Synthesis and design of the modified metal-organic framework adsorbent using boehmite for remarkable adsorption of cationic contaminants in the aqueous solutions

The modified metal-organic framework (MOF) nanocomposites were fabricated using the various facile preparation methods including co-precipitation, hydrothermal, solvothermal for the adsorption of methylene blue (MB) ions in the batch process. The modification of the MOFs nanocomposites was carried out using boehmite as a low cost material. The characterization tests comprising XRD, FTIR, FESEM, TEM and BET were also performed to recognize the physico-chemical properties of the prepared adsorbents. The well dispersed samples synthesized by hydrothermal method with more surface area (about 560 m2/g) with octahedral and cubic morphology (with size less than 50 nm) compared to the other nanocomposites had a better performance in adsorption of dye pollutant. The maximum adsorption capacity was measured for the prepared BTC-MOF sample to be about 250 mg/g in comparison with the other samples by employing linearized Langmuir equation. The good matching between the pseudo second order kinetic and experimental data showed the strong electrostatic adsorption in the present work. Thermodynamic parameters including Gibbs free energy (Delta G0), entropy (Delta S0), and enthalpy (Delta H0) were studied for the adsorption of MB on the Cu-BTC@Bo.H sample at the different temperatures. Reusing adsorbent in adsorption of MB ions in the seven consecutive cycles indicated that the investigated nanocomposites can be employed on an industrial scale.