Microstructure controlling and dielectric relaxation dynamic of ZIF-8 synthesized in different solvents

Deeply understanding the structure and electrical properties of ZIF-8 is very important due to many practical applications of porous materials. We present the crystal structure and microstructure details of ZIF-8 prepared in three different solvents. The solvents play an important role on grain growth of ZIF-8, furthermore, a small fraction of monoclinic phase can be found in the ZIF-8s prepared in water or in amonium hydroxide. Radio-frequency dielectric and impedance spectra studies of dynamic dielectric response of ZIF-8s indicate two additional dielectric relaxation processes associated with the introduced water molecules in as-prepared samples. The dielectric response can be described by the combination of the dc conductivity, the universal dielectric response, the Cole-Cole relation and intrinsic response. The results exhibit the solvents make an important influence on the electrical properties due to different contents water in ZIF-8s. Our results will pave a way to modify the dielectric property of ZIF-based dielectrics in radio-frequency applications.