P-doped titania xerogels as efficient UV-visible photocatalysts

In the present study, sol-gel process is used to synthesize P-doped TiO2 xerogels by the cogelation method of a functionalized P alkoxide, (NH2-(CH2)2-NH-(CH2)2-P(O)-(OC2H5)2) with Ti(OC3H7)4 in either 2-methoxyethanol or isopropanol. The phosphorus-doping improved the thermal stability of titania and decreased the phase transformation of anatase into rutile. This modification by phosphorus shifted the absorption edge of titania to the visible region as proved by Diffuse reflectance measurements, and thus offers the possibility to produce visible light effective TiO2 photocatalyst. The excellent photocatalