The ultra efficient magnetic recyclable photocatalyst CoFe2O4/TiO2 based on kaolinite for mineral processing wastewater treatment

Developing new photocatalysts to handle sodium ethyl xanthate used in the flotation process is critical for the achievement of green mining construction in China. In this paper, CoFe 2 O 4 /TiO 2 /kaolinite (C/T/AK) ternary composites were prepared using hydrothermal and calcination methods. The materials were tested and analyzed by various characterizations, and their photocatalytic degradation performance of sodium ethyl xanthate was evaluated. The C/T/AK, acquired under optimal conditions, degraded 99% of sodium ethyl xanthate in 60 min, and the significant improvement in photocatalytic efficiency was attributed to two factors, namely, the built–in electric field formed by the p–n junction accelerated the separation of electron–hole pair, and the addition of kaolinite solved the nanoparticle agglomeration problem. Additionally, the excellent magnetic properties of the materials resulted in minimal catalyst loss during cycling experiments. This work provided ideas and ways for advancing the industrial application of magnetic materials for the treatment of mineral processing wastewater. An efficient and recyclable CoFe 2 O 4 /TiO 2 /kaolinite photocatalyst was prepared and its photocatalytic performance for mineral processing wastewater treatment was studied. • A novel CoFe 2 O 4 /TiO 2 /kaolinite photocatalyst was synthesized using hydrothermal and calcination methods. • Kaolinite prevented nanoparticle agglomeration, enhancing surface area and photocatalytic performance. • The photocatalyst achieved 99% degradation of sodium ethyl xanthate in 60 min and was magnetically recoverable. • The possible photocatalytic enhancement mechanisms were discussed.