TiO2-based nanomaterials for wastewater treatment

Abstract Wastewater effluents from textile industries contain toxic chemicals, which need to be treated prior to effluent disposal. Semiconductor photocatalysis is emerging as potential technique for treating such effluents. The main advantage of this technique is the fact that organic contaminants are completely mineralized without requiring any further treatment. Titanium dioxide (TiO2) is the most efficient semiconductor photocatalyst as it is stable in aqueous media and tolerant to both alkaline and acidic solutions. Due to its wide bandgap (Eg ≈ 3.0 eV), TiO2 can absorb only the light in the UV region, and that is one of the biggest drawbacks of TiO2. Several attempts have been made recently to improve the photocatalytic performances of a TiO2 photocatalyst by extending the photoresponse of the UV-active semiconductor into the visible region through the bandgap engineering. This chapter outlines the interaction of fluorine and carbon nanotubes in TiO2 structure and the changes in photocatalytic activity of TiO2 and multiwalled carbon nanotube-fluorine-codoped TiO2 nanocomposites, which find potential applications of the nanocomposite in water treatment.