Influence of Annealing and UV Irradiation on Hydrophilicity of Ag-TiO2 Nanostructured Thin Films

Abstract EN

Ag-TiO2 nanostructured thin films with silver content of 5 vol% have been deposited on silicon, glass, and quartz substrates by RF magnetron sputtering and annealed in ambient air at 900°C for 15, 30, 60, 90, and 120 min.

Their crystal structure, surface morphology, and hydrophilicity have been characterized by X-ray diffractometer, atomic force microscope, and water contact angle apparatus, respectively.

The influence of annealing time and UV irradiation time on hydrophilic property of Ag-TiO2 thin films have been studied in detail.

It is shown that annealing time influences crystal structure of Ag-TiO2 thin films.

The unannealed film is amorphous and shows poor hydrophilicity.

With the increase of annealing time from 15 to 120 min, the grain-size slowly increases and tends to uniformity.

A suitable annealing time can significantly enhance the hydrophilic behavior of Ag-TiO2 films.

Water contact angle decreases with the increase of irradiation time.

The mechanism of hydrophilicity has been proposed and can be attributed to the increase of oxygen anion radicals O2- and reactive center of surface Ti3+.