LAUSR

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.