Regulating Excitonic Effects in Covalent Organic Frameworks to Promote Free Charge Carrier Generation
Regulating Excitonic Effects in Covalent Organic Frameworks to Promote Free Charge Carrier Generation
复制标题
DOI：
10.1021/acscatal.2c02173
复制
发表时间：
2022-08-05
期刊：
影响因子：
12.9
通讯作者：
Chen, Yong
中科院分区：
文献类型：
--
作者：
Liu, Fulai;He, Yanyan;Chen, Yong
在有机半导体中，光生电子与空穴之间的库仑相互作用引起的强激子效应严重阻碍了自由载流子的产生。在这里，我们报告了一个内置的控制的供体-受体（D-A）的相互作用策略，以调节激子的影响内苯并二噻唑桥连的共价有机框架（Tz-COFs）。理论计算和超快光谱表明，Tz-COFs中的D-A相互作用通过这种内在的控制策略可以加速激子的解离，从而产生更多长寿命的光生载流子用于光氧化还原反应。结果表明，优化后的Tz-COF-3光催化放氢活性高达43.2 mmol g（-1）h（-1），在420 nm处的表观量子产率为6.9%。这项工作从激子方面指导COFs的发展。
Strong excitonic effects, induced by the Coulombic interactions between photogenerated electrons and holes, seriously hinder the generation of free charge carriers in organic semiconductors for conducting photocatalysis. Herein, we report a built-in control of the donor-acceptor (D-A) interaction strategy to regulate excitonic effects within benzobisthiazole-bridged covalent organic frameworks (Tz-COFs). Theoretical calculation and ultrafast spectroscopy reveal that strengthening D-A interactions by this built-in control strategy in Tz-COFs can accelerate exciton dissociation, thus generating more long-lived photo-generated charge carriers for photoredox reactions. As a result, the optimized Tz-COF-3 exhibits high photocatalytic H2 evolution activity as high as 43.2 mmol g(-1) h(-1), with an apparent quantum yield of 6.9% at 420 nm. This work guides the development of COFs from excitonic aspects for photocatalysis.