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4. Non-covalent ligand-oxide interaction promotes oxygen evolutionQianbao Wu, Junwu Liang, Mengjun Xiao, Chang Long, Lei Li, Zhenhua Zheng, Andraž Mavrič, Xia Zheng, Hai-Wei Liang, Hongfei Liu, Matjaž Valant, Wei Wang, Zhengxing Lv, Jiong Li, Chunhua Cui, 2023, original scientific article Abstract: Strategies to generate high-valence metal species capable of oxidizing water often employ composition and coordination tuning of oxide-based catalysts, where strong covalent interactions with metal sites are crucial. However, it remains unexplored whether a relatively weak “non-bonding” interaction between ligands and oxides can mediate the electronic states of metal sites in oxides. Here we present an unusual non-covalent phenanthroline-CoO2 interaction that substantially elevates the population of Co4+ sites for improved water oxidation. We find that phenanthroline only coordinates with Co2+ forming soluble Co(phenanthroline)2(OH)2 complex in alkaline electrolytes, which can be deposited as amorphous CoOxHy film containing non-bonding phenanthroline upon oxidation of Co2+ to Co3+/4+. This in situ deposited catalyst demonstrates a low overpotential of 216 mV at 10 mA cm−2 and sustainable activity over 1600 h with Faradaic efficiency above 97%. Density functional theory calculations reveal that the presence of phenanthroline can stabilize CoO2 through the non-covalent interaction and generate polaron-like electronic states at the Co-Co center. Found in: osebi Keywords: water oxidation, cobalt hydroxide, ligand-metal interactions Published: 23.02.2023; Views: 280; Downloads: 9
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5. Tracking the reversibility of Ni redox states in Ni(OH)[sub]2 oxygen evolution electrocatalyst at high current densityAndraž Mavrič, Mattia Fanetti, Matjaž Valant, Chunhua Cui, 2021, published scientific conference contribution abstract Found in: osebi Keywords: oxygen evolution reaction, spectroelectrochemistry, nickel hydroxide, stability, amorphization Published: 29.11.2021; Views: 1027; Downloads: 0
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