Photocatalytic Degradation of Methyl Orange by Fe2O3-Fe3O4 Nanoparticles and Fe2O3-Fe3O4-Montmorillonite Nanocomposites

Zero-valent iron nanoparticles (nZVI) are emerging multifunctional agents for contaminant treatment. However, Fe2O3-Fe3O4 nanoparticles (NIO), which are generated when nZVI is oxidized, can also make a meaningful contribution to the photocatalytic degradation of organics. Taking this into account, NIO and a Fe2O3-Fe3O4-montmorillonite nanocomposite (NIO-M) were prepared, and their morphology and microstructure were investigated via a series of characterization methods. The presence of montmorillonite is critical to decreasing the aggregation and size of the crystals, which helps improve the thermal stability of the crystals. The photocatalysis performance of NIO and NIO-M for the degradation of methyl orange was evaluated, and the data indicated that NIO-M exhibited an excellent optical response and photocatalytic activity in the visible region. The degradation rate of methyl orange was 1.47 times faster within 45 min of irradiation compared with NIO. The results indicate that NIO-M is a promising type of visible-light-driven photocatalyst for the degradation of organics in aqueous solutions.