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Multihole water oxidation catalysis on haematite photoanodes revealed by operando spectroelectrochemistry and DFT

Matters Arising to this article was published on 09 November 2020

Abstract

Water oxidation is the key kinetic bottleneck of photoelectrochemical devices for fuel synthesis. Despite advances in the identification of intermediates, elucidating the catalytic mechanism of this multi-redox reaction on metal–oxide photoanodes remains a significant experimental and theoretical challenge. Here, we report an experimental analysis of water oxidation kinetics on four widely studied metal oxides, focusing particularly on haematite. We observe that haematite is able to access a reaction mechanism that is third order in surface-hole density, which is assigned to equilibration between three surface holes and M(OH)–O–M(OH) sites. This reaction exhibits low activation energy (Ea ≈ 60 meV). Density functional theory is used to determine the energetics of charge accumulation and O–O bond formation on a model haematite (110) surface. The proposed mechanism shows parallels with the function of the oxygen evolving complex of photosystem II, and provides new insights into the mechanism of heterogeneous water oxidation on a metal oxide surface.

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Fig. 1: Kinetic analysis of the water oxidation reaction on metal oxide photoanodes.
Fig. 2: Mechanistic analyses of water oxidation on α-Fe2O3.
Fig. 3: Potential water oxidation reaction mechanisms on α-Fe2O3.
Fig. 4: Potential transition state for the third-order kinetics on α-Fe2O3.
Fig. 5: Schematic of the key steps in the proposed third-order water oxidation reaction.

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Data availability

The complete optical and electrochemical dataset is available at http://zenodo.org with the identifier 10.5281/zenodo.851635.

References

  1. Zhu, S. & Wang, D. Photocatalysis: basic principles, diverse forms of implementations and emerging scientific opportunities. Adv. Energy Mater. 17, 1700841 (2017).

    Google Scholar 

  2. Berardi, S. et al. Molecular artificial photosynthesis. Chem. Soc. Rev. 43, 7501–7519 (2014).

    CAS  PubMed  Google Scholar 

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

    CAS  PubMed  Google Scholar 

  4. Lewis, N. S. & Nocera, D. G. Powering the planet: chemical challenges in solar energy utilization. Proc. Natl Acad. Sci. USA 103, 15729–15735 (2006).

    CAS  PubMed  Google Scholar 

  5. Sun, K. et al. A comparison of the chemical, optical and electrocatalytic properties of water-oxidation catalysts for use in integrated solar-fuel generators. Energy Environ. Sci. 10, 987–1002 (2017).

    CAS  Google Scholar 

  6. McCrory, C. C. L., Jung, S., Peters, J. C. & Jaramillo, T. F. Benchmarking heterogeneous electrocatalysts for the oxygen evolution reaction. J. Am. Chem. Soc. 135, 16977–16987 (2013).

    CAS  Google Scholar 

  7. Kärkäs, M. D. & Åkermark, B. Water oxidation using earth-abundant transition metal catalysts: opportunities and challenges. Dalton Trans. 45, 14421–14461 (2016).

    PubMed  Google Scholar 

  8. Blakemore, J. D., Crabtree, R. H. & Brudvig, G. W. Molecular catalysts for water oxidation. Chem. Rev. 115, 12974–13005 (2015).

    CAS  PubMed  Google Scholar 

  9. Llobet, A. Molecular Water Oxidation Catalysis: A Key Topic for New Sustainable Energy Conversion Schemes (2014, Wiley).

  10. Dau, H. et al. The mechanism of water oxidation: from electrolysis via homogeneous to biological catalysis. ChemCatChem 2, 724–761 (2010).

    CAS  Google Scholar 

  11. Shinagawa, T., Garcia-Esparza, A. T. & Takanabe, K. Insight on Tafel slopes from a microkinetic analysis of aqueous electrocatalysis for energy conversion. Sci. Rep. 5, 13801 (2015).

    PubMed  PubMed Central  Google Scholar 

  12. Gerischer, H. The impact of semiconductors on the concepts of electrochemistry. Electrochim. Acta 35, 1677–1699 (1990).

    CAS  Google Scholar 

  13. Francàs, L., Mesa, C. A., Pastor, E., Le Formal, F. & Durrant, J. R. in Advances in Photoelectrochemical Water Splitting: Theory, Experiment and Systems Analysis (eds Tilley, S. D., Lany, S. & van de Krol, R.) Ch. 5 (Royal Society of Chemistry, 2018).

  14. Pastor, E. et al. Spectroelectrochemical analysis of the mechanism of (photo)electrochemical hydrogen evolution at a catalytic interface. Nat. Commun. 8, 14280 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  15. Mesa, C. A. et al. Kinetics of photoelectrochemical oxidation of methanol on hematite photoanodes. J. Am. Chem. Soc. 139, 11537–11543 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  16. Le Formal, F. et al. Rate law analysis of water oxidation on a hematite surface. J. Am. Chem. Soc. 137, 6629–6637 (2015).

