Structural and optical characterization of Ag-doped TiO2 nanoparticles prepared by a sol–gel method

Abstract

Undoped and silver-doped TiO2 nanoparticles (Ti1−xAgxO2, where x = 0.00–0.10) were synthesized by a sol–gel method. The synthesized products were characterized by X-ray diffraction (XRD), particle size analyzer (PSA), scanning electron microscope (SEM), and UV–Visible spectrophotometer. XRD pattern confirmed the tetragonal structure of synthesized samples. Average crystallite size of synthesized nanoparticles was determined from X-ray line broadening using the Debye–Scherrer formula. The crystallite size was varied from 8 to 33 nm as the calcination temperature was increased from 300 to 800 °C. The incorporation of 3 to 5% Ag+ in place of Ti4+ provoked a decrease in the size of nanocrystals as compared to undoped TiO2. The SEM micrographs revealed the agglomerated spherical-like morphology of particles. SEM, PSA, and XRD measurements show that the particles size of the powder is in nanoscale. Optical absorption measurements indicated a red shift in the absorption band edge upon silver doping. Direct allowed band gap of undoped and Ag-doped TiO2 nanoparticles measured by UV–Vis spectrometer were 3.00 and 2.80 eV, respectively, at 500 °C.