▎ 摘　　要

In this study, ZnxCd1-xS/N-GQDs composites with different Zn/Cd ratios were synthesized via a facile solvothermal process. A series of techniques were introduced to investigate the effect of Zn/Cd ratios and N-GQDs on the performances of ZnxCd1-xS/N-GQDs. The results show that the crystal structure and photoelectric performance of the composites can be tuned via adjusting the Zn/Cd ratios. ZnxCd1-xS/N-GQDs composites transform from a hexagonal structure to a cubic structure with the increase of Zn content, and the diffraction peaks are located between hexagonal phase CdS and cubic phase ZnS. Meanwhile, the photocurrent responses and electrochemical impedance present good tunability via adjusting the Zn/Cd ratios. Zn0.9Cd0.1S/N-GQDs composites with the higher photocurrent value of 3.79 mu A cm(-2) and lower interfacial impedance are superior to ZnxCd1-xS/N-GQDs composites with other Zn/Cd ratios. Moreover, the introduction of N-GQDs obviously enhances the photoelectric properties of the semiconductor. (C) 2019 Elsevier B.V. All rights reserved.