Hybrid magnetic core-shell TiO2@CoFe3O4 composite towards visible light-driven photodegradation of Methylene blue dye and the heavy metal adsorption: isotherm and kinetic study.

Abstract

Magnetic core-shell TiO2@CoFe3O4 (TCM) composite photocatalytic particles with a core-shell structure were synthesized by the co-precipitation method as a novel catalyst for methylene blue (MB) dye degradation and adsorption efficiency of heavy-metal ion Pb(II) from aqueous solution. Various analytical techniques have verified the formation of the TCM core-shell through TEM, XRD, FT-IR, Raman, PL, and UV analysis. The presence of TiO2 and cobalt magnetite in the TCM core shell is confirmed by XRD analysis. The formation of a homogenous CoFe3O4shell on TiO2 spheres is confirmed by HR-TEM investigation. TiO2 nanoparticle has a rutile structure with an average crystallite size of about 57.44 and a TCM core-shell of about 64.62nm. From UV and PL studies, it was found that the core shell absorbs the visible range of the electromagnetic spectrum, which improves the effective separation between photo carriers. This study focused on several factors that influence metal ion adsorption, including initial concentrations, adsorbent dose, pH, and contact time. The TCM nanocomposite successfully separated the heavy metal ion Pb(II) from aqueous solutions, and the model predictions exactly matched the experimental results. For TCM material, the maximum adsorption efficiency for Pb(II) was 33.09mg/g. The photocatalytic performance of TiO2 and TCM is about 12% and 91% after 60min for MB dye degradation. It was found that TiO2@CoFe3O4 core-shell nanoparticles perform better as photo catalysts than pure TiO2 and CoFe3O4due to their high efficiency and reusability. Furthermore, the analysis revealed that heavy metal adsorption from aqueous solutions could be reused over seven cycles with no adsorption capacity modification.