Journal article

Authors list: Weber, Tim; Vonk, Vedran; Abb, Marcel J. S.; Evertsson, Jonas; Stierle, Andreas; Lundgren, Edvin; Over, Herbert

Publication year: 2022

Pages: 20243-20250

Journal: Journal of Physical Chemistry C

Volume number: 126

Issue number: 48

ISSN: 1932-7447

eISSN: 1932-7455

DOI Link: https://doi.org/10.1021/acs.jpcc.2c06429

Publisher: American Chemical Society

Abstract: 

In situ stability studies of an IrO₂(110)–TiO₂(110) model electrode are carried out under acidic water electrolysis conditions, employing synchrotron-based techniques including surface X-ray diffraction (SXRD) and X-ray reflectometry (XRR) with a photon energy of 21.5 keV. These experiments are complemented by ex situ scanning electron microscopy (SEM), scanning tunneling microscopy (STM), and X-ray photoelectron spectroscopy (XPS) experiments. Even at an anodic current density of 250 mA·cm^–2 during electrochemical water splitting, the IrO₂(110)–TiO₂(110) model electrode turned out to be stable against Ir dissolution. However, radiation-induced damages of the IrO₂(110) film are observed: Part of the IrO₂(110) film delaminates upon heavy exposure to the synchrotron beam, while subsequently the uncovered TiO₂(110) is subject to further (photon-induced) corrosion. We propose that the X-ray photons induce oxygen vacancy formation by displacing O^2– ions of TiO₂ from regular to interstitial sites, while the potential drop across the TiO₂(110) substrate leads to a migration of interstitial O^2– ions from interface toward bulk TiO₂. This reduction step at the interface between IrO₂(110) and TiO₂(110) weakens the adhesion of the epitaxially grown IrO₂(110) film to the TiO₂(110) substrate so that the strained IrO₂(110) film is partially delaminated. Higher X-ray photon energies of 60–90 keV mitigate this degradation process.

Harvard Citation style: Weber, T., Vonk, V., Abb, M., Evertsson, J., Stierle, A., Lundgren, E., et al. (2022) In Situ Synchrotron-Based Studies of IrO2(110)-TiO2(110) under Harsh Acidic Water Splitting Conditions: Anodic Stability and Radiation Damages, Journal of Physical Chemistry C, 126(48), pp. 20243-20250. https://doi.org/10.1021/acs.jpcc.2c06429

APA Citation style: Weber, T., Vonk, V., Abb, M., Evertsson, J., Stierle, A., Lundgren, E., & Over, H. (2022). In Situ Synchrotron-Based Studies of IrO2(110)-TiO2(110) under Harsh Acidic Water Splitting Conditions: Anodic Stability and Radiation Damages. Journal of Physical Chemistry C. 126(48), 20243-20250. https://doi.org/10.1021/acs.jpcc.2c06429