Lu Jia-Ni, Liu Jing-Jing, Dong Long-Zhang, Lin Jiao-Min, Yu Fei, Liu Jiang, Lan Ya-Qian
Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials, Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, P. R. China.
School of Chemistry, South China Normal University, Guangzhou, 510006, P. R. China.
Angew Chem Int Ed Engl. 2023 Sep 4;62(36):e202308505. doi: 10.1002/anie.202308505. Epub 2023 Jul 27.
Photocatalytic synthesis of hydrogen peroxide (H O ) is a potential clean method, but the long distance between the oxidation and reduction sites in photocatalysts hinders the rapid transfer of photogenerated charges, limiting the improvement of its performance. Here, a metal-organic cage photocatalyst, Co (L-CH ) , is constructed by directly coordinating metal sites (Co sites) used for the O reduction reaction (ORR) with non-metallic sites (imidazole sites of ligands) used for the H O oxidation reaction (WOR), which shortens the transport path of photogenerated electrons and holes, and improves the transport efficiency of charges and activity of the photocatalyst. Therefore, it can be used as an efficient photocatalyst with a rate of as high as 146.6 μmol g h for H O production under O -saturated pure water without sacrificial agents. Significantly, the combination of photocatalytic experiments and theoretical calculations proves that the functionalized modification of ligands is more conducive to adsorbing key intermediates (*OH for WOR and *HOOH for ORR), resulting in better performance. This work proposed a new catalytic strategy for the first time; i.e., to build a synergistic metal-nonmetal active site in the crystalline catalyst and use the host-guest chemistry inherent in the metal-organic cage (MOC)to increase the contact between the substrate and the catalytically active site, and finally achieve efficient photocatalytic H O synthesis.
光催化合成过氧化氢（H₂O₂）是一种潜在的清洁方法，但光催化剂中氧化和还原位点之间的长距离阻碍了光生电荷的快速转移，限制了其性能的提升。在此，通过将用于氧还原反应（ORR）的金属位点（Co位点）与用于过氧化氢氧化反应（WOR）的非金属位点（配体的咪唑位点）直接配位，构建了一种金属有机笼状光催化剂Co₂(L-CH₃)₄，这缩短了光生电子和空穴的传输路径，提高了电荷传输效率和光催化剂的活性。因此，它可作为一种高效的光催化剂，在无氧饱和纯水且无牺牲剂的条件下，H₂O₂生成速率高达146.6 μmol g⁻¹ h⁻¹。值得注意的是，光催化实验和理论计算相结合证明，配体的功能化修饰更有利于吸附关键中间体（WOR中的OH和ORR中的HOOH），从而产生更好的性能。这项工作首次提出了一种新的催化策略；即在晶体催化剂中构建协同的金属-非金属活性位点，并利用金属有机笼（MOC）固有的主客体化学来增加底物与催化活性位点之间的接触，最终实现高效的光催化H₂O₂合成。
