The Polymer Composite Particles for Adsorption and Photocatalytic Degradation of Reactive Black 5: Equilibrium, Kinetics, Thermodynamic, and Isotherms Studies

Abstract

Fe₃O₄-poly(EGDMA-VPBA)-TiO₂ particles with magnetic and photocatalytic properties were prepared using suspension polymerization with 4-vinylphenylboronic acid and ethylene glycol dimethacrylate for the adsorption and photocatalytic color removal of Reactive Black 5 (RB5) from aqueous solutions. Various analyses were made for the characterization processes of synthesized Fe₃O₄-poly(EGDMA-VPBA)-TiO₂. These polymer composite particles were tested for both adsorption and photocatalytic color removal of RB5. In adsorption studies, the effects of solution pH, initial color concentration, adsorbent amount, contact time, and solution temperature on the adsorption capacity of composite particles were studied. Maximum removal in RB5 adsorption was achieved at pH 3. Adsorption removal increased with increasing temperature and decreased with increasing amount of adsorbent. The experimental adsorption data were found to be consistent with the Langmuir isotherm model, and the adsorption kinetics were determined to follow the pseudo-second-order equation mechanism. Thermodynamic parameters of RB5 adsorption were calculated. For the photocatalytic removal of the remaining colors in the aqueous solution without being adsorbed, the parameters of photocatalyst amount, color concentration, and time were examined, and the color removal kinetics were clarified. The photocatalytic effect for Fe₃O₄-poly(EGDMA-VPBA)-TiO₂ was observed at low RB5 concentrations and high photocatalyst content. In addition, decolorization kinetics were found to be coherent with the Langmuir–Hinshelwood (L–H) model.