Carbon-coated ZnFe2O4 nanoparticles as an efficient, robust and recyclable catalyst for photocatalytic ozonation of organic pollutants

ZnFe 2 O 4 is a promising photocatalyst in the advanced oxidation process for wastewater treatment due to its unique electronic and magnetic properties. Nevertheless, its practical application is greatly restrained by the high recombination rate of photoinduced charge carriers and the leaching of metal ions. Herein, carbon-coating strategy was employed to advance ZnFe 2 O 4 photocatalyst by virtue of the unique functionalities of carbon layer. ZnFe 2 O 4 coated with thin carbon-layer (ZFO@C) exhibited improved separation of photogenerated charge carriers and increased utilization of ozone, resulting in an enhanced photocatalytic ozonation of organic contaminants. Meanwhile, the carbon coating also inhibited the leaching of metals, which endowed ZFO@C with a robust durability for wastewater treatment. Furthermore, ZFO@C was easily separated by applying an external magnetic field. This study demonstrates that carbon-coated metal oxide semiconductors should be a promising catalyst for the remediation of organic pollutants. Carbon-coated ZnFe 2 O 4 (ZFO@C) behaved as an efficient, robust and recyclable catalyst for photocatalytic ozonation of organic pollutants. • Carbon layer improved the photogenerated charge carrier behavior of ZnFe 2 O 4 . • ZnFe 2 O 4 @C exhibited a synergistic effect between photocatalysis and ozonation. • ZnFe 2 O 4 @C demonstrated a good stability without metal ions leaching. • ZnFe 2 O 4 @C could be easily separated under an external magnetic field.