Glossary

Titanium dioxide (chemical formula TiO₂) is a white, inorganic compound made from the element titanium and oxygen. It is one of the whitest and brightest substances known, valued for its exceptional opacity, brightness, and UV resistance. Titanium dioxide occurs naturally in minerals such as rutile, anatase, and brookite, and it is extensively refined and processed for industrial use.

The compound’s primary function is as a white pigment and opacifier, meaning it reflects and scatters light extremely efficiently. This makes it indispensable in products like paints, coatings, plastics, papers, ceramics, rubber, inks, fibers, cosmetics, and food. In fact, titanium dioxide is the most widely used white pigment in the world, often labeled as “Titanium White” or Pigment White 6. Its chemical stability and non-reactivity allow it to retain color brilliance and opacity even in harsh environments, and it does not yellow or degrade over time.

Beyond its use as a pigment, titanium dioxide also has important photocatalytic and UV-protective properties. In sunscreens, it acts as a physical UV blocker, reflecting and scattering ultraviolet light to protect skin from sun damage. In photocatalysis, TiO₂ is used in self-cleaning coatings, air purifiers, and antimicrobial surfaces—when exposed to UV light, it generates reactive oxygen species that break down organic pollutants and kill bacteria.

There are two main crystalline forms used industrially: rutile and anatase. Rutile TiO₂ has a higher refractive index and greater stability, making it ideal for paints and coatings that require high opacity and durability. Anatase TiO₂, on the other hand, has superior photocatalytic activity and is preferred for environmental and catalytic applications.

Titanium dioxide is produced from titanium-bearing ores such as ilmenite (FeTiO₃) and rutile (TiO₂) through one of two methods: the sulfate process, which uses sulfuric acid, or the chloride process, which involves titanium tetrachloride (TiCl₄) and is cleaner and more efficient.