Zinc Oxide Vs Titanium Dioxide-Is Titanium Dioxide Covalently Bonded Together

Titanium dioxide (TiO2) is not covalently bonded together throughout its structure. Instead, it is an ionic compound, which means it is composed of titanium cations (Ti^4+) and oxide anions (O^2-). In the crystal lattice of titanium dioxide, the titanium and oxygen atoms are held together by ionic bonds, which involve the electrostatic attraction between the positively charged titanium ions and the negatively charged oxygen ions.

However, within the titanium dioxide molecule itself, the titanium and oxygen atoms are connected by covalent bonds. This might seem contradictory, but it’s important to distinguish between the bonding within a single molecule of TiO2 and the bonding in the bulk material.

In the molecular form of titanium dioxide (which is not commonly found in nature), the titanium atom would be covalently bonded to two oxygen atoms. But when TiO2 is part of a solid material, such as in its most common form as a white pigment or in sunscreen, the individual molecules are arranged in a lattice where the ionic bonds predominate. This ionic lattice structure is what gives titanium dioxide its characteristic properties, such as its high refractive index and opacity.