title: Molecular engineering of a cobalt-based electrocatalytic nanomaterial for H₂ evolution under fully aqueous conditions.
abstract: The viability of a hydrogen economy depends on the design of efficient catalytic systems based on earth-abundant elements. Innovative breakthroughs for hydrogen evolution based on molecular tetraimine cobalt compounds have appeared in the past decade. Here we show that such a diimine-dioxime cobalt catalyst can be grafted to the surface of a carbon nanotube electrode. The resulting electrocatalytic cathode material mediates H(2) generation (55,000 turnovers in seven hours) from fully aqueous solutions at low-to-medium overpotentials. This material is remarkably stable, which allows extensive cycling with preservation of the grafted molecular complex, as shown by electrochemical studies, X-ray photoelectron spectroscopy and scanning electron microscopy. This clearly indicates that grafting provides an increased stability to these cobalt catalysts, and suggests the possible application of these materials in the development of technological devices.
authors.affiliation: Laboratoire de Chimie et Biologie des Métaux (CEA/Université Grenoble 1/CNRS), 17 rue des Martyrs, F-38054                 Grenoble Cedex 9, France.
authors.forename: Eugen S
authors.initials: ES
authors.lastname: Andreiadis
authors.forename: Pierre-André
authors.initials: PA
authors.lastname: Jacques
authors.forename: Phong D
authors.initials: PD
authors.lastname: Tran
authors.forename: Adeline
authors.initials: A
authors.lastname: Leyris
authors.forename: Murielle
authors.initials: M
authors.lastname: Chavarot-Kerlidou
authors.forename: Bruno
authors.initials: B
authors.lastname: Jousselme
authors.forename: Muriel
authors.initials: M
authors.lastname: Matheron
authors.forename: Jacques
authors.initials: J
authors.lastname: Pécaut
authors.forename: Serge
authors.initials: S
authors.lastname: Palacin
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave
authors.forename: Vincent
authors.initials: V
authors.lastname: Artero
mesh_terms: D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D006859:Hydrogen / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D049329:Nanostructures / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D007097:Imines; D037742:Nanotubes, Carbon; D009942:Organometallic Compounds; D014867:Water; D003035:Cobalt; D006859:Hydrogen