Synthesis of core-shell nanoparticles for the removal of toxic pollutants in aqueous medium

In this work two active photo-catalysts were synthetized and tested for the removal of methylene blue and arsenic in aqueous solutions. The two catalysts (Fe3O4/SiO2/TiO2-Al and Fe3O4-SiO2/Zr-TiO2) were characterized by nano-size, guaranteeing a large specific surface area and a noticeable number of active sites and resulted active in the visible spectra (400-800 nm). The nanoparticles were characterized by BET, FE-SEM and EDS methods. The two nano-materials showed high As and methylene blue removal efficiency and were tested varying the contact time from 1 h up to 24 h. The Fe3O4/SiO2/TiO2-Al nanoparticles demonstrated to be more versatile, since showed a noticeable removal efficiency considering both pollutants As (73.5 %) and methylene blue (78 %) after 24 h. The Fe3O4-SiO2/Zr-TiO2) nanoparticles showed a higher affinity towards methylene blue removal (90.5 %) whereas the As removal efficiency was negligible (0.5 %). The two nanomaterials were tested also in a bi-component solution, loading both As and methylene blue target pollutants.