Abstract
In this work, we are mainly interested in the development of active photocatalysts based on TiO2 modified by coupling to ZnO:Mn/SiO2 (Zn–Si). Structural characterization by XRD and microstructural study by TEM performed on samples of TiO2 nanoparticles and Zn–Si/TiO2 (Ti-SZ) nanocomposites revealed the formation of anatase nanoparticles and Zn–Si phase. However, analysis of optical properties of these samples has shown a significant improvement in absorption over the visible range. The study of the optical properties of TiO2 modified by the SZ shows a displacement of the absorption front towards the visible range that is in between 420 and 550 nm, reflecting a significant enlarge in the energy gap band of the TiO2 at 3.30 eV. The emission PL around 535 nm is attributed to the recombination of photo-generated electrons with oxygen defects at the surface. This photo-activity was compared with that of the commercial catalyst TiO2–P25. The obtained photocatalytic results show that the activity of TiO2 modified by SZ remains close to that of the reference TiO2–P25.