Tuning the structural, magnetic, and optical properties of ZnO/NiFe2O4 heterojunction photocatalyst for simultaneous photodegradation of Rhodamine B and Methylene Blue under natural sunlight

Abstract

The magnetic nanocomposites of ZnO/NiFe2O4 were synthesized using a hydrothermal method in organic solvent-free media for application as a heterojunction photocatalyst. XRD measurements confirmed the formation of the required phases of nanocomposites with no impurity phases observed. The SEM and TEM analysis confirmed the morphology and shape of composite as being spherical and square-like grain. The magnetic properties of composites measured using vibrating sampler magnetometer (VSM) under an applied field of ±2 T showed a soft ferromagnetism. Band gap energy of the ZnO/NiFe2O4 sample was found to be lower than the pure ZnO nanoparticles. The photocatalytic activity of samples was evaluated by monitoring the simultaneous degradation of the mixed dye model of Rhodamine B and Methylene Blue under visible-light irradiation. Compared with pure ZnO, the nanocomposites exhibited a better photocatalytic performance with a degradation percentage of 98% for Rhodamine B and 97% for Methylene Blue in mix solution after 3 h of irradiation.