Cobalt-Based Catalysts for Electrochemical Water Splitting: A Review of Mechanisms, Performance, and Applications

Abstract

The development of efficient, stable, and earth-abundant electrocatalysts is critical for advancing electrochemical water splitting as a sustainable hydrogen production technology. Among non-precious candidates, cobalt-based materials have garnered significant attention due to their structural versatility and tunable electronic properties. This review comprehensively examines recent progress in cobalt-based catalysts for the hydrogen and oxygen evolution reactions. We discuss key optimization strategies, including nanostructuring, heteroatom doping, and defect/interface engineering, that enhance activity and stability by increasing active site density, improving conductivity, and optimizing intermediate adsorption energetics. A particular focus is placed on the dynamic reconstruction of pre-catalysts into active (oxy)hydroxide phases under operational conditions, a crucial consideration for rational design. By integrating mechanistic insights from advanced in situ characterization and theoretical calculations, we elucidate structure-activity relationships and reaction pathways. Finally, we outline persistent challenges and future directions, emphasizing the need for standardized evaluation and the design of durable catalysts capable of operating at industrial-scale current densities to bridge the gap between laboratory research and practical application.

Keywords

cobalt-based catalysts / electrocatalysis / hydrogen production / in situ characterization / oxygen evolution reaction / water splitting

References

[1] M. A. Gaikwad, V. V. Burungale, D. B. Malavekar, et al., “Self-Supported Fe-Based Nanostructured Electrocatalysts for Water Splitting and Selective Oxidation Reactions: Past, Present, and Future,” Advanced Energy Materials14, no. 15 (2024): 2303730, https://doi.org/10.1002/aenm.202303730.

[2] Z. Liang, D. Shen, L. Wang, and H. Fu, “Recent Progress of Cobalt-Based Electrocatalysts for Water Splitting: Electron Modulation, Surface Reconstitution, and Applications,” Nano Research17, no. 4 (2023): 2234-2269, https://doi.org/10.1007/s12274-023-6219-4.

[3] M. Chen and J. Guan, “Achievements and Challenges in Cobalt-Based Catalysts for Water Electrolysis,” Chemical Engineering Journal500 (2024): 157080, https://doi.org/10.1016/j.cej.2024.157080.

[4] X. Zhang, L. Wang, Y. Xie, and H. Fu, “Theoretical Insights Into Performance Descriptors and Their Impact on Activity Optimization Strategies for Cobalt-Based Electrocatalysts,” Coordination Chemistry Reviews533 (2025): 216560, https://doi.org/10.1016/j.ccr.2025.216560.

[5] A. Kazemi, F. Manteghi, and Z. Tehrani, “Metal Electrocatalysts for Hydrogen Production in Water Splitting,” ACS Omega9, no. 7 (2024): 7310-7335, https://doi.org/10.1021/acsomega.3c07911.

[6] W. J. V. Townsend, D. Lopez-Alcala, M. A. Bird, et al., “The Role of Carbon Catalyst Coatings in the Electrochemical Water Splitting Reaction,” Nature Communications16, no. 1 (2025): 4460, https://doi.org/10.1038/s41467-025-59740-z.

[7] T. Schmidt, A. Wark, R. Haid, et al., “Elucidating the Active Sites and Synergies in Water Splitting on Manganese Oxide Nanosheets on Graphite Support,” Advanced Energy Materials13, no. 43 (2023): 2302039, https://doi.org/10.1002/aenm.202302039.

[8] S. Singh, A. Irshad, G. D. De la Cruz, et al., “Bifunctional Noble Metal-Free Ternary Chalcogenide Electrocatalysts for Overall Water Splitting,” Chemistry of Materials37, no. 3 (2025): 823-832, https://doi.org/10.1021/acs.chemmater.4c01684.

[9] B. Fang, J. Yang, Y. Li, et al., “Coordination Regulated Cobalt-Based Electrocatalysts for Electrochemical Water Splitting,” Separation and Purification Technology336 (2024): 126188, https://doi.org/10.1016/j.seppur.2023.126188.

[10] H. Liu, X. Liu, A. Sun, et al., “Enhancing Oxygen Evolution Electrocatalysis in Heazlewoodite: Unveiling the Critical Role of Entropy Levels and Surface Reconstruction,” Advanced Materials37, no. 21 (2025): 202501186, https://doi.org/10.1002/adma.202501186.

[11] B. Guo, Y. Ding, H. Huo, et al., “Recent Advances of Transition Metal Basic Salts for Electrocatalytic Oxygen Evolution Reaction and Overall Water Electrolysis,” Nano-Micro Letters15, no. 1 (2023): 57, https://doi.org/10.1007/s40820-023-01038-0.

[12] K. Ren, W. J. Xu, K. Li, et al., “Br-Induced d-Band Regulation on Superhydrophilic Isostructural Cobalt Phosphide for Efficient Overall Water Splitting,” Advanced Functional Materials35, no. 8 (2024): 2415585, https://doi.org/10.1002/adfm.202415585.

[13] K. Chen, Y. H. Cao, S. Yadav, et al., “Electronic Structure Reconfiguration of nickel-cobalt Layered Double Hydroxide Nanoflakes via Engineered Heteroatom and oxygen-vacancies Defect for Efficient Electrochemical Water Splitting,” Chemical Engineering Journal463 (2023): 142396, https://doi.org/10.1016/j.cej.2023.142396.

[14] B. Chong, M. Xia, Y. Lv, et al., “Hierarchical Phosphorus-Oxygen Incorporated Cobalt Sulfide Hollow Micro/Nano-Reactor for Highly-Efficient Electrocatalytic Overall Water Splitting,” Chemical Engineering Journal465 (2023): 142853, https://doi.org/10.1016/j.cej.2023.142853.

[15] Y. Zhang, F. Gao, D. Wang, et al., “Amorphous/Crystalline Heterostructure Transition-Metal-Based Catalysts for High-Performance Water Splitting,” Coordination Chemistry Reviews475 (2023): 214916, https://doi.org/10.1016/j.ccr.2022.214916.

