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Development of a photoelectrochemically self-improving Si/GaN photocathode for efficient and durable H2 production

Abstract

Development of an efficient yet durable photoelectrode is of paramount importance for deployment of solar-fuel production. Here, we report the photoelectrochemically self-improving behaviour of a silicon/gallium nitride photocathode active for hydrogen production with a Faradaic efficiency approaching ~100%. By using a correlative approach based on different spectroscopic and microscopic techniques, as well as density functional theory calculations, we provide a mechanistic understanding of the chemical transformation that is the origin of the self-improving behaviour. A thin layer of gallium oxynitride forms on the side walls of the gallium nitride grains, via a partial oxygen substitution at nitrogen sites, and displays a higher density of catalytic sites for the hydrogen-evolving reaction. This work demonstrates that the chemical transformation of gallium nitride into gallium oxynitride leads to sustained operation and enhanced catalytic activity, thus showing promise for oxynitride layers as protective catalytic coatings for hydrogen evolution.

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Fig. 1: Self-improving behaviour of Si/GaN photocathodes.
Fig. 2: Photoconductive AFM characterization on CA-0 h and CA-10 h samples.
Fig. 3: Chemical analysis of Si/GaN photocathode surface.
Fig. 4: DFT calculation on N-polar c plane and non-polar m plane.

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Data availability

The data that support the findings of this study are available at HydroGEN Data Hub (http://datahub.h2awsm.org/). Additional data reported in the Supplementary Information are available from the corresponding authors upon request. Source data for Figs. 1–4 are available at https://datahub.h2awsm.org/project/about/photoelectrochemically-self-improving-si-gan-photocathode.

References

  1. Walter, M. G. et al. Solar water splitting cells. Chem. Rev. 110, 6446–6473 (2010).

    Article  CAS  Google Scholar 

  2. Vanka, S. et al. Long-term stability studies of a semiconductor photoelectrode in three-electrode configuration. J. Mater. Chem. A 7, 27612–27619 (2019).

    Article  CAS  Google Scholar 

  3. Hu, S. et al. Thin-film materials for the protection of semiconducting photoelectrodes in solar-fuel generators. J. Phys. Chem. C 119, 24201–24228 (2015).

    Article  CAS  Google Scholar 

  4. Khaselev, O. & Turner, J. A. A monolithic photovoltaic-photoelectrochemical device for hydrogen production via water splitting. Science 280, 425–427 (1998).

    Article  CAS  Google Scholar 

  5. Chen, L. et al. p-Type transparent conducting oxide/n-type semiconductor heterojunctions for efficient and stable solar water oxidation. J. Am. Chem. Soc. 137, 9595–9603 (2015).

    Article  CAS  Google Scholar 

  6. Scheuermann, A. G. et al. Design principles for maximizing photovoltage in metal-oxide-protected water-splitting photoanodes. Nat. Mater. 15, 99–105 (2016).

    Article  CAS  Google Scholar 

  7. Strandwitz, N. C. et al. Photoelectrochemical behavior of n-type Si(100) electrodes coated with thin films of manganese oxide grown by atomic layer deposition. J. Phys. Chem. C 117, 4931–4936 (2013).

    Article  CAS  Google Scholar 

  8. Hu, S. et al. Amorphous TiO2 coatings stabilize Si, GaAs, and GaP photoanodes for efficient water oxidation. Science 344, 1005–1009 (2014).

    Article  CAS  Google Scholar 

  9. Fang, F. Z., Chen, Y. H., Zhang, X. D., Hu, X. T. & Zhang, G. X. Nanometric cutting of single crystal silicon surfaces modified by ion implantation. CIRP Ann. 60, 527–530 (2011).

    Article  Google Scholar 

  10. Gu, J. et al. A graded catalytic-protective layer for an efficient and stable water-splitting photocathode. Nat. Energy 2, 16192 (2017).

