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

ZnFe2O4 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 ZnFe2O4 photocatalyst by virtue of the unique functionalities of carbon layer. ZnFe2O4 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.

Automated summary

ZnFe2O4 is a promising photocatalyst in wastewater treatment, but its high recombination rate and metal ion leaching greatly limit its practical application. Carbon-coating strategy improved the photocatalytic performance by enhancing charge carrier separation and ozone utilization, and inhibiting metal leaching. Moreover, the carbon-coated ZnFe2O4 can be easily separated using an external magnetic field.