Study of the optical properties of TiO2 semiconductor nanoparticles synthesized using Salvia rosmarinus and its effect on photocatalytic activity

In recent years, the green synthesis of nanomaterials has gained interest as an efficient and environmentally friendly method for obtaining metal oxide nanoparticles. This work presents a study on the effect of Salvia rosmarinus extract in the optical properties and photocatalytic activity of titanium oxide (TiO2) nanoparticles (NPs) synthetized through a green route. Titanium tetrachloride (TiCl4) was used as the Ti source, while Salvia rosmarinus extract with different amounts (1%, 2%, and 4% w/v) was used as a stabilizing agent. Fouriertransform infrared spectroscopy (FTIR) characterization shows the presence of the Ti-O-Ti band at 408 cm-1, while X-ray diffraction (XRD) results identified the crystalline structure of anatase phase TiO2 with no impurities and scanning electron microscope (SEM) images showed a spherical shape with agglomerations. The calculated band gap values decreased from 3.21 eV to 2.93 eV as the extract concentration increased. The NPs showed great photocatalytic activity under solar irradiation, achieving over 90% degradation for methylene blue (MB) in just 20 min. Additionally, the NPs showed great degradation of methyl orange (MO), and rhodamine B (RhB) under UV irradiation, with the best sample reaching over 90% degradation in under 60 min of exposure.

Automated summary

This study synthesized titanium oxide nanoparticles using Salvia rosmarinus extract and investigated their optical properties and photocatalytic activity. The results showed that increasing the concentration of the extract resulted in a decrease in the band gap values of the nanoparticles, leading to enhanced photocatalytic activity.