Constructing two-dimensional covalent organic frameworks (2DCOFs) with a desirable crystalline structure and morphology is promising but remains a significant challenge. Herein, we report self-templated synthesis of uniform hollow spherical 2DCOFs based on 2,3,6,7,10,11-hexakis(4-aminophenyl) triphenylene. A detailed time-dependent study of hollow sphere formation reveals an intriguing transformation from initial homogeneous solid spheres into uniform hollow spheres with the Ostwald ripening mechanism. Impressively, the resultant spherical 2DCOFs are composed of high crystallinity nanosheets and even hexagonal single crystals, as demonstrated by transmission electron microscopy. Thanks to its uniform morphology and high crystallinity, the pore volume of the obtained 2DCOFs is up to 1.947 cm³ g^–1, which makes it function as superior nanocarriers for efficient controlled drug delivery. This result provides an avenue for improving COFs’ performance by regulating their morphology.

中文翻译：

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用于药物递送的基于苯并菲的均匀空心球形二维共价有机骨架的自模板合成

构建具有理想晶体结构和形态的二维共价有机框架 (2DCOF) 很有希望，但仍然是一项重大挑战。在此，我们报告了基于 2,3,6,7,10,11-六（4-氨基苯基）苯并菲的均匀空心球形 2DCOF 的自模板合成。对空心球形成的详细时间依赖性研究揭示了从最初的均匀实心球到具有奥斯特瓦尔德成熟机制的均匀空心球的有趣转变。令人印象深刻的是，如透射电子显微镜所证明的，由此产生的球形 2DCOF 由高结晶度纳米片甚至六方单晶组成。由于其均匀的形貌和高结晶度，所获得的 2DCOF 的孔体积高达 1.947 cm ³ g ^–1，这使其成为高效控制药物输送的优质纳米载体。该结果为通过调节其形态来改善 COF 的性能提供了途径。