Titanium dioxide nanoparticles are valued for their wide bandgap, high chemical stability, and strong UV‐driven photocatalytic response, which is enhanced by their large surface area at the nanoscale. They are the most explored photocatalytic nanoparticles and they efficiently generate reactive oxygen species under irradiation, enabling the degradation of organic pollutants. TiO₂ is therefore widely used in environmental photocatalysis for air and water purification, as well as in self‐cleaning coatings, UV-shielding and dye‐sensitized solar cells.