This research set out to provide a faster, easier, and more efficient process for nanoparticle (NP) synthesis of aluminum oxide NPs preparation by microwave irradiation, using plant extracts separately and in the same way (tea, coffee, rosemary), which is an easy-to-use and inexpensive method. The structural properties were investigated by X-ray diffractometer analysis technique (XRD). The X-ray analysis shows the structure has a polycrystalline nature with a hexagonal phase. The optical properties were studied using ultraviolet visible (UV-Vis) spectrometer, where the energy gap was determined. The surface morphology properties of the prepared aluminum NPs were examined by atomic force microscope (AFM). The Fourier transform infrared (FTIR) spectroscopy verified the presence of Al-O, C–O, and C–H bonds, this study confirms the high reducing and capping capacity of aluminum NPs via biomolecules found in the plant extract. The inhibitory activity of these Al2O3-NPs was observed, along with their potential to enter the bacterial cell wall and hinder its activity.
