Photocatalytic Degradation of Rhodamine B Dye by Using Tin-Doped CeO2-Fe2O3 Nanocomposite

Organic dyes are frequently used in various industries such as textiles, medicines, plastics, etc. and contribute as a major source of environmental pollutants, which leads to harmful effects on livings. Therefore, in this study, a Sn-doped CeO2-Fe2O3 photocatalyst was synthesized using the thermal decomposition method and applied for the effective degradation and removal of rhodamine B dye under solar irradiation. The as-synthesized catalyst was characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller (BET) and UV-vis diffuse reflectance (UV-vis DRS) techniques. The particle size of the photocatalyst was found 1-2 μm with a high surface area. The band gap energies of the catalyst narrowed to 2.2 eV after the Sn doping. The doping of Sn4+ ions into CeO2 lattice leads to the enhanced photocatalytic activity of CeO2-Fe2O3 composite by modified the Fermi levels of catalyst. The catalyst has shown a fast degradation rate under solar irradiance and is able to perform complete degradation of rhodamine B dye. The photocatalyst showed the COD removal up to 96% from the dye solution. Further, the scavenger test revealed the active species hydroxyl (•OH) and superoxide (O2 •−) radical are involved in the degradation of rhodamine B dye. The complete degradation of rhodamine B dye was studied and confirmed by high-performance liquid chromatography. A plausible mechanism is proposed for the degradation process and charge transfer during the degradation.