Graphene quantum dot incorporation in the zeolitic imidazolate framework with sodalite (SOD) topology: Synthesis and improving the adsorption ability in liquid phase

An amazing combination of zero-dimensional graphene quantum dots (GQDs) with three-dimensional metal-organic frameworks (MOFs) improves the resulting nanocomposite properties. Herein, The GQD was incorporated in the ZIF-8 surface, to emphasize another application of GQD that has been less considered before. The characteristics of synthesized nanomaterials were confirmed by FTIR, XRD, TGA, BET, Raman, SEM, and HRTEM. The removal of malachite green (MG) was investigated to compare the adsorption properties of nanocomposite with pristine GQD and ZIF-8. The effects of GQD loading dose in composite (2–20%), adsorbents dosage (0.7–2.5 mg), initial dye concentration (20–50 mg/L), and the pH of MG solution (4−7) as the influential parameters on pollutant removal were investigated. The dye adsorption capacity of hybrid nanocomposite (2500 mg/g) was reasonably better than pure GQD (294 mg/g) and MOF (1111 mg/g). Besides, this process was in good agreement with the pseudo-second-order kinetics and the Langmuir isotherm model