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.