    PubMed  PubMed Central  Google Scholar 

  17. Ma, Y. et al. Rate law analysis of water oxidation and hole scavenging on a BiVO4 photoanode. ACS Energy Lett. 1, 618–623 (2016).

    CAS  Google Scholar 

  18. Kafizas, A. et al. Water oxidation kinetics of accumulated holes on the surface of a TiO2 photoanode: a rate law analysis. ACS Catal. 7, 4896–4903 (2017).

    CAS  Google Scholar 

  19. Pesci, F. M., Cowan, A. J., Alexander, B. D., Durrant, J. R. & Klug, D. R. Charge carrier dynamics on mesoporous WO3 during water splitting. J. Phys. Chem. Lett. 2, 1900–1903 (2011).

    CAS  Google Scholar 

  20. Barroso, M., Pendlebury, S. R., Cowan, A. J. & Durrant, J. R. Charge carrier trapping, recombination and transfer in hematite (α-Fe2O3) water splitting photoanodes. Chem. Sci. 4, 2724–2734 (2013).

    CAS  Google Scholar 

  21. Roger, I., Shipman, M. A. & Symes, M. D. Earth-abundant catalysts for electrochemical and photoelectrochemical water splitting. Nat. Rev. Chem. 1, 0003 (2017).

    CAS  Google Scholar 

  22. Rosser, T. E., Gross, M. A., Lai, Y.-H. & Reisner, E. Precious-metal free photoelectrochemical water splitting with immobilised molecular Ni and Fe redox catalysts. Chem. Sci. 7, 4024–4035 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  23. Zhang, Y. et al. Rate-limiting O−O bond formation pathways for water oxidation on hematite photoanode. J. Am. Chem. Soc. 140, 3264–3269 (2018).

    CAS  PubMed  Google Scholar 

  24. Schulze, M., Kunz, V., Frischmann, P. D. & Würthner, F. A supramolecular ruthenium macrocycle with high catalytic activity for water oxidation that mechanistically mimics photosystem II. Nat. Chem. 8, 576–583 (2016).

    CAS  PubMed  Google Scholar 

  25. Kafizas, A. et al. Optimizing the activity of nanoneedle structured WO3 photoanodes for solar water splitting: direct synthesis via chemical vapor deposition. J. Phys. Chem. C 121, 5983–5993 (2017).

    CAS  Google Scholar 

  26. Cowan, A. J., Leng, W., Barnes, P. R. F., Klug, D. R. & Durrant, J. R. Charge carrier separation in nanostructured TiO2 photoelectrodes for water splitting. Phys. Chem. Chem. Phys. 15, 8772 (2013).

    CAS  PubMed  Google Scholar 

  27. Ma, Y., Le Formal, F., Kafizas, A., Pendlebury, S. R. & Durrant, J. R. Efficient suppression of back electron/hole recombination in cobalt phosphate surface-modified undoped bismuth vanadate photoanodes. J. Mater. Chem. A 3, 20649–20657 (2015).

    CAS  Google Scholar 

  28. Wang, X. H. et al. Pyrogenic iron(iii)-doped TiO2 nanopowders synthesized in RF thermal plasma: phase formation, defect structure, band gap and magnetic properties. J. Am. Chem. Soc. 127, 10982–10990 (2005).

    CAS  PubMed  Google Scholar 

  29. Wahlström, E. et al. Bonding of gold nanoclusters to oxygen vacancies on rutile TiO2 (110). Phys. Rev. Lett. 90, 026101 (2003).

    PubMed  Google Scholar 

  30. Zandi, O. & Hamann, T. W. Determination of photoelectrochemical water oxidation intermediates on haematite electrode surfaces using operando infrared spectroscopy. Nat. Chem. 8, 778–783 (2016).

    CAS  PubMed  Google Scholar 

  31. Cowan, A. J. et al. Activation energies for the rate-limiting step in water photooxidation by nanostructured α-Fe2O3 and TiO2. J. Am. Chem. Soc. 133, 10134–10140 (2011).

    CAS  PubMed  Google Scholar 

  32. Kosmulski, M. pH-dependent surface charging and points of zero charge. IV. Update and new approach. J. Colloid Interface Sci. 337, 439–448 (2009).

    CAS  PubMed  Google Scholar 

  33. Aharon, E. & Toroker, M. C. The effect of covering Fe2O3 with a Ga2O3 overlayer on water oxidation catalysis. Catal. Lett. 147, 2077–2082 (2017).

