In situ growth of microporous ZIF-8 nanocrystals on a macroporous phyllosilicate mineral

Microporous zeolitic imidazolate frameworks (ZIFs) have shown great potential in many application fields. However, the small dimensions of ZIF nanoparticles make them difficult to employ in practical systems. To overcome this problem, a novel and efficient strategy has been developed to immobilize ZIF crystals on a macroporous phyllosilicate mineral. As an example, water-stable ZIF-8 nanocrystals were synthesized and assembled on the dopamine-modified surface of expanded vermiculite using the sequential addition of methanol solutions of Zn(NO3)2·6H2O and 2-methylimidazole. The ZIF-8 nanoparticle-decorated mineral exhibited a dense growth of microporous ZIF-8 nanocrystals of 80 ± 10 nm, resulting in 9.8 wt% of ZIF-8 loading and a BET surface area of 120 m2/g.