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X-ray spectroscopies studies of the 3d transition metal oxides and applications of photocatalysis

Published online by Cambridge University Press:  08 February 2017

Yifan Ye ,
Mukes Kapilashrami ,
Cheng-Hao Chuang ,
Yi-sheng Liu ,
Per-Anders Glans  and
Jinghua Guo
Yifan Ye
Affiliation:
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
Mukes Kapilashrami
Affiliation:
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
Cheng-Hao Chuang
Affiliation:
Department of Physics, Tamkang University, New Taipei City 25137, Taiwan
Yi-sheng Liu
Affiliation:
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
Per-Anders Glans
Affiliation:
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
Jinghua Guo*
Affiliation:
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA 95064, USA
*
Address all correspondence to Jinghua Guo at [email protected]
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Abstract

Recent advances in synchrotron based x-ray spectroscopy enable materials scientists to emanate fingerprints on important materials properties, e.g., electronic, optical, structural, and magnetic properties, in real-time and under nearly real-world conditions. This characterization in combination with optimized materials synthesis routes and tailored morphological properties could contribute greatly to the advances in solid-state electronics and renewable energy technologies. In connection to this, such perspective reflects the current materials research in the space of emerging energy technologies, namely photocatalysis, with a focus on transition metal oxides, mainly on the Fe2O3- and TiO2-based materials.

Type
Functional Oxides Research Letter
Information
MRS Communications , Volume 7 , Issue 1 , March 2017 , pp. 53 - 66
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Copyright
Copyright © Materials Research Society 2017 

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Footnotes

† These authors contributed equally to this paper.

References

1. Kapilashrami, M., Zhang, Y., Liu, Y.-S., Hagfeldt, A., and Guo, J.: Probing the optical property and electronic structure of TiO2 nanomaterials for renewable energy applications. Chem. Rev. 114, 9662 (2014).CrossRefGoogle ScholarPubMed
2. Fujishima, A. and Honda, K.: Electrochemical photolysis of water at a semiconductor electrode. Nature 238, 37 (1972).CrossRefGoogle Scholar
3. Maeda, K. and Domen, K.: New non-oxide photocatalysts designed for overall water splitting under visible light. J. Phys. Chem. C 111, 7851 (2007).Google Scholar
4. Himpsel, F.J., Cook, P.L., de la Torre, G., Garcia-Lastra, J.M., Gonzalez-Moreno, R., Guo, J.H., Hamers, R.J., Kronawitter, C.X., Johnson, P.S., Ortega, J.E., Pickup, D., Ragoussi, M.E., Rogero, C., Rubio, A., Ruther, R.E., Vayssieres, L., Yang, W., and Zegkinoglou, I.: Design of solar cell materials via soft X-ray spectroscopy. J. Electron Spectrosc. Relat. Phenom. 190(Part A), 2 (2013).Google Scholar
5. Linsebigler, A.L., Lu, G., and Yates, J.T.: Photocatalysis on TiO2 surfaces: principles, mechanisms, and selected results. Chem. Rev. 95, 735 (1995).CrossRefGoogle Scholar
6. Jing, D., Guo, L., Liang, Z., Zhang, X., Liu, H., Li, M., Shen, S., Liu, G., Hu, X., and Zhang, X.: Efficient solar hydrogen production by photocatalytic water splitting: from fundamental study to pilot demonstration. Int. J. Hydrog. Energy 35, 7087 (2010).Google Scholar