[16] S. Han, J. Park, and J. Yoon, “Surface Reconstruction of Co-Based Catalysts for Enhanced Oxygen Evolution Activity in Anion Exchange Membrane Water Electrolysis,” Advanced Functional Materials34, no. 21 (2024): 2314573, https://doi.org/10.1002/adfm.202314573.

[17] C. Rong, Q. Sun, J. Zhu, et al., “Advances in Stabilizing Spinel Cobalt Oxide-Based Catalysts for Acidic Oxygen Evolution Reaction,” Advanced Science12, no. 35 (2025): 09415, https://doi.org/10.1002/advs.202509415.

[18] M. Wolf, N. Fischer, and M. Claeys, “Water-Induced Deactivation of Cobalt-Based Fischer-Tropsch Catalysts,” Nature catalysis3, no. 12 (2020): 962-965, https://doi.org/10.1038/s41929-020-00534-5.

[19] W. Hu, Q. Yan, X. Wang, et al., “In Situ Controllably Self-Assembled Cofe-Tdpat Metal-Organic Framework Nanosheet Arrays on Iron Foam as Highly Efficient Bifunctional Catalytic Electrodes for Overall Water Splitting at Large Current Density,” Advanced Functional Materials35, no. 1 (2024): 2411904, https://doi.org/10.1002/adfm.202411904.

[20] Z. Lv, H. Zhang, C. Liu, J. Song, and J. He, “Oxygen-Bridged Cobalt-Chromium Atomic Pair in MOF-Derived Cobalt Phosphide Networks as Efficient Active Sites Enabling Synergistic Electrocatalytic Water Splitting in Alkaline Media,” Advanced Science11, no. 3 (2024): e2306678, https://doi.org/10.1002/advs.202306678.

[21] Y. Q. Jiao, H. J. Yan, C. G. Tian, and H. G. Fu, “Structure Engineering and Electronic Modulation of Transition Metal Interstitial Compounds for Electrocatalytic Water Splitting,” Accounts of Chemical Research4, no. 1 (2022): 42-56, https://doi.org/10.1021/accountsmr.2c00188.

[22] Y. Liu, Y. Chen, R. Ge, et al., “3D Freestanding Flower-Like Nickel-Cobalt Layered Double Hydroxides Enriched With Oxygen Vacancies as Efficient Electrocatalysts for Water Oxidation,” Sustainable Materials and Technologies25 (2020): e00170, https://doi.org/10.1016/j.susmat.2020.e00170.

[23] Q. Ngo, T. Nguyen, Q. Le, J. H. Lee, and N. H. Kim, “Unveiling the Synergistic Effect of Atomic Iridium Modulated Zirconium-Doped Pure Phase Cobalt Phosphide for Robust Anion-Exchange Membrane Water Electrolyzer,” Advanced Energy Materials13, no. 44 (2023): 2301841, https://doi.org/10.1002/aenm.202301841.

[24] M. Bi, Y. Zhang, X. Jiang, et al., “Ruthenium-Induced Activation of Molybdenum-Cobalt Phosphide for High-Efficiency Water Splitting,” Advanced Functional Materials34, no. 2 (2023): 2309330, https://doi.org/10.1002/adfm.202309330.

[25] A. H. Al-Naggar, N. M. Shinde, J. S. Kim, and R. S. Mane, “Water Splitting Performance of Metal and Non-Metal-Doped Transition Metal Oxide Electrocatalysts,” Coordination Chemistry Reviews474 (2023): 214864, https://doi.org/10.1016/j.ccr.2022.214864.

[26] J. Fan, J. Jiang, Y. Wang, et al., “Etching Accelerates Reconstruction and Activates Lattice Oxygen of Anion Vacancies-Enriched Cobalt-Iron Phosphide/(Oxy)Hydroxide Nanohybrid Frameworks for Enhanced Oxygen Evolution,” Advanced Functional Materials35, no. 38 (2025): 2425770, https://doi.org/10.1002/adfm.202425770.

[27] Y. Zhao, W. Wan, R. Erni, L. Pan, and G. R. Patzke, “Operando Spectroscopic Monitoring of Metal Chalcogenides for Overall Water Splitting: New Views of Active Species and Sites,” Angewandte Chemie International Edition63, no. 24 (2024): e202400048, https://doi.org/10.1002/ange.202400048.

[28] G. Bahuguna and F. Patolsky, “Universal Approach to Direct Spatiotemporal Dynamic in Situ Optical Visualization of On-Catalyst Water Splitting Electrochemical Processes,” Advanced Science11, no. 24 (2024): 2401258, https://doi.org/10.1002/advs.202401258.

[29] D. Li, Y. Cao, R. Ye, et al., “Self-Supported Transition-Metal-Based Electrocatalysts on Iron Foam for Water Splitting,” Chemical Engineering Journal516 (2025): 163602, https://doi.org/10.1016/j.cej.2025.163602.

[30] Y. Dong, A. Wu, G. Yang, et al., “Lower-Temperature Synthesis of Nitrogen-Rich Molybdenum Nitride/Nickel (Cobalt) Heterojunctional Assembly for the Effective Water Electrolysis,” Advanced Functional Materials35, no. 2 (2024): 2412979, https://doi.org/10.1002/adfm.202412979.

[31] M. A. Tekalgne, J. H. Cho, J. Kim, H. W. Jang, S. H. Ahn, and S. Y. Kim, “Augmenting Overall Water Splitting With Transition-Metal-Doped NiCr-LDH as a Bifunctional Electrocatalyst,” Chemical Engineering Journal514 (2025): 163398, https://doi.org/10.1016/j.cej.2025.163398.

[32] J. Huang, C. N. Borca, T. Huthwelker, et al., “Surface Oxidation/Spin State Determines Oxygen Evolution Reaction Activity of Cobalt-Based Catalysts in Acidic Environment,” Nature Communications15, no. 1 (2024): 3067, https://doi.org/10.1038/s41467-024-47409-y.

[33] F. M. Yap, J. Y. Loh, S. F. Ng, and W. Ong, “Self-Supported Earth-Abundant Carbon-Based Substrates in Electrocatalysis Landscape: Unleashing the Potentials Toward Paving the Way for Water Splitting and Alcohol Oxidation,” Advanced Energy Materials14, no. 16 (2023): 2303614, https://doi.org/10.1002/aenm.202303614.

