Aluminum oxide, or alumina, is renowned for its hardness, chemical stability, and corrosion resistance. It is extensively used in ceramics and refractories for high-temperature applications, as well as in abrasives like grinding wheels and sandpaper due to its hardness. Additionally, aluminum oxide serves as an electrical insulator in electronic components and as a catalyst support in petrochemical processes. Its biocompatibility makes it suitable for biomedical applications, and it is also utilized in protective coatings to enhance surface durability and wear resistance.

Aluminumoxide is used in composite materials, such as those combining covalent organicframeworks (COFs) with alumina, which serve as efficient separators inlithium-sulfur batteries.