Enhancement of Urbach's energy and non-lattice oxygen content of TiO1.7 ultra-thin films for more photocatalytic activity

Abstract This research presents strong photocatalytic activity for amorphous TiO1.7 prepared by atomic layer deposition to decompose the LBR (Levafix Brilliant Red) dye. LBR is an example of the pollutant dyes in the textile industrial wastewater. This activity has been enhanced significantly through decreasing the thickness from 40 to 8 nm. This behavior is explained by correlating the photocatalytic, optical, structural and photoluminescence properties. The thinner film has higher Urbach's energy (wider tail of localized states) and higher life time of the photo-generated charge carriers. This is attributed to increasing the non-lattice oxygen content which enhances the photocatalytic behavior of thinner films. Moreover, these ultra-thin films have ability to be recycled by the same efficiency indicating its promising application in the water purification from the organic dyes and pollutants.