Synthesis of a new porous Graphene Oxide Framework (GOF) for high-performance ultrasonic-assisted removal of cadmium and lead ions from aqueous solution

A novel chelating adsorbent was successfully synthesized by cross-linking of 4, 4', 4''-s-triazine-1, 3, 5-triyltri-p-aminobenzoic acid as a linker with nanosheets of graphene oxide to provide a 3-dimensional framework. Therefore, the adsorption process of Cd+2 and Pb+2 on the adsorbent was investigated by employing an ultrasonic bath. The optimum condition containing the small amount of adsorbent (10 mg) for both metals at pH=8 for Cd+2 and pH=5 for Pb+2, and a short time of two minutes caused gaining an absorption capacity at a high level. The presence of nitrogen-functionalized groups in the porous Graphene Oxide Framework (GOF) contributed to the absorption of lead and cadmium ions. The kinetic models of pseudo-first-order and pseudo-second-order were used to define the kinetic process. The experimental adsorption datum was properly suited to the kinetic model of the pseudo-second-order (R-2 = 0:990). It indicated that adsorbing ions of heavy metals onto GOF happens through a chemical process, and adsorption isotherms of Cd+2 and Pb+2 ions were in high-grade accordance with the Longmuir model. Eventually, because of the rapid adsorption kinetics, high removal capacity, perfect stability, and being reusable, this GOF can be used as a remediation adsorbent with high-performing heavy metals removal from aqueous solutions. (c) 2023 Sharif University of Technology. All rights reserved.