Well-ordered vertically aligned ZnO/CdS core/shell nanowires with enhanced photocatalytic performance

Well-ordered vertically aligned ZnO/CdS core/shell nanowires (NWs) were successfully synthesized on Si substrates through two-step ion exchange approaches. The morphology, crystal structure and composition were characterized by scanning electron microscope, X-ray diffraction, and high-resolution transmission electron microscope. The shell thickness can be easily tuned between 10 and 25 nm via changing ion exchange time and solution concentration. It is found that ZnO/CdS core/shell NWs exhibit enhanced light-harvesting ability in both UV and visible light range which leads to improved photocatalytic performance as compared to bare ZnO. In addition, the mechanism of the photo-performance is discussed to illustrate the efficiency enhancement of ZnO/CdS photocatalysts.