Dye removal from aqueous solution by magnetic nanocomposites of metal-organic framework with NiFe2O4@SiO2

Magnetic nanocomposites of nickel ferrite nanoparticles, uniformly dispersed in the silica matrix, were synthesized successfully by a sol-gel process using tetraethyl orthosilicate (TEOS) and metallic nitrates as precursors. NiFe2O4@SiO2@HKUST-1 magnetic nanocomposites were synthesized and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), vibrating sample magnetometry (VSM), nitrogen adsorption porosimetry, Thermal Analysis (TGA), photoluminescence analysis, and UV-visible. The more acidic pHs and lower concentrations of the dye solution, the less the dye molecules are present in the solution; therefore, the pore volumes and surface areas will be filled slowly and with higher removal efficiency. Magnetic nanocomposite of metal-organic, ferrite-nickel, and silica framework have high efficiency and absorbability for cationic dyes such as methylene blue. Within 60 minutes, approximately 98% of the dye molecules were removed using the magnetic metal-organic framework nanocomposite 30% NiFe2O4@SiO2@HKUST-1 under optimum condition. Adsorption isotherms, kinetics, and adsorption studies have shown that R2 is the most frequent Freundlich isotherm, which means that the adsorption process was mainly multilayered on heterogeneous surfaces of the metal-organic framework nanocomposites.