近日，复旦大学赵东元团队研究了具有中空结构的单晶介孔金属-有机骨架的分层工程。2025年4月21日，《美国化学会杂志》发表了这一成果。

尽管分级结构的优越性推动了广泛的应用需求，但由于单晶和可控分级结构之间的固有竞争和矛盾，在长程有序单晶中建立分级结构仍然是一个艰巨的挑战。研究组展示了一种生长和离解动力学协同策略，用于合成具有分级结构的中空单晶介孔金属-有机框架（meso-MOF）家族。该方法采用双模板方法，集成了硬模板和软模板。

通过调节HCl/CH₃COOH比，可以调节反应体系的pH值，以调节作为形成中空结构的硬模板的酸敏种子的离解动力学，同时改变二元酸的浓度，以控制介观MOF壳的生长动力学。可以有效地平衡保持单一结晶度和实现明确界定的层次结构之间的竞争。在两种界面动力学的驱动下，研究组成功获得了八面体meso-MOF纳米粒子，该纳米粒子不仅具有明确的中空结构，具有精确可控的中空尺寸（约81-1120nm）和可调的壁厚（约28.6-61.3nm），而且保持了其单晶完整性。

具体而言，种子的离解动力学决定了中空结构的形成，而单晶介观MOF壳的生长动力学确保了均匀的覆盖和结构完整性。基于这一策略，研究组进一步开发了一系列具有分级纳米结构的新型中空介观MOF，包括中空开胶囊介观MOF、二维中空介观MOFs、中空层间结构介观MOFs和宏观-中观-微观三模态多孔MOFs等。

附：英文原文

Title: Hierarchical Engineering of Single-Crystalline Mesoporous Metal–Organic Frameworks with Hollow Structures

Author: Zirui Lv, Minchao Liu, Yi Yang, Tianhao Chen, Wenyu Yang, Yijin Wang, Zaiwang Zhao, Kun Lan, Tiancong Zhao, Qiaowei Li, Xiaomin Li, Dongyuan Zhao

Issue&Volume: April 21, 2025

Abstract: Although the superiority of hierarchical structure has driven extensive demand for applications, establishing hierarchy in a long-range-ordered single crystal remains a formidable challenge due to the inherent competition and contradiction between single crystallinity and controllable hierarchical structure. Herein, we demonstrate a growth and dissociation kinetics cooperative strategy for synthesizing a family of hollow single-crystalline mesoporous metal–organic frameworks (meso-MOFs) with hierarchical structures. The approach employs a dual-template method, integrating both hard and soft templates. By adjusting the HCl/CH3COOH ratio, the reaction system’s pH can be tuned to regulate the dissociation kinetics of the acid-sensitive seeds serving as hard templates for the formation of hollow structure, while simultaneously modifying the concentration of the dual acids to control the growth kinetics of meso-MOF shells. The competition between maintaining a single crystallinity and achieving a well-defined hierarchical structure can be effectively balanced. Driven by the two interfacial kinetics, we successfully obtained the octahedral meso-MOF nanoparticles that not only exhibit a well-defined hollow structure with precisely controllable hollow size (～81–1120 nm) and tunable wall thickness (～28.6–61.3 nm) but also retain their single-crystal integrity. Specifically, the dissociation kinetics of seeds governed the formation of  hollow structures, while the growth kinetics of single-crystalline meso-MOF shells ensured uniform coverage and structural integrity. Based on this strategy, we further developed a series of novel hollow meso-MOFs with hierarchical nanostructures, including hollow open-capsule meso-MOFs, 2D hollow meso-MOFs, hollow interlayer-structured meso-MOFs, macro-meso-micro trimodal porous MOFs, and so on.

DOI: 10.1021/jacs.5c01415

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c01415