A simple method to synthesize whorl-shaped zinc oxide (ZnO) nanostructures using hydrothermal conditions with ZnSO4, liquid ammonia, and double-distilled water. The technique involves combining drop coating with spin coating successive ionic layer adsorption and reaction (SILAR) to develop ZnO thin films. The samples were characterized using XRD, SEM, FTIR, and UV-Vis spectroscopy. The results show that the average crystal size of the ZnO nanostructure is around 500nm and can be readily synthesized in hydrothermal conditions. The UV-Vis absorption spectra indicate that the energy of ZnO...