金属有机骨架（MOF）单层膜作为一类新型的单层膜，具有比表面积大、结构可调、超薄且独特的分子排列、扩散路径短、高度暴露的活性位点以及无限且有序的多孔结构等特点，在分离、传感、催化及能量存储等领域具有良好的应用前景。然而，MOF单层膜的制备仍然是一个很大的挑战，在MOF单层膜中引入官能团更是鲜少报道。在这一工作中，我们报告了首个厘米级横向尺寸的、光可切换的、自支撑的MOF单层膜。该膜是由表面接枝功能性聚合物刷的MOF纳米粒子在水−空气界面自组装形成的。这种自组装MOF单层（SAMM）膜的厚度极薄（~220或50 nm），且具有高的MOF负载量（85 wt %），在365 nm紫外光和白光交替照射下表现出显著的可逆光切换特性。此外，基于这种具有光切换性质的MOF单层膜，我们制备了一种光门控离子纳米通道器件。这一器件实现了离子通量的可逆的“OFF−ON”变化，在光电转换领域具有广阔的应用前景。这一研究为设计大面积、自支撑的功能性MOF单层膜提供了一种新方法。

相关成果发表在《ACS Appl. Nano Mater.》上，第一作者是博士研究生肖洁。以上研究工作得到国家自然科学基金项目、我所创新特区组启动基金、兴辽英才计划等项目的支持。

Photoswitchable Nanoporous Metal−Organic Framework Monolayer Film for Light-Gated Ion Nanochannel

Jie Xiao, Zhenqiang Shi, Muyu Cong, Dongdong Wang, Haijuan Qin, Qiongya Li, Wenqi Lu, Zhimou Guo, Xinmiao Liang*, Guangyan Qing*

ACS Appl. Nano Mater., 2023, DOI: 10.1021/acsanm.2c05200.

Two-dimensional metal–organic framework (MOF) monolayer films, which can be considered as large-area, periodically ordered thin films with atom- or single-unit thickness, have attracted extensive attention due to their special properties and wide range of potential applications. However, the preparation of MOF monolayer films is still a great challenge, and the introduction of functional groups into MOF monolayer films is seldom reported. Here, we report the first centimeter-scale, photo-switchable, free-standing MOF monolayer film formed by self-assembly of poly(methyl methacrylate-co-acrylamidoazobenzene)–coated MOF nanoparticles at the water–air interface. This self-assembled MOF monolayer film is extremely thin (~220 or 50 nm) and has a high MOF loading (85 wt %), while exhibiting remarkable reversible photoswitching properties under alternating exposure to 365 nm UV and white light. Inspired by this, a light-gated ion nanochannel device is fabricated, which enables reversible "OFF–ON" changes of the ionic flux and has promising applications in the field of photoelectric conversion. This provides a modular route to design large-area, free-standing functional MOF monolayer films.