Preparation and characterisation of two‐dimensional magnetic chitosan nanosheets for removal of azo dyes from aqueous solutions

In this work, two-dimensional magnetic chitosan nanosheets (CSMNSs) for azo dye adsorption were successfully synthesised by a simple hydrothermal method. The as-prepared CSMNSs was characterised by scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and vibrating sample magnetometer. Then, the CSMNSs as the dye adsorbent were applied to the removal of two kinds of azo dyes (methyl orange and amido black). The effect of solution pH and adsorbent dosage, adsorption isotherm, adsorption kinetics and the reusability of CSMNSs were examined. Adsorption isotherms obeyed Freundlich model and adsorption kinetics was described as pseudo-second-order model. Furthermore, the CSMNSs have the advantage of simple synthesis route, high absorption efficiency, rapid magnetic separation from aqueous solutions and excellent reusability. The CSMNSs as the dye adsorbent was applied to removal of azo dyes with broad prospects.