96, 181–185 (1996).

    CAS  Article  Google Scholar 

  21. Rao, N., Dube, S. & Natarajan, P. Photocatalytic reduction of nitrogen over (Fe, Ru or Os)/TiO2 catalysts. Appl. Cat. B 5, 33–42 (1994).

    CAS  Article  Google Scholar 

  22. Bauer, N. Theoretical pathways for the reduction of N2 molecules in aqueous media: thermohynamics of N2Hn . J. Phys. Chem. 64, 833–837 (1960).

    CAS  Article  Google Scholar 

  23. Bazhenova, T. & Shilov, A. Nitrogen fixation in solution. Coord. Chem. Rev. 144, 69–145 (1995).

    CAS  Article  Google Scholar 

  24. Shilov, A. Catalytic reduction of molecular nitrogen in solutions. Russ. Chem. Bull. 53, 2555–2562 (2003).

    Article  Google Scholar 

  25. Yandulov, D. V. & Schrock, R. R. Catalytic reduction of dinitrogen to ammonia at a single molybdenum center. Science 301, 76–78 (2003).

    CAS  Article  Google Scholar 

  26. Ertl, G. Surface science and catalysis: Studies on the mechanism of ammonia synthesis. Catal Rev. Sci. Engr. 21, 201–223 (1980).

    CAS  Article  Google Scholar 

  27. Rayment, T., Schlogl, R., Thomas, J. M. & Ertl, G. Structure of the ammonia-synthesis catalyst. Nature 315, 311–313 (1985).

    CAS  Article  Google Scholar 

  28. Alpatova, N., Krishtalik, L. & Pleskov, Y. Electrochemistry of solvated electrons. Top. Curr. Chem. 138, 149–219 (1987).

    CAS  Article  Google Scholar 

  29. Roduner, E. Hydrophobic solvation, quantum nature, and diffusion of atomic hydrogen in liquid water. Radiat. Phys. Chem. 72, 201–206 (2005).

    CAS  Article  Google Scholar 

  30. Michael, B., Hart, E. & Schmidt, K. The absorption spectrum of eaq in the temperature range −4 to 390. J. Phys. Chem. 144, 69–145 (1971).

    Google Scholar 

  31. Pálfi, T., Wojnárovits, L. & Takács, E. Calculated and measured transient product yields in pulse radiolysis of aqueous solutions: Concentration dependence. Radiat. Phys. Chem. 79, 1154–1158 (2010).

    Article  Google Scholar 

  32. Hart, E. J. & Boag, J. W. Absorption spectrum of the hydrated electron in water and in aqueous solutions. J. Am. Chem. Soc. 84, 4090–4095 (1962).

    CAS  Article  Google Scholar 

  33. Nakken, K. & Pihl, A. On the ability of nitrous oxide to convert hydrated electrons into hydroxyl radical. Radiat. Res. 26, 519–526 (1965).

    CAS  Article  Google Scholar 

  34. Hoshino, K., Kuchii, R. & Ogawa, T. Dinitrogen photofixation properties of different titanium oxides in conducting polymer/titanium oxide hybrid systems. Appl. Cat. B 79, 81–88 (2008).

    CAS  Article  Google Scholar 

  35. Litter, M. & Navio, J. Photocatalytic properties of iron-doped titania semiconductors. J. Photochem. Photobiol. A 98, 171–181 (1996).

    CAS  Article  Google Scholar 

  36. Soria, J. et al. Dinitrogen photoreduction to ammonia over titanium dioxide powders doped with ferric ions. J. Phys. Chem. 95, 274–282 (1991).

    CAS  Article  Google Scholar 

  37. Mozzanega, H., Herrmann, J. M. & Pichat, P. Ammonia oxidation over UV-irradiated titanium dioxide at room temperature. J. Phys. Chem. 83, 2251–2255 (1979).

