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BibTex format

@article{Liang:2026:10.1038/s41563-026-02514-9,
author = {Liang, C and Garcia, Verga L and Moss, B and Kumar, S and Scott, SB and Turner, MA and Ferrer, P and Celorrio, V and Grinter, DC and Tao, Y and Halder, S and Wang, Y and Tseng, C and Yang, G and Held, G and Haigh, SJ and Walsh, A and Stephens, IEL and Durrant, JR and Rao, RR},
doi = {10.1038/s41563-026-02514-9},
journal = {Nat Mater},
title = {Key role of oxidizing species driving water oxidation revealed by time-resolved optical and X-ray spectroscopies.},
url = {http://dx.doi.org/10.1038/s41563-026-02514-9},
year = {2026}
}
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TY  - JOUR
AB  - Oxidation states underpin the understanding of active states, reaction mechanisms and catalytic performance of electrocatalysts. However, determining them at complex solid-liquid interfaces is challenging. Here we use multimodal spectroscopy to investigate polarized iridium oxide (IrOx) electrodes, a model water oxidation catalyst, to identify potential-dependent iridium and oxygen oxidation states. By integrating multiple operando spectroscopies (optical (ultraviolet-visible), Ir L-edge and O K-edge X-ray absorption spectroscopy) with electrochemistry mass spectrometry and density functional theory calculations, we identify the sequential depletion of electron densities from the Ir5d band (corresponding to Ir3+→Ir4+→Ir5+), followed by electron removal from the O2p band, forming electrophilic oxygen species (O-1) due to enhanced Ir-O covalency and electronic state overlap. Time-resolved measurements reveal distinct lifetimes for Ir5+ and O-1 states under water oxidation conditions, Ir5+ remains unreactive whereas O-1 is consumed at a time constant commensurate with the reaction rate, indicating that O-1 drives the oxygen evolution reaction. These findings demonstrate the necessity of using multiple operando techniques to gain a unified understanding of the evolution of oxidation states and active sites with potential for water oxidation on oxide catalysts.
AU  - Liang,C
AU  - Garcia,Verga L
AU  - Moss,B
AU  - Kumar,S
AU  - Scott,SB
AU  - Turner,MA
AU  - Ferrer,P
AU  - Celorrio,V
AU  - Grinter,DC
AU  - Tao,Y
AU  - Halder,S
AU  - Wang,Y
AU  - Tseng,C
AU  - Yang,G
AU  - Held,G
AU  - Haigh,SJ
AU  - Walsh,A
AU  - Stephens,IEL
AU  - Durrant,JR
AU  - Rao,RR
DO  - 10.1038/s41563-026-02514-9
PY  - 2026///
TI  - Key role of oxidizing species driving water oxidation revealed by time-resolved optical and X-ray spectroscopies.
T2  - Nat Mater
UR  - http://dx.doi.org/10.1038/s41563-026-02514-9
UR  - https://www.ncbi.nlm.nih.gov/pubmed/41748930
ER  -
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