1. Non-covalent ligand-oxide interaction promotes oxygen evolutionQianbao Wu, Junwu Liang, Mengjun Xiao, Chang Long, Lei Li, Zhenhua Zeng, Andraž Mavrič, Xia Zheng, Jing Zhu, Matjaž Valant, 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.
Keywords: water oxidation, cobalt hydroxide, ligand-metal interactions
Published in RUNG: 23.02.2023; Views: 1378; Downloads: 15
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2. Gender agreement with exclusive disjunction in SlovenianFranc Marušič, Zheng Shen, 2021, original scientific article Abstract: This paper addresses two issues: 1. Empirically, we report novel experimental data on agreement with exclusively disjoined subjects in Slovenian; 2. Theoretically, we look into the nature of attested agreement strategies with coordinated NPs. In particular, we investigate how these strategies behave under coordinators with different semantics, i.e. exclusive disjunction and conjunction. Based on the elicitation results, we argue that closest conjunct agreement, resolved agreement, and highest conjunct agreement are all present under exclusive disjunction to different extents, which suggests a uniform set of agreement strategies under disjunction and conjunction despite the semantic difference. Further, we argue against the presence of default agreement under both disjunction and conjunction in Slovenian, and argue for a particular set of gender resolution rules.
Keywords: Slovenian, conjunct agreement, exclisuve disjunction, resolution, default agreement
Published in RUNG: 15.11.2021; Views: 1564; Downloads: 0
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3. CVD Growth of Molybdenum Diselenide Surface Structures with Tailored MorphologyM. Naeem Sial, Usman Muhammad, Binjie Zheng, Yanan Yu, Andraž Mavrič, Fangzhu Qing, Matjaž Valant, Zhiming M. Wang, 2018, original scientific article Abstract: Controllable atmospheric pressure CVD has been optimized to grow transition metal dichalcogenide MoSe2 with tunable morphology at 750 °C on a silicon substrate with a native oxide layer of 250 nm. Utilizing tetrapotassium perylene-3,4,9,10-tetracarboxylate (PTAS) as a seed promoter and varying the vertical distance between the substrate and the precursor MoO3, different morphologies of MoSe2 were achieved, including 2D triangles, hexagons, 3D pyramids and vertically aligned MoSe2 sheets. We find that the shape of MoSe2 is highly dependent upon the distance h between the substrate and the precursor. The change in the morphology is attributed to the confinement of vapor (MoO3 and Se) precursors and their concentrations due to the change in h. These results are helpful in improving our understanding about the factors which influence the morphology (shape evolution) and also the continuous growth of MoSe2 films.
Keywords: Transition metal dichalcogenides, 2D materials, Seed promotor, Chemical vapor deposition, Molybdenum diselenide
Published in RUNG: 20.08.2018; Views: 3731; Downloads: 14
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