Growth mechanism, optical and photocatalytic properties of ZnO nanorods@nanoflowers (quantum dots) hybrid nanostructures

ZnO nanorods@nanoflowers (quantum dots) hybrid nanostructures have been successfully fabricated by the spin coating method. The transmission electron micrograph (TEM) and field-emission scanning electron microscopy (FE-SEM) images showed that ZnO quantum dots (QDs) and ZnO nanoflowers (NFs) had been assembled on the surfaces of ZnO nanorods (NRs) or in the upper parts of the gaps between the rods. The morphology of ZnO nanoflowers was formed through a general route of zero-dimensional (0D)→2D→3D, controlling by sodium dodecyl sulfate (SDS) during the experiment. The blue-shifts of Raman and PL spectra were observed for the hybrid nanostructures at room temperature, which were explained by the quantum confinement effects. Compared with the photocatalytic activities of the samples, ZnO NRs@NFs showed enhanced photocatalytic performance for the degradation of RhB under UV radiation, which could be attributed to the special structural feature with an open and porous nanostructured surface layer and the surface defects. ZnO NRs@NFs would show a wider application for its particular porous morphology.