    Article  CAS  Google Scholar 

  11. Vanka, S. et al. High efficiency Si photocathode protected by multifunctional GaN nanostructures. Nano Lett. 18, 6530–6537 (2018).

    Article  CAS  Google Scholar 

  12. Huang, G. et al. Integrated MoSe2 with n+p-Si photocathodes for solar water splitting with high efficiency and stability. Appl. Phys. Lett. 112, 013902 (2018).

    Article  CAS  Google Scholar 

  13. King, L. A., Hellstern, T. R., Park, J., Sinclair, R. & Jaramillo, T. F. Highly stable molybdenum disulfide protected silicon photocathodes for photoelectrochemical water splitting. ACS Appl. Mater. Interfaces 9, 36792–36798 (2017).

    Article  CAS  Google Scholar 

  14. Kibria, M. G. et al. Atomic-scale origin of long-term stability and high performance of p-GaN nanowire arrays for photocatalytic overall pure water splitting. Adv. Mater. 28, 8388–8397 (2016).

    Article  CAS  Google Scholar 

  15. Lutterman, D. A., Surendranath, Y. & Nocera, D. G. A self-healing oxygen-evolving catalyst. J. Am. Chem. Soc. 131, 3838–3839 (2009).

    Article  CAS  Google Scholar 

  16. Malara, F., Fabbri, F., Marelli, M. & Naldoni, A. Controlling the surface energetics and kinetics of hematite photoanodes through few atomic layers of NiOx. ACS Catal. 6, 3619–3628 (2016).

    Article  CAS  Google Scholar 

  17. Bergmann, A. et al. Reversible amorphization and the catalytically active state of crystalline Co3O4 during oxygen evolution. Nat. Commun. 6, 8625 (2015).

    Article  CAS  Google Scholar 

  18. Wang, D. et al. Wafer-level photocatalytic water splitting on GaN nanowire arrays grown by molecular beam epitaxy. Nano Lett. 11, 2353–2357 (2011).

    Article  CAS  Google Scholar 

  19. Toma, F. M. et al. Mechanistic insights into chemical and photochemical transformations of bismuth vanadate photoanodes. Nat. Commun. 7, 12012 (2016).

    Article  Google Scholar 

  20. He, Y. et al. Dependence of interface energetics and kinetics on catalyst loading in a photoelectrochemical system. Nano Res. 12, 2378–2384 (2019).

    Article  CAS  Google Scholar 

  21. Jiang, K. et al. Effects of surface roughness on the electrochemical reduction of CO2 over Cu. ACS Energy Lett. 5, 1206–1214 (2020).

    Article  CAS  Google Scholar 

  22. Yang, J. et al. A multifunctional biphasic water splitting catalyst tailored for integration with high-performance semiconductor photoanodes. Nat. Mater. 16, 335–341 (2017).

    Article  CAS  Google Scholar 

  23. Bermudez, V. M. The fundamental surface science of wurtzite gallium nitride. Surf. Sci. Rep. 72, 147–315 (2017).

    Article  CAS  Google Scholar 

  24. Akimov, A. V., Muckerman, J. T. & Prezhdo, O. V. Nonadiabatic dynamics of positive charge during photocatalytic water splitting on GaN(10-10) surface: charge localization governs splitting efficiency. J. Am. Chem. Soc. 135, 8682–8691 (2013).

    Article  CAS  Google Scholar 

  25. Wang, J., Pedroza, L. S., Poissier, A. & Fernández-Serra, M. V. Water dissociation at the GaN(101̅0) surface: structure, dynamics and surface acidity. J. Phys. Chem. C 116, 14382–14389 (2012).

    Article  CAS  Google Scholar 

  26. Stutzmann, M. et al. Playing with polarity. Phys. Stat. Sol. B 512, 505–512 (2001).

    Article  Google Scholar 

  27. Hellman, E. S. The polarity of GaN: a critical review. MRS Internet J. Nitride Semicond. Res. 3, E11 (1999).

    Article  Google Scholar 

  28. Zeng, G., Sun, W., Song, R., Tansu, N. & Krick, B. A. Crystal orientation dependence of gallium nitride wear. Sci. Rep. 7, 14126 (2017).

