Combining g-C3N4 with CsPbI3 for efficient photocatalysis under visible light

Cesium lead halide perovskites (CsPbX3, X = Cl, Br, and I) have been used to develop CsPbX3-based novel composite photocatalysts that can work under visible light, but cesium lead triiodide/graphitic carbon nitride (CsPbI3/g-C3N4) composite was not reported previously. Herein, a new photocatalyst denoted as CsPbI3/protonated g-C3N4 (CsPbI3/pCN) was first prepared by mixing pCN with CsPbI3 in hexane, followed by ultrasonic treatment, magnetic stirring, and drying. The photocatalytic performance of relevant samples was evaluated under visible light irradiation. CsPbI3/pCN exhibited higher photocatalytic activity in the degradation of Rhodamine B than CsPbI3 and pCN. The same trend was found in photocatalytic water splitting to produce hydrogen using Pt as a co-catalyst. Several characterization tools were used to study the reasons for the improved photocatalytic performance of CsPbI3/pCN and Pt-CsPbI3/pCN, and the photocatalytic mechanisms were proposed. This study provides a new example on the development of CsPbX3-based composite photocatalysts that can work under visible light.