3D interconnected porous g-C3N4 hybridized with Fe2O3 quantum dots for enhanced photo-Fenton performance

Highlights: • The FCN hybrids exhibited excellent photo-Fenton oxidation performance. • The Fe₂O₃ QDs loading improved the charge mobility and catalytic sites. • Enhanced activity mechanism and roles of active species were elucidated. Currently, the photo-Fenton oxidation has been increasingly studied in the domain of contaminant elimination. However, the lack of active sites and the slow charge migration in the catalytic process, still limit its practical application. 3D/0D hybrids offer a better opportunity for improving photo-Fenton activity due to their high charge mobility and increased number of catalytic sites, which is highly desirable but remains a large challenge. Herein, 3D interconnected porous g-C₃N₄ hybridized with Fe₂O₃ QDs (FCN) was developed and exhibited a porous structure and large specific areas. A large number of active sites and rapid charge separation/migration were achieved by the loading of ultrasmall Fe₂O₃ QDs on the surface of g-C₃N₄. Moreover, the high charge mobility of this material promoted the fast conversion of Fe³⁺ to Fe²⁺, resulting in the optimum synergistic effect between the photocatalytic and Fenton oxidation processes. Thus, the FCN catalysts exhibited excellent photo-Fenton oxidation activity towards the decomposition of organic contaminants (such as phenol, 2,4-dibromophenol, 2,4,6-trichlorophenol, rhodamine B and methyl orange). In addition, the roles of active species in the photo-Fenton oxidation reaction were also studied, and the results imply that the hydroxyl radicals played the most important role in the degradation of organic contaminants.