    CAS  Article  Google Scholar 

  38. Li, Q., Domen, K., Naito, S., Onishi, T. & Tamaru, K. Photocatalytic synthesis and photodecomposition of ammonia over SrTiO3 and BaTiO3 based catalysts. Chem. Lett. 3, 321–324 (1983).

    Article  Google Scholar 

  39. Fujishima, A. & Honda, K. Electrochemical photolysis of water at a semiconductor electrode. Nature 238, 37–38 (1972).

    CAS  Article  Google Scholar 

  40. Vouagner, D., Show, Y., Kiraly, B., Champagnon, B. & Girardeau-Montaut, J. P. Photoemission characteristics of diamond films. Appl. Surf. Sci. 168, 79–84 (2000).

    CAS  Article  Google Scholar 

  41. Cui, J., Ristein, J. & Ley, L. Low-threshold electron emission from diamond. Phys. Rev. B 60, 16135–16142 (1999).

    CAS  Article  Google Scholar 

  42. Baumann, P. K. & Nemanich, R. J. Surface cleaning, electronic states and electron affinity of diamond (100), (111) and (110) surfaces. Surf. Sci. 409, 320–335 (1998).

    CAS  Article  Google Scholar 

  43. Baumann, P. & Nemanich, R. Electron affinity and Schottky barrier height of metal diamond (100),(111), and (110) interfaces. J. Appl. Phys. 83, 2072–2082 (1998).

    CAS  Article  Google Scholar 

  44. Boucher, D. L., Davies, J. A., Edwards, J. G. & Mennad, A. An investigation of the putative photosynthesis of ammonia on iron-doped titania and other metal oxides. J. Photochem. Photobiol. 88, 53–64 (1995).

    CAS  Article  Google Scholar 

  45. The HITRAN molecular spectroscopic database and HAWKS (HITRAN Atmospheric Workstation): 1996 Edition. J. Quant. Spectrosc. Radiat. Transf. 111, 1568–1613 (2010).

  46. Hwang, D-Y. & Mebel, A. M. Reaction mechanism of N2/H2 conversion to NH3: A theoretical study. J. Phys. Chem. A 107, 2865–2874 (2003).

    CAS  Article  Google Scholar 

  47. Siegbahn, P. & Westerberg, J. Nitrogen fixation by nitrogenases: a quantum chemical study. The J. Phys. Chem. B 102, 1615–1623 (1998).

    CAS  Article  Google Scholar 

  48. Thoms, B. D., Owens, M. S., Butler, J. E. & Spiro, C. Production and characterization of smooth, hydrogen terminated diamond C(100). Appl. Phys. Lett. 65, 2957–2959 (1994).

    CAS  Article  Google Scholar 

  49. Bolt, D. F. Colorimetric Determination of Nonmetals, Vol. 2 (Wiley, 1978).

    Google Scholar 

Download references

Acknowledgements

The authors acknowledge L. C. Hamers, S. Hogendoorn, B. Putans and N. Becknell for their assistance with early stages of this work. The authors would also like to thank J. R. Schmidt, J. Christianson and G. Nathanson for useful insights into the N2 reduction mechanisms. This work was supported by the National Science Foundation DMR-1207281. Initial exploratory experiments were obtained through support from National Science Foundation DMR-1121288.

Author information

Authors and Affiliations

Authors

Contributions

R.J.H. designed and supervised the project, D.Z. carried out the experiments and wrote the paper, L.Z. assisted with infrared isotope labelling studies, and R.E.R. provided expertise in ultraviolet photoemission studies. All of the co-authors contributed to discussion and analysis of the data.

Corresponding author

Correspondence to Robert J. Hamers.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 696 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Zhu, D., Zhang, L., Ruther, R. et al. Photo-illuminated diamond as a solid-state source of solvated electrons in water for nitrogen reduction. Nature Mater 12, 836–841 (2013). https://doi.org/10.1038/nmat3696

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nmat3696

Further reading

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