Effect of the cobalt and zinc ratio on the preparation of zeolitic imidazole frameworks (ZIFs): synthesis, characterization and supercapacitor applications

Dalton Trans. 2019 Oct 7;48(39):14808-14819. doi: 10.1039/c9dt03306h.

Abstract

The effect of the cobalt nitrate hexahydrate/zinc nitrate hexahydrate molar ratio on the physicochemical features of the zeolitic imidazole framework (ZIF) was studied. ZIFs were prepared by using 2-methyl imidazole as the cross-linker at room temperature without any additives in methanol solution. From the obtained results, it was found that the Co/Zn ratio has a tremendous impact on the surface area, crystallinity, pore diameter and electrochemical performance of ZIFs. Upon increasing the Co/Zn content the surface area, pore volume, pore diameter and specific capacitance decreased. The maximum BET surface area was found to be 1043.65 m2 g-1 for ZIF Co/Zn = 0.5. The present work offers a new intuition in relation to the role of the Co/Zn ratio in the synthesis method of ZIFs.