Liu Bin, Cheng Haiyan, Xia Yu, Wang Lei, An Ning, Huang Jingwei, She Houde, Wang Qizhao
Key Laboratory of Eco-Environment-Related Polymer Materials, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
College of Chemistry and Chemical Engineering, Lanzhou Jiaotong University, Lanzhou 730070, Gansu, China.
Inorg Chem. 2025 Jul 28;64(29):14892-14901. doi: 10.1021/acs.inorgchem.5c01416. Epub 2025 Jul 11.
For most organic structures, the donor-acceptor (D-A) effect can effectively regulate the separation efficiency of photogenerated carriers, thereby enhancing the photocatalytic performance. However, the internal correlation between the structure and charge transportation, especially at the molecular level, is insufficiently explored. Herein, Cu(PyCA) (PyCA = pyrazolate-4-carboxaldehyde), tris(4-aminophenyl) amine, and [2,2'-bipyridine]-5,5'-diamine were employed to prepare two metal-covalent organic frameworks (MCOFs), namely, Tap-MCOF and Bpy-MCOF, both of which are D-A-type structure. In accordance, Tap-MCOF exhibits improved conversion of HO and O to HO in the absence of sacrificial agent, achieving the HO production rate of 288.58 μmol g h, which is approximately 2.7-fold higher than that of Bpy-MCOF. It is considered due to the intensified D-A effect within Tap-MCOF, it presents a narrower band gaps and greater separation of photoinduced carriers, compared with that of Bpy-MCOF. The transient photocurrent response intensity of Tap-MCOF is significantly higher than that of Bpy-MCOF, indicating its superior charge separation and transport efficiency. These results not only provide a strategy for manipulating the carrier separation efficiency of photocatalysts at the molecular level but also furnish insights into the effective photocatalytic ORR and WOR transformations of organic semiconducting catalysts.
对于大多数有机结构而言，供体-受体（D-A）效应能够有效调节光生载流子的分离效率，从而提高光催化性能。然而，结构与电荷传输之间的内在关联，尤其是在分子水平上，尚未得到充分探索。在此，采用Cu(PyCA)（PyCA = 吡唑-4-甲醛）、三（4-氨基苯基）胺和[2,2'-联吡啶]-5,5'-二胺制备了两种金属-共价有机框架（MCOF），即Tap-MCOF和Bpy-MCOF，二者均为D-A型结构。相应地，在无牺牲剂的情况下，Tap-MCOF表现出更高的将HO和O转化为HO的效率，实现了288.58 μmol g h的HO产率，这比Bpy-MCOF高出约2.7倍。据认为，由于Tap-MCOF内部的D-A效应增强，与Bpy-MCOF相比，它具有更窄的带隙和更大的光生载流子分离度。Tap-MCOF的瞬态光电流响应强度明显高于Bpy-MCOF，表明其具有卓越的电荷分离和传输效率。这些结果不仅提供了一种在分子水平上调控光催化剂载流子分离效率的策略，还为有机半导体催化剂有效的光催化氧还原反应（ORR）和析氧反应（WOR）转化提供了见解。
