Iron Sulfide Functionalized Polyaniline Nanocomposite for the Removal of Eosin Y from Water: Equilibrium and Kinetic Studies

Iron sulfide functionalized polyaniline nanocomposite was successfully synthesized using the in-situ polymerization technique. SAED, TEM, SEM, FTIR, XRD, and BET measurements were used to characterize the materials. Thermodynamic and kinetic studies using the batch approach were performed on the adsorption of Eosin yellow from aqueous solutions using the nanocomposite. The pseudo-second order kinetic model and the Langmuir isotherm fitted the adsorption process. An endothermic process was indicative from the positive ∆ H ° (11.84 kJ/mol) value. The negative values of ∆ G ° (from –1.49 to –2.28 kJ/mol for temperatures from 300 to 318 K, respectively) showed the thermodynamically viable nature of the adsorption process and the spontaneity of the reaction within the temperature ranges. A high disorderliness in the system was indicative from the positive magnitude of ∆ S ° (0.044 kJ/(mol K)). These results present a potential for the use of iron sulfide functionalized polyaniline material for the uptake of Eosin Y from water.