Fabrication of nitrogen defect mediated direct Z scheme g-C3Nx/Bi2WO6 hybrid with enhanced photocatalytic properties

A direct Z scheme g-C3Nx/Bi2WO6 heterojunctions with enhanced photocatalytic performances were successfully prepared through nitrogen defect mediated method. HRTEM analyses illustrate Bi2WO6 nanoparticles are closely bonded with the g-C3Nx-0.05 nanosheets to form the g-C3Nx-0.05/Bi2WO6 heterogeneous structures. An outstanding visible light absorption ability is shown in the g-C3Nx-0.05/Bi2WO6 hybrid, which combines both the light absorption advantages of g-C3Nx-0.05 and Bi2WO6 together. In comparison with other photocatalysts the nitrogen defect mediated g-C3Nx-0.05/Bi2WO6 hybrid shows the best photocatalytic properties, whose degradation efficiency can reach 83%. PL results indicate that an obvious larger amount of ·OH radical is produced on the g-C3Nx-0.05/Bi2WO6 surface in the photocatalytic process. In the nitrogen defect mediated g-C3Nx-0.05/Bi2WO6 the binding energies of C and N shift positively to the larger binding energy and the Bi, W and O elements shift negatively compared with that of the pristine g-C3Nx-0.05 and Bi2WO6. The MS results show the g-C3Nx-0.05 has a more negative Ef than that of Bi2WO6. All the experimental results support the direct Z scheme charge transfer mechanism proposed in the g-C3Nx-0.05/Bi2WO6 photocatalyst. The developing of direct Z scheme g-C3Nx-0.05/Bi2WO6 hybrid with excellent photocatalytic performance through defect mediated method shows great potential for more photocatalytic fields.