TY - JOUR
T1 - Operando Analyses of Solar Fuels Light Absorbers and Catalysts
AU - Lewerenz, Hans Joachim
AU - Lichterman, Michael F.
AU - Richter, Matthias H.
AU - Crumlin, Ethan J.
AU - Hu, Shu
AU - Axnanda, Stephanus
AU - Favaro, Marco
AU - Drisdell, Walter
AU - Hussain, Zahid
AU - Brunschwig, Bruce S.
AU - Liu, Zhi
AU - Nilsson, Anders
AU - Bell, Alexis T.
AU - Lewis, Nathan S.
AU - Friebel, Daniel
N1 - Funding Information:
This work was supported by the Office of Science of the U.S. Department of Energy (DOE) through award no. DE-SC0004993 to the Joint Center for Artificial Photosynthesis. The Advanced Light Source acknowledges support by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract no. DE-AC02-05CH11231 . XAS data collection was carried out at Stanford Synchrotron Radiation Lightsource, a National User Facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences. Computational work was carried out through NERSC computational resources under DOE Contract No. DE-AC02-05CH11231.
PY - 2016/9/1
Y1 - 2016/9/1
N2 - Operando synchrotron radiation photoelectron spectroscopy in the tender X-ray energy range has been used to obtain information on the energy-band relations of semiconductor and metal-covered semiconductor surfaces while in direct contact with aqueous electrolytes under potentiostatic control. The system that was investigated consists of highly doped Si substrates that were conformally coated with ∼70 nm titania films produced by atomic-layer deposition. TiO2/electrolyte and Si/TiO2/Ni/electrolyte interfaces were then analyzed by synchrotron radiation photoelectron spectroscopy. The PES data allows for determination of the flat-band position and identification of potential regions in which Fermi level pinning, depletion, or accumulation occurred. Operando X-ray absorption spectroscopy (XAS) techniques were additionally used to investigate the properties of heterogeneous electrocatalysts for the oxygen-evolution reaction. Operando XAS including the pre-edge, edge and EXAFS regions allowed the development of a detailed picture of the catalysts under operating conditions, and elucidated the changes in the physical and electronic structure of the catalyst that accompanied increases in the applied potential. Specifically, XAS data, combined with DFT studies, indicated that the activity of the electrocatalyst correlated with the formation of Fe dopant sites in γ-NiOOH.
AB - Operando synchrotron radiation photoelectron spectroscopy in the tender X-ray energy range has been used to obtain information on the energy-band relations of semiconductor and metal-covered semiconductor surfaces while in direct contact with aqueous electrolytes under potentiostatic control. The system that was investigated consists of highly doped Si substrates that were conformally coated with ∼70 nm titania films produced by atomic-layer deposition. TiO2/electrolyte and Si/TiO2/Ni/electrolyte interfaces were then analyzed by synchrotron radiation photoelectron spectroscopy. The PES data allows for determination of the flat-band position and identification of potential regions in which Fermi level pinning, depletion, or accumulation occurred. Operando X-ray absorption spectroscopy (XAS) techniques were additionally used to investigate the properties of heterogeneous electrocatalysts for the oxygen-evolution reaction. Operando XAS including the pre-edge, edge and EXAFS regions allowed the development of a detailed picture of the catalysts under operating conditions, and elucidated the changes in the physical and electronic structure of the catalyst that accompanied increases in the applied potential. Specifically, XAS data, combined with DFT studies, indicated that the activity of the electrocatalyst correlated with the formation of Fe dopant sites in γ-NiOOH.
KW - Catalysis
KW - Protection
KW - Semiconductors
KW - artificial photosynthesis
KW - operando spectroscopy
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U2 - 10.1016/j.electacta.2016.06.006
DO - 10.1016/j.electacta.2016.06.006
M3 - Article
AN - SCOPUS:84976593919
VL - 211
SP - 711
EP - 719
JO - Electrochimica Acta
JF - Electrochimica Acta
SN - 0013-4686
ER -