Rapid and Cost-Effective Synthesis of Nanosized Zeolitic Imidazolate Framework-7 with N,N′-Dimethylformamide as Solvent and Metal Acetate Salt as Metal Source

In this study, a new method was developed for the rapid and cost-effective synthesis of nanosized zeolitic imidazolate framework-7 (ZIF-7) nanocrystals with a high yield and a low molar ratio of benzimidazole ligand to metal salt (2:1) by using N , N′- dimethylformamide (DMF) as the solvent and zinc acetate dihydrate (Zn(OAc) 2 ⋅2 H 2 O) as the metal source. The synthesized ZIF-7 nanocrystals have a size of approximately 50–80 nm, and tend to aggregate or become intergrown to form irregular nanoparticles of about 200–300 nm in size. The morphology and yield of the ZIF-7 nanocrystals can be tuned easily by changing the synthetic parameters such as the composition of the solvent and concentrations of reagents. The synthesized ZIF-7 nanocrystals exhibit good thermal and chemical stability, CO 2 capture capability, and fluorescent properties. Remarkably, we find that the synthetic strategy developed here can be extended to the syntheses of other kinds of ZIFs including ZIF-69 and ZIF-90. This study offers a new, simple synthetic strategy for the high-yield preparation of ZIF materials. Graphical Zeolitic nanocrystal control : We have developed a new method for the rapid and cost-effective synthesis of nanosized zeolitic imidazolate framework (ZIF-7) nanocrystals with a high yield and a stoichiometric molar ratio of ligand to metal salt (2:1) by using N , N ′-dimethylformamide (DMF) as the solvent and zinc acetate as the metal source (see figure). This strategy can also be extended to the synthesis of ZIF-69 and ZIF-90.