Sustainable porous graphene/Co-MOF for the removal of water pollutants: Combined theoretical and experimental studies

In this research, a novel composite of maleic acid derived 3D porous graphene and zeolatic imidazolate framework (ZIF-67) was developed by using one step in-situ preparation method. The synergistic impact of ZIF-67 embedded on 3D porous graphene network enhances the adsorption capacity of the organic dyes (Congo Red and Methylene Blue). The obtained structured composite material possesses macroporous and mesoporous channels up to 14.42 nm with enhanced morphological stability. The resultant 3DPGZF composite exhibits the maximum adsorption capacity towards the CR (589.46 mg g −1 ) and MB (350.79 mg g −1 ), with a removal rate of 100 % within 50 min. The kinetic study and isothermal analysis showed that pseudo second-order-kinetic model and non-linear form of the Freundlich isotherm model were more fitted with adsorption data. The adsorption of CR and MB occurred spontaneously and exhibited an endothermic nature. The DFT studies and characterization after utilization of the composite demonstrated that electrostatic attractions, pi-pi interaction, pore filling and surface binding reactions were the primary forces of the sorption process. The after adsorption XPS, FTIR, TEM and XRD results revealed that the prepared composite 3DPGZF is highly stable and was successfully regenerated multiple times without deforming its internal structure and morphology.