Novel, composite silver/titania immobilized on glass substrates were prepared, characterized
and their photocatalytic activity was evaluated. The undoped original material consists of rough, high surface
area nanocrystalline titanium dioxide (TiO2) thin films. To increase their efficiency, the TiO2 films were
modified by silver cations deposition and subsequent UV-C irradiation. SEM pictures confirmed the existence
of an open porous network of interconnected titania particles on the semiconductor surface. AFM
analysis proved the presence of spherical silver particles on the catalyst surface and provided quantitative
surface parameters as fractal dimension, surface roughness and mean particle diameter. Spectroreflectometry
showed the presence of an increase in optical absorbance attributed to plasmon resonance absorption of
the silver clusters. The photocatalytic properties of the surface modified materials were investigated through
photodegradation of Methyl Orange. The silver deposition conditions were optimized for maximum photocatalytic
efficiency and crucial parameters such as dipping period, UV irradiation time, and concentration
of the dipping solution were determined. The optimum silver nitrate concentration of the dipping solution
was found to be 10-3 M. This silver doped photocatalyst decomposes the azo-dye pollutant 3-times faster
than the un-doped Degussa P25 TiO2 film. A concentration increase results in a decrease of the films photocatalytic
performance. Strength and reproducibility tests proved that the photocatalytic activity of the silver
doped titania was perfectly reproducible.
