Abstract
Achieving sustainable water oxidation presents significant challenges, particularly employing cobalt-based electrocatalysts. Despite promising activities, many cobalt-based electrocatalysts undergo in-situ partial restructuring into disordered (oxy)hydroxides, as indicated by the Pourbaix diagram. This restructuring typically degrades structural integrity and electronic conductivity, undermining catalytic stability. Here, we propose a complex doping strategy to stabilize LiCoO2, a cobalt oxide that can be sourced from spent lithium-ion batteries, for sustainable water oxidation. Specifically, by co-doping LiCoO2 with Ni, Fe, and Pd, we mitigate the reconstructed extent of the in-situ generated spinel phase during water oxidation reaction and enhance electrochemical stability. Furthermore, complex doping improves the surface conductivity and facilitates gas removal, boosting mechanical robustness. Consequently, the optimized LiCo0.79Ni0.1Fe0.1Pd0.01O2 achieves a competitive water oxidation stability of over 2000 hours. Additionally, in membrane electrolyzer tests, LiCo0.79Ni0.1Fe0.1Pd0.01O2 outperforms the benchmark RuO2, delivering 2.5 A cm−2 at 1.58 V and maintaining stability for over 1400 hours. By elucidating the role of each dopant in LiCo0.79Ni0.1Fe0.1Pd0.01O2, this work offers critical insights for the rational design of sustainable water splitting electrodes.
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Source data are provided with this paper. Numerical data generated in this study are provided in the Source Data file. The authors declare that the main data supporting the findings of this study are available within the article and its Supplementary Information files. Additional data, including raw data files from apparatus data acquisition software, are available from the corresponding authors upon request. Source data are provided with this paper.
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Acknowledgements
J.W. acknowledge the support from the National Natural Science Foundation of China through the projects 52302312, the Research Grants Council of Hong Kong through the projects ECS 21308523 and C1003-24Y, the Innovation and Technology Commission of Hong Kong through the project ITS/130/23FP, the City University of Hong Kong through projects 9667262, 9610537, and 7005921, the Department of Science and Technology of Guangdong Province through project 2022A1515010212, 2023B1515130004, and 2024A1515013020, the Department of Science and Technology of Sichuan Province through project 2024NSFSC0275, and the joint support from the Innovation and Technology Commission of the Hong Kong SAR (Project No. GHP/290/23SZ) and the Science, Technology and Innovation Bureau of Shenzhen Municipality (Project No. SGDX20240115110505010) under the Mainland-Hong Kong Technology Cooperation Funding Scheme. Z.B.W. acknowledge the support from the City University of Hong Kong through project 9020004.
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Hongsheng Wang, Jia Lei, Jiashun Wu, and Yan Shi contributed equally to this work. H.S.W. and J.L. carried out the experiment, processed the experimental data, performed the analysis, drafted the manuscript, and designed the figures. Y.S., H.K., and C.F.Y. conducted the electrolyzer stability test. Y.Z.Z., M.W., H.F., S.Y.W., Z.Y.W., R.Q.L., and T.L. contributed to data analysis. T.S.C., S.C.H., and C.W.K. contributed to the XAFS and sXAS experiments. J.S.W., Z.B.W. contributed to theoretical calculations and analysis. A.W.B.W. and F.R.C. supported the STEM analysis. J.W. conceived the idea, supervised the project, analyzed the data, and revised the manuscript. All authors reviewed and commented on the manuscript before publication.
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Wang, H., Lei, J., Wu, J. et al. Sustainable water oxidation enabled by a complex-doped cobalt oxide electrode. Nat Commun (2025). https://doi.org/10.1038/s41467-025-68064-x
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DOI: https://doi.org/10.1038/s41467-025-68064-x
