Wu Kun, Liu Xin-Yi, Cheng Pei-Wen, Huang Yong-Liang, Zheng Ji, Xie Mo, Lu Weigang, Li Dan
College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University, Guangzhou, Guangdong 510632, P.R. China.
Department of Chemistry, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China.
J Am Chem Soc. 2023 Aug 30;145(34):18931-18938. doi: 10.1021/jacs.3c05585. Epub 2023 Aug 17.
Interfacial charge transfer on the surface of heterogeneous photocatalysts dictates the efficiency of reactive oxygen species (ROS) generation and therefore the efficiency of aerobic oxidation reactions. Reticular chemistry in metal-organic frameworks (MOFs) allows for the rational design of donor-acceptor pairs to optimize interfacial charge-transfer kinetics. Herein, we report a series of isostructural -topology Ni-MOFs (termed , , , and ) with linearly bridged bipyrazoles as organic linkers. These crystalline Ni-MOFs can maintain their structural integrity in 7 M NaOH at 100 °C for 24 h. Experimental studies reveal that linker engineering by tuning the electron-accepting capacity of the pyrazole-bridging units renders these Ni-MOFs with significantly improved charge separation and transfer efficiency under visible-light irradiation. Among them, the one containing a benzoselenadiazole unit () exhibits the best photocatalytic performance in the aerobic oxidation of benzylamines with a conversion rate of 99% in 24 h. Recycling experiments were carried out to confirm the stability and reusability of as a robust heterogeneous catalyst. Significantly, the systematic modulation of the electron-accepting capacity of the bridging units in donor-acceptor-donor MOFs provides a new pathway to develop viable noble-metal-free heterogeneous photocatalysts for aerobic oxidation reactions.
异质光催化剂表面的界面电荷转移决定了活性氧（ROS）生成的效率，进而决定了需氧氧化反应的效率。金属有机框架（MOF）中的网状化学使得能够合理设计供体-受体对，以优化界面电荷转移动力学。在此，我们报道了一系列具有线性桥联双吡唑作为有机连接体的同构拓扑Ni-MOF（分别称为 、 、 和 ）。这些结晶态的Ni-MOF在100℃的7M NaOH中可保持其结构完整性24小时。实验研究表明，通过调节吡唑桥联单元的吸电子能力进行连接体工程，可使这些Ni-MOF在可见光照射下具有显著提高的电荷分离和转移效率。其中，含有苯并硒二唑单元的Ni-MOF（ ）在苄胺的需氧氧化中表现出最佳的光催化性能，24小时内转化率为99%。进行了循环实验以证实 作为一种稳健的多相催化剂的稳定性和可重复使用性。值得注意 的是，对供体-受体-供体MOF中桥联单元吸电子能力的系统调节为开发用于需氧氧化反应的可行的无贵金属多相光催化剂提供了一条新途径。
