Photo-Conversion and Photo-Catalytic Efficiency of Hydrothermally Treated Anatase-TiO2 Films and Nanoparticles

We describe the influence of hydrothermal and solvothermal treatment conditions of anatase TiO2 nanotube (Ntb) films and nanoparticles (Nps) on the UV light conversion and photo-catalytic efficiency. Our results indicated that additional hydrothermal and solvothermal treatment in the ethanol-water solution resulted in the remarkable increase of photo-conversion efficiency of calcined TiO2 Ntb films. Similarly, in case of crystalline TiO2 Nps, the additional hydrothermal and solvothermal treatments are beneficial for significant enhancement of their photo-catalytic activity. X-ray diffraction, Raman and X-ray photoelectron spectra as well as thermo-gravimetric plots implied that these improved performances can be mainly attributed to the binding of water molecules to the surface of TiO2 crystallites creating numerous attached OH¯ species capable of trapping the holes and reducing recombination of excited h+e- pairs.