γ-Al2O3–NPs were synthesized by a green synthesis process based on Boswellia carterii resin extract and aluminum sulphate in an alkaline medium. Boswellia carterii resin extract is a significant reducing and stabilizing agent for synthesizing γ-Al2O3–NPs.Several techniques, including Fourier–transform infrared (FT-IR), UV–visible spectroscopy, x-ray diffraction, electron microscopy (XRD), energy dispersive x-ray (EDX), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and atomic force microscopy (AFM), were utilized to investigate the final product. XRD and SEM confirmed a plate-like crystalline structure with an average size of 17.5 nm. FT-IR analysis identified aluminum oxide stretching vibrations (655, 451) cm-1, U.V.-visible spectroscopy exhibits an absorption band at 252 nm, and the energy gap, Eg, of 4.91 eV. EDX confirmed the presence of Al, and O TEM and AFM showed agglomerated spherical plates. Antimicrobial assay revealed the highest inhibition at 0.25mg/mL with a decrease in concentration from 2mg/mL to 0.25mg/mL for Staphylococcus aureus, Escherichia coli, and Candida albicans fungi. Adsorption studies by U.V-visible spectroscopy demonstrated high metal ion (II) removal efficiencies: Co (89.18 %), Ni (87.33 %), and Cu (90.42 %).
