Photocatalytic properties of La₂Ti₂O₇ synthesized by glycine-assisted sol-gel method and its impact on intestinal and blood-brain barriers

Abstract

International audienceThe La₂Ti₂O₇ photocatalyst, synthesized using a glycine-assisted sol-gel method, demonstrates excellent efficiency in the photodegradation of both anionic dyes, such as Naphthol Green B and Eosin Y, and cationic dyes like Crystal Violet, at a pH of 5.8 under UV irradiation. Kinetic studies reveal that the degradation process follows first-order kinetics, specifically described by the Langmuir-Hinshelwood model. Additionally, this photocatalyst has been successfully utilized for the photoreduction of Cr(VI) to Cr(III). Mott-Schottky analysis of La₂Ti₂O₇ confirms its n-type semiconductor behavior and provides insights into its flat band potential. The conduction and valence band levels were determined experimentally through flat band potential measurements and optical band gap analysis, showing good agreement with theoretical values obtained from the Mulliken electronegativity approach. Furthermore, photocurrent transient response measurements under both UV and solar excitation reveal a higher photocurrent density in the UV spectral region, consistent with the material's absorption characteristics. This suggests the photocatalyst's potential applicability in treating various pollutants, making it a promising candidate for wastewater remediation. For the first time, to the best of our knowledge, the impact of La₂Ti₂O₇ toxicity on the human body was also investigated. Specifically, its effects were studied on the human intestinal barrier and a human in vitro blood-brain barrier model. The results indicate no cytotoxicity at concentrations ranging from 0.1 to 1 μg.mL−1, highlighting its potential as a safe and effective material for environmental and biomedical applications