General Scheme for Oxidative Quenching of a Copper Bis-Phenanthroline Photosensitizer for Light-Driven Hydrogen Production

A new, general reaction scheme for photocatalytic hydrogen production is presented based on oxidative quenching of a homoleptic copper(I) bis‐1,10‐phenanthroline photosensitizer (PS) by 1‐methyl‐4‐phenyl‐pyridinium (MPP+) as the electron relay and subsequent regeneration of the so formed copper(II)...

Full description

Saved in:
Bibliographic Details
Published in:ChemSusChem 2016-07, Vol.9 (13), p.1719-1726
Main Authors: Windisch, J., Orazietti, M., Hamm, P., Alberto, R., Probst, B.
Format: Article
Language:English
Subjects:
1-Methyl-4-phenylpyridinium - chemistry
Catalysis
Catalysts
Copper
Copper - chemistry
Hydrogen - chemistry
Hydrogen production
Light
Organometallic Compounds - chemistry
Oxidation-Reduction
oxidative quenching
Phenanthrolines - chemistry
Photocatalysis
Photochemical Processes
Photosensitizing Agents - chemistry
Quenching
reaction mechanisms
Reduction
Relay
time-resolved spectroscopy
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A new, general reaction scheme for photocatalytic hydrogen production is presented based on oxidative quenching of a homoleptic copper(I) bis‐1,10‐phenanthroline photosensitizer (PS) by 1‐methyl‐4‐phenyl‐pyridinium (MPP+) as the electron relay and subsequent regeneration of the so formed copper(II) complex by a sacrificial electron donor. Electron transfer from the relay to various cobalt based water reduction catalysts and subsequent H2 production was shown to close the catalytic cycle. Transient absorption experiments unambiguously confirmed the proposed pathway, both the oxidative quenching and subsequent regeneration of oxidized PS. Photocatalytic test runs further confirmed the role of MPP+ and up to 10 turnovers were achieved in the relay. The performance limiting factor of the system was shown to be the decomplexation of the copper PS. Quantum yields of the system were 0.03 for H2 production, but 0.6 for MPP. formation, clearly indicating that unproductive pathways still prevail. Changing the direction! Oxidative quenching of a homoleptic copper phenanthroline photosensitizer enables a very general scheme for photocatalytic proton reduction. 1‐Methyl‐4‐phenylpyridinium serves as a reversible electron relay between the excited copper dye and several water reduction catalysts. The oxidized copper dye is subsequently regenerated by a sacrificial agent to close the catalytic cycle.
ISSN:1864-5631
1864-564X
DOI:10.1002/cssc.201600422