Lin Zeheng, Han Zhaojun, O'Connell George E P, Wan Tao, Zhang Ding, Ma Zhipeng, Chu Dewei, Lu Xunyu
Particles and Catalysis Research Group, School of Chemical Engineering, The University of New South Wales, Kensington, New South Wales, 2052, Australia.
CSIRO Manufacturing, 36 Bradfield Road, Lindfield, New South Wales, 2070, Australia.
Adv Mater. 2024 May;36(19):e2312797. doi: 10.1002/adma.202312797. Epub 2024 Feb 7.
The integration of graphene and metal-organic frameworks (MOFs) has numerous implications across various domains, but fabricating such assemblies is often complicated and time-consuming. Herein, a one-step preparation of graphene-MOF assembly is presented by directly impregnating vertical graphene (VG) arrays into the zeolitic imidazolate framework (ZIF) precursors under ambient conditions. This approach can effectively assemble multiple ZIFs, including ZIF-7, ZIF-8, and ZIF-67, resulting in their uniform dispersion on the VG with adjustable sizes and shapes. Hydrogen defects on the VG surface are critical in inducing such high-efficiency ZIF assembly, acting as the reactive sites to interact with the ZIF precursors and facilitate their crystallisation. The versatility of VG-ZIF-67 assembly is further demonstrated by exploring the process of MOF amorphization. Surprisingly, this process leads to an amorphous thin-film coating formed on VG (named VG-IL-amZIF-67), which preserves the short-range molecular bonds of crystalline ZIF-67 while sacrificing the long-range order. Such a unique film-on-graphene architecture maintains the essential characteristics and functionalities of ZIF-67 within a disordered arrangement, making it well-suited for electrocatalysis. In electrochemical oxygen reduction, VG-IL-amZIF-67 exhibits exceptional activity, selectivity, and stability to produce HO in acid media.
石墨烯与金属有机框架（MOF）的整合在各个领域都有诸多影响，但制备此类组件往往复杂且耗时。在此，通过在环境条件下将垂直石墨烯（VG）阵列直接浸渍到沸石咪唑酯框架（ZIF）前驱体中，提出了一种一步法制备石墨烯-MOF组件的方法。这种方法可以有效地组装多种ZIF，包括ZIF-7、ZIF-8和ZIF-67，使其在VG上均匀分散，尺寸和形状可调。VG表面的氢缺陷对于诱导这种高效的ZIF组装至关重要，它作为与ZIF前驱体相互作用并促进其结晶的反应位点。通过探索MOF非晶化过程，进一步证明了VG-ZIF-67组件的多功能性。令人惊讶的是，这个过程会在VG上形成一层非晶薄膜涂层（命名为VG-IL-amZIF-67），它保留了结晶ZIF-67的短程分子键，同时牺牲了长程有序性。这种独特的石墨烯上薄膜结构在无序排列中保持了ZIF-67的基本特性和功能，使其非常适合电催化。在电化学氧还原中，VG-IL-amZIF-67在酸性介质中表现出卓越的活性、选择性和稳定性以产生HO。
