Well-Dispersed Fe2O3 Nanoparticles on g-C3N4 for Efficient and Stable Photo-Fenton Photocatalysis under Visible-Light Irradiation

Graphical A heterogeneous photo-Fenton system (Fe 2 O 3 /g-C 3 N 4 /H 2 O 2 /visible light) has been developed for highly efficient and stable catalytic degradation of organic pollutants in water. The combination of the Fenton's reagent Fe 2 O 3 /H 2 O 2 and the photocatalyst g-C 3 N 4 greatly enhances the rate of the Fenton's reaction with the assistance of the photocatalytic process. In this study, a highly efficient heterogeneous photo-Fenton system (Fe 2 O 3 /g-C 3 N 4 /H 2 O 2 /visible light) has been developed. The heterogeneous catalyst Fe 2 O 3 /g-C 3 N 4 in this system was successfully prepared by growing Fe 2 O 3 nanoparticles on the surface of g-C 3 N 4 . The Fe 2 O 3 nanoparticles could achieve high dispersion on the surface of g-C 3 N 4 and form a heterojunction with g-C 3 N 4 to improve the charge separation. In addition, the combination of the Fenton's reagent Fe 2 O 3 /H 2 O 2 and the photocatalyst g-C 3 N 4 greatly enhances the rate of the Fenton's reaction with the assistance of the photocatalytic process. The results showed that the Fe 2 O 3 /g-C 3 N 4 catalyst had a superior catalytic activity as compared with the single component of Fe 2 O 3 or g-C 3 N 4 and the mechanical mixture of Fe 2 O 3 and g-C 3 N 4 . The catalyst prepared with 3 mL of FeCl 3 aqueous solution shows the best photo-Fenton photocatalytic efficiency with a reaction rate constant of 0.02461 mg L –1 min –1 , which is about 45.4, 8.4 and 7.2 times larger than that of pure Fe 2 O 3 (0.0005418 mg L –1 min –1 ), pure g-C 3 N 4 (0.00294 mg L –1 min –1 ) and the mechanically mixed Fe 2 O 3 /g-C 3 N 4 (0.0034 mg L –1 min –1 ), respectively. A possible mechanism for the visible-light-irradiated photo-Fenton photocatalysis is proposed, and the Fe 2 O 3 /g-C 3 N 4 catalyst exhibited stable performance without obvious loss of catalytic activity after four successive runs, showing a good application prospect for the photo-oxidative degradation of organic contaminants in wastewater.