Green synthesis of FeO nanoparticles and its use i̇n heterogeneous elektro-fenton

In the first part of the study, a simple one-pot iron oxide nanoparticle synthesis was carried out by mixing the extract obtained from the dried leaf powders of raspberry, blackberry and strawberry and the metal salt solution of FeCl3 and FeSO4.7H2O. In the synthesis made with FeCl3 metal salt solution, the optimization of the parameters was carried out with the classical experimental design method and the optimum parameter values were found as pH 6, volume ratio 1:1, metal salt solution concentration 0.5 M, temperature 25 ⁰C and time 30 min. Synthesis was also carried out with FeSO4.7H2O metal salt solution with the same optimum values. Phenolic content, total flavonoid content and antioxidant activity (DPPH) analyzes were performed on the leaf extract and synthesis supernatant. The synthesized iron oxide nanoparticles were characterized by SEM/EDS, FTIR and XRD. From the SEM/EDS images, it was seen that iron oxide nanoparticles synthesized with FeCl3 metal salt solution had a layer-like structure, while iron oxide nanoparticles synthesized with FeSO4.7H2O metal salt had a spherical-like structure and agglomerated. Iron oxide nanoparticles synthesized in the second part of the study were used as a catalyst for the heterogeneous electro-Fenton process. In heterogeneous electro-Fenton experiments, 50 mg/L aqueous solutions of reactive red 195A and reactive blue 222 dyes used in the textile industry were used and the effects of voltage, pH, time, Na2SO4 concentration and catalyst amount on dye removal efficiency and energy consumption were investigated by Taguchi orthogonal array method. . In addition, the reusability of the catalysts was investigated.