Preparation of Magnetic g-C3N4/Fe3O4 Composite and Its Application in the Separation of Catechol from Water

Catechol has strong toxicity and deformity as well as carcinogenicity, and it is difficult to degrade naturally. Therefore, it is of great practical significance to develop efficient adsorbents to separate catechol from water quickly and effectively. In this work, g-C₃N₄/Fe₃O₄ magnetic nanocomposites were prepared using g-C₃N₄ as the matrix by chemical co-precipitation, mixing with Fe²⁺ and Fe³⁺ solutions. Then, g-C₃N₄/Fe₃O₄ was used, for the first time, as an adsorbent to investigate the removal rate of catechol under different conditions by the magnetic field separation method. The adsorption parameters of the g-C₃N₄/Fe₃O₄ nanocomposite were evaluated by the Langmuir and Freundlich adsorption models. The results showed that the g-C₃N₄/Fe₃O₄ nanocomposite presented a two-step adsorption behavior and a considerably high adsorption capacity. The removal rate of catechol reached 70% at the dosage of 50 mg, adsorption time of 30 min, and pH value of 6. Five adsorption-desorption cycles demonstrated that the g-C₃N₄/Fe₃O₄ material had good stability and reusability.