[34] W. T. Chung, I. Mekhemer, M. Mohamed, et al., “Recent Advances in Metal/Covalent Organic Frameworks Based Materials: Their Synthesis, Structure Design and Potential Applications for Hydrogen Production,” Coordination Chemistry Reviews483 (2023): 215066, https://doi.org/10.1016/j.ccr.2023.215066.

[35] A. Chatterjee, P. Mondal, P. Chakraborty, et al., “Unveiling Synergistic Effectiveness of Strategically Designed Cobalt Clusters for Efficient Water Electrolysis,” ACS Catalysis15, no. 3 (2025): 2472-2483, https://doi.org/10.1021/acscatal.4c06466.

[36] S. Wang, A. Lu, and C. J. Zhong, “Hydrogen Production From Water Electrolysis: Role of Catalysts,” Nano Convergence8, no. 1 (2021): 4, https://doi.org/10.1186/s40580-021-00254-x.

[37] W. Fang, Z. Zhu, J. Yu, et al., “First Principles Study on High-Efficient Overall Water Splitting by Anchoring Cobalt Boride With Transition Metal Atoms,” International Journal of Hydrogen Energy53 (2024): 1310-1322, https://doi.org/10.1016/j.ijhydene.2023.11.347.

[38] D. P. Sahoo, K. K. Das, S. Mansingh, S. Sultana, and K. Parida, “Recent Progress in First Row Transition Metal Layered Double Hydroxide (LDH) Based Electrocatalysts Towards Water Splitting: A Review With Insights on Synthesis,” Coordination Chemistry Reviews469 (2022): 214666, https://doi.org/10.1016/j.ccr.2022.214666.

[39] M. Yu, E. Budiyanto, and H. Tuysuz, “Principles of Water Electrolysis and Recent Progress in Cobalt-Nickel-and Iron-Based Oxides for the Oxygen Evolution Reaction,” Angewandte Chemie International Edition61, no. 1 (2022): e202103824, https://doi.org/10.1002/anie.202103824.

[40] W. Zhang, L. Cui, and J. Liu, “Recent Advances in Cobalt-Based Electrocatalysts for Hydrogen and Oxygen Evolution Reactions,” Journal of Alloys and Compounds821 (2020): 153542, https://doi.org/10.1016/j.jallcom.2019.153542.

[41] Y. Guo, X. Tong, and N. Yang, “Design and Performance of Rh Nanocatalysts for Boosted H₂ Generation in Alkaline Media,” Accounts of Chemical Research5, no. 1 (2023): 89-102, https://doi.org/10.1021/accountsmr.3c00146.

[42] D. T. Tran, P. K. Tran, D. Malhotra, et al., “Current Status of Developed Electrocatalysts for Water Splitting Technologies: From Experimental to Industrial Perspective,” Nano Convergence12, no. 1 (2025): 9, https://doi.org/10.1186/s40580-024-00468-9.

[43] H. Shi, X. Y. Sun, Y. Liu, et al., “Multicomponent Intermetallic Nanoparticles on Hierarchical Metal Network as Versatile Electrocatalysts for Highly Efficient Water Splitting,” Advanced Functional Materials33, no. 19 (2023): 2214412, https://doi.org/10.1002/adfm.202214412.

[44] X. Ding, R. Jiang, J. Wu, et al., “Ni₃N-CeO₂ Heterostructure Bifunctional Catalysts for Electrochemical Water Splitting,” Advanced Functional Materials33, no. 47 (2023): 2306786, https://doi.org/10.1002/adfm.202306786.

[45] Y. Zhong, X. Xia, F. Shi, J. Zhan, J. Tu, and H. J. Fan, “Transition Metal Carbides and Nitrides in Energy Storage and Conversion,” Advanced Science3, no. 5 (2016): 1500286, https://doi.org/10.1002/advs.201500286.

[46] D. Li, R. Xiang, F. Yu, et al., “In Situ Regulating Cobalt/Iron Oxide-Oxyhydroxide Exchange by Dynamic Iron Incorporation for Robust Oxygen Evolution at Large Current Density,” Advanced Materials36, no. 5 (2024): e2305685, https://doi.org/10.1002/adma.202305685.

[47] M. Zhao, J. Wang, C. Wang, et al., “Enriched Edge Sites of Ultrathin Ni₃S₂/NiO Nanomeshes Promote Surface Reconstruction for Robust Electrochemical Water Splitting,” Nano Energy129 (2024): 110020, https://doi.org/10.1016/j.nanoen.2024.110020.

[48] C. He, L. Yang, J. Wang, et al., “Research Progress on Electronic and Active Site Engineering of Cobalt-Based Electrocatalysts for Oxygen Evolution Reaction,” Carbon Energy6, no. 8 (2024): 573, https://doi.org/10.1002/cey2.573.

[49] C. K. Peng, Y. C. Lin, C. L. Chiang, et al., “Zhang-Rice Singlets State Formed by Two-Step Oxidation for Triggering Water Oxidation Under Operando Conditions,” Nature Communications14, no. 1 (2023): 529, https://doi.org/10.1038/s41467-023-36317-2.

[50] Y. Wang, T. Wang, H. Arandiyan, et al., “Advancing Catalysts by Stacking Fault Defects for Enhanced Hydrogen Production: A Review,” Advanced Materials36, no. 21 (2024): e2313378, https://doi.org/10.1002/adma.202313378.

[51] C. Wang, W. Liu, M. Liao, et al., “Novel Nano Spinel-Type High-Entropy Oxide (HEO) Catalyst for Hydrogen Production Using Ethanol Steam Reforming,” Nanoscale15, no. 19 (2023): 8619-8632, https://doi.org/10.1039/d2nr07195a.

[52] S. Ma, Q. Fu, J. Han, et al., “Magnetic Field-Assisted Water Splitting: Mechanism, Optimization Strategies, and Future Perspectives,” Advanced Functional Materials34, no. 26 (2024): 2316544, https://doi.org/10.1002/adfm.202316544.

[53] W. Zhang, N. Han, Y. Dou, et al., “Applications of Cobalt Phosphide-Based Materials in Electrocatalysis,” ACS Catalysis15, no. 7 (2025): 5457-5479, https://doi.org/10.1021/acscatal.5c00623.

