Synergistic effect of Cu metal-organic framework grafted polyaniline (Cu-MOF@PANI) on adsorptive removal of anionic...

The adsorption process for controlling water pollution and treating aqueous wastewater has emerged as an attractive area of applied research. Herein, the Cu metal-organic framework (MOF) grafted on eco-friendly Polyaniline polymer (PANI) (tagged as Cu-MOF@PANI nanocomposite) was fabricated by one-pot solvothermal method. The potential of Cu-MOF@PANI adsorbent to effectively remove anionic food dyes, namely Sunset Yellow (E110) and Tartrazine (E102), was explored. The PANI enhanced the surface area of the Cu-MOF@PANI adsorbent to 489.7 m²/g, thereby improving the capture performance of anionic dyes. The nanocomposite demonstrated a remarkably high adsorption capacity of 696.6 mg/g and 649.3 mg/g for Sunset Yellow and Tartrazine, respectively, attributable to the synergistic effect of the electronic properties, π-π interaction, and electrostatic forces of the PANI modifier, in conjunction with the distinctive porous structure of Cu-MOF. Furthermore, the synergistic effect of the PANI component and Cu-MOF achieved removal efficiencies of 99% and 97% for Sunset Yellow and Tartrazine within 20 min and 25 min, respectively. A classic adsorption study demonstrated that the nonlinear form of the pseudo-second-order (PSO) kinetic model provided a satisfactory description of dye contaminants onto the Cu-MOF@PANI adsorbent. The isotherm study using Langmuir, Freundlich, Sips, and Temkin isotherm equations established a strong correlation with the Sips isotherm for the capture of dye contaminants. Based on thermodynamic parameters, the adsorption process on the Cu-MOF@PANI nanocomposite was found to be endothermic. The research findings indicated that MOF-based composites have considerable potential for treating wastewater containing organic dyes.