Photocatalytic properties of ZnO thin film with different morphologies from seed, array to grass

ZnO thin film with different morphologies from seed, array to grass was grown by simple aqueous solution method under room temperature. The morphologies, structure, optical properties and photocatalytic properties of the samples were characterised by transmission electron microscope, scanning electron microscope, X-ray diffraction, fluorescence spectrometer, UV-Vis spectrophotometer and photocurrent response. The results showed that the ZnO arrays and grassy ZnO were both hexagonal wurtzite with uniform distribution and regular growth on the glass substrate. ZnO thin film with different morphologies affected the utilisation efficiency of the ultraviolet light. Multiple light reflections inside the grassy ZnO greatly increase the light efficiency. The methyl blue degradation rate of grassy ZnO photocatalyst was superior under the UV light compared to the other ZnO morphologies. Grassy ZnO showed favourable stability after five cycles. The comparison of the ZnO semiconductor in different dimensions is helpful for further research on other photocatalysts as well as their potential application.