▎ 摘　　要

Nitrogen-doped graphene quantum dots (N-GQDs) have been synthesized using a hydrothermal process. The N-GQDs are highly crystalline with a size of 3-7nm and made up of 1-3 layers of graphene. UV/Vis absorption studies reveal two major absorption peaks at 237 and 334nm, which are attributed to the * transition of C=C and n* transition of C=O bonds, respectively. The additional broad peak observed at 460-500nm is attributed to the n* transition of C=N bonds. The N-GQDs are highly luminescent and exhibit excitation-dependent emission. The photoelectrochemical properties of pristine ZnO and N-GQD-sensitized ZnO nanorods have been investigated. N-GQD-sensitized nanorod photoanodes demonstrate superior photoconversion efficiency, incident photon-to-current conversion efficiency, and power conversion efficiency compared with pristine ZnO nanorods.