In this study, the synthesis of magnetic carbon nitride nanocomposite (Ag2CrO4/Fe2O3/g-C3N4) and the elucidation of its structural characteristics were conducted using conventional analytical techniques. Subsequently, the efficacy of this nanocomposite as a photocatalyst in the degradation of Rhodamine B dye was assessed. The outcomes of diverse characterization methods substantiated the successful fabrication of the nanocomposite above, delineating the deposition of Fe2O3 and Ag2CrO4 particles onto g-C3N4 plates. The X-ray diffraction (XRD) analysis revealed that the synthesized samples of iron oxide, carbon nitride, and silver dichromate were effectively layered and well-aligned, a configuration designed to enhance their photocatalytic performance. Moreover, these results facilitated the determination of key parameters of the synthesized spherical shape nanocomposite, including an average particle size of 48.5 nm, a surface area of 24 m2/g, a pore size of 0.01cm3/g, and an average pore diameter of 15.5 nm. The ferromagnetic properties with a magnetization of 10 emu/g. Its band gap energy was found to be 2.25 eV. The surface charge of the synthesized nanocomposite was determined to be −37.8 mV. To optimize the experimental conditions, three pivotal parameters influencing the process were selected, modeled, and optimized utilizing experimental design methodology. Through analysis of variance (ANOVA) and Response Surface Methodology (RSM), the discernible dependence and correlation between the selected variables and the percentage of dye degradation within the proposed model with calculated Adj-R2, and Pred-R2 values in the model were 0.9655, and 0.8829 respectively, indicating a strong proportion between the model fitting and experimental data. The optimal operational conditions were established at pH=6.86, dye concentration of 13.5 mg/L, and nanocomposite dosage of 343.01 mg/L under visible light, resulting in the degradation of 87.1% of the dye within a 45-minute duration. The kinetics study indicated a pseudo-first-order kinetics model with a rate constant of 0.065 min−1. Finally, under optimal process, the electrical energy consumption (EEC) was evaluated and achieved at 59.07 KWh/m3. In addition, the criteria for a consistent assessment of the process were proposed and its value of 4.3 × 10-3 was calculated.
