Design and fabrication of core-shell magnetic and non-magnetic supported carbonaceous metal organic framework nanocomposites for adsorption of dye

A novel core-shell cobalt and nickel based metal organic framework (MOF) nano-composites in the presence of the magnetic and non-magnetic walnut based activated carbon (AC) were subsequently employed for the adsorption of methylene blue (MB) in the batch system which were synthesized by an efficient and a facile preparation method. The nano-composites were characterized by applying general tests including XRD, FTIR, FESEM, EDX, TEM, VSM, TGA and BET. The findings indicated that the nanoparticle size of the well dispersed magnetic nano-composites was less than 20 nm. The core-shell structure of magnetic nanocomposites was detected from TEM images. The analytical achievements also demonstrated that the thermal resistance of the magnetic composites was higher than that of other samples. The maximum adsorption capacities were calculated to be 128 and 112.32 mg/g for the cobalt based MOF supported on the non-magnetic and magnetic ACs, respectively which was higher compared with the nickel based composites. Langmuir isotherm and a pseudo second order kinetic equation were fit models to describe the equilibrium adsorption and the kinetic behavior of MB on the adsorbents, respectively. The usability of the prepared samples was also studied for six cycles which showed the acceptable performance of the magnetic adsorbents for the real applications. [Display omitted] •Novel magnetic MOF nanocomposites were prepared by a facile preparation method.•Magnetic MOF nanocomposites were included magnetic walnut based activated carbon.•Prepared MOF nanocomposites were promising adsorbents for methylene blue adsorption.•Maximum adsorption capacity was measured to be 128.72 mg/g for cobalt MOF composites.•Nanocomposites were evaluated by XRD, FTIR, BET, FESEM, TEM, TGA and VSM technique.