7. Greiner, M.T., Helander, M.G., Tang, W.-M., Wang, Z.-B., Qiu, J., and Lu, Z.-H.: Universal energy-level alignment of molecules on metal oxides. Nat. Mater. 11, 76 (2012).Google Scholar
8. Xia, X., Zeng, Z., Li, X., Zhang, Y., Tu, J., Fan, N.C., Zhang, H., and Fan, H.J.: Fabrication of metal oxide nanobranches on atomic-layer-deposited TiO2 nanotube arrays and their application in energy storage. Nanoscale 5, 6040 (2013).Google Scholar
9. Kapilashrami, M., Kronawitter, C.X., Torndahl, T., Lindahl, J., Hultqvist, A., Wang, W.-C., Chang, C.-L., Mao, S.S., and Guo, J.: Soft X-ray characterization of Zn1−xSnxOy electronic structure for thin film photovoltaics. Phys. Chem. Chem. Phys. 14, 10154 (2012).Google Scholar
10. Chen, X. and Mao, S.S.: Titanium dioxide nanomaterials: synthesis, properties, modifications, and applications. Chem. Rev. 107, 2891 (2007).CrossRefGoogle ScholarPubMed
11. Park, Y., McDonald, K.J., and Choi, K.-S.: Progress in bismuth vanadate photoanodes for use in solar water oxidation. Chem. Soc. Rev. 42, 2321 (2013).CrossRefGoogle ScholarPubMed
12. Kim, T.W. and Choi, K.-S.: Nanoporous BiVO4 photoanodes with dual-layer oxygen evolution catalysts for solar water splitting. Science 343, 990 (2014).CrossRefGoogle ScholarPubMed
13. Vayssieres, L.: On the effect of nanoparticle size on water-oxide interfacial chemistry. J. Phys. Chem. C 113, 4733 (2009).CrossRefGoogle Scholar
14. Liu, C., Dasgupta, N.P., and Yang, P.: Semiconductor nanowires for artificial photosynthesis. Chem. Mater. 26, 415 (2014).Google Scholar
15. Yahya, A. and Fan, Z.Y.: A TiO2 nanostructure transformation: from ordered nanotubes to nanoparticles. Nanotechnology 20, 405610 (2009).Google Scholar
16. Kapilashrami, M., Liu, Y.S., Glans, P.A., and Guo, J.: Soft X-Ray Spectroscopy and Electronic Structure of 3d Transition Metal Compounds in Artificial Photosynthesis Materials (Springer International Publishing, Cham, Switzerland, 2015), p. 269.CrossRefGoogle Scholar
17. Guo, J.: Synchrotron radiation, soft-X-ray spectroscopy and nanomaterials. Int. J. Nanotechnol. 1, 193 (2004).Google Scholar
18. Guo, J.H., Butorin, S.M., Wassdahl, N., Skytt, P., Nordgren, J., and Ma, Y.: Electronic structure of La2−xSrxCuO4 studied by soft-x-ray-fluorescence spectroscopy with tunable excitation. Phys. Rev. B 49, 1376 (1994).Google Scholar
19. Dong, C.L., Persson, C., Vayssieres, L., Augustsson, A., Schmitt, T., Mattesini, M., Ahuja, R., Chang, C.L., and Guo, J.H.: Electronic structure of nanostructured ZnO from x-ray absorption and emission spectroscopy and the local density approximation. Phys. Rev. B 70, 195325 (2004).Google Scholar
20. Guo, J.H., Butorin, S.M., Wassdahl, N., Nordgren, J., Berastegut, P., and Johansson, L.G.: Electronic structure of YBa2Cu3Ox and YBa2Cu4O8 studied by soft-x-ray absorption and emission spectroscopies. Phys. Rev. B 61, 9140 (2000).Google Scholar
21. Ye, Y., Kawase, A., Song, M.-K., Feng, B., Liu, Y.-S., Marcus, M., Feng, J., Cairns, E., Guo, J., and Zhu, J.: X-ray absorption spectroscopy characterization of a Li/S cell. Nanomaterials 6, 14 (2016).Google Scholar
22. Harada, Y., Kinugasa, T., Eguchi, R., Matsubara, M., Kotani, A., Watanabe, M., Yagishita, A., and Shin, S.: Polarization dependence of soft-x-ray Raman scattering at the L edge of TiO2 . Phys. Rev. B 61, 12854 (2000).Google Scholar
