Surface properties enhancement by sulfur-doping TiO2 films

TiO2 films were sulfur-doped through an alternative route based on the decomposition of H2S at low temperatures. MOCVD technique was used to grown the films on borosilicate glass substrates at 400 degrees C. The doping was carried out at 50, 100 and 150 degrees C under a mixture of H-2-2%v.H2S. SO42- groups were observed in the surface revealing the substitution of Ti4+ by S6+. Superficial roughness and wettability were also modified by the formation of these sulfate groups on the surface. Photocatalytic experiments of methyl-orange dye decolorization under visible light indicated that the 8 at.% S-TiO2 film exhibited the highest photocatalytic activity, with 72.1% of dye decolorization. The results suggest that the exposition of TiO2 films to the mixture H-2-H2S at low temperatures is an efficient method of doping. These films allow the decolorization of the dye under visible light irradiation, which enable its practical use under sunlight or even indoor.

Automated summary

TiO2 films were sulfur-doped through the decomposition of H2S at low temperatures using MOCVD technique, resulting in the formation of SO42- groups on the surface. The sulfur-doped TiO2 films exhibited high photocatalytic activity under visible light, enabling dye decolorization.