Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 97: Solid-liquid interfaces: Reactions and electrochemistry III

O 97.4: Vortrag

Freitag, 13. März 2026, 10:30–10:45, TRE/PHYS

Exploring the Surface Structure of Ni Anodes and the Role of pH for Alkaline Oxygen Evolution Using SERS — •Justus Leist, Annika Neufischer, Roman Jocher, Benjamin Schilling, Timo Jacob, and Albert Engstfeld — Ulm University, Institute of Electrochemistry, Ulm, Germany

Sustainable hydrogen can be generated by electrochemical water splitting, but the process is typically limited by the sluggish kinetics of the oxygen evolution reaction (OER) at the anode. To avoid reliance on noble-metal catalysts such as Ir and Ru, Ni-based catalysts have attracted considerable interest due to their abundance and efficiency. Under OER conditions, where the Ni anode surface is accepted to be NiOOH, Raman spectroscopy enables in situ monitoring of both the surface structure and possible OER intermediates. In this work, using Surface-enhanced Raman spectroscopy (SERS) combined with DFT, we challenge the assumed presence of NiOOH under OER conditions.[1]

To probe the atomic composition of the oxidized Ni anodes, isotope-labelled Raman experiments were performed, revealing the absence of hydrogen in the lattice. The presence of NiO*, rather than NiOOH, is further supported by DFT-calculated spectra. Additionally, we illustrate that a band previously attributed to an OO- species is more likely related to overtones. By varying the pH from alkaline to near-neutral conditions, we examine the impact of pH on the Raman spectra during the OER and discuss these changes in relation to the vibrational Stark effect and possible OER intermediates.

[1] J. Leist et al. ChemRxiv DOI: 10.26434/chemrxiv-2025-jb73p

Keywords: NiOOH; Raman; OER; Overtones; DFT