23. Li, J., Wang, Z., Zhao, A., Wang, J., Song, Y., and Sham, T.-K.: Nanoscale clarification of the electronic structure and optical properties of TiO2 nanowire with an impurity phase upon sodium intercalation. J. Phys. Chem. C 119, 17848 (2015).Google Scholar
24. Kronawitter, C.X., Bakke, J.R., Wheeler, D.A., Wang, W.-C., Chang, C., Antoun, B.R., Zhang, J.Z., Guo, J., Bent, S.F., Mao, S.S., and Vayssieres, L.: Electron enrichment in 3d transition metal oxide hetero-nanostructures. Nano Lett. 11, 3855 (2011).CrossRefGoogle ScholarPubMed
25. Guo, J., Glans, P.-A., Liu, Y.-S., and Chang, C.: Electronic structure study of nanostructured transition metal oxides using soft x-ray spectroscopy. In On Solar Hydrogen & Nanotechnology, edited by Vayssieres, L. (John Wiley & Sons, Ltd, Chichester, UK, 2010), p. 123.Google Scholar
26. Krüger, P.: Multichannel multiple scattering calculation of L 2,3-edge spectra of TiO2 and SrTiO3: importance of multiplet coupling and band structure. Phys. Rev. B 81, 125121 (2010).Google Scholar
27. Glawion, S., Heidler, J., Haverkort, M.W., Duda, L.C., Schmitt, T., Strocov, V.N., Monney, C., Zhou, K.J., Ruff, A., Sing, M., and Claessen, R.: Two-spinon and orbital excitations of the spin-Peierls system TiOCl. Phys. Rev. Lett. 107, 107402 (2011).Google Scholar
28. Augustsson, A., Henningsson, A., Butorin, S.M., Siegbahn, H., Nordgren, J., and Guo, J.-H.: Lithium ion insertion in nanoporous anatase TiO2 studied with RIXS. J. Chem. Phys. 119, 3983 (2003).Google Scholar
29. Higuchi, T., Tsukamoto, T., Watanabe, M., Grush, M.M., Callcott, T.A., Perera, R.C., Ederer, D.L., Tokura, Y., Harada, Y., Tezuka, Y., and Shin, S.: Crystal-field splitting and the on-site Coulomb energy of LaxSr1−xTiO3 from resonant soft-x-ray emission spectroscopy. Phys. Rev. B 60, 7711 (1999).Google Scholar
30. Chen, C.L., Dong, C.L., Asokan, K., Chen, J.L., Liu, Y.S., Guo, J.H., Yang, W.L., Chen, Y.Y., Hsu, F.C., Chang, C.L., and Wu, M.K.: Role of 3d electrons in the rapid suppression of superconductivity in the dilute V doped spinel superconductor LiTi2O4 . Supercond. Sci. Technol. 24, 115007 (2011).CrossRefGoogle Scholar
31. Ni, M., Leung, M.K.H., Leung, D.Y.C., and Sumathy, K.: A review and recent developments in photocatalytic water-splitting using for hydrogen production. Renew. Sustain. Energy Rev. 11, 401 (2007).Google Scholar
32. De Angelis, F., Di Valentin, C., Fantacci, S., Vittadini, A., and Selloni, A.: Theoretical studies on anatase and less common TiO2 phases: bulk, surfaces, and nanomaterials. Chem. Rev. 114, 9708 (2014).CrossRefGoogle ScholarPubMed
33. Takagahara, T. and Takeda, K.: Theory of the quantum confinement effect on excitons in quantum dots of indirect-gap materials. Phys. Rev. B 46, 15578 (1992).CrossRefGoogle ScholarPubMed
34. Kim, T.-Y., Park, N.-M., Kim, K.-H., Sung, G.Y., Ok, Y.-W., Seong, T.-Y., and Choi, C.-J.: Quantum confinement effect of silicon nanocrystals in situ grown in silicon nitride films. Appl. Phys. Lett. 85, 5355 (2004).Google Scholar
35. Raty, J.-Y., Galli, G., Bostedt, C., van Buuren, T.W., and Terminello, L.J.: Quantum confinement and fullerenelike surface reconstructions in nanodiamonds. Phys. Rev. Lett. 90, 037401 (2003).CrossRefGoogle ScholarPubMed
