2D/1D Z-scheme WO3/g-C3N4 photocatalytic heterojunction with enhanced photo-induced charge-carriers separation

Abstract

Graphitic carbon nitride (g-C3N4) is a photocatalytic semiconductor with great potential for application, whereas, its photocatalytic activity is limited by the high re-combination rate of photo-generated electrons and holes. Here, we load two-dimensional (2D) WO3 nanosheets on the surface of one-dimensional (1D) g-C3N4 porous nanotubes to form a Z-scheme heterojunction. The built-in electric field at the interface of the heterojunction is conducive to promoting electrons transfer from the conduction band of WO3 to the valence band of g-C3N4 and therein combine with the holes. This inhibits electron–hole re-combination in g-C3N4 and WO3, and thus retains the high redox potential of the photo-generated charge-carriers. Therefore, the 2D/1D WO3/g-C3N4 heterojunction shows excellent photocatalytic hydrogen production and Rhodamine B degradation activities. Under simulated sunlight, photocatalytic hydrogen production rate of the WO3/g-C3N4 heterojunction reaches 7.78 mmol g−1 h−1, 2.7 times that of the single g-C3N4 porous nanotubes.