Abstract:
ZIF-7 crystals were in situ grown on graphene oxide (GO) by three synthetic routes, and the resulting graphene oxide/ZIF-7 composites (GZR-
n) were characterized by PXRD, FTIR, SEM, TEM, and N
2 isothermal adsorption-desorption. The effects of the synthetic routes on the growth, crystallinity, microscopic morphology and pore size of ZIF-7 crystals on GO were investigated. ZIF-7 crystals were grown on the surface and sheet of GO by three synthetic routes. The crystallinity of ZIF-7 crystals on GZR-
n was significantly enhanced and some were wrapped by GO. The shape and size of ZIF-7 crystals growing on GZR-
n were modulated by the synthesis routes. In particular, the ZIF-7 crystals are spherical particle with a diameter of 50 nm in GZR-II. For GZR-I and GZR-III, the ZIF-7 crystals are regular polyhedron with a size of 200 nm. Additional, their dispersion properties in solvents, adsorption properties and kinetic simulations for organic dyes were explored. GZR-
n show good dispersion in methanol and chloroform. Compared with ZIF-7 crystals, the adsorption capacities of GZR-I, GZR-II and GZR-III for methylene blue are increased by 226%, 302% and 278%, respectively. The kinetic simulations indicate that the adsorption of GZR-II and GZR-III for methylene blue are chemisorption and that of GZR-I is physical adsorption.