[54] C. Huang, P. Qin, Y. Luo, et al., “Recent Progress and Perspective of Cobalt-Based Catalysts for Water Splitting: Design and Nanoarchitectonics,” Materials Today Energy23 (2022): 100911, https://doi.org/10.1016/j.mtener.2021.100911.

[55] X. Peng, X. Jin, B. Gao, Z. Liu, and P. K. Chu, “Strategies to Improve Cobalt-Based Electrocatalysts for Electrochemical Water Splitting,” Journal of Catalysis398 (2021): 54-66, https://doi.org/10.1016/j.jcat.2021.04.003.

[56] A. Samanta, B. Dutta, and S. Halder, “Cobalt-Based Nanoscale Material: An Emerging Electrocatalyst for Hydrogen Production,” Chemistry - An Asian Journal19, no. 16 (2024): e202400209, https://doi.org/10.1002/asia.202400209.

[57] M. Mekete Meshesha, D. Chanda, S. Gwon Jang, and B. Lyong Yang, “Enhancing Cobalt-Based Bimetallic Selenide Performance for Urea and Water Electrolysis Through Interface Engineering,” Chemical Engineering Journal474 (2023): 145708, https://doi.org/10.1016/j.cej.2023.145708.

[58] S. Subhadarshini, K. Ghosh, and M. Pumera, “Multiscale Hierarchical Nanoarchitectonics With Stereographically 3D-Printed Electrodes for Water Splitting and Energy Storage,” Materials Today74 (2024): 34-45, https://doi.org/10.1016/j.mattod.2024.02.004.

[59] R. Santhosh Kumar, S. C. Karthikeyan, S. Ramakrishnan, et al., “Anion Dependency of Spinel Type Cobalt Catalysts for Efficient Overall Water Splitting in an Acid Medium,” Chemical Engineering Journal451 (2023): 138471, https://doi.org/10.1016/j.cej.2022.138471.

[60] A. Badreldin, A. E. Abusrafa, and A. Abdel-Wahab, “Oxygen-Deficient Cobalt-Based Oxides for Electrocatalytic Water Splitting,” ChemSusChem14, no. 1 (2021): 10-32, https://doi.org/10.1002/cssc.202002002.

[61] B. Singh and A. Indra, “Surface and Interface Engineering in Transition Metal-Based Catalysts for Electrochemical Water Oxidation,” Materials Today Chemistry16 (2020): 100239, https://doi.org/10.1016/j.mtchem.2019.100239.

[62] X. Han, Y. Hu, F. Zhang, et al., “Enhanced Bifunctional Electrocatalysis for Alkaline Water Splitting via NiCo Alloy on Nitrogen-Doped Carbon: Synergistically Promote Hydrogen and Oxygen Evolution Reactions,” Journal of Molecular Structure1343 (2025): 142834, https://doi.org/10.1016/j.molstruc.2025.142834.

[63] H. Gunaseelan, A. V. Munde, R. Patel, and B. Sathe, “Metal-Organic Framework Derived Carbon-based Electrocatalysis for Hydrogen Evolution Reactions: A Review,” Materials Today Sustainability22 (2023): 100371, https://doi.org/10.1016/j.mtsust.2023.100371.

[64] X. Zhai, Z. Wei, Z. Lu, et al., “Cobalt Single Atom-Enhanced Photocatalysis: Hetero-Phase Elemental Phosphorus for Visible Light Hydrogen Production From Pure Water Splitting,” Advanced Functional Materials35, no. 38 (2025): 2503667, https://doi.org/10.1002/adfm.202503667.

[65] U. Rashid, X. Ma, Y. Zhu, C. Cao, and M. Zou, “A Comprehensive Review of Cobalt-Based Electrocatalysts Synthesized via New Microwave-Assisted Methodology,” Materials Chemistry Frontiers9, no. 9 (2025): 1459-1474, https://doi.org/10.1039/d4qm00929k.

[66] B. You, N. Jiang, M. Sheng, S. Gul, J. Yano, and Y. Sun, “High-Performance Overall Water Splitting Electrocatalysts Derived From Cobalt-Based Metal-Organic Frameworks,” Chemistry of Materials27, no. 22 (2015): 7636-7642, https://doi.org/10.1021/acs.chemmater.5b02877.

[67] J. Khan, A. Ahmed, and A. A. Al-Kahtani, “From Design to Efficiency: Cobalt-Based MOFs for Efficient and Stable Electrocatalysis in Hydrogen and Oxygen Evolution Reactions,” RSC Advances15, no. 11 (2025): 8420-8429, https://doi.org/10.1039/d5ra00286a.

[68] Y. Zheng, W. Xu, J. Yang, et al., “Catalytic Oxidation of VOCs and CO on Cobalt-Based Materials: Strategies and Mechanisms for Improving Activity and Stability,” Chemical Engineering Journal484 (2024): 149296, https://doi.org/10.1016/j.cej.2024.149296.

[69] E. Fabbri and T. J. Schmidt, “Oxygen Evolution Reaction-The Enigma in Water Electrolysis,” ACS Catalysis8, no. 10 (2018): 9765-9774, https://doi.org/10.1021/acscatal.8b02712.

[70] Y. Du, B. Li, G. Xu, and L. Wang, “Recent Advances in Interface Engineering Strategy for Highly-Efficient Electrocatalytic Water Splitting,” InfoMat5, no. 1 (2022): e12377, https://doi.org/10.1002/inf2.12377.

[71] J. B. Gerken, J. G. McAlpin, J. Y. Chen, et al., “Electrochemical Water Oxidation With Cobalt-Based Electrocatalysts From pH 0–14: The Thermodynamic Basis for Catalyst Structure, Stability, and Activity,” Journal of the American Chemical Society133, no. 36 (2011): 14431-14442, https://doi.org/10.1021/ja205647m.

[72] A. Raveendran, M. Chandran, and R. Dhanusuraman, “A Comprehensive Review on the Electrochemical Parameters and Recent Material Development of Electrochemical Water Splitting Electrocatalysts,” RSC Advances13, no. 6 (2023): 3843-3876, https://doi.org/10.1039/d2ra07642j.

