Study of the structural phase transformation, and optical behavior of the as synthesized ZnO–SnO2–TiO2 nanocomposite

Bulk nanocomposites ZnO-SnO2-TiO2 were synthesized by solid-state reaction method. The X-ray diffraction patterns and Raman spectra of bulk nanocomposite as a function of sintering temperature (700 degrees C-1300 degrees C) indicate that the structural phases of SnO2 and TiO2 depend on the sintering temperature while the ZnO retains its hexagonal wurtzite phase at all sintering temperatures and SnO2 started to transform into SnO at 900 degrees C and completely converted into SnO at 1100 degrees C, whereas the titanium dioxide (TiO2) exhibits its most stable phase such as rutile at low sintering temperature (<= 900 degrees C) and it transforms partially into brookite phase at high sintering temperature (>= 900 degrees C). The optical band gap of nanocomposite ZnO-SnO2-TiO2 sintered at 700 degrees C, 900 degrees C, 1100 degrees C and 1300 degrees C for 16 hours is calculated using the transformed diffuse reflectance ultra violet visible near infra red (UV-VisNIR) spectra and has been found to be 3.28, 3.29, 3.31 and 3.32 eV, respectively.