Computation-based regulation of excitonic effects in donor-acceptor covalent organic frameworks for enhanced photocatalysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37248231.
- Also identified by DOI 10.1038/s41467-023-38884-w and PMC identifier 10227069.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The strong excitonic effects widely exist in polymer-semiconductors and the large exciton binding energy (E<sub>b</sub>) seriously limits their photocatalysis. Herein, density functional theory (DFT) calculations are conducted to assess band alignment and charge transfer feature of potential donor-acceptor (D-A) covalent organic frameworks (COFs), using 1,3,5-tris(4-aminophenyl)triazine (TAPT) or 1,3,5-tris(4-aminophenyl)benzene (TAPB) as acceptors and tereph-thaldehydes functionalized diverse groups as donors. Given the discernable D-A interaction strengths in the D-A pairs, their E<sub>b</sub> can be systematically regulated with minimum E<sub>b</sub> in TAPT-OMe. Guided by these results, the corresponding D-A COFs are synthesized, where TAPT-OMe-COF possesses the best activity in photocatalytic H<sub>2</sub> production and the activity trend of other COFs is associated with that of calculated E<sub>b</sub> for the D-A pairs. In addition, further alkyne cycloaddition for the imine linkage in the COFs greatly improves the stability and the resulting TAPT-OMe-alkyne-COF with a substantially smaller E<sub>b</sub> exhibits ~20 times higher activity than the parent COF.