[73] Y. Wang, P. Guo, J. Zhou, et al., “Tuning the Co Pre-Oxidation Process of Co₃O₄ via Geometrically Reconstructed F-Co-O Active Sites for Boosting Acidic Water Oxidation,” Energy & Environmental Science17, no. 22 (2024): 8820-8828, https://doi.org/10.1039/d4ee03982c.

[74] S. Wang, Q. Jiang, S. Ju, et al., “Identifying the Geometric Catalytic Active Sites of Crystalline Cobalt Oxyhydroxides for Oxygen Evolution Reaction,” Nature Communications13, no. 1 (2022): 6650, https://doi.org/10.1038/s41467-022-34380-9.

[75] A. Aljabour, “Long-Lasting Electrospun Co₃O₄ Nanofibers for Electrocatalytic Oxygen Evolution Reaction,” ChemistrySelect5, no. 25 (2020): 7482-7487, https://doi.org/10.1002/slct.202001291.

[76] A. Shahzad, F. Zulfiqar, and M. Arif Nadeem, “Cobalt Containing Bimetallic ZIFs and Their Derivatives as OER Electrocatalysts: A Critical Review,” Coordination Chemistry Reviews477 (2023): 214925, https://doi.org/10.1016/j.ccr.2022.214925.

[77] M. S. Burke, M. G. Kast, L. Trotochaud, A. M. Smith, and S. W. Boettcher, “Cobalt-Iron (Oxy)Hydroxide Oxygen Evolution Electrocatalysts: The Role of Structure and Composition on Activity, Stability, and Mechanism,” Journal of the American Chemical Society137, no. 10 (2015): 3638-3648, https://doi.org/10.1021/jacs.5b00281.

[78] Y. Zhang, S. Wei, P. Xing, L. Dai, and Y. Wang, “Iron-Doped Nickel Sulfide Nanoparticles Grown on N-Doped Reduced Graphene Oxide as Efficient Electrocatalysts for Oxygen Evolution Reaction,” Journal of Electroanalytical Chemistry936 (2023): 117323, https://doi.org/10.1016/j.jelechem.2023.117323.

[79] M. Singh, D. R. Paudel, H. Kim, T. H. Kim, J. Park, and S. Lee, “Interface Engineering Strategies for Enhanced Electrocatalytic Hydrogen Evolution Reaction,” Energy Advances4, no. 6 (2025): 716-742, https://doi.org/10.1039/d5ya00022j.

[80] D. Ding, Y. Liu, and F. Xia, “Interface Engineering via Molecules/Ions/Groups for Electrocatalytic Water Splitting,” Nano Research17, no. 9 (2024): 7864-7879, https://doi.org/10.1007/s12274-024-6869-x.

[81] M. Sohail, M. Ayyob, A. Wang, et al., “Cobalt-Based CoSe/CoO Heterostructure: A Catalyst for Efficient Oxygen Evolution Reaction,” International Journal of Hydrogen Energy67 (2024): 1000-1008, https://doi.org/10.1016/j.ijhydene.2023.12.278.

[82] P. Wang and B. Wang, “Designing Self-Supported Electrocatalysts for Electrochemical Water Splitting: Surface/Interface Engineering Toward Enhanced Electrocatalytic Performance,” ACS Applied Materials & Interfaces13, no. 50 (2021): 59593-59617, https://doi.org/10.1021/acsami.1c17448.

[83] A. E. Thorarinsdottir, S. S. Veroneau, and D. G. Nocera, “Self-Healing Oxygen Evolution Catalysts,” Nature Communications13, no. 1 (2022): 1243, https://doi.org/10.1038/s41467-022-28723-9.

[84] F. Kashif, M. Y. Naz, Z. Kashif, et al., “Indoor Water Splitting for Hydrogen Production Through Electrocatalysis Using Composite Metal Oxide Catalysts,” AIP Advances13, no. 11 (2023): 115024, https://doi.org/10.1063/5.0179459.

[85] L. Gu, H. Zhu, D. Yu, et al., “A Facile Strategy to Synthesize Cobalt-Based Self-Supported Material for Electrocatalytic Water Splitting,” Particle & Particle Systems Characterization34, no. 10 (2017): 1700189, https://doi.org/10.1002/ppsc.201700189.

[86] S. Gupta, R. Fernandes, R. Patel, M. Spreitzer, and N. Patel, “A Review of Cobalt-Based Catalysts for Sustainable Energy and Environmental Applications,” Applied Catalysis661 (2023): 119254, https://doi.org/10.1016/j.apcata.2023.119254.

[87] Z. Xu and Z. S. Wu, “Scalable Production of High-Performance Electrocatalysts for Electrochemical Water Splitting at Large Current Densities,” eScience5, no. 4 (2025): 100334, https://doi.org/10.1016/j.esci.2024.100334.

[88] Y. Devi, P. J. Huang, W. T. Chen, R. H. Jhang, and C. H. Chen, “Roll-to-Roll Production of Electrocatalysts Achieving High-Current Alkaline Water Splitting,” ACS Applied Materials & Interfaces15, no. 7 (2023): 9231-9239, https://doi.org/10.1021/acsami.2c19710.

[89] B. Wang, F. Yang, and L. Feng, “Recent Advances in Co-Based Electrocatalysts for Hydrogen Evolution Reaction,” Small19, no. 45 (2023): e2302866, https://doi.org/10.1002/smll.202302866.

[90] R. Y. Fan, J. Y. Xie, N. Yu, Y. M. Chai, and B. Dong, “Interface Design and Composition Regulation of Cobalt-Based Electrocatalysts for Oxygen Evolution Reaction,” International Journal of Hydrogen Energy47, no. 19 (2022): 10547-10572, https://doi.org/10.1016/j.ijhydene.2021.12.239.

[91] H. Wang and H. S. Kim, “Development of High-Performance Cobalt Oxide Electrocatalysts for Alkaline Water Splitting via Integrated Pulsed Laser Ablation in Liquid (PLAL) and Electrophoretic Deposition (EPD),” International Journal of Hydrogen Energy132 (2025): 102-115, https://doi.org/10.1016/j.ijhydene.2025.04.347.

