Defective MIL-88B(Fe) metal-organic frameworks: Peculiar photocatalysts for enhanced degradation of organic pollutants
Samira Sadeghi, Ahmad Najafidoust, Seyedeh Zahra Haeri, Masoumeh Zargar
Abstract
Environmental pollution, particularly water contamination from organic compounds like synthetic dyes, poses a major global challenge. In this study, defective MIL-88B(Fe) MOFs under varying solvothermal conditions (70–150 °C) for 12 and 24 h were synthesized to enhance methylene blue (MB) and methyl orange (MO) dye degradation. The MOF synthesized at 100 °C for 24 h showed the highest efficiency, achieving 97 % and 40 % degradation of MB and MO, respectively, in 60 min due to increased porosity, surface area, and optimized crystal growth along the [100] direction. A 24-h synthesis produced well-formed particles with the highest surface area and lowest band gap energy; however, temperatures above 110 °C led to particle collapse. Optimal MB degradation occurred at pH 7, 0.4 g/L catalyst dosage, and 30 mg/L MB concentration. The prepared samples were characterized using XRD, FESEM, BET, TEM, FTIR, PL, and DRS analyses. The photocatalysts maintained their efficiency and structural integrity after four cycles, demonstrating excellent reusability and sustainability. These results provide novel insights into harnessing and optimizing Fe-MOF catalysts for efficient dye removal, offering a reliable solution for wastewater treatment at ambient temperature.