Photocatalytic Degradation of Paracetamol and Antibacterial Activity of La-Modified TiO 2 Obtained by Non-Hydrolytic Sol–Gel Route.

The current study aims to synthesize and analyze both pure and La-doped TiO₂, and evaluate the photocatalytic and antibacterial activity of as-prepared samples. Doped and undoped samples were prepared by the non-hydrolytic sol–gel method from titanium(IV) chloride, benzyl alcohol, and lanthanum(III) nitrate followed by thermal treatment. Lanthanum content in synthesized samples was 0.4, 1, and 5 mol%. The resulting nanopowders' structure and morphology were described using XRD, IR, and UV–Vis analysis. The average particle sizes of pure and doped TiO₂ were about 6–15 nm and anatase was found to be a dominant crystalline phase in the samples. It was observed that particle sizes decreased on increasing La content. The photocatalytic activity of the pure and La-doped sol–gel powders was estimated in the decomposition of paracetamol in distilled water using ultraviolet light illumination. Doping with lanthanum ions has been shown to increase the photocatalytic properties on the degradation of paracetamol. Furthermore, the annealed catalysts (pure and La³⁺ doped) showed increased photocatalytic activity and degradation of the analgesic in comparison with non-annealed materials. In both cases, the highest photocatalytic efficiency is observed at the optimal La³⁺ (1 mol%) concentration. The antimicrobial activity of 1 mol% La/TiO₂ was tested against a reference strain E. coli in the presence of ultraviolet light and in dark conditions. The number of viable bacterial cells was determined by a spread plate method, and kill curves were performed. The results showed that photoactivated 1 mol% La/TiO₂ exhibited a strong bactericidal effect, and in concentration, 1 mg/mL efficiently killed bacteria at an initial cell density of about 10⁵ colony forming units in 1 mL within 15 min. [ABSTRACT FROM AUTHOR]