    Article  CAS  Google Scholar 

  29. Zeng, G., Tan, C. K., Tansu, N. & Krick, B. A. Ultralow wear gallium nitride. Appl. Phys. Lett. 109, 051602 (2016).

    Article  CAS  Google Scholar 

  30. Bernal, R. A. et al. Effect of growth orientation and diameter on the elasticity of GaN nanowires. A combined in situ TEM and atomistic modeling investigation. Nano Lett. 11, 548–555 (2011).

    Article  CAS  Google Scholar 

  31. Wolter, S. D. et al. X-ray photoelectron spectroscopy and X-ray diffraction study of the thermal oxide on gallium nitride. Appl. Phys. Lett. 70, 2156 (1997).

    Article  CAS  Google Scholar 

  32. Wolter, S. D., DeLucca, J. M., Mohney, S. E., Kern, R. S. & Kuo, C. P. An investigation into the early stages of oxide growth on gallium nitride. Thin Solid Films 371, 153–160 (2000).

    Article  CAS  Google Scholar 

  33. Zhao, Y. et al. Precise determination of surface band bending in Ga-polar n-GaN films by angular dependent X-ray photoemission spectroscopy. Sci. Rep. 9, 16969 (2019).

    Article  CAS  Google Scholar 

  34. Sun, Q., Selloni, A., Myers, T. H. & Doolittle, W. A. Oxygen adsorption and incorporation at irradiated GaN (0001) and GaN (000 1) surfaces: first-principles density-functional calculations. Phys. Rev. B 74, 195317 (2006).

    Article  CAS  Google Scholar 

  35. Wu, Y., Lazic, P., Hautier, G., Persson, K. & Ceder, G. First principles high throughput screening of oxynitrides for water-splitting photocatalysts. Energy Environ. Sci. 6, 157–168 (2013).

    Article  CAS  Google Scholar 

  36. Abe, R., Higashi, M. & Domen, K. Facile fabrication of an efficient oxynitride TaON photoanode for overall water splitting into H2 and O2 under visible light irradiation. J. Am. Chem. Soc. 132, 11828–11829 (2010).

    Article  CAS  Google Scholar 

  37. Yang, X. et al. Nitrogen-plasma treated hafnium oxyhydroxide as an efficient acid-stable electrocatalyst for hydrogen evolution and oxidation reactions. Nat. Commun. 10, 1543 (2019).

    Article  CAS  Google Scholar 

  38. Kreider, M. E. et al. Nitride or oxynitride? Elucidating the composition–activity relationships in molybdenum nitride electrocatalysts for the oxygen reduction reaction. Chem. Mater. https://doi.org/10.1021/acs.chemmater.9b05212 (2020).

  39. Yang, M. et al. Anion order in perovskite oxynitrides. Nat. Chem. 3, 47–52 (2011).

    Article  CAS  Google Scholar 

  40. Lim, H. et al. High performance III–V photoelectrodes for solar water splitting via synergistically tailored structure and stoichiometry. Nat. Commun. 10, 3388 (2019).

    Article  CAS  Google Scholar 

  41. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865 (1996).

    Article  CAS  Google Scholar 

  42. Giannozzi, P. et al. QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials. J. Phys. Condens. Matter 21, 395502 (2009).

    Article  Google Scholar 

  43. Vanderbilt, D. Soft self-consistent pseudopotentials in a generalized eigenvalue formalism. Phys. Rev. B 41, 7892 (1990).

    Article  CAS  Google Scholar 

  44. Zhou, B. et al. A GaN:Sn nanoarchitecture integrated on a silicon platform for converting CO2 to HCOOH by photoelectrocatalysis. Energy Environ. Sci. 12, 2842–2848 (2019).

