Facile Preparation of Magnetically Separable Fe3O4/ZnO Nanocomposite with Enhanced Photocatalytic Activity for Degradation of Rhodamine B

Magnetic separation of photocatalysts holds great promise for water treatment. A magnetic separation method has a positive effect on the recovery of catalysts after degradation. In this paper, an efficient and reusable catalytic system is developed based on coating magnetic Fe3O4 by depositing Fe2+ on the surface of ZnO. The Fe3O4/ZnO nanocomposite exhibits enhanced performance for organic pollutant degradation. The Fe3O4/ZnO system demonstrates a high photocatalytic activity of 100% degradation efficiency in Rhodamine B (RhB) degradation under UV light irradiation for 50 min. The excellent photocatalytic activity is primarily due to the separation of photogenerated electron-hole pairs being facilitated by the strong interaction between Fe3O4 and ZnO. The induction of the magnetic Fe3O4 endows the Fe3O4/ZnO composite with superior magnetic separation capability from water. Experiments with different radical scavengers revealed that the hydroxyl radical (·OH) is the key reactive radical for the effective degradation of RhB. This work innovatively affords a common interfacial dopant deposition strategy for catalytic application in the degradation of organic dye pollutants and catalyst separation from wastewater efficiently.

Graphitic carbon nitride-based materials in activating persulfate for aqueous organic pollutants degradation: A review on materials design and mechanisms

With the increasingly serious water environment problem, the persulfate-based advanced oxidation process (PS-AOP) has attracted considerable attention in water pollution treatment. To date, graphitic carbon nitride (g-C₃N₄) has been greatly favored by researchers in activating PS for its capability and unique superiorities. Though g-C₃N₄-based PS-AOP exhibits huge development prospects in removing organic pollutants, the review about its research progress has not been reported. Herein, this paper reviews the modification of g-C₃N₄ on the basis of its applications and properties for PS activation systematically. The activation mechanisms of g-C₃N₄-based modified materials are analyzed in detail, and the main formation pathways of radicals and non-radicals and their interaction mechanism with pollutants are thoroughly summarized. Finally, the existing challenges and future development directions of the PS-AOP driven by g-C₃N₄-based materials are critically discussed. The key purpose is to provide a reference for promoting the further popularization of this novel and efficient cooperative AOP in water purification industries, as well as multidisciplinary inspirations for g-C₃N₄-involved fields.