Facile synthesis of 2D/2D Co3(PO4)2/g-C3N4 heterojunction for highly photocatalytic overall water splitting under visible light

Abstract

The photocatalytic overall water splitting is an ideal pathway to generate hydrogen gas for sustainable energy production. Herein, the 2D/2D Co3(PO4)2/g-C3N4 heterojunctions were successfully synthesized for overall water splitting from pure water by a simple direct precipitation route under the effect of coulomb electrostatic interaction. The introduction of Co3(PO4)2 nanosheets broadens the light absorption range of Co3(PO4)2/g-C3N4 heterojunction, and in addition, the unusual 2D/2D heterostructure can provide more contact areas to promote the interfacial charge transfer between g-C3N4 nanosheets and Co3(PO4)2 nanosheets, which considerably enhances the photogenerated charge separation. Among the Co3(PO4)2/g-C3N4 heterojunctions, 35% Co3(PO4)2/g-C3N4 exhibits the optimal H2 and O2 evolution rates which are 375.6 and 177.4 μmol g−1 h−1, respectively. Moreover, the apparent quantum efficiency of the 35% Co3(PO4)2/g-C3N4 reaches up to 1.32% at 420 nm. Furthermore, the 2D/2D Co3(PO4)2/g-C3N4 composite possesses the prominent stability and recyclability, testifying a potential application for the conversion of the sustainable energy.