36. Dong, C.-L., Gou, J., Chen, Y.-Y., and Chang, C.-L.: Soft-x-ray spectroscopy probes nanomaterial-based devices. SPIE Newsroom (2007). http://spie.org/newsroom/0812-soft-x-ray-spectroscopy-probes-nanomaterial-based-devices (accessed August 15, 2007).Google Scholar
37. Cooper, J.K., Gul, S., Toma, F.M., Chen, L., Liu, Y.-S., Guo, J., Ager, J.W., Yano, J., and Sharp, I.D.: Indirect bandgap and optical properties of monoclinic bismuth vanadate. J. Phys. Chem. C 119, 2969 (2015).Google Scholar
38. Ma, Y., Wassdahl, N., Skytt, P., Guo, J., Nordgren, J., Johnson, P.D., Rubensson, J.E., Boske, T., Eberhardt, W., and Kevan, S.D.: Soft-x-ray resonant inelastic scattering at the C K edge of diamond. Phys. Rev. Lett. 69, 2598 (1992).Google Scholar
39. Eich, D., Fuchs, O., Groh, U., Weinhardt, L., Fink, R., Umbach, E., Heske, C., Fleszar, A., Hanke, W., Gross, E.K.U., Bostedt, C., Buuren, T.V., Franco, N., Terminello, L.J., Keim, M., Reuscher, G., Lugauer, H., and Waag, A.: Resonant inelastic soft x-ray scattering of Be chalcogenides. Phys. Rev. B 73, 115212 (2006).Google Scholar
40. Gilbert, B., Frandsen, C., Maxey, E.R., and Sherman, D.M.: Band-gap measurements of bulk and nanoscale hematite by soft x-ray spectroscopy. Phys. Rev. B 79, 035108 (2009).Google Scholar
41. Jovic, V., Laverock, J., Rettie, A.J.E., Zhou, J.S., Mullins, C.B., Singh, V.R., Lamoureux, B., Wilson, D., Su, T.Y., Jovic, B., Bluhm, H., Sohnel, T., and Smith, K.E.: Soft X-ray spectroscopic studies of the electronic structure of M:BiVO4 (M = Mo, W) single crystals. J. Mater. Chem. A 3, 23743 (2015).CrossRefGoogle Scholar
42. Vayssieres, L., Sathe, C., Butorin, S.M., Shuh, D.K., Nordgren, J., and Guo, J.: One-dimensional quantum-confinement effect in α-Fe2O3 ultrafine nanorod arrays. Adv. Mater. 17, 2320 (2005).Google Scholar
43. Duda, L.C., Nordgren, J., Dräger, G., Bocharov, S., and Kirchner, T.: Polarized resonant inelastic X-ray scattering from single-crystal transition metal oxides. J. Electron Spectrosc. Relat. Phenom. 110–111, 275 (2000).Google Scholar
44. Skinner, H.W.B., Bullen, T.G., and Johnston, J.E.: CXIX. Notes on soft X-ray spectra, particularly of the Fe group elements. Lond. Edinb. Dublin Philos. Mag. J. Sci. 45, 1070 (1954).CrossRefGoogle Scholar
45. Akl, A.A.: Optical properties of crystalline and non-crystalline iron oxide thin films deposited by spray pyrolysis. Appl. Surf. Sci. 233, 307 (2004).Google Scholar
46. Vayssieres, L., Persson, C., and Guo, J.-H.: Size effect on the conduction band orbital character of anatase TiO2 nanocrystals. Appl. Phys. Lett. 99, 183101 (2011).Google Scholar
47. Li, J., Sham, T.-K., Ye, Y., Zhu, J., and Guo, J.: Structural and optical interplay of palladium-modified TiO2 nanoheterostructure. J. Phys. Chem. C 119, 2222 (2015).CrossRefGoogle Scholar
48. Ray, S.C., Low, Y., Tsai, H.M., Pao, C.W., Chiou, J.W., Yang, S.C., Chien, F.Z., Pong, W.F., Tsai, M.-H., Lin, K.F., Cheng, H.M., Hsieh, W.F., and Lee, J.F.: Size dependence of the electronic structures and electron–phonon coupling in ZnO quantum dots. Appl. Phys. Lett. 91, 262101 (2007).CrossRefGoogle Scholar
49. Chiou, J.W., Jan, J.C., Tsai, H.M., Bao, C.W., Pong, W.F., Tsai, M.-H., Hong, I.-H., Klauser, R., Lee, J.F., Wu, J.J., and Liu, S.C.: Electronic structure of ZnO nanorods studied by angle-dependent x-ray absorption spectroscopy and scanning photoelectron microscopy. Appl. Phys. Lett. 84, 3462 (2004).Google Scholar
