Health & Environmental Research Online (HERO)


Print Feedback Export to File
7903318 
Journal Article 
Molecular triad containing a TEMPO catalyst grafted on mesoporous ITO electrode as photoelectrocatalytic anode for visible light-driven alcohol oxidation 
Odobel, F; Pati, PB; Abdellah, M; Diring, S; Hammarström, L 
2021 
Yes 
ChemSusChem
ISSN: 1864-5631
EISSN: 1864-564X 
English 
33973386 
Photoelectrochemical cell based on a semiconductor is among the most studied approach for artificial photosynthesis. Here, we investigated a recent concept based on the immobilization, on a mesoporous conducting ITO electrode (nano-ITO), of a molecular triad. The triad NDADI-P-Ru-TEMPO contained a ruthenium tris-bipyridine complex (Ru) as photosensitizer, which was connected in one end to 2,2,6,6-tetramethyl-1-piperidine N-oxyl (TEMPO) as alcohol oxidation catalyst, and in the other end to the electron acceptor naphthalene-dicarboxyanhydride-dicarboximide (NDADI). Light irradiation of the molecular triad (NDADI-P-Ru-TEMPO) grafted to nano-ITO performs selective oxidation of para -methoxy benzylalcohol (MeO-BA) to para -methoxy benzaldehyde in a carbonate buffer (pH = 10) with a TON of ~ 150 after 1 hour of photolysis at a bias of 0.4 V vs. SCE and the faradaic efficiency (FE) is found to be of 80±5%. The photophysical study indicates that the photoinduced electron transfer from the Ru complex to NDADI is a slow process and must compete with direct electron injection into ITO to have a better performing system. This work sheds some light on some of the important features to design more efficient molecular systems for the preparation of photoelectrocatalytic cell based on the immobilized on conducting electrode of a "Catalyst-Dye-Acceptor" molecular array.