The inhibition of photocatalytic activity of rutile nanoparticles surface encrustation with La(OH) quantum dots.

Strategic materials for UV filters focus on creating substances that effectively block UV radiation while ensuring safety and stability. This study demonstrates the use of La(OH) quantum dots (QDs) to modify the surface of rutile TiO nanoparticles, aiming to reduce their photocatalytic activity under UV exposure, thus improving sunscreen safety. In-depth material characterisation techniques, including X-ray diffraction and transmission electron microscopy were carried out and UV filtering properties were confirmed through UV-visible spectroscopy and evaluation of photocatalytic activity (PCA). It was demonstrated that La(OH) QDs modulated the surface properties of TiO, leading to lower PCA compared to uncoated TiO. The most effective composite contained TiO modified with 5 wt% La(OH) paving the way for its potential use in sunscreen applications.