Abstract: ZnO/TiO₂ core-shell nanorod arrays were prepared via hydrothermal method and liquid phase deposition. Then N-doped ZnO/TiO₂ core-shell nanorod arrays were obtained by ECR nitrogen plasma. The morphology and structural properties were characterized by SEM，TEM，XRD，XPS，and the effect of nitrogen doping on its crystalline structure，element composition，and surface electronic state were studied. The optical performance and visible light photocatalytic performance were investigated using ultraviolet-visible spectrophotometer and photocatalytic performance testing device. The results indicate that nitrogen plasma treatment has no significant impacts on the crystalline structure of the nanorods and the nitrogen exists mainly in the form of substitutional N. With the decrease of the working pressure，the concentration of the substitutional N increases，while the optical bandgap of the nanorod arrays decreases. The photocatalytic activity tests show that the visible light photocatalytic efficiency of the N-doped ZnO/TiO₂ core-shell nanorod arrays increases with the concentration of the substitutional N. Based on the energy band theory，the enhancement mechanism of visible light photocatalytic performance was discussed.

Key words: soluble starch, nano-SiO₂, plasticizer, composite film