Chitosan-carboxylic acid grafted multifunctional magnetic nanocomposite as a novel adsorbent for effective removal of methylene blue dye from aqueous environment

In this work, magnetite nanoparticle decorated graphene oxide (MGO) is modified with triethylenetetramine (TETA), which is supported by maleated chitosan (MACS), named MGO@TETA@MACS. The novel magnetic nanohybrid is successfully fabricated via an in situ coprecipitation method, which is for methylene blue (MB) uptake from liquid phase environment. XRD, FTIR, TGA, nitrogen isotherm, SEM, and Zeta potential experiments were utilized to explore the MGO@TETA@MACS nanocomposite. The mean particle size and surface area of MGO@TETA@MACS were measured to be 11.5 nm and 128.04 m2·g−1, respectively. The nonlinear kinetic and isotherm models were utilized to evaluate the adsorption equilibrium. Data analysis revealed that the uptake kinetics fits the PFO model while the adsorption equilibrium follows the Langmuir isotherm. The maximum adsorption capacity of MGO@TETA@MACS nanocomposite, estimated from Langmuir isotherm, was 247.37 mg/g at the ambient temperature. Thermodynamic calculations confirmed the exothermic and spontaneous nature of the MB decontamination.