By employing a conjugated amine-functionalized dicarboxylic ligand (H₂L = 2,2′-diamino-4,4′-stilbenedicarboxylic acid, H₂SDCA-NH₂), we have successfully synthesized and characterized a porous and visible light responsive zirconium metal–organic framework ([Zr₆O₄(OH)₄(L)₆]·8DMF, denoted as Zr-SDCA-NH₂). This Zr-MOF showed good chemical stability and broad visible light absorption with an absorption edge at about 600 nm. When used as a photocatalyst, Zr-SDCA-NH₂ exhibits visible-light activity for CO₂ reduction with a formate formation rate of 96.2 μmol h⁻¹ mmol_MOF⁻¹, which is higher than the series of reported amine-functionalized Zr-MOFs. Mott–Schottky measurements, photoluminescence study and photocatalytic experiments demonstrated that the Zr₆ oxo cluster through the LMCT process and the organic ligand both contributed to the CO₂ photoreduction. This study indicates that the combination of amino groups and highly conjugated molecules is a feasible and simple strategy to extend light absorption of the organic ligand, which is beneficial for designing a visible light responsive MOF photocatalyst.

中文翻译：

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使用胺官能化的锆金属-有机骨架 提高可见光驱动的CO ₂还原性能†

通过使用共轭胺官能化的二羧酸配体（H ₂ L = 2,2'-二氨基-4,4'-二苯乙烯二羧酸，H ₂ SDCA-NH ₂），我们已经成功地合成并表征了多孔和可见光响应的锆金属-有机骨架（[Zr ₆ O ₄（OH）₄（L）₆ ]·8DMF，表示为Zr-SDCA-NH ₂）。该Zr-MOF显示出良好的化学稳定性和宽的可见光吸收，吸收边缘在约600nm。当用作光催化剂时，Zr-SDCA-NH ₂表现出用于CO ₂还原的可见光活性，甲酸形成速率为96.2μmolh ^-1mmol _MOF ^-1，高于一系列报道的胺官能化Zr-MOF。Mott-Schottky测量，光致发光研究和光催化实验表明，通过LMCT过程形成的Zr ₆羰基簇和有机配体都有助于CO _2的光还原。这项研究表明，氨基和高度共轭的分子的组合是一种可行且简单的策略，可以扩展有机配体的光吸收，这对于设计可见光响应型MOF光催化剂是有益的。