武汉大学张先正团队开发出用于红外光驱动CO₂还原的大π-共轭金属有机框架。相关研究成果于2022年1月14日发表在国际知名学术期刊《美国化学会杂志》。

通过近红外（NIR）光激发传统光催化剂仍然具有挑战性。使用近红外光响应材料进行光化学还原的尝试通常会由于极窄的带隙而受到不对位带位置的影响。

该文中，研究人员报道了大π-共轭有机半导体工程金属-有机骨架（MOF）可以产生具有高光催化活性的近红外光驱动CO₂还原催化剂。合成了一系列具有逐渐增加的大环π-共轭单元的介孔MOFs，用于调节光吸附范围和催化性能。这些MOFs以单晶形式的实现揭示了组成有机半导体单元和金属簇的相同拓扑结构和精确的空间排列。

此外，超快光谱研究证实了电荷分离态的形成和光激发动力学的机制。综合X射线光电子能谱和原位电子顺磁共振研究，验证了近红外光驱动CO₂还原的MOFs内光诱导电子转移途径。具体而言，四（4-羧基联苯）萘卟啉MOF（TNP-MOF）光催化剂在近红外光照射下表现出前所未有的高CO₂还原率，超过6630μmol h^–1 g^–1，760和808 nm处的表观量子效率（AQE）分别超过2.03%和1.11%。光催化性能优于所有其他MOF基光催化剂，甚至优于可见光驱动的MOF基催化剂。

附：英文原文

Title: Large π-Conjugated Metal–Organic Frameworks for Infrared-Light-Driven CO2 Reduction

Author: Jin-Yue Zeng, Xiao-Shuang Wang, Bo-Ru Xie, Qian-Ru Li, Xian-Zheng Zhang

Issue&Volume: January 14, 2022

Abstract: It remains challenging to excite traditional photocatalysts through near-infrared (NIR) light. Attempts to use NIR-light-response materials for photochemical reduction usually suffer from inapposite band position due to extremely narrow band gaps. Here, we report that large π-conjugated organic semiconductor engineered metal–organic framework (MOF) can result in NIR-light-driven CO2 reduction catalyst with high photocatalytic activity. A series of mesoporous MOFs, with progressively increased macrocyclic π-conjugated units, were synthesized for tuning the light adsorption range and catalytic performance. Attainment of these MOFs in single-crystal form revealed the identical topology and precise spatial arrangements of constituent organic semiconductor units and metal clusters. Furthermore, the ultrafast spectroscopic studies confirmed the formation of charge separation state and the mechanism underlying photoexcited dynamics. This combined with X-ray photoelectron spectroscopy and in situ electron paramagnetic resonance studies verified the photoinduced electron transfer pathway within MOFs for NIR-light-driven CO2 reduction. Specifically, tetrakis(4-carboxybiphenyl)naphthoporphyrin) MOF (TNP-MOF) photocatalyst displayed an unprecedentedly high CO2 reduction rate of over 6630 μmol h–1 g–1 under NIR light irradiation, and apparent quantum efficiencies (AQE) at 760 and 808 nm were over 2.03% and 1.11%, respectively. The photocatalytic performance outperformed all the other MOF-based photocatalysts, even visible-light-driven MOF-based catalysts.

DOI: 10.1021/jacs.1c10110

Source: https://pubs.acs.org/doi/10.1021/jacs.1c10110