50. Guo, J.H., Vayssieres, L., Persson, C., Ahuja, R., Johansson, B., and Nordgren, J.: Polarization-dependent soft-x-ray absorption of highly oriented ZnO microrod arrays. J. Phys.: Condens. Matter 14, 6969 (2002).Google Scholar
51. Ra, W., Nakayama, M., Cho, W., Wakihara, M., and Uchimoto, Y.: Electronic and local structural changes in Li2+xTi3O7 ramsdellite compounds upon electrochemical Li-ion insertion reactions by X-ray absorption spectroscopy. Phys. Chem. Chem. Phys. 8, 882 (2006).CrossRefGoogle ScholarPubMed
52. Chen, C.L., Dong, C.-L., Chen, C.-H., Wu, J.-W., Lu, Y.-R., Lin, C.-J., Hsuan Liou, S. Y., Tseng, C.-M., Kumar, K., Wei, D.-H., Guo, J., Chou, W.-C., and Wu, M.-K.: Electronic properties of free-standing TiO2 nanotube arrays fabricated by electrochemical anodization. Phys. Chem. Chem. Phys. 17, 22064 (2015).Google Scholar
53. Choi, W., Termin, A., and Hoffmann, M.R.: The role of metal ion dopants in quantum-sized TiO2: correlation between photoreactivity and charge carrier recombination dynamics. J. Phys. Chem. B 98, 13669 (1994).Google Scholar
54. Valentin, C.D., Pacchioni, G., Onishi, H., and Kudo, A.: Cr/Sb co-doped TiO2 from first principles calculations. Chem. Phys. Lett. 469, 166 (2009).CrossRefGoogle Scholar
55. Long, R. and English, N.J.: First-principles calculation of synergistic (N, P)-codoping effects on the visible-light photocatalytic activity of anatase TiO2 . J. Phys. Chem. C 114, 11984 (2010).CrossRefGoogle Scholar
56. Han, X. and Shao, G.: Electronic properties of rutile TiO2 with nonmetal dopants from first principles. J. Phys. Chem. C 116, 8274 (2011).Google Scholar
57. Singh, D., Singh, N., Sharma, S.D., Kant, C., Sharma, C.P., Pandey, R.R., and Saini, K.K.: Bandgap modification of TiO2 sol–gel films by Fe and Ni doping. J. Sol–Gel Sci. Technol. 58, 269 (2011).Google Scholar
58. Wang, Y., Zhang, R., Li, J., Li, L., and Lin, S.: First-principles study on transition metal-doped anatase TiO2 . Nanoscale Res. Lett. 9, 1 (2014).Google Scholar
59. Matthey, D., Wang, J.G., Wendt, S., Matthiesen, J., Schaub, R., Lægsgaard, E., Hammer, B., and Besenbacher, F.: Enhanced bonding of gold nanoparticles on oxidized TiO2(110). Science 315, 1692 (2007).Google Scholar
60. Hansen, J.Ø., Lira, E., Galliker, P., Wang, J.-G., Sprunger, P.T., Li, Z., Lægsgaard, E., Wendt, S., Hammer, B., and Besenbacher, F.: Enhanced bonding of silver nanoparticles on oxidized TiO2(110). J. Phys. Chem. C 114, 16964 (2010).Google Scholar
61. Gray, T.J., McCain, C.C., and Masse, N.G.: Defect structure and catalysis in the TiO2 system (semi-conducting and magnetic properties). J. Phys. Chem. 63, 472 (1959).Google Scholar
62. Ganduglia-Pirovano, M.V., Hofmann, A., and Sauer, J.: Oxygen vacancies in transition metal and rare earth oxides: current state of understanding and remaining challenges. Surf. Sci. Rep. 62, 219 (2007).Google Scholar
63. Chernyshova, I.V., Hochella, M.F. Jr., and Madden, A.S.: Size-dependent structural transformations of hematite nanoparticles. 1. Phase transition. Phys. Chem. Chem. Phys. 9, 1736 (2007).Google Scholar
64. Aiura, Y., Nishihara, Y., Haruyama, Y., Komeda, T., Kodaira, S., Sakisaka, Y., Maruyama, T., and Kato, H.: Effects of surface oxygen vacancies on electronic states of TiO2(110), TiO2(001) and SrTiO3(001) surfaces. Phys. B: Condens. Matter 194, 1215 (1994).Google Scholar
