Multifunctional TiO2/MIL-100(Fe) to conduct adsorption, photocatalytic, and heterogeneous photo-Fenton reactions for removing organic dyes

Since TiO2 photocatalysts were only ultraviolet-light-responsive and homogeneous photo-Fenton had some drawbacks in generating iron sludge, multifunctional TiO2/MIL-100(Fe) composites were synthesized to remove organic dyes under simulated solar light irradiation. Commercial TiO2 and MIL-100(Fe) precursors were mixed in one pot using a modified reflux method in 12 h, 18 h, and 24 h to fabricate TiO2/MIL-100(Fe) with different weight ratios of the TiO2 and Fe(NO3)2 precursors, including 0.07, 0.15, and 0.30. MIL-100(Fe) was used to efficiently distribute TiO2 and adsorb dyes due to its high specific surface area. Besides, TiO2/MIL-100(Fe) composites could absorb visible light to conduct photocatalytic and heterogeneous photo-Fenton reactions simultaneously. For the TiO2/MIL-100(Fe) composites (TF15-18), the individual kinetics analysis of removing organic dyes, including dark adsorption and light reaction, belonged to the pseudo-second-order model with the rate constants of 1.682 and 7.702 g·mg−1·min−1, respectively. The completed dye removal was achieved under 90 min dark adsorption and 180 min light reaction under the best conditions of pH=3.5 and 40 μL H2O2 addition in 150 mL MB solution.