Analysis of the electrical double layer using electrochemical X-ray photoelectron spectroscopy

Electrochimica Acta, vol. 572, pp. 149132

Abstract

The element-sensitivity of X-ray spectroscopies offers the potential to disentangle the individual chemistries of water, ions, and adsorbates at the electrode-electrolyte interface in an element-by-element manner. However, targeted experimental design is needed to establish interface-sensitive in situ X-ray spectroscopy in a realistic electrochemical environment. Here, we demonstrate how electrochemical X-ray photoelectron spectroscopy (EC-XPS) in the dip-and-pull geometry can be used to specifically probe the behavior of ions in the electrical double layer. Taking the case study of a polycrystalline Au foil in 50 mM KClO 4 electrolyte, we tracked the electrochemical response of interfacial K + cations across a broad potential range. We show how, in combination with modeling, key parameters such as the potential of zero charge (PZC), ion packing behavior, dielectric saturation, and the electrostatic potential decay in the double layer can be extracted from the data. Importantly, we also analyze how the experimental conditions and non-idealities can influence the results and put forward criteria for reliable experimentation and data analysis.

Authors 12

1. Sheena Louisia corresponding Aachen

   Leiden University · Centre National de la Recherche Scientifique · Sorbonne Université · Laboratoire Interfaces et Systèmes Électrochimiques

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands

   Sorbonne Université, CNRS, Laboratoire Interfaces et Systèmes Électrochimiques (LISE), F-75005 Paris, France

2. Jordy J. J. Eggebeen Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands

3. Ariba Adnan Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands

4. Nipon Deka Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands

5. Lucas B. T. de Kam Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands

6. Kees E. Kolmeijer Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands

7. Nicci L. Fröhlich Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands

8. Rick S. Kort Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands

9. Katharina Doblhoff-Dier Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands

10. Ethan J. Crumlin

    Lawrence Berkeley National Laboratory · Advanced Light Source

    Affiliation as printed

    Chemical Sciences Division and Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States

11. Marc T. M. Koper Aachen

    Leiden University

    Affiliation as printed

    Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands

12. Rik Valentijn Mom Aachen

    Leiden University

    Affiliation as printed

    Leiden Institute of Chemistry, Leiden University, Leiden 2300 RA, The Netherlands