Clean Donor Oxidation Enhances the H2 Evolution Activity of a Carbon Quantum Dot–Molecular Catalyst Photosystem. Issue 32 (29th June 2016)

• Record Type: Journal Article
• Authors: Martindale, Benjamin C. M.; Joliat, Evelyne; Bachmann, Cyril; Alberto, Roger; Reisner, Erwin
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 32(2016)
• Page Start: 9402
• Page End: 9406
• Publication Date: 2016-06-29
• Subjects: carbon quantum dots -- hydrogen evolution -- molecular catalysis -- photocatalysis -- photosensitizers; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201604355
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Carbon quantum dots (CQDs) are new‐generation light absorbers for photocatalytic H2 evolution in aqueous solution, but the performance of CQD‐molecular catalyst systems is currently limited by the decomposition of the molecular component. Clean oxidation of the electron donor by donor recycling prevents the formation of destructive radical species and non‐innocent oxidation products. This approach allowed a CQD‐molecular nickel bis(diphosphine) photocatalyst system to reach a benchmark lifetime of more than 5 days and a record turnover number of 1094±61 molH2 (molNi ) −1 for a defined synthetic molecular nickel catalyst in purely aqueous solution under AM1.5G solar irradiation. Abstract : Re‐cycling carbon dots : A recyclable ascorbate donor system coupled to clean two‐electron phosphine oxidation circumvents the radical‐mediated decomposition of molecular catalysts that limit sacrificial photocatalytic systems. When paired with a carbon quantum dot light absorber and DuBois‐type nickel catalyst, the resultant hybrid photosystem sustained H2 evolution for 5 days and reached a record TONNi of 1094±61 in aqueous solution under AM1.5G solar irradiation.