Synthesis of chitosan composite of metal-organic framework for the adsorption of dyes; kinetic and thermodynamic approach

The iron metal-organic framework composite with chitosan (CS/MOF-235) was synthesized using a solvothermal method and its synthesis was confirmed by surface area, PZC, XRD, FESEM, XPS, TGA, TEM, EDX mapping and EDX analysis. The chitosan composite of the iron metal-organic framework (CS/MOF-235), MOF-235 and chitosan were used for the removal of methylene blue (MB) and methyl orange (MO) from aqueous solutions. The maximum adsorption capacities were found to be 2857 - 2326 mg/g for CS/MOF-235, 357 – 236 mg/g for MOF-235 and 209-171mg/g for chitosan (CS) which reveal that the adsorption capacity of CS/MOF-235 is almost 8 and 14 times greater than MOF-235 and chitosan respectively.  The adsorption selectivity of the (CS/MOF-235) towards the dye was in the order MO > MB.  Moreover, hydrogen bonding, pi-pi bonding, pore-filling, electrostatic interactions and chemisorption were proposed as possible mechanisms for the removal of dyes onto CS/MOF-235. 

The intraparticle diffusion and Richenberg models confirmed that the adsorption process was jointly controlled by the pore and film diffusion. The negative values of the isosteric heat of adsorption (Δ) fall with surface coverage indicating that a lesser amount of heat is required for the greater uptake of dyes.

He has completed my Ph.D., in May 2022 from National center of Excellence in Physical Chemistry, University of Peshawar, Pakistan. During his Ph.D. project, he developed a novel method to obtain different Polymer composites of metal organic frameworks and metal oxide composites via solvo as well as non-solvothermal approach. These materials were applied further for different water purification techniques including photocatalytic degradation, static and dynamic adsorption processes for the removal of organic pollutants.

Currently, He is serving as Assistant Professor of Physical/ Environmental/Material Chemistry. His research group is working on novel polymer based composites for the separation and purification of Wastewater and Catalytic Degradation of various organic pollutants.