Catalytic H-2 Evolution with CoO, Co(OH)(2) and CoO(OH) Nanoparticles Generated from a Molecular Polynuclear Co Complex

Electrochemical water reduction by employing first-row transition-metal nanoparticles (NPs) constitutes a sustainable way for the generation of H-2. We have synthesized Co-based NPs from a molecular Co-II/Co-III precursor after its reductive decomposition at -1.86 V versus NHE in different organic s...

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Detalles Bibliográficos
Autores: Gil-Sepulcre, Marcos, Gimbert-Suriñach, Carolina, Aguilà Avilés, David, Velasco Amigó, Verónica, Garcia-Anton, Jordi, Llobet, Antoni, Aromí Bedmar, Guillem, Bofill, Roger, Sala, Xavier
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2018
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/153559
Acceso en línea:https://hdl.handle.net/2445/153559
Access Level:acceso abierto
Palabra clave:Cobalt
Hidrogen
Nanopartícules
Electrocatàlisi
Hydrogen
Nanoparticles
Electrocatalysis
Descripción
Sumario:Electrochemical water reduction by employing first-row transition-metal nanoparticles (NPs) constitutes a sustainable way for the generation of H-2. We have synthesized Co-based NPs from a molecular Co-II/Co-III precursor after its reductive decomposition at -1.86 V versus NHE in different organic solvents. These NPs are able to electrochemically reduce water at pH 14. SEM, EDX and XPS analyses have allowed the determination of the chemical nature of the as-deposited NPs: CoO when using MeCN as the solvent and CoO(OH) when employing either dichloromethane (DCM) or MeOH. After 2 h of constant polarization at 10 mAcm(-2), the electrocatalytic activity of the NPs obtained in MeCN and DCM decreases, whereas it increases for those obtained in MeOH. In this solvent, the overpotential is reduced by 215-220 mV and the specific current density is tripled. Interestingly, during this activation process in MeOH, the precursor CoO(OH) NPs are converted into Co(OH)(2). The implications of these results in the context of the current research in the field are also discussed.