Effect of chitosan-incorporated Fe3O4 nanocomposites on the photocatalytic removal of organic molecules

The bare iron oxide (IO) and iron oxide/chitosan (IOC) nanocomposites were prepared by co-precipitation method. The iron oxide and iron oxide-chitosan nanocomposites were characterized using X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Ultraviolet spectroscopy (UV). The XRD pattern of iron oxide and iron oxide-chitosan nanocomposites reveals the formation of the Fe3O4 structure. Flake and sheet-like morphology were observed for Fe3O4 and Fe3O4/chitosan nanocomposites. The EDX exhibits the presence of C, O, N, and Fe in the IOC nanoparticles. The optical bandgap energy of Fe3O4 decreased from 2.4 eV to 1.9 eV with the substitution of chitosan. IOC composites shows more than 99% of methylene violet (MV) degradation and 71% of rhodamine B (RhB) degradation. The Kapp rate constant and TOF of IO and IOC catalysts were investigated and discussed in more detail. IOC revealed highest rate constant of 4.12 x 10(-2) min(-1) for MV degradation. In presence of IOC catalysts after three cycles, it revealed 99% of MV and 70% of RhB. The prepared IOC catalyst is efficient to remove organic contaminants from the wastewater.