Removal of RR198 dye by TiO2/Fe3O4/persulfate nanoparticles under UV-LED irradiation and comparision of OFAT and CCD experimental design in RSM modelling

The photocatalytic activity of TiO₂/Fe₃O₄ nanocomposite has been determined. The XRD spectrum and FESEM analysis have been used to evaluate TiO2 / Fe3O4 nanoparticles. The photocatalytic activity of nanoparticles is assessed by degradation of the RR198 solution under the influence of UV-LED radiation. Response Surface Methodology (RSM) is employed to determine the relationships between the studied parameters. The experiments were designed and performed in two ways: One-factor-at-a-time method (OFAT) and Central composite design (CCD). Here nanoparticles with synergistic 2-effect of S₂O₈ were very successful in eliminating the dye. The results of the RSM model with the two mentioned experiment design methods indicated that the model derived from the CCD method had a better predictive capability and favoured from the ability to generalize to other results rather than OFAT method.