Preparation and size control of zif-8 particles in aqueous solution

We report here the room-temperature synthesis of zeolitic imidazolate framework-8 (ZIF-8) in aqueous system. Our synthesis method is a simple and straightforward that ZIF-8 crystals were prepared by mixing 2-methylimidazole (Hmim) with zinc nitrate hexahydrate (Zn(NO3)2 6H2O ; Zn) in deionized water. We tried to prepare ZIF-8 crystals at different molar ratio of Hmim to Zn. In addition, we examined the effect of Hmim concentration on the particles size. The products prepared at Hmim/Zn molar ratios of above 40 were assigned to SOD type structure. It suggests that the synthesis of ZIF-8 crystals in water requires adding an excess of Hmim. At high Hmim concentration, the morphology of the products had a shape reflected the SOD type topology. The synthesized ZIF-8 particle size decreased with increasing the concentration of Hmim. The average particle size varied from 100 nm to 3 mum.