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Title: Using “Tender” x-ray ambient pressure x-Ray photoelectron spectroscopy as a direct probe of solid-liquid interface

We report a new method to probe the solid-liquid interface through the use of a thin liquid layer on a solid surface. An ambient pressure XPS (AP-XPS) endstation that is capable of detecting high kinetic energy photoelectrons (7 keV) at a pressure up to 110 Torr has been constructed and commissioned. Additionally, we have deployed a “dip & pull” method to create a stable nanometers-thick aqueous electrolyte on platinum working electrode surface. Combining the newly constructed AP-XPS system, “dip & pull” approach, with a “tender” X-ray synchrotron source (2 keV–7 keV), we are able to access the interface between liquid and solid dense phases with photoelectrons and directly probe important phenomena occurring at the narrow solid-liquid interface region in an electrochemical system. Using this approach, we have performed electrochemical oxidation of the Pt electrode at an oxygen evolution reaction (OER) potential. Under this potential, we observe the formation of both Pt²⁺ and Pt⁴⁺ interfacial species on the Pt working electrode in situ. We believe this thin-film approach and the use of “tender” AP-XPS highlighted in this study is an innovative new approach to probe this key solid-liquid interface region of electrochemistry.
 [1] ;  [1] ;  [2] ;  [1] ;  [2] ;  [3] ;  [3] ;  [3] ;  [3] ;  [1] ;  [1] ;  [4]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chinese Academy of Sciences, Shanghai (Republic of China)
  3. VG Scienta,Uppsala (Sweden)
  4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chinese Academy of Sciences, Shanghai (Republic of China); Shanghai Tech Univ., Shanghai (China)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 5; Journal Issue: 5; Journal ID: ISSN 2045-2322
Nature Publishing Group
Research Org:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Org:
Country of Publication:
United States
25 ENERGY STORAGE batteries; surface spectroscopy; electrocatalysis