[92] W. Meng, R. Pang, M. Li, et al., “Integrated Catalyst-Substrate Electrodes for Electrochemical Water Splitting: A Review on Dimensional Engineering Strategy,” Small21, no. 28 (2025): e2310469, https://doi.org/10.1002/smll.202310469.

[93] A. Suryawanshi, R. A. B. John, A. Bhide, et al., “Designing Bifunctional Electrocatalysts Based on Complex Cobalt-Sulfo-Boride Compound for High-Current-Density Alkaline Water Electrolysis,” Energy & Fuels38, no. 19 (2024): 18965-18975, https://doi.org/10.1021/acs.energyfuels.4c03171.

[94] L. Zhou, M. Yang, Y. Liu, F. Kang, and R. Lv, “Intrinsic Metal-Support Interactions Break the Activity-Stability Dilemma in Electrocatalysis,” Nature Communications16, no. 1 (2025): 8739, https://doi.org/10.1038/s41467-025-63397-z.

[95] Q. Wang, D. Liu, and X. He, “Metal-Organic Framework-Derived Fe-N-C Nanohybrids as Highly-Efficient Oxygen Reduction Catalysts,” Acta Physico-Chimica Sinica35, no. 7 (2019): 740-748, https://doi.org/10.3866/pku.whxb201809003.

[96] R. Samanta, R. Mishra, B. K. Manna, and S. Barman, “Two-Dimensional Amorphous Cobalt Oxide Nanosheets/N-Doped Carbon Composites for Efficient Water Splitting in Alkaline Medium,” ACS Applied Nano Materials5, no. 11 (2022): 17022-17032, https://doi.org/10.1021/acsanm.2c03941.

[97] C. Gao, H. Wang, S. Li, et al., “Enhanced Cobalt-Based Catalysts Through Alloying Ruthenium to Cobalt Lattice Matrix as an Efficient Catalyst for Overall Water Splitting,” Electrochimica Acta327 (2019): 134958, https://doi.org/10.1016/j.electacta.2019.134958.

[98] W. Guo, H. Luo, Z. Jiang, et al., “Ge-Doped Cobalt Oxide for Electrocatalytic and Photocatalytic Water Splitting,” ACS Catalysis12, no. 19 (2022): 12000-12013, https://doi.org/10.1021/acscatal.2c03730.

[99] Y. Zang, D. Q. Lu, K. Wang, et al., “A Pyrolysis-Free Ni/Fe Bimetallic Electrocatalyst for Overall Water Splitting,” Nature Communications14, no. 1 (2023): 1792, https://doi.org/10.1038/s41467-023-37530-9.

[100] W. Wang, X. Yu, H. He, et al., “Electrochemical Reconstitution of Prussian Blue Analogue for Coupling Furfural Electro-Oxidation With Photo-Assisted Hydrogen Evolution Reaction,” Chemical Engineering Journal465 (2023): 142865, https://doi.org/10.1016/j.cej.2023.142865.

[101] M. Batool, A. Hameed, and M. A. Nadeem, “Recent Developments on Iron and Nickel-Based Transition Metal Nitrides for Overall Water Splitting: A Critical Review,” Coordination Chemistry Reviews480 (2023): 215029, https://doi.org/10.1016/j.ccr.2023.215029.

[102] N. Kumar, A. Sharma, K. Rajput, R. Kataria, and S. Mehta, “Cobalt-Based Co-Ordination Complex-Derived Nanostructure for Efficient Oxygen Evolution Reaction in Acidic and Alkaline Medium,” Heliyon8, no. 10 (2022): e10939, https://doi.org/10.1016/j.heliyon.2022.e10939.

[103] M. Abdelwahab, G. Mohamed, M. Zayed, and A. Eliwa, “Synthesis and Characterization of Cobalt-Organic Framework as an Electrocatalyst for Water Splitting Application,” Applied Organometallic Chemistry39, no. 3 (2024): e7889, https://doi.org/10.1002/aoc.7889.

[104] A. Hassan, A. Haq, M. Arif, et al., “Rationally Design and Modulation Strategies of Cobalt-Based Covalent Organic Frameworks (COFs) Electrocatalysts Towards Energy Conversion Applications,” Coordination Chemistry Reviews543 (2025): 216926, https://doi.org/10.1016/j.ccr.2025.216926.

[105] F. Gong, M. Liu, L. Gong, et al., “Modulation of Mo-Fe-C Sites over Mesoscale Diffusion-Enhanced Hollow Sub-Micro Reactors Toward Boosted Electrochemical Water Oxidation,” Advanced Functional Materials32, no. 30 (2022): 2202141, https://doi.org/10.1002/adfm.202202141.

[106] P. Das, B. Ball, and P. Sarkar, “Bifunctional Electrocatalytic Activity of Two-Dimensional Metallophthalocyanine-Based Metal-Organic-Frameworks for Overall Water Splitting: A DFT Study,” ACS Catalysis13, no. 24 (2023): 16307-16317, https://doi.org/10.1021/acscatal.3c03967.

[107] Y. Zhou, Z. Wang, M. Cui, et al., “NiFe-Based Electrocatalysts for Alkaline Oxygen Evolution: Challenges, Strategies, and Advances Toward Industrial-Scale Deployment,” Advanced Functional Materials34, no. 52 (2024): 2410618, https://doi.org/10.1002/adfm.202410618.

[108] W. Liu, J. Yang, Y. Zhao, et al., “Laser-Ironing Induced Capping Layer on Co-ZIF-L Promoting In Situ Surface Modification to High-Spin Oxide-Carbon Hybrids on the ‘Real Catalyst’ for High OER Activity and Stability,” Advanced Materials36, no. 8 (2024): e2310106, https://doi.org/10.1002/adma.202310106.

[109] M. Chen, Y. Yang, Y. Ding, and J. Liu, “Toward a Molecular-Scale Picture of Water Electrolysis: Mechanistic Insights, Fundamental Kinetics and Electrocatalyst Dynamic Evolution,” Coordination Chemistry Reviews536 (2025): 216651, https://doi.org/10.1016/j.ccr.2025.216651.

[110] F. Gong, Y. Liu, Y. Zhao, et al., “Universal Sub-Nanoreactor Strategy for Synthesis of Yolk-Shell MoS₂ Supported Single Atom Electrocatalysts Toward Robust Hydrogen Evolution Reaction,” Angewandte Chemie International Edition62, no. 40 (2023): e202308091, https://doi.org/10.1002/ange.202308091.

