Abstract: The photocatalysis N/TiO2 doped with different amount of urea was prepared by sol-gel method. Doped urea has little impact on the mean particle size which is about 30-50nm. The doping of urea doesn’t make the absorption threshold wavelength have an obvious red-shift. However, it leads to an increase in optical absorption intensity in the visible-light region. FI-IR spectra indicate that urea involves in the hydrolysis process of tetrabutyl titanate and forms a new covalent bond with TiO2 0.01% and 0.1% doped urea can increase visible-light photoactivity of the catalyst. The activity decreases as the doping amount continues to increase. The high initial concentration of the dye solution results in a decrease in the decolorization ratio. 0.01% N/TiO2 decolors methylene blue solution (4mg/L) under visible light and the performance of 92.8% for color removal reaches.

Key words: urea∕TiO2, photocatalytic activity, visible-light, dye decolorization