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Efficient Electrochemical Water Oxidation by a Trinuclear Ru(bda) Macrocycle Immobilized on Multi‐Walled Carbon Nanotube Electrodes
Author(s) -
Schindler Dorothee,
GilSepulcre Marcos,
Lindner Joachim O.,
Stepanenko Vladimir,
Moonshiram Dooshaye,
Llobet Antoni,
Würthner Frank
Publication year - 2020
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.202002329
Subject(s) - overpotential , catalysis , materials science , carbon nanotube , cyclic voltammetry , electrochemistry , water splitting , electrode , activated carbon , chemical engineering , inorganic chemistry , nanotechnology , chemistry , adsorption , organic chemistry , photocatalysis , engineering
Catalytic water splitting is a viable process for the generation of renewable fuels. Here it is reported for the first time that a trinuclear supramolecular Ru(bda) (bda: 2,2′‐bipyridine‐6,6′‐dicarboxylate) catalyst, anchored on multi‐walled carbon nanotubes and subsequently immobilized on glassy carbon electrodes, shows outstanding performance in heterogeneous water oxidation. Activation of the catalyst on anodes by repetitive cyclic voltammetry (CV) scans results in a catalytic current density of 186 mA cm −2 at a potential of 1.45 V versus NHE. The activated catalyst performs water oxidation at an onset overpotential of 330 mV. The remarkably high stability of the hybrid anode is demonstrated by X‐ray absorption spectroscopy and electrochemically, revealing the absence of any degradation after 1.8 million turnovers. Foot of the wave analysis of CV data of activated electrodes with different concentrations of catalyst indicates a monomolecular water nucleophilic attack mechanism with an apparent rate constant of TOF max (turnover frequency) of 3200 s −1 .