    CAS  Google Scholar 

  34. Yatom, N., Elbaz, Y., Navon, S. & Caspary Toroker, M. Identifying the bottleneck of water oxidation by ab initio analysis of in situ optical absorbance spectrum. Phys. Chem. Chem. Phys. 19, 17278–17286 (2017).

    CAS  PubMed  Google Scholar 

  35. Seriani, N. Ab initio simulations of water splitting on hematite. J. Phys. Condens. Matter 29, 463002 (2017).

    PubMed  Google Scholar 

  36. Grave, D. A., Yatom, N., Ellis, D. S., Toroker, M. C. & Rothschild, A. The ‘rust’ challenge: on the correlations between electronic structure, excited state dynamics and photoelectrochemical performance of hematite photoanodes for solar water splitting. Adv. Mater. 30, 1706577 (2018).

    Google Scholar 

  37. Nguyen, M.-T., Seriani, N. & Gebauer, R. Back cover: defective α-Fe2O3 (0001): an ab initio study. ChemPhysChem 15, 3136–3136 (2014).

    CAS  Google Scholar 

  38. Zhang, X., Klaver, P., Van Santen, R., Van De Sanden, M. C. M. & Bieberle-Hütter, A. Oxygen evolution at hematite surfaces: the impact of structure and oxygen vacancies on lowering the overpotential. J. Phys. Chem. C 120, 18201–18208 (2016).

    CAS  Google Scholar 

  39. Kay, A., Cesar, I. & Grätzel, M. New benchmark for water photooxidation by nanostructured α-Fe2O3 films. J. Am. Chem. Soc. 128, 15714–15721 (2006).

    CAS  PubMed  Google Scholar 

  40. Cornuz, M., Grätzel, M. & Sivula, K. Preferential orientation in hematite films for solar hydrogen production via water splitting. Chem. Vap. Depos. 16, 291–295 (2010).

    CAS  Google Scholar 

  41. Yamada, H., Siems, W. F., Koike, T. & Hurst, J. K. Mechanisms of water oxidation catalyzed by the cis,cis-[(bpy)2Ru(OH2)]2O4+ ion. J. Am. Chem. Soc. 126, 9786–9795 (2004).

    CAS  PubMed  Google Scholar 

  42. Pham, H. H., Cheng, M.-J., Frei, H. & Wang, L.-W. Surface proton hopping and fast-kinetics pathway of water oxidation on Co3O4 (001) surface. ACS Catal. 6, 5610–5617 (2016).

    CAS  Google Scholar 

  43. Askerka, M., Brudvig, G. W. & Batista, V. S. The O2-evolving complex of photosystem II: recent insights from quantum mechanics/molecular mechanics (QM/MM), extended X-ray absorption fine structure (EXAFS), and femtosecond X-ray crystallography data. Acc. Chem. Res. 50, 41–48 (2017).

    CAS  PubMed  Google Scholar 

  44. Amin, M. et al. Proton-coupled electron transfer during the S-state transitions of the oxygen-evolving complex of photosystem II. J. Phys. Chem. B 119, 7366–7377 (2015).

    CAS  PubMed  Google Scholar 

  45. Rossmeisl, J. et al. Electrolysis of water on oxide surfaces. J. Electroanal. Chem. 607, 83–89 (2007).

    CAS  Google Scholar 

  46. Siegbahn, P. E. M. O–O bond formation in the S4 state of the oxygen-evolving complex in photosystem II. Eur. J. Chem. A 12, 9217–9227 (2006).

    CAS  Google Scholar 

  47. Siegbahn, P. E. M. Water oxidation mechanism in photosystem II, including oxidations, proton release pathways, O–O bond formation and O2 release. Biochim. Biophys. Acta 1827, 1003–1019 (2013).

    CAS  PubMed  Google Scholar 

  48. Pecoraro, V. L., Baldwin, M. J., Caudle, M. T., Hsieh, W.-Y. & Law, N. A. A proposal for water oxidation in photosystem II. Pure Appl. Chem. 70, 925–929 (1998).

    CAS  Google Scholar 

  49. Vrettos, J. S., Limburg, J. & Brudvig, G. W. Mechanism of photosynthetic water oxidation: combining biophysical studies of photosystem II with inorganic model chemistry. Biochim. Biophys. Acta 1503, 229–245 (2001).

    CAS  PubMed  Google Scholar 

  50. Sproviero, E. M., Gascó, J. A., Mcevoy, J. P., Brudvig, G. W. & Batista, V. S. Quantum mechanics/molecular mechanics study of the catalytic cycle of water splitting in photosystem II. J. Am. Chem. Soc. 130, 3428–3442 (2008).

    CAS  PubMed  Google Scholar 

  51. Barber, J. A mechanism for water splitting and oxygen production in photosynthesis. Nat. Plants 3, 17041 (2017).

    CAS  PubMed  Google Scholar 

  52. Barber, J. Photosystem II: the water splitting enzyme of photosynthesis and the origin of oxygen in our atmosphere. Q. Rev. Biophys. 49, e14 (2017).

