STUDIES REGARDING SOME PROPERTIES OF TIO2 THIN LAYERS DEPOSITED THROUGH SPUTTERING METHOD

The aim of our project is to enhance photocatalytic properties of titanium dioxide for further air depollution applications. Photocatalysis as an advanced oxidative process, offers valuable solutions for depollution of water and air, simply or in combination with other methods. From photocatalysis advantages one could point to possibilities of use it far from the source of pollution and to a very low consumption of energy. Sometimes only solar energy needed. It is proved that hundreds of undesirable substances could be neutralized by photocatalysis. Pure or doped TiO2 is the most studied photocatalyst because exhibits proper properties as far as concern the band gap, costs and availability. The first stage of studies is deposition of thin nanostructured layers to study physical and chemical properties. Films of titania were obtained by sputtering method on different substrates, as silicon, mica and glass. A self made vacuum device with a direct current magnetron was used. Pressure, temperature, gas composition (mixture of argon and oxygen), current intensity and voltage were monitored and varied to assure different conditions for sputtering deposition. The surfaces of the samples were studied by optical microscopy and by atomic force microscopy. Structure, effective area and composition of films, correlated with deposition conditions serve to optimize the process of fabrication for next stages of the project.