[111] Z. Ye, C. Li, Q. Chen, Y. Xu, and S. E. J. Bell, “Ultra-Stable Plasmonic Colloidal Aggregates for Accurate and Reproducible Quantitative SE(R)RS in Protein-Rich Biomedia,” Angewandte Chemie International Edition58, no. 52 (2019): 19054-19059, https://doi.org/10.1002/anie.201911608.

[112] H. Zhang, Y. Li, X. Liu, et al., “Exploration of Multiscale Design Strategies of Electrocatalysts for Efficient Electrochemical Hydrogen and Oxygen Evolution Reactions,” Chemical Engineering Journal522 (2025): 167757, https://doi.org/10.1016/j.cej.2025.167757.

[113] X. Jia, Z. Zhou, F. Liu, et al., “Closed-Loop Framework for Discovering Stable and Low-Cost Bifunctional Metal Oxide Catalysts for Efficient Electrocatalytic Water Splitting in Acid,” Journal of the American Chemical Society147, no. 26 (2025): 22642-22654, https://doi.org/10.1021/jacs.5c04079.

[114] S. Ram, A. S. Lee, S. C. Lee, and S. Bhattacharjee, “Advanced Multifunctional Electrocatalysts: Integrating DFT and Machine Learning for OER, HER, and ORR Reactions,” Chemistry of Materials37, no. 10 (2025): 3608-3621, https://doi.org/10.1021/acs.chemmater.4c03213.

[115] F. Gong, Z. Chen, C. Chang, et al., “Hollow Mo/MoS_Vn Nanoreactors With Tunable Built-in Electric Fields for Sustainable Hydrogen Production,” Advanced Materials37, no. 5 (2025): 2415269, https://doi.org/10.1002/adma.202415269.

[116] B. Zhang, X. Zheng, O. Voznyy, et al., “Homogeneously Dispersed, Multimetal Oxygen-Evolving Catalysts,” Science352, no. 6283 (2016): 333-337, https://doi.org/10.1126/science.aaf1525.

[117] F. Song and X. Hu, “Exfoliation of Layered Double Hydroxides for Enhanced Oxygen Evolution Catalysis,” Nature Communications5, no. 1 (2014): 4477, https://doi.org/10.1038/ncomms5477.

[118] E. Fabbri, M. Nachtegaal, T. Binninger, et al., “Dynamic Surface Self-Reconstruction Is the Key of Highly Active Perovskite Nano-Electrocatalysts for Water Splitting,” Nature Materials16, no. 9 (2017): 925-931, https://doi.org/10.1038/nmat4938.

[119] B. M. Hunter, W. Hieringer, J. R. Winkler, H. B. Gray, and A. M. Müller, “Effect of Interlayer Anions on [NiFe]-LDH Nanosheet Water Oxidation Activity,” Energy & Environmental Science9, no. 5 (2016): 1734-1743, https://doi.org/10.1039/c6ee00377j.

[120] A. Zhu, L. Qiao, K. Liu, et al., “Rational Design of Precatalysts and Controlled Evolution of Catalyst-Electrolyte Interface for Efficient Hydrogen Production,” Nature Communications16, no. 1 (2025): 1880, https://doi.org/10.1038/s41467-025-57056-6.

[121] A. Zou, C. Wu, Q. Zhang, et al., “Promoting Surface Reconstruction in Spinel Oxides via Tetrahedral-Octahedral Phase Boundary Construction for Efficient Oxygen Evolution,” Angewandte Chemie International Edition63, no. 42 (2024): e202409912, https://doi.org/10.1002/ange.202409912.

[122] Z. H. Yin, Y. M. Fan, K. Song, et al., “Fe-Ni Synergy Reinforced by Zn Leaching: A Hydroxyl Spillover Pathway to Bridge the Gap Between Lattice Oxygen Activity and Robust Water Oxidation,” Advanced Functional Materials (2025): e12013, https://doi.org/10.1002/adfm.202512013.

[123] R. Wan, T. Yuan, L. Wang, B. Li, M. Liu, and B. Zhao, “Earth-Abundant Electrocatalysts for Acidic Oxygen Evolution,” Nature catalysis7, no. 12 (2024): 1288-1304, https://doi.org/10.1038/s41929-024-01266-6.

[124] H. Yang, P. Duan, Z. Zhuang, et al., “Understanding the Dynamic Evolution of Active Sites Among Single Atoms, Clusters, and Nanoparticles,” Advanced Materials37, no. 7 (2025): e2415265, https://doi.org/10.1002/adma.202415265.

[125] W. Hu, L. Xie, C. Gu, et al., “The Nature of Active Sites of Molybdenum Sulfide-Based Catalysts for Hydrogen Evolution Reaction,” Coordination Chemistry Reviews506 (2024): 215715, https://doi.org/10.1016/j.ccr.2024.215715.

[126] W. Wan, L. Kang, A. Schnegg, et al., “Carbon-Supported Single Fe/Co/Ni Atom Catalysts for Water Oxidation: Unveiling the Dynamic Active Sites,” Angewandte Chemie International Edition64, no. 25 (2025): e202424629, https://doi.org/10.1002/anie.202424629.

[127] A. Bhowmick, S. Srinivas, J. Zhang, et al., “Active Sites in the Dealuminated Beta Zeolite-Supported Cobalt Catalyst for Non-Oxidative Ethane Dehydrogenation,” ACS Catalysis15, no. 12 (2025): 10372-10390, https://doi.org/10.1021/acscatal.5c00494.

[128] C. Luan, D. Escalera-López, U. Hagemann, et al., “Revealing Dynamic Surface and Subsurface Reconstruction of High-Entropy Alloy Electrocatalysts During the Oxygen Evolution Reaction at the Atomic Scale,” ACS Catalysis14, no. 17 (2024): 12704-12716, https://doi.org/10.1021/acscatal.4c02792.

[129] J. Zhou, F. Qiao, Z. Ren, et al., “Amorphization Engineering of Bimetallic Metal-Organic Frameworks to Identify Volcano-Type Trend Toward Oxygen Evolution Reaction,” Advanced Functional Materials34, no. 1 (2023): 2304380, https://doi.org/10.1002/adfm.202304380.

