ZIF‐67/g‐C ₃ N ₄ Incorporated Chitosan Composite for the Adsorptive Removal of Methyl Orange and Chromium Ions From Aqueous Media

ABSTRACT In the present work, ZIF‐67/g‐C 3 N 4 composite was integrated into a chitosan substrate via simple sonication and co‐precipitation techniques and evaluated as an adsorbent for the removal of methyl orange (MO) and chromium (Cr (VI)) ions. The prepared ternary composite material was characterized using various techniques to investigate its crystallinity, thermal stability, and surface topography. TGA demonstrated that the composite retained approximately 56.29% of its mass compared with chitosan. BET analysis revealed a significant increase in pore volume and surface area relative to chitosan, which contributed to the enhanced adsorption capacity toward Cr (VI) and MO. The material exhibited the maximum adsorption capacities of 121.951 mg/g (pH = 3) for Cr (VI) and 82.644 mg/g (pH = 5) for MO. The isotherm and kinetic studies showed that Cr (VI) adsorption obeyed the Freundlich isotherm, whereas MO adsorption conformed to the Langmuir isotherm, and the adsorption of both pollutants followed the pseudo second‐order kinetics. Furthermore, the recyclability studies indicated that the material retained removal efficiencies of approximately 87.12% for MO and 52.68% for Cr (VI). Therefore, these findings highlight that the ternary composite is an efficient and reusable adsorbent for the remediation of MO and Cr (VI) ions from aqueous solutions.