In-situ growth of ZIF-8/CP with ultra-high adsorption capacity for removing Malachite green from water

An environmentally friendly and low-cost chitosan-containing polysaccharide (CP) composite ZIF-8/CP was designed and prepared based on the difficulty of separating the traditional adsorbent from the water phase. ZIF-8/CP was synthesized through in-situ growth approach. The physical, chemical and structure properties of ZIF-8/CP were determined through a series of characterization methods, including SEM, FT-IR and PXRD. The effects of touch time, pH, temperature, and co-existing ions on adsorption were assessed. In addition, kinetics, isotherms of adsorption and thermodynamics were examined. The data of isotherms for adsorption indicated that the adsorption of ZIF-8/CP on MG was similar to the Langmuir model, with a maximum adsorption capacity of 1428.57 mg/g. Moreover, the kinetic parameters were consistent with the pseudo-2nd-order equation. Thermodynamic studies (Δ G  < 0, Δ H  > 0) demonstrated a heat-absorbing and spontaneous adsorption process. Our study reveals that ZIF-8/CP has good adsorption properties and environmental properties.