Recent advancements of spinel ferrite based binary nanocomposite photocatalysts in wastewater treatment

A lot of studies on spinel ferrites (MFe₂O₄, M = divalent metal ion) and their binary nanocomposites as photocatalysts in the decontamination of wastewater have been performed, because MFe₂O₄ nanoparticles are relatively stable, biocompatible and low-cost efficient photocatalyst. The separation of MFe₂O₄ photocatalyst is easy owing to its excellent magnetic behavior. With this background, the recent developments on photocatalytic performances of MFe₂O₄ based binary nanocomposites were comprehensively reviewed. Especially, a focus on MFe₂O₄/metal oxides, MFe₂O₄/carbon based materials, MFe₂O₄/polymers, MFe₂O₄/metal nanoparticles and MFe₂O₄/other compounds for the photocatalytic degradation of dyes, emerging contaminants and inorganic pollutants has been thoroughly given. The advantages of MFe₂O₄ based nanocomposites as photocatalysts were also discussed. In addition, the possible pathway of active free radical generation by these photocatalysts under visible and ultraviolet irradiation has been explained. A comparison of photocatalytic activities of MFe₂O₄ based binary nanocomposites with recent reports has been carried out. This review concludes that MFe₂O₄ based binary nanocomposites have potential capacity in water purification technology. Nevertheless, their practical utilization in water treatment plants still needs to be further studied.