Synthesis of reduced graphene oxide/nickel ferrite composite nanoparticles and investigation of their photocatalytic activity

In this study, it is planned to produce nickel ferrite (NiFe2O4) nanoparticles and nickel ferrite/reduced graphene oxide (NiFe2O4@rGO) composites by hydrothermal synthesis method. Then these materials were used as photocatalysts in the removal of dyes from wastewater by photocatalytic oxidation method and to compare their photocatalytic activities. Accordingly, the study was planned in three stages. In the first part, first graphene oxide and then reduced graphene oxide were produced starting from graphite powder by the modified hummers method. In the second stage, pure NiFe2O4 nanoparticles and a composite material consisting of reduced graphene oxide and NiFe2O4 nanoparticles the was produced by hydrothermal synthesis method. In the third stage of the study, pure NiFe2O4 and NiFe2O4@rGO composite nanoparticles produced by hydrothermal synthesis method was used as a photocatalyst in the photocatalytic oxidation of a textile dye known as procion yellow HE-3G, and the observed removal efficiencies for both materials were compared. Reduced graphene oxide powder was successfully synthesized by the modified Hummers method. NiFe2O4 nanoparticles were synthesized by hydrothermal synthesis method on the obtained reduced graphene oxide. The structural and morphological properties of the products obtained were comprehensively characterized by XRD, FT-IR, SEM, TEM, BET and VSM techniques. The results obtained showed that NiFe2O4 nanoparticles were successfully synthesized and the product nanoparticles had a particle size of approximately 10-20 nm. In addition, it was determined that the synthesized NiFe2O4 nanoparticles formed strong and stable composites with reduced graphene oxide. Then pure NiFe2O4 nanoparticles and NiFe2O4@rGO composite nanoparticles were used as photocatalysts in the photocatalytic oxidation removal of dyestuffs from dye-containing wastewater. In order to compare the photocatalytic activities of the produced particles, experiments were carried out with both catalysts with catalyst dosages of 0.010 g/L, 0.025 g/L, 0.050 g/L and 0.10 g/L. The data obtained demonstrated that both catalysts exhibited a very good photocatalytic activity in dye removal and the dyestuff in the solution could be completely removed in about 60 minutes. It was observed that the composite of nickel ferrite and reduced graphene oxide (NiFe2O4 @ rGO) exhibited a much more effective photocatalytic activity. In addition, according to the experimental data obtained from the photocatalysis experiments, it was determined that this process is fully compatible with the Pseudo-first-order kinetic model.