| Abstract | Nanostructure titanium dioxide (TiO2) has been synthesized by hydrolysis of titanium tetrachloride in
aqueous solution and Ag–TiO2 nanoparticles were synthesized by photoreduction method. The resulting
materials were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM),
Fourier-transforminfrared (FT-IR) and UV–vis absorption spectroscopy. The experimental results showed
that the sizes of the synthesized TiO2 and Ag–TiO2 particles are in the range of 1.9–3.2 nm and 2–10 nm,
respectively. Moreover, Ag–TiO2 nanoparticles exhibit enhanced photocatalytic activity on photodegradation
of Safranin-O (SO) dye as compared to pure TiO2. The positive effect of silver on the
photocatalytic activity of TiO2 may be explained by its ability to trap electrons. This process reduces
the recombination of light generated electron–hole pairs at TiO2 surface and therefore enhances the
photocatalytic activity of the synthesized TiO2 nanoparticles. The effects of initial dye and nanoparticle
concentrations on the photocatalytic activity have been studied and the results demonstrate that the dye
photodegradation follows pseudo-first-order kinetics. The observed maximum degradation efficiency of
SO is about 60% for TiO2 and 96% for Ag–TiO2. |