Photocatalysis;Co-precipitation; ZnO; rGO; Nanocomposite; Organic pollutants

For photocatalytic degradation of organic pollutants, ZnO and NiFe2O4 nanoparticles are synthesized via co-precipitation method. ZnO/NiFe2O4 and composite with reduced graphene oxide (ZnO/NiFe2O4@rGO) is syn-thesized via ultra-sonication method. Reduced graphene oxide is used because of its excellent behaviour in photocatalysis such as high stability, huge surface area and rapid transfer of electrons. The physicochemical properties of synthesized nanoparticles are studied using X-ray diffraction technique (XRD), Field emission-scanning electron microscopy (FE-SEM), Fourier transform-infrared spectroscopic method (FT-IR) and UV-Vi-sible spectroscopic analysis. Electrochemical measurements are also done to investigate electrical properties of synthesized samples. Photo-degradation efficiency of fabricated photocatalysts was studied using crystal violet as coloured and phenol as colourless dye. When similar conditions are applied, these synthesized nanoparticles degrade 80.5% crystal violet and 42% phenol in 140 min in sunlight. Combination of ZnO and NiFe2O4 boost separation of charges and also diminishes the chances of recombination of charge carrier species, which as a result enhance photocatalytic activity. Photocatalytic activity of ZnO/NiFe2O4@rGO is greater than bare ZnO and NiFe2O4. Due to magnetic nature of nickel ferrite, sample is not agglomerated and it can be recycled easily. It is observed that ZnO/NiFe2O4@rGO is used as a potential photocatalyst in treatment of polluted water.