Visible light active, magnetically retrievable Fe3O4@SiO2@g-C3N4/TiO2 nanocomposite as efficient photocatalyst for removal of dye pollutants

Magnetically retrievable and visible light active Fe3O4@SiO2@g-C3N4/TiO2 core-shell microsphere nanocomposite photocatalyst was successfully synthesized. It comprises Fe3O4@SiO2 magnetic core and g-C3N4/TiO2 nanocomposite as an outer shell. The core-shell structure imparts reusability by magnetic retrieval and at the same time SiO2 encapsulated core acts as an efficient host for g-C3N4/TiO2 composite photocatalyst. The photocatalytic performance was examined using Rhodamine B (Rh B) and Methyl Orange (MO) at 10 ppm in solution. Photodegradation studies show the 10 wt.% g-C3N4/TiO2 a composite catalyst can degrade over 91% of both cationic and anionic dyes. The rate constant of reaction determined to be 3.2 fold higher for Rh B and 27.7 fold higher for MO in comparison to TiO2 thus proving its utility as useful photocatalyst for cationic dyes and as a high rate remover of anionic dyes. Free radical scavenger test shows superoxide and hydroxyl radical species play a major role in the degradation.