Colloid-chemical fabrication of graphene-oxide–wrapped zeolite crystals

Graphene oxide (GO) is a thin laminate that exhibits high flexibility, stiffness, and hydrophilicity. The combination of these properties makes GO promising for application as a colloidal wrapping agent. In this study, we wrap MFI zeolite nanocrystals with GO laminates through a colloid-chemical approach. Electrically repulsive MFI zeolite nanocrystals and GO laminates disperse separately in water in the absence of NH 4 Cl, whereas GO laminates wrap MFI zeolite nanocrystals in the presence of an appropriate amount of NH 4 Cl. The wrapping structure in aqueous solution can be controlled by controlling the concentration of NH 4 Cl and amount of GO laminates. The wrapping consists of three stages—proximity configuration, assembly wrapping, and crystal wrapping—depending on the amount on NH 4 Cl. GO wrapping improves the dispersibility of MFI zeolite nanocrystals for more than two weeks and preserves the inherent porosity of MFI zeolite.