Insights into the mechanism and aging of a noble-metal free H2-evolving dye-sensitized photocathode - CEA - Commissariat à l’énergie atomique et aux énergies alternatives Accéder directement au contenu
Article Dans Une Revue Chemical Science Année : 2018

Insights into the mechanism and aging of a noble-metal free H2-evolving dye-sensitized photocathode

Résumé

Dye-sensitized photo-electrochemical cells (DS-PECs) form an emerging technology for the large-scale storage of solar energy in the form of (solar) fuels because of the low cost and ease of processing of their constitutive photoelectrode materials. Preparing such molecular photocathodes requires a well-controlled co-immobilization of molecular dyes and catalysts onto transparent semiconducting materials. Here we used a series of surface analysis techniques to describe the molecular assembly of a push-pull organic dye and a cobalt diimine-dioxime catalyst co-grafted on a p-type NiO electrode substrate. (Photo) electrochemical measurements allowed characterization of electron transfer processes within such an assembly and to demonstrate for the first time that a Co$^I$ species is formed as the entry into the light-driven H$_2$ evolution mechanism of a dye-sensitized photocathode. This co-grafted noble-metal free H$_2$-evolving photocathode architecture displays similar performances to its covalent dye-catalyst counterpart based on the same catalytic moiety. Post-operando time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis of these photoelectrodes after extensive photoelectrochemical operation suggested decomposition pathways of the dye and triazole linkage used to graft the catalyst onto NiO, providing grounds for the design of optimized molecular DS-PEC components with increased robustness upon turnover.

Domaines

Matériaux Catalyse
Fichier principal
Vignette du fichier
c8sc00899j.pdf (1.89 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

cea-01884495 , version 1 (01-10-2018)

Identifiants

Citer

Nicolas Kaeffer, Christopher D. Windle, Romain Brisse, Corinne Gablin, Didier Léonard, et al.. Insights into the mechanism and aging of a noble-metal free H2-evolving dye-sensitized photocathode. Chemical Science, 2018, 9 (32), pp.6721 - 6738. ⟨10.1039/c8sc00899j⟩. ⟨cea-01884495⟩
115 Consultations
182 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More