Effect of oxygen vacancy on enhanced photocatalytic activity of reduced ZnO nanorod arrays

Partially reduced ZnO nanorod arrays (NRAs) were synthesized in a reducing reagent of NaBH4. The NaBH4 treatment substantially increased the density of oxygen vacancies. The ZnO NRAs with a partially reduced surface exhibited much higher photocatalytic activity. The improvement of activity was ascribed to the introducing oxygen vacancies. The increased surface oxygen vacancy decreased the surface recombination centers, and improved the charge separation efficiency, thus enhances the photocatalytic activity.