65. Henrich, V.E. and Kurtz, R.L.: Surface electronic structure of TiO2: atomic geometry, ligand coordination, and the effect of adsorbed hydrogen. Phys. Rev. B 23, 6280 (1981).Google Scholar
66. Mattioli, G., Alippi, P., Filippone, F., Caminiti, R., and Amore Bonapasta, A.: Deep versus shallow behavior of intrinsic defects in rutile and anatase TiO2 polymorphs. J. Phys. Chem. C 114, 21694 (2010).Google Scholar
67. Yan, W., Sun, Z., Pan, Z., Liu, Q., Yao, T., Wu, Z., Song, C., Zeng, F., Xie, Y., Hu, T., and Wei, S.: Oxygen vacancy effect on room-temperature ferromagnetism of rutile Co:TiO2 thin films. Appl. Phys. Lett. 94, 042508 (2009).Google Scholar
68. Wang, W., Ye, Y., Feng, J., Chi, M., Guo, J., and Yin, Y.: Enhanced photoreversible color switching of redox dyes catalyzed by barium-doped TiO2 nanocrystals. Angew. Chem. Int. Ed. 54, 1321 (2015).Google Scholar
69. Rusydi, A., Dhar, S., Roy Barman, A., Ariando, D.-C. Qi, Motapothula, M., Yi, J.B., Santoso, I., Feng, Y.P., Yang, K., Dai, Y., Yakovlev, N.L., Ding, J., Wee, A.T.S., Neuber, G., Breese, M.B.H., Ruebhausen, M., Hilgenkamp, H., and Venkatesan, T.: Cationic-vacancy-induced room-temperature ferromagnetism in transparent, conducting anatase Ti1−xTaxO2 (x~0.05) thin films. Philos. Trans. R. Soc. Lond. A: Math. Phys. Eng. Sci. 370, 4927 (2012).Google Scholar
70. Osorio-Guillén, J., Lany, S., and Zunger, A.: Atomic control of conductivity versus ferromagnetism in wide-gap oxides via selective doping: V, Nb, Ta in anatase TiO2 . Phys. Rev. Lett. 100, 036601 (2008).Google Scholar
71. Chen, X. and Burda, C.: The electronic origin of the visible-light absorption properties of C-, N- and S-doped TiO2 nanomaterials. J. Am. Chem. Soc. 130, 5018 (2008).Google Scholar
72. Braun, A., Akurati, K.K., Fortunato, G., Reifler, F.A., Ritter, A., Harvey, A.S., Vital, A., and Graule, T.: Nitrogen doping of TiO2 photocatalyst forms a second eg state in the oxygen 1s NEXAFS pre-edge. J. Phys. Chem. C 114, 516 (2010).Google Scholar
73. Braun, A., Sivula, K., Bora, D.K., Zhu, J., Zhang, L., Grätzel, M., Guo, J., and Constable, E.C.: Direct observation of two electron holes in a hematite photoanode during photoelectrochemical water splitting. J. Phys. Chem. C 116, 16870 (2012).Google Scholar
74. Bora, D.K., Braun, A., Erat, S., Ariffin, A.K., Löhnert, R., Sivula, K., Töpfer, J., Grätzel, M., Manzke, R., Graule, T., and Constable, E.C.: Evolution of an oxygen near-edge X-ray absorption fine structure transition in the upper Hubbard band in α-Fe2O3 upon electrochemical oxidation. J. Phys. Chem. C 115, 5619 (2011).Google Scholar
75. Axnanda, S., Crumlin, E.J., Mao, B., Rani, S., Chang, R., Karlsson, P.G., Edwards, M.O.M., Lundqvist, M., Moberg, R., Ross, P., Hussain, Z., and Liu, Z.: Using “Tender” X-ray ambient pressure X-ray photoelectron spectroscopy as a direct probe of solid-liquid interface. Sci. Rep. 5, 9788 (2015).CrossRefGoogle Scholar
76. Velasco-Velez, J.-J., Wu, C.H., Pascal, T.A., Wan, L.F., Guo, J., Prendergast, D., and Salmeron, M.: The structure of interfacial water on gold electrodes studied by x-ray absorption spectroscopy. Science 346, 831 (2014).Google Scholar
77. Wu, C.H., Weatherup, R.S., and Salmeron, M.B.: Probing electrode/electrolyte interfaces in situ by X-ray spectroscopies: old methods, new tricks. Phys. Chem. Chem. Phys. 17, 30229 (2015).Google Scholar