Microwave-assisted route to fabricate coaxial ZnO/C/CdS nanocables with enhanced visible light-driven photocatalytic activity

In this work, novel one-dimensional (1D) coaxial nanostructures composed of ZnO nanorod cores, intermediate amorphous carbonaceous layers, and CdS nanoparticle sheaths (i.e. ZnO/C/CdS nanocables) have been successfully synthesized via a multi-step process. First, ZnO/C core-shell nanocables are assembled via a facile hydrothermal reaction of ZnO nanorods and glucose in water at 160 degrees C for 6 h. Second, CdS nanoparticles are uniformly anchored on the surface of the ZnO/C core-shell nanocables through a rapid microwave irradiation route to form ternary coaxial ZnO/C/CdS nanocables. Further investigation reveals that the thickness of carbonaceous layer and the amount of CdS nanoparticles can be regulated by controlling of the glucose intake and the cadmium salt concentration, respectively. Due to stronger adsorption, and the synergistic effect of the ternary ZnO/C/CdS interface, the as-prepared nanohybrids exhibit an exceptionally higher activity than that of pure ZnO nanorods, pure CdS and ZnO/C core-shell nanocables for the degradation of rhodamine-B (RhB) and methylene blue (MB) under visible-light irradiation. The result also indicates that controlling the thickness of the carbonaceous layer and the amount of CdS nanoparticles in coaxial ZnO/C/CdS nanocables are crucial to obtaining an optimal synergistic effect between the three of them. Furthermore, it is believed that this facile strategy is scalable and its application can be extended to synthesize other 1D coaxial ternary nanocables for different applications.