FeBTC MOF‐Derived Fe₃O₄@C Nanocomposite: Controlled Synthesis and Application as Potential Adsorbent for Rhodamine Dye Elimination From Wastewater

Abstract

ABSTRACT This study explores the controlled synthesis of a novel Fe 3 O 4 @C magnetic nanocomposite derived from FeBTC metal–organic framework (MOF) and its application as an efficient adsorbent for the removal of rhodamine dye from wastewater. The FeBTC MOF was first synthesized and then thermally decomposed in a controlled oxygen atmosphere at 375°C (1 h) to form the Fe 3 O 4 @C nanocomposite with a magnetic Fe 3 O 4 core embedded in a porous carbon matrix. A comprehensive characterization of the nanocomposite was performed using x‐ray diffraction (XRD), transmission electron microscopy (TEM), and x‐ray photoelectron spectroscopy (XPS) to confirm the successful formation and to evaluate its structural and morphological properties. The morphological investigation revealed that the particles of Fe 3 O 4 had a spherical shape with diameter of 10–15 nm. The carbon coating appeared as a thin amorphous layer surrounding the Fe 3 O 4 nanoparticles. The adsorption capacity of Fe 3 O 4 @C for rhodamine B (RhB) dye was assessed under various conditions, including different pH values, contact times, initial dye concentrations, and temperatures. Complete dye removal was attained in 45 min using 50 mg of the nanocomposite and 50 mL of 5.0 ppm RhB at the optimum pH of 9.1. Under the same experimental conditions, the highest adsorption capacity of 13.0 mg/g was obtained, but using 15.0 mg of the nanocomposite. Fe 3 O 4 @C nanocomposite exhibits high adsorption efficiency, with a maximum removal capacity of 100%, which is clearly superior to many conventional adsorbents. This performance can be attributed to the synergistic effects of the magnetic Fe 3 O 4 and the large surface area of the carbon matrix. Kinetic models were employed to understand the adsorption mechanism. The adsorption kinetics followed a pseudo‐second‐order model. The reusability of the adsorbent was tested over multiple cycles and showed a minimal loss of performance (drops to 93.0% after five removal cycles). The study demonstrates that the Fe 3 O 4 @C nanocomposite is a promising candidate for the effective removal of organic dyes from wastewater, offering potential benefits for environmental remediation and sustainable water management.