The inhibition of photocatalytic activity of rutile nanoparticles via surface encrustation with La(OH)3 quantum dots

Abstract

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)₃ quantum dots (QDs) to modify the surface of rutile TiO₂ 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)₃ QDs modulated the surface properties of TiO₂, leading to lower PCA compared to uncoated TiO₂. The most effective composite contained TiO₂ modified with 5 wt% La(OH)₃ paving the way for its potential use in sunscreen applications.