Design of a novel Ag-MOF@GO composite with a high specific surface area and structural stability for the efficient removal of malachite green

Abstract

In this study, a silver metal–organic framework (Ag-MOF) was immobilized on graphene oxide (GO) sheets via an ultrasonication process. The Ag-MOF@GO composite showed enhanced physicochemical properties, including an improved surface area and lower agglomeration, as confirmed using characterization techniques such as X-ray diffraction (XRD), the Brunauer–Emmett–Teller (BET) method, and scanning electron microscopy (SEM). Malachite green (MG) is a typical cationic dye, which can be toxic, cause environmental damage and threaten human health. Therefore, the adsorption capacities of Ag-MOF and Ag-MOF@GO for the MG dye were also evaluated at room temperature. Kinetic analysis revealed a significant increase in the adsorption capacity and rate of adsorption of Ag-MOF@GO compared with Ag-MOF. The addition of GO increases the surface area of Ag-MOF@GO and reduces the agglomeration effect, resulting in an improved adsorption capacity. Ag-MOF@GO showed a greater than 90% regenerability after three cycles.