MMT and ZrO2 jointly regulate the pore size of graphene oxide-based composite aerogel materials to improve the selective removal ability of Cu (II)

In this study, based on the cross-linking effect of Ca(II) and Sodium Alginate (SA), the basic skeleton was established with the accumulation of nanosheets of Graphene oxide (GO) and Montmorillonite (MMT), and the Zirconia (ZrO2) nanoparticles were further loaded on it to successfully prepare GMZ. Selective removal of hydrated copper ions from complex wastewater systems was achieved by increasing the cross-linking density within the aerogel spheres as well as by providing binding sites for metal ions to functionalize the aerogel into a controlled slit pore structure. The system adsorption experiments showed that Cu(II) was selectively eliminated by GMZ, with a maximum removal rate of 97.35% and a distribution coefficient of 26.33 L g-1. Adsorption kinetics and isothermal adsorption tests demonstrated that it was a multi-molecular layer chemical adsorption process (155.712 mg g-1), which was stronger than the previous similar adsorption materials. SEM morphology analysis confirmed that the aerogel was endowed with controllable slit pores. FT-IR and XPS verified the synergistic effects of ion exchange, high electrostatic force, and complexation, which contributed to the remarkable adsorption performance of GMZ. In case of adsorbing Cu(II) on GO, the roles of MMT, ZrO2, and SA were also confirmed using Density Functional Theory (DFT). In summary, GMZ had infinitely feasibility that Cu(II) was selectively removed from complicated wastewater systems.