Fabrication of porous g-C3N4/Ag/Fe2O3 composites with enhanced visible light photocatalysis performance

Abstract

Porous graphitic carbon nitride (pg-C₃N₄) synthetized by pyrolysis of urea was hybridized with Ag-doped Fe₂O₃ to form a visible-light-driven photocatalyst pg-C₃N₄/Ag/Fe₂O₃ via a simple chemical adsorption method. The obtained pg-C₃N₄/Ag/Fe₂O₃ composites with different Ag/Fe₂O₃ content were characterized in terms of composition, morphology, and optical properties by XRD, EDS, FT-IR, TEM and UV-vis DRS. The photocatalytic activities were evaluated by degradation of Rhodamine B (RhB) as a representative organic pollutant under visible light irradiation. The results showed Ag/Fe₂O₃ (5 wt%) modified pg-C₃N₄ exhibited excellent photocatalytic activity in the degradation of RhB and the degradation rate was 2.74 times higher than that of pure pg-C₃N₄. The heterostructured coupling of pg-C₃N₄ with a novel metal, Ag, and semiconductor, Fe₂O₃, in the aspect of energy level matching would effectively improve visible-light absorption capability and facilitate photogenerated electron–hole pairs separation, synergistically accounting for the enhancement of photocatalytic activity. A possible photocatalytic mechanism was also tentatively proposed.