Promoting Charge Separation in g-C3N4/Graphene/MoS2 Photocatalysts by Two-Dimensional Nanojunction for Enhanced Photocatalytic H2 Production

Abstract

Graphitic carbon nitride (g-C3N4) is a promising photocatalyst for solar H2 generation, but the practical application of g-C3N4 is still limited by the low separation efficiency of photogenerated charge carriers. Herein, we report the construction of ternary g-C3N4/graphene/MoS2 two-dimensional nanojunction photocatalysts for enhanced visible light photocatalytic H2 production from water. As demonstrated by photoluminescence and transient photocurrent studies, the intimate two-dimensional nanojuction can efficiently accelerate the charge transfer, resulting in the high photocatalytic activity. The g-C3N4/graphene/MoS2 composite with 0.5% graphene and 1.2% MoS2 achieves a high H2 evolution rate of 317 μmol h–1 g–1, and the apparent quantum yield reaches 3.4% at 420 nm. More importantly, the ternary g-C3N4/graphene/MoS2 two-dimensional nanojunction photocatalyst exhibits much higher photocatalytic activity than the optimized Pt-loaded g-C3N4 photocatalyst.