In Situ Photocorrosion Assessment of Protected Hematite Photoanodes During Accelerated Stress Tests

Benavente Llorente V, Jenewein KJ, Hofer A, Körner A, Hutzler A, Kormányos A, Bachmann J, Cherevko S (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Solar RRL Wiley-VCH

DOI: 10.1002/solr.202500570

Abstract

Nanostructured α-hematite (Fe2O3) is a widely studied material for photoanode applications, particularly for driving the oxygen evolution reaction (OER) under visible light irradiation in photoelectrochemical (PEC) cells. Our recent work has shown that Fe2O3 suffers from photocorrosion in alkaline and neutral electrolytes, with a noticeable decline in performance after 5 h of operation. This highlights the need for strategies that enhance the stability of Fe2O3-based photoanodes. To enhance the stability of Fe2O3 nanorods (NR), we employed atomic layer deposition (ALD) to coat the NR with a well-defined, controlled TiO2 overlayer designed to protect the photoanode from photocorrosion during PEC operation. The influence of overlayer thickness is evaluated regarding the PEC activity, stability, and photocurrent retention in alkaline electrolyte using a PEC scanning flow cell coupled to an inductively coupled plasma mass spectrometer (PEC-ICP-MS). This setup can quantify metal dissolution during PEC OER, allowing the characterization of the photo-degradation under realistic illumination conditions. An accelerated stress test (AST) protocol was designed to drive degradation faster and obtain insightful information about the stability of the TiO2@Fe2O3 heterostructures using in situ PEC-ICP-MS. PEC-ICP-MS measurements demonstrate that the TiO2 coating significantly enhances the photocorrosion resistance of Fe2O3 NR in alkaline electrolytes during operation. A TiO2 thickness of 2.8 nm (50 ALD cycles) offered the most favorable compromise between activity, photocurrent retention, and decrease of Fe dissolution. The proposed methodology combines in situ stability quantification and ASTs as a powerful tool to advance material development and can be extended to other protected photoanodes.

Authors with CRIS profile

André Hofer Lehrstuhl für Chemistry of thin film materials Julien Bachmann Lehrstuhl für Chemistry of thin film materials

Involved external institutions

Forschungszentrum Jülich / Research Centre Jülich (FZJ) DE Germany (DE) University of Szeged / József Attila Tudományegyetem Szeged HU Hungary (HU)

How to cite

APA:

Benavente Llorente, V., Jenewein, K.J., Hofer, A., Körner, A., Hutzler, A., Kormányos, A.,... Cherevko, S. (2025). In Situ Photocorrosion Assessment of Protected Hematite Photoanodes During Accelerated Stress Tests. Solar RRL. https://doi.org/10.1002/solr.202500570

MLA:

Benavente Llorente, Victoria, et al. "In Situ Photocorrosion Assessment of Protected Hematite Photoanodes During Accelerated Stress Tests." Solar RRL (2025).

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