CoCO3 hierarchical structure embedded on g-C3N4 nanosheets to assemble 3D/2D Z-scheme heterojunction towards efficiently and stably photocatalytic hydrogen production

Abstract

Structure and interface control of heterojunction is usually a challenging issue to improve the photocatalytic performance. Herein, a new 3D/2D CoCO3/g-C3N4 heterojunction is assembled by embedding hexahedral CoCO3 on g-C3N4 nanosheets. The unique step-like hierarchical structure of CoCO3, the formed built-in electric field and Z-scheme charge transfer behavior at the interface jointly drive the high-efficient separation of photogenerated carriers to boost the photocatalytic H2 production. It achieves the optimal H2 production rate that is almost 2.6 times than g-C3N4, apparent quantum efficiency (AQE) of 10.1% at 400 nm and continuous running of 60 h over the 3D/2D CoCO3/g-C3N4 heterojunction. This work endows a fresh structural control strategy for the fabrication of 3D/2D Z-scheme heterojunction to improve the photocatalytic H2 production performance.