    Article  CAS  Google Scholar 

  45. Liu, R., Schaller, R., Chen, C. Q. & Bayram, C. High internal quantum efficiency ultraviolet emission from phase-transition cubic GaN integrated on nanopatterned Si(100). ACS Photonics 5, 955–963 (2018).

    Article  CAS  Google Scholar 

  46. Nguyen, H. P. T. et al. Breaking the carrier injection bottleneck of phosphor-free nanowire white light-emitting diodes. Nano Lett. 13, 5437–5442 (2013).

    Article  CAS  Google Scholar 

  47. Chuah, L. S., Hassan, Z., Ng, S. S. & Hassan, H. A. High carrier concentrations of n- and p-doped GaN on Si(111) by nitrogen plasma-assisted molecular-beam epitaxy. J. Mater. Res. 22, 2623–2630 (2007).

    Article  CAS  Google Scholar 

  48. Kistler, T. A. et al. Integrated membrane-electrode-assembly photoelectrochemical cell under various feed conditions for solar water splitting. J. Electrochem. Soc. 166, H3020–H3028 (2019).

    Article  CAS  Google Scholar 

  49. Chen, R., Fan, F., Dittrich, T. & Li, C. Imaging photogenerated charge carriers on surfaces and interfaces of photocatalysts with surface photovoltage microscopy. Chem. Soc. Rev. 47, 8238–8262 (2018).

    Article  CAS  Google Scholar 

  50. Zhang, X. & Plasinska, S. Electronic and chemical structure of the H2O/GaN(0001) interface under ambient conditions. Sci. Rep. 6, 24848 (2016).

    Article  CAS  Google Scholar 

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Acknowledgements

We gratefully acknowledge research support from the HydroGEN Advanced Water Splitting Materials Consortium, established as part of the Energy Materials Network under the US Department of Energy, Office of Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office, under contract no. DE-AC02-05CH11231 for Lawrence Berkeley National Laboratory, under contract no. DE-EE0008086 for the University of Michigan. Part of the work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under contract no. DE-AC52-07NA27344. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under contract no. DE-AC02-05CH11231. We thank N. Danilovic, A. K. Buckley, J. L. Young, H. Li, D. Wang, R. Chen and Y. He for insightful discussions. We would also like to acknowledge the HydroGEN EMN data team, led by the National Renewable Energy Laboratory (NREL), for their assistance in reviewing the uploaded data and metadata to the Data Hub repository, making it public and obtaining the DOIs for the data. The HydroGEN Data Hub (https://datahub.h2awsm.org/) combines experimental and computational data into a searchable water splitting materials data infrastructure and distributes data to the scientific community and the public.

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Contributions

F.M.T., Z.M. and T.O. conceived the idea. F.M.T. supervised the work. G.Z. conducted the PEC testing, pc-AFM and XPS measurements. G.Z. and F.M.T. analysed and interpreted the results. J.K.C. helped with XPS experiment design and data interpretation. S.V. synthesized the material and conducted intensified stability tests. T.A.P. and T.O. performed the DFT calculations. G.L. and C.S. conducted the STEM–EELS experiments. G.Z., T.A.P. and F.M.T. wrote the manuscript. All of the authors contributed to the final version of the manuscript.

Corresponding authors

Correspondence to Zetian Mi, Tadashi Ogitsu or Francesca M. Toma.

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Some intellectual property related to the synthesis of GaN nanowires was licensed to NS Nanotech Inc., which was co-founded by Z.M.

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Peer review information Nature Materials thanks Nathan Neale, Yuan Ping and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Information

Supplementary Figs. 1–10, Tables 1–3 and refs. 1–10.

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Zeng, G., Pham, T.A., Vanka, S. et al. Development of a photoelectrochemically self-improving Si/GaN photocathode for efficient and durable H2 production. Nat. Mater. 20, 1130–1135 (2021). https://doi.org/10.1038/s41563-021-00965-w

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