Cerium phosphate nanoparticles with low photocatalytic activity for UV light absorption application in photoprotection

In this work a pigment material, cerium phosphate (CePO4) was investigated as a new UV filter with excellent morphological characteristics, desirable UV absorption features, low toxicity, and ideal particle size for application in sunscreen formulations. To this end, nanostructured CePO4 were synthesized by two different procedures: the Pechini (modified) method with, varying calcination temperatures (700–900 °C), and hydrothermal synthesis with different Ce3+|P3O105−Ce3+|P3O105− molar ratios, 1:1 and 1:2. The samples were characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy, diffuse reflectance spectroscopy, and photocatalytic activity. The excellent morphological properties, low photocatalytic activity, and high absorption in the UV region of the resulting compound indicated the possible application of CePO4 as a UV filter in sunscreen formulations, in order to substitute the currently employed inorganic UV filters ZnO and TiO2.

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► CePO4 nanoparticles were prepared by Pechini and Hydrothermal methods.
► Desirable UV absorption features and ideal particle size for sunscreen formulations.
► Little diffuse reflectance in the UV region indicating high UV absorption.
► CePO4 is highly attractive as an inorganic UV absorber.