In-situ Soft X-ray Spectroscopy of Electrochemical Interfaces at the B07 Beamline:
From Reaction Cell and Sample Design to Mechanistic Insight
In-situ soft X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) enable element-specific probing of electrochemical interfaces under realistic conditions but require advanced reaction cell and sample designs to bridge aqueous electrochemistry and vacuum-based detection (Figure 1). We present a modular spectro-electrochemical flow cell and window-free working electrode assembly (WEA) compatible with near-ambient-pressure XPS and NEXAFS. [1,2] The platform combines interchangeable SiNₓ or polymer membranes (such as Nafion™) with controlled hydration, enabling stable in-situ measurements under electrochemical operation. Using metal oxide-based electrodes [1-5], we demonstrate operando tracking of redox processes, surface hydration, and oxygen evolution chemistry. In-situ XPS and NEXAFS reveal potential dependent metal oxidation and the formation of reactive oxygen species, providing direct insight into reaction mechanisms at electrochemical interfaces. This approach establishes a versatile methodology for operando soft X-ray studies of electrocatalysts. More importantly, the spectro-electrochemical flow cell is available for user community of B07 beamlines at Diamond Light Source.
Figure 1. Schematic of the in-situ spectro-electrochemical flow-cell configurations used for combined, surface-sensitive XPS and NEXAFS measurements under experimental conditions: (left) B07-C and (right) B07-B.
References
- An Electrochemical Flow Cell for Operando XPS and NEXAFS Investigation of Solid–Liquid Interfaces, Journal of Physics: Energy 6, 036001 (2024).
- VerSoX B07-B: A High-Throughput XPS and Ambient Pressure NEXAFS Beamline at Diamond Light Source, Journal of Synchrotron Radiation 31, 578–589 (2024).
- A Catalyst-Coated Mesoporous Carbon–Membrane Electrode Assembly for In Situ Soft X-ray XPS and NEXAFS Studies of Electrocatalytic Interfaces, ACS Electrochemistry 2 (5): 1226–1237 (2026).
- Key Role of Oxidizing Species Driving Water Oxidation Revealed by Time-Resolved Optical and X-ray Spectroscopies, Nature Materials 25 (5), 799–807 (2026).
- Mechanistic Study of Glycerol Electro-Oxidation on Ni(OH)₂/NiOOH Electrodes
Journal of the American Chemical Society 148 (15), 16119–16128 (2026).