Photochemical Characterization and Photocatalytic Properties of a Nanostructure CompositeTiO2Film

An efficient and new composite titania film photocatalyst was fabricated by sol-gel technique, using precalcined nanopowder titanium dioxide filler mixed with a sol, spin coating, and heat treatment. The structural and photocatalytic properties of these films were characterized using SEM, XRD, and UV/Vis spectroscopies. Problems of film inhomogenity and defects which caused peeling and cracking during calcination because of film shrinkage were overcome by using methylcellulose (MC) as a dispersant. Composite films heat-treated at approximately 500∘C have the greatest hardness values. Surface morphology of composite deposits by scanning electron microscopy (SEM) showed that the composite films have much rougher surface than films made without MC. Photocatalytic activities of the composites film were evaluated through the degradation of three commercial diazo textile dyes, Light Yellow X6G (C.I. Reactive Yellow 2), Solophenyl red 3BL (C.I. Direct 80), and Tertrodirect light blue R (C.I. Direct blue 71) as a model pollutant.