rGO/ZIF-8 Aerogel for Effective Removal of Malachite Green from Wastewater

In this study, dopamine-modified graphene aerogel (DGA) is synthesized through a one-step hydrothermal method using graphene oxide as the precursor and dopamine as the reducing agent. Subsequently, in situ immersion synthesis is conducted to obtain ZIF-8 loaded on a dopamine-modified graphene aerogel skeleton (ZDGA), featuring a regular honeycomb interconnected mesoporosity and a high specific surface area of 532.8 m²/g. The synthesized ZDGA exhibited exceptional adsorption performance for the cationic dye malachite green. At room temperature, ZDGA achieved an impressive equilibrium adsorption capacity of 6578.34 mg/g. The adsorption process followed pseudo-secondary kinetics and adhered to the Langmuir model, indicating chemically dominated adsorption on a monomolecular layer. Intraparticle diffusion was the primary rate determinant, with π-π stacking, electrostatic adsorption, hydrogen bonding, and Lewis acid-base interactions serving as the key driving forces. It has an ideal specific surface area and good cycling performance, which highlights its potential application in dye wastewater treatment.