Ternary Hybrid Aerogels of g-C3N4/alpha-Fe2O3 on a 3D Graphene Network: An Efficient and Recyclable Z-Scheme Photocatalyst

Abstract

A Z-scheme graphitic carbon nitride (g-C3N4)/alpha-Fe2O3 has been incorporated into a three-dimensional porous graphene aerogel. Graphene aerogels are a promising framework in their use for practical photocatalysis by abundant reaction sites, efficient mass transport of reactants and recyclability through their free-standing framework. At the same time, Z-scheme charge transfer among g-C3N4, alpha-Fe2O3, and conductive graphene inhibits the rapid recombination of the photoinduced electrons and holes. Ternary g-C(3)N4/alpha-Fe2O3/graphene aerogels (CNFGA) showed significantly enhanced photocatalytic activity which demonstrated 4.75 times greater methylene blue degradation and 17.5 times higher photocurrent density than those of exfoliated g-C3N4 under visible light. In addition, CNFGA exhibited a robust photostability with a simple recovery method while showing only a ca. 2 % decrease in photocatalytic performance after five cycles. These results suggest that this ternary Z-scheme photocatalyst based on a graphene aerogel has potential use in practical photocatalysis for various environmental applications.