Introduction: A low cost alternative is always needed for the fabrication of ZnO nanostructured thin film with simplified route and minimum chemical use. In this study, we report a simple one-step green synthesis of zinc oxide nanostructured thin film by anodizing of 99 % pure zinc plate in distilled water. Method: Anodizing was conducted by using two electrodes cell at voltage of 30 V and the temperature of distilled water was varied from 5 to 25 °C. We observed that the morphology of ZnO thin film depends significantly on the temperature of the distilled water. FESEM images showed that ZnO thin film without nanostructures is formed when anodizing was conducted in distilled water of 5 °C while ZnO nanostructures are formed in the distilled water with anodizing temperature between 10 °C to 25 °C. The density of the ZnO nanostructures increases with the temperature of distilled water. Conclusion: Energy-dispersive X-ray spectroscopy analysis showed that Zn and O species are present in both ZnO thin films formed at 5 °C and 25 °C, respectively. X-ray diffraction results confirmed that ZnO is present in all Zn plates that were anodized in distilled water ranged from 5 to 25 °C. The intensities of the peaks in XRD patterns corresponding to ZnO increase as the temperature of the distilled water increased from 5 to 25 °C. Photoluminescence spectra of the anodized Zn plate show 2 emissions, at around 380-400 nm and at 650 nm respectively, regardless of the temperature of the distilled water.
