3D/2D Fe2O3/g-C3N4 Z-scheme heterojunction catalysts for fast, effective and stable photo Fenton degradation of azo dyes

Abstract

Graphite-phase carbon nitride (g-C3N4) as a common low-cost photocatalyst can be used for the degradation of dye wastewater. However, it mainly suffers from the rapid recombination of charge carriers, which limits its photodegradation activity. In this work, a Z-scheme heterostructure system composed of three-dimensional flower-like Fe2O3 and two-dimensional sheet-like g-C3N4 was constructed by a simple solvothermal method. The introduction of Fe2O3 not only enhances the absorption of visible light, but also strengthens its conductivity so as to improve the charge transport performance. Meanwhile, the heterojunction formation between Fe2O3 and g-C3N4 also promotes the efficient separation and transfer of photogenerated electrons and holes. By optimizing the experimental conditions of such as H2O2 dosage, Fe2O3 loaded amount and pH value, 8% Fe2O3/g-C3N4 exhibited excellent photocatalytic degradation activity on amaranth that the degradation efficiency could reach 97.6% within 10 min, which is among the best results reported thus far. Based on the analysis of degradation products, a photodegradation pathway of amaranth azo dye was also proposed.