Synthesis and Characterization of ZnO Nanostructures Grown via a Novel Atmospheric Pressure Solution Evaporation Method

In this study, a novel method called “atmospheric pressure solution evaporation (APSE)” wasdeveloped for growing of Zinc Oxide (ZnO) nanostructures on Al2O3 surface. Zinc acetate dihydrate,Polyvinyl Pyrrolidone, and deionized water were used as precursor, capping, and solvent, respectively.The growth of ZnO nanostructures from evaporated solution was performed at three temperatures of300, 400, and 500°C. Field emission scanning electron microscopy (FESEM) demonstrated that ZnOnanostructures formed in nanorods or cauliflower-like rods based on the growth temperature. X-raydiffraction patterns of ZnO nanostructures prepared at different growth temperatures were indexed ashexagonal Wurtzite structure without any impurity. The optical band gap energy evaluated by diffusereflectance spectroscopy (DRS) was 3.22∼3.29 eV. Optical properties of the ZnO nanostructures areinvestigated by UV–Vis spectroscopy. There is a blue shift in the band edge with changing of thegrowth temperature. The degradation of Methylene Blue (MB) dye demonstrated that ZnO nanorodsgrown at the growth temperature of 300°C showed better photodegradation compared to othernanostructures. Antifungal properties of ZnO nanorods against Candida albicans were much higherthan that of the other nanostructures. This method, compared to other synthesis methods of ZnOnanostructures, offers several advantages, such as simplicity, cost-effectiveness, low-temperature,atmospheric pressure, and large area deposition. Such a low-temperature growth method may exposegreat opportunities for synthesis of ZnO nanorods onto various low-temperature-endurance substratesand extend the field of ZnO-based nanoscale devices.