Dresden 2026 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 97: Solid-liquid interfaces: Reactions and electrochemistry III
O 97.8: Vortrag
Freitag, 13. März 2026, 11:30–11:45, TRE/PHYS
Understanding of degradation of catalyst/semiconductor interfaces — Sergej Levashov1, Tim Rieth1,2, Ian D. Sharp1,2, and •Johanna Eichhorn1 — 1TUM School of Natural Sciences, TU Munich — 2Walter Schottky Institute, TU Munich
The performance of photoelectrochemical (PEC) materials are governed by interfacial processes where atomic structure, electronic states, and chemical reactions meet. Local defects and dynamic surface transformations at the nanoscale can dominate charge transfer and often trigger degradation under operating conditions. Accessing such mechanisms requires in-situ/operando techniques that probe interfacial structure and dynamics with nanoscale resolution. We employ in situ scanning probe microscopy to study the interfacial stability of TiO2/Pt photocathodes by monitoring local surface transformations and detachment events during operation. Pt catalysts are deposited on conformal TiO2 coatings either by sputtering, yielding continuous films, or by atomic layer deposition (ALD), forming discrete nanoislands and enabling atom-efficient utilization of precious metals. Under PEC conditions, both architectures show comparable onset potentials and saturation current densities, yet chronoamperometry reveals an enhanced long-term stability for the nanostructured ALD-Pt electrodes. We attribute this contrasting behavior to different bubble formation and detachment dynamics at the catalyst-semiconductor interface. These nanoscale insights highlight the importance of interfacial and morphological engineering, as well as the necessity of controlling reaction processes, to achieve durable and efficient PEC material systems.
Keywords: Nanoscale characterization; Photoelectrochemical energy conversion; Liquid-solid interface; Thin films; Reaction mechanism