Graphene and MOF assembly: Manufacturing and functional derivation enhanced by MOF amorphization

The integration of graphene and metal organic frameworks (MOFs) has many impacts in various fields, but manufacturing such components is often very complex and time-consuming. Here, a method for one-step preparation of graphene MOF components is proposed by directly impregnating a vertical graphene (VG) array into a zeolite imidazolate framework (ZIF) precursor under environmental conditions. This method can effectively assemble multiple ZIFs, including ZIF-7, ZIF-8, and ZIF-67, so that they are evenly dispersed on VG and have adjustable size and shape. The hydrogen defects on the VG surface are crucial for inducing efficient ZIF assembly, serving as reaction sites that interact with ZIF precursors and promote their crystallization. By exploring the amorphization process of MOF, the multifunctionality of VG-ZIF-67 assembly was further demonstrated. Surprisingly, this process resulted in the formation of an amorphous thin film coating on VG (known as VG IL amZIF-67), which retained the short-range molecular bonds of crystalline ZIF-67 while sacrificing long-range ordering. This unique graphene film structure maintains the basic characteristics and functions of ZIF-67 in a disordered arrangement, making it highly suitable for electrocatalysis. VG-IL-amZIF-67 exhibits excellent activity, selectivity, and stability in electrochemical oxygen reduction when producing H2O2 in acidic media.