Phytosynthesis of TiO2 Nanoparticles Using E. crassipes Leaf Extracts, Their Photocatalytic Evaluation and Microbicide Effect

In the present research work, the photocatalytic and microbicidal activities of titanium nanoparticles (TiO2 NPs) were evaluated. TiO2 NPs were obtained through the phytosynthesis process, using Eichhornia crassipes leaf extract. In order to determine whether particle size improves photocatalytic and microbicidal activities, the pH of the photosynthesized was modified to 12, 7, and 4. The TiO2 NPs modified were characterized by UV-Vis spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), and high-resolution transmission electron microscopy (HR-TEM) to reveal the crystalline and morphological nature of the phytosynthesized TiO2 NPs. UV-Vis analysis revealed that the wavelength for the TiO2 NPs was 327 nm, while FT-IR confirmed the presence of TiO2 NPs at peaks located between 536 and 532 cm-1. Finally, HR-TEM analysis showed that all nanoparticles had a TiO2 composition and a particle size ranging from 25 to 35 nm. For the photocatalytic and microbicidal tests, three concentrations of nanoparticles were used (100, 50, and 10 mg/L), and the results showed that TiO2 nanoparticles at a concentration of 10 mg·L-1 demonstrated excellent photocatalytic activity in photodegrading phenol [10 mg·L-1] up to 98.7%, while their microbicidal activity was more effective in contact with S. aureus than with E. coli, using a TiO2 NPs concentration of 100 mg·L-1.