Aluminum Oxide Nanoparticles: Properties and Applications Overview

Aluminum oxide nanoparticles (Al2O3 NPs) have attracted significant attention to various scientific and industrial fields due to their unique bio−/physicochemical properties: high surface area, high hardness, thermal stability, biocompatibility, surface functionalization, and electrical insulation. This chapter exposes the key aspects of Al2O3 NPs synthesis that include sol-gel, hydrothermal, combustion, and green methods. Each method provides control over the particle size, shape, and chemical surface, enabling tailored nanoparticles for specific applications. In catalysis, Al2O3 NPs serve as efficient catalyst supports, enhancing reaction rates and selectivity. Additionally, their remarkable dielectric properties make them valuable for electronic and optoelectronic devices. Moreover, Al2O3 NPs have demonstrated promising results in biomedical applications, including drug delivery systems, biomedical imaging, biosensing, and tissue engineering. Furthermore, recent studies have shown that Al2O3 NPs have potent antimicrobial and antiviral properties. Due to their small size, they can penetrate bacterial and viral cells more effectively, increasing the efficacy of their action. Al2O3 NPs can be incorporated into coatings for medical devices and hospital surfaces, helping prevent bacterial adhesion and biofilm formation, thereby reducing the risk of infections. In addition, Al2O3 NPs have demonstrated potent adjuvant activity for several vaccines throughout history, targeting and neutralizing a wide range of microorganisms. In the future, Al2O3 NPs hold great promise as key components in a wide range of advanced materials and applications, like advanced coatings, energy storage systems, catalysis, biomedical applications, environmental remediation, optoelectronics, photonics, and personal care products.