Structural and Optical Properties of Al2O3 Nanostructures Prepared by Hot Water Treatment Method

Aluminum oxide (Al2O3) nanostructures were synthesized on an aluminum foil substrate by green synthesis method using the hot water treatment method at 75°C for 1, 7, 15, and 30 minutes.In this study, growth time was varied to study its effect on the Al2O3 nanostructure's size and density.The morphological and structural properties of the as-prepared Al2O3 nanostructures were investigated using SEM imaging and XRD analysis, and the optical properties were studied through UV-Vis spectroscopy.Scanning electron microscopy (SEM) investigations revealed porous agglomerated Al2O3 nanostructures, and the porous nanostructured particle size decreased in the 80 nm-35 nm range as the synthesis reaction time increased from 1 to 30 minutes.X-ray diffraction (XRD) analysis indicated the crystalline behavior increased with increasing time.The optical properties results showed that Al2O3 nanostructures display a relatively broad absorption spectrum across the ultraviolet region.Furthermore, the energy gap (Eg) increased from 3.44 to 3.78 eV when the immersion time increased from 1 minute to 30 minutes, respectively.These results have a significant impact on the Al2O3-assisted electronic application based on HWT Al2O3 nanostructures for a sustainable green earth.