This study investigated the photocatalytic degradation of Rhodamine B dye from aqueous solutions using a green-synthesized tin oxide/iron oxide nanocomposite derived from pomegranate peel extract. The properties of nanocomposites have been evaluated by conventional methods, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), and vibrating sample magnetometry (VSM). Characterization results showed an average particle size of 22.5 nm, surface load of +38 mV, and magnetic properties of 20 emu/g. To design the experiments and model the degradation process, a central composite design (CCD) was employed. The key operating parameters included pH, the amount of photocatalyst used, the initial concentration of dye, and the presence of the oxidizing agents hydrogen peroxide (H2O2) and ferrous ions (Fe2+). Under optimal conditions of pH 5.5, an initial Rhodamine B concentration of 52.5 mg/L, and 0.75 g/L of the nanocomposite, a degradation efficiency of 83.4% was achieved after 120 minutes. By adding 200 mg/L of hydrogen peroxide and 3.5 mg/L of ferric ions, the destruction of the dye was accomplished in just 45 minutes. Furthermore, the kinetics of the degradation process showed pseudo-first-order behavior at a rate constant of 0.0513 min-1. The electrical energy consumption (EEC) for the process was measured at 124.76 KWh/m³.
