Preparation and Characterization of MIL-53(Al)-(NH2)@PANI for Tetracycline Removal

Abstract

The growing global demand for water and persistent shortages have underscored the importance of wastewater treatment from industrial and urban sources. Among various approaches, the use of adsorbent materials, particularly metal–organic frameworks (MOFs), has gained significant attention over the past decade due to their exceptional adsorption properties. This study presents a rapid, water-based synthesis method for MIL-53(Al)-(NH₂) and its surface modification using polyaniline (PANI). The modified MOFs, MIL-53(Al)-(NH₂)@PANI, were utilized for the removal and photocatalytic degradation of tetracycline from aqueous solutions. Optimal operational conditions were determined to include an adsorbent dosage of 0.12 g/L, an initial tetracycline concentration of 30 mg/L, a reaction time of 30 min, and a solution pH of 2.5. Kinetic analyses revealed that the adsorption process conforms to the Pseudo-second-order kinetic model, with the surface modification by PANI significantly enhancing the adsorption efficiency. The proposed mechanism for photocatalytic degradation involves the generation of reactive radical species, including h⁺, ˙OH, and ˙O₂⁻, under sunlight irradiation, which synergistically improves the removal efficiency. This study highlights the potential of MIL-53(Al)-(NH₂)@PANI as an effective adsorbent and photocatalyst for the treatment of antibiotic-contaminated water, offering a sustainable solution to water pollution challenges.