A review of graphene-oxide/metal–organic framework composites materials: characteristics, preparation and applications

Graphene-oxide (GO) is an oxidized derivative of graphene. GO has a large number of oxygen-containing functional groups, including hydroxyl, carboxyl, and epoxy groups. The introduction of these groups makes its physical and chemical properties more complicated. For example, although GO films are impermeable to other liquids and even gases, they exhibit abnormally high permeance of water through the GO film. As a three-dimensional hollow material, metal–organic frameworks (MOFs) have a very large specific surface area and pore volume, and have a wide range of applications in catalysis, adsorption, and separations. Combining GO with MOFs can alter the distance between the layers of the GO to affect the transport and screening of specific molecules. This gives composites many potential applications in areas such as gas treatment and water treatment. This review summarizes the current status of GO/MOF composites, expanding on the following aspects: (1) We begin by reviewing the current status of research on GO and MOF with a focus on the physical properties. The mechanical strength of single-layer graphene is very weak, and in most solvents, GO spontaneously aggregates and is very difficult to effectively disperse. On the other hand, MOFs have high specific surface area, high crystallinity, and high porosity, but relatively low stability. Their relative instability greatly limited their practical applications. The formation of GO/MOF composites can take advantage of desirable properties of both material types, while improving their physical characteristics. (2) We next review the characteristics, preparation and applications of GO/MOF composites. At present, various GO/MOF composite materials, such as GO/ZIF-8, GO/MOF-5 have been prepared by in-situ synthesis and other methods. They are widely used in gas adsorption and separation, wastewater treatment applications, and molecular sieve applications. (3) We conclude this review by summarizing the opportunities for achieving composites materials with hydrophilic, antifouling, high-throughput, and high-repulsion properties by efficient, controllable, and low-cost methods. As GO/MOF technology improves, we suggest that these versatile materials have additional prospective applications in other areas, including as materials for medical applications.