    Google Scholar 

  53. Li, X. & Siegbahn, P. E. M. Water oxidation for simplified models of the oxygen‐evolving complex in photosystem II. Chem. A Eur. J. 21, 18821–18827 (2015).

    CAS  Google Scholar 

  54. Klauss, A., Haumann, M. & Dau, H. Seven steps of alternating electron and proton transfer in photosystem II water oxidation traced by time-resolved photothermal beam deflection at improved sensitivity. J. Phys. Chem. B 119, 2677–2689 (2015).

    CAS  PubMed  Google Scholar 

  55. Vinyard, D. J. & Brudvig, G. W. Progress toward a molecular mechanism of water oxidation in photosystem II. Annu. Rev. Phys. Chem. 68, 101–116 (2017).

    CAS  PubMed  Google Scholar 

  56. Zhang, M. & Frei, H. Water oxidation mechanisms of metal oxide catalysts by vibrational spectroscopy of transient intermediates. Annu. Rev. Phys. Chem. 68, 209–231 (2017).

    CAS  PubMed  Google Scholar 

  57. Zhang, M., De Respinis, M. & Frei, H. Time-resolved observations of water oxidation intermediates on a cobalt oxide nanoparticle catalyst. Nat. Chem. 6, 362–367 (2014).

    CAS  PubMed  Google Scholar 

  58. Yang, K. R. et al. Solution structures of highly active molecular Ir water-oxidation catalysts from density functional theory combined with high-energy X-ray scattering and EXAFS spectroscopy. J. Am. Chem. Soc. 138, 5511–5514 (2016).

    CAS  PubMed  Google Scholar 

  59. Gamba, I., Codolà, Z., Lloret-Fillol, J. & Costas, M. Making and breaking of the O–O bond at iron complexes. Coord. Chem. Rev. 334, 2–24 (2017).

    CAS  Google Scholar 

  60. Tinberg, C. E. & Lippard, S. J. Dioxygen activation in soluble methane monooxygenase. Acc. Chem. Res. 280, 280–288 (2011).

    Google Scholar 

  61. Shu, L. et al. An Fe2IVO2 diamond core structure for the key intermediate Q of methane monooxygenase. Science 275, 515–518 (1997).

    CAS  PubMed  Google Scholar 

  62. Friedle, S., Reisner, E. & Lippard, S. J. Current challenges of modeling diiron enzyme active sites for dioxygen activation by biomimetic synthetic complexes. Chem. Soc. Rev. 39, 2768–2779 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

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Acknowledgements

J.R.D. acknowledges financial support from the European Research Council (project Intersolar 291482) and H2020 project A-LEAF (732840). C.A.M. thanks COLCIENCIAS (call 568) for funding. L.F. thanks the EU for a Marie Curie fellowship (658270) and E.P. thanks the EPRSC for a DTP scholarship. V.S.B. acknowledges support from the Air Force Office of Scientific Research (AFSOR) grant no. FA9550-17-0198 and high performance computer time from the National Energy Research Scientific Computing Center (NERSC). P.G.B. acknowledges “la Caixa” foundation for the PhD grant. A.K. thanks Imperial College for a Junior Research Fellowship. M.G. acknowledges support from the Swiss National Science Foundation (project 140709) and Swiss Federal Office for Energy (project PECHouse 3; contract no. SI/500090–03). T.E.R. thanks the EPSRC for a DTC studentship and E.R. the Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy, and the National Foundation for Research, Technology and Development) and the OMV Group for financial support. M.T.M. acknowledges the Helmholtz Association’s Initiative and Networking Fund.

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C.A.M. and L.F. contributed equally to this work. All authors discussed the results and commented on and revised the manuscript. C.A.M., L.F. and J.R.D. conceived and designed the experiments. K.R.Y., P.G. and V.S.B. contributed the DFT work. E.P., Y.M., A.K., T.E.R., M.T.M., E.R. and M.G. contributed materials and data.

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Correspondence to Victor S. Batista or James R. Durrant.

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Supplementary Information

Supplementary Figs. 1–16, Tables 1–3, experimental methods, density functional theory calculations, optical and photoelectrochemical characterization of the materials used, supporting data for the activation energy calculation as well as the kinetic isotope effect and the pH dependence studies and discussion of the first-order mechanism and optimized geometries.

Optimised geometries

Optimized geometries for the density functional theory calculations.

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Mesa, C.A., Francàs, L., Yang, K.R. et al. Multihole water oxidation catalysis on haematite photoanodes revealed by operando spectroelectrochemistry and DFT. Nat. Chem. 12, 82–89 (2020). https://doi.org/10.1038/s41557-019-0347-1

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