Abstract

Covalent organic frameworks (COFs) have constituted an emerging class of organic photocatalysts showing enormous potential for visible photocatalytic H2 evolution from water. However, suffering from sluggish reaction kinetics, COFs often cooperate with precious metal co-catalysts for essential proton-reducing capability. Here, we synthesize a chiral β-ketoenamine-linked COF coordinated with 10.51 wt% of atomically dispersed Cu(II) as an electron transfer mediator. The enantioselective combination of the chiral COF-Cu(II) skeleton with L-/D-cysteine sacrificial donors remarkably strengthens the hole extraction kinetics, and in turn, the photoinduced electrons accumulate and rapidly transfer via the coordinated Cu ions. Also, the parallelly stacking sequence of chiral COFs provides the energetically favorable arrangement for the H-adsorbed sites. Thus, without precious metal, the visible photocatalytic H2 evolution rate reaches as high as 14.72 mmol h−1 g−1 for the enantiomeric mixtures. This study opens up a strategy for optimizing the reaction kinetics and promises the exciting potential of chiral COFs for photocatalysis.

Chiral covalent organic frameworks are demonstrated to enable the docking of sacrificial electron donors via enantioselective combination, thereby improving oxidative half-reaction kinetics and boosting visible photocatalytic H2 production.

Details

Title
The effect of enantioselective chiral covalent organic frameworks and cysteine sacrificial donors on photocatalytic hydrogen evolution
Author
Weng, Weijun 1 ; Guo, Jia 1   VIAFID ORCID Logo 

 Fudan University, State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Shanghai, China (GRID:grid.8547.e) (ISNI:0000 0001 0125 2443) 
Publication year
2022
Publication date
2022
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2719938845
Copyright
© The Author(s) 2022. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.