[130] J. Huang, C. Fu, J. Chen, N. Senthilkumar, X. Peng, and Z. Wen, “The Enhancement of Selectivity and Activity for Two-Electron Oxygen Reduction Reaction by Tuned Oxygen Defects on Amorphous Hydroxide Catalysts,” CCS Chemistry4, no. 2 (2022): 566-583, https://doi.org/10.31635/ccschem.021.202000750.

[131] J. Y. Zhao, K. Huang, C. Liu, et al., “Electro-Induced Crystallization Over Amorphous Indium Hydroxide Gels Toward Ampere-Level Current Density Formate Electrosynthesis,” Advanced Functional Materials34, no. 24 (2024): 2316167, https://doi.org/10.1002/adfm.202316167.

[132] G. Xu, X. Peng, C. Wu, et al., “Atomically Precise Ni Clusters Inducing Active NiN₂ Sites With Uniform-Large Vacancies Towards Efficient CO₂-to-CO Conversion,” Nature Communications16, no. 1 (2025): 3774, https://doi.org/10.1038/s41467-025-59079-5.

[133] B. Sun, S. Zhang, H. Yang, et al., “Revealing the Active Sites in Atomically Dispersed Multi-Metal-Nitrogen-Carbon Catalysts,” Advanced Functional Materials34, no. 29 (2024): 2315862, https://doi.org/10.1002/adfm.202315862.

[134] P. Guo, B. Liu, F. Tu, et al., “Breaking Sabatier's Vertex via Switching the Oxygen Adsorption Configuration and Reaction Pathway on Dual Active Sites for Acidic Oxygen Reduction,” Energy & Environmental Science17, no. 9 (2024): 3077-3087, https://doi.org/10.1039/d4ee00823e.

[135] J. N. Hall, A. J. Kropf, M. Delferro, and P. Bollini, “Kinetic and X-Ray Absorption Spectroscopic Analysis of Catalytic Redox Cycles Over Highly Uniform Polymetal Oxo Clusters,” ACS Catalysis13, no. 8 (2023): 5406-5427, https://doi.org/10.1021/acscatal.2c06023.

[136] J. Koh, C. Kwon, H. Kim, et al., “Defect-Driven Evolution of Oxo-Coordinated Cobalt Active Sites With Rapid Structural Transformation for Efficient Water Oxidation,” ACS Nano18, no. 42 (2024): 28986-28998, https://doi.org/10.1021/acsnano.4c09856.

[137] S. Wang, B. Ge, Z. Yang, et al., “Construction of Highly Active Pd-Ti³⁺ Sites in Defective Pd/TiO₂ Catalysts for Efficient Hydrogenation of Styrene-Butadiene-Styrene,” ACS Catalysis14, no. 3 (2024): 1432-1442, https://doi.org/10.1021/acscatal.3c04811.

[138] M. Ning, S. Wang, J. Wan, et al., “Dynamic Active Sites in Electrocatalysis,” Angewandte Chemie International Edition63, no. 50 (2024): e202415794, https://doi.org/10.1002/anie.202415794.

[139] F. Sun, Z. Li, H. Xu, et al., “Exploring Structural Evolution Behaviors of Ligand-Defect-Rich Ferrocene-Based Metal-Organic Frameworks for Electrochemical Oxygen Evolution via Operando X-Ray Absorption Spectroscopy,” Advanced Energy Materials14, no. 36 (2024): 2400875, https://doi.org/10.1002/aenm.202400875.

[140] Y. Zeng, J. Zhao, S. Wang, et al., “Unraveling the Electronic Structure and Dynamics of the Atomically Dispersed Iron Sites in Electrochemical CO₂ Reduction,” Journal of the American Chemical Society145, no. 28 (2023): 15600-15610, https://doi.org/10.1021/jacs.3c05457.

[141] R. Chen, J. Zhao, Y. Li, et al., “Operando Mossbauer Spectroscopic Tracking the Metastable State of Atomically Dispersed Tin in Copper Oxide for Selective CO₂ Electroreduction,” Journal of the American Chemical Society145, no. 37 (2023): 20683-20691, https://doi.org/10.1021/jacs.3c06738.

[142] M. Scolaro and N. Kittner, “Optimizing Hybrid Offshore Wind Farms for Cost-Competitive Hydrogen Production in Germany,” International Journal of Hydrogen Energy47, no. 10 (2022): 6478-6493, https://doi.org/10.1016/j.ijhydene.2021.12.062.

[143] N. Armaroli and V. Balzani, “The Future of Energy Supply: Challenges and Opportunities,” Angewandte Chemie International Edition46, no. 1–2 (2007): 52-66, https://doi.org/10.1002/anie.200602373.

[144] J. K. Norskov, T. Bligaard, J. Rossmeisl, and C. H. Christensen, “Towards the Computational Design of Solid Catalysts,” Nature Chemistry1, no. 1 (2009): 37-46, https://doi.org/10.1038/nchem.121.

[145] F. Gong, M. Liu, S. Ye, et al., “All-pH Stable Sandwich-Structured MoO₂/MoS₂/C Hollow Nanoreactors for Enhanced Electrochemical Hydrogen Evolution,” Advanced Functional Materials31, no. 27 (2021): 2101715, https://doi.org/10.1002/adfm.202101715.

[146] V. Stamenkovic, B. S. Mun, K. J. Mayrhofer, et al., “Changing the Activity of Electrocatalysts for Oxygen Reduction by Tuning the Surface Electronic Structure,” Angewandte Chemie International Edition45, no. 18 (2006): 2897-2901, https://doi.org/10.1002/anie.200504386.

[147] J. Greeley, T. F. Jaramillo, J. Bonde, I. Chorkendorff, and J. K. Nørskov, “Computational High-Throughput Screening of Electrocatalytic Materials for Hydrogen Evolution,” Nature Materials5, no. 11 (2006): 909-913, https://doi.org/10.1038/nmat1752.

RIGHTS & PERMISSIONS

2025 The Author(s). EcoEnergy published by John Wiley & Sons Australia, Ltd on behalf of China Chemical Safety Association.