Synergistic adsorption-photocatalytic degradation of methylene blue by Fe₃O₄/HKUST-1 composite modified with graphene oxide

Abstract

Abstract Methylene blue (MB) is the most commonly used cationic dye, but the complex structure of MB makes it harder to be removed from the wastewater by conventional techniques. The integration of adsorption and photocatalytic has been proposed to overcome the drawbacks of the sole technology for more efficient and eco-friendly removal. A magnetic MOF composite, Fe 3 O 4 /HKUST-1, was successfully synthesized using the solvothermal method. The addition of graphene oxide (GO) uses the in situ method. XRD and FTIR results revealed the presence of GO, which was dispersed into the composite. SEM images for the composite showed GO(20)/Fe 3 O 4 /HKUST-1 was octahedral with Fe 3 O 4 and GO distributed on the surface and between HKUST-1. When the initial concentration of MB was 50 mg/L, the composites exhibited high MB removal efficiency (92,75%) under irradiation through the combination of adsorption-photocatalytic. The effective removal of Fe 3 O 4 /HKUST-1 combined with the photocatalyst properties of GO, makes the composite highly efficient for applications in water purification. The adsorption kinetics of MB on the GO(20)/Fe 3 O 4 /HKUST-1 were well-fitted with the pseudo-second-order kinetic model.