metalloksidid

Metalloksidid, or metal oxides, are binary inorganic compounds composed of metal cations and oxide anions (O2−). They exhibit a wide range of oxidation states and crystal structures, from simple oxides such as MO or MeO2 to more complex stoichiometries like Me2O3 or Me3O4. Their bonding is predominantly ionic with varying covalent character depending on the metal.

Metalloksidid occur widely in nature as minerals (for example hematite Fe2O3, magnetite Fe3O4, corundum Al2O3, rutile TiO2). They are typically high-melting compounds and can be insulators or semiconductors. Many metal oxides are colorful and are used as pigments (TiO2 white, Fe2O3 red/brown). They also play major roles in catalysis, electronics, ceramics, and construction materials; titanium dioxide is used as a white pigment and photocatalyst, vanadium pentoxide as a catalyst in sulfuric acid production, and zinc oxide in electronics and sensors.

Formation and reactivity: metal oxides form by oxidation of metals in air or oxygen at elevated temperatures, by roasting metal sulfides or carbonates, or by precipitation from metal salts followed by heat treatment. They often react with acids or bases; some, such as Al2O3 and Cr2O3, are amphoteric, while many basic oxides (CaO, FeO) form hydroxides in water.

Common examples include Fe2O3 (hematite), Fe3O4 (magnetite), Al2O3 (alumina), TiO2 (titania), ZnO, SnO2, and Cr2O3. Metalloksidid are central to materials science, geology, and industrial chemistry due to their stability, abundance, and diverse applications.