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Surface-Promoted Evolution of Ru-bda Coordination Oligomers Boosts the Efficiency of Water Oxidation Molecular Anodes

[Image: see text] A new Ru oligomer of formula {[Ru(II)(bda-κ-N(2)O(2))(4,4′-bpy)](10)(4,4′-bpy)}, 10 (bda is [2,2′-bipyridine]-6,6′-dicarboxylate and 4,4′-bpy is 4,4′-bipyridine), was synthesized and thoroughly characterized with spectroscopic, X-ray, and electrochemical techniques. This oligomer e...

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Detalles Bibliográficos
Autores principales: Gil-Sepulcre, Marcos, Lindner, Joachim O., Schindler, Dorothee, Velasco, Lucía, Moonshiram, Dooshaye, Rüdiger, Olaf, DeBeer, Serena, Stepanenko, Vladimir, Solano, Eduardo, Würthner, Frank, Llobet, Antoni
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2021
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8343522/
https://www.ncbi.nlm.nih.gov/pubmed/34293261
http://dx.doi.org/10.1021/jacs.1c04738
Descripción
Sumario:[Image: see text] A new Ru oligomer of formula {[Ru(II)(bda-κ-N(2)O(2))(4,4′-bpy)](10)(4,4′-bpy)}, 10 (bda is [2,2′-bipyridine]-6,6′-dicarboxylate and 4,4′-bpy is 4,4′-bipyridine), was synthesized and thoroughly characterized with spectroscopic, X-ray, and electrochemical techniques. This oligomer exhibits strong affinity for graphitic materials through CH−π interactions and thus easily anchors on multiwalled carbon nanotubes (CNT), generating the molecular hybrid material 10@CNT. The latter acts as a water oxidation catalyst and converts to a new species, 10′(H(2)O)(2)@CNT, during the electrochemical oxygen evolution process involving solvation and ligand reorganization facilitated by the interactions of molecular Ru catalyst and the surface. This heterogeneous system has been shown to be a powerful and robust molecular hybrid anode for electrocatalytic water oxidation into molecular oxygen, achieving current densities in the range of 200 mA/cm(2) at pH 7 under an applied potential of 1.45 V vs NHE. The remarkable long-term stability of this hybrid material during turnover is rationalized based on the supramolecular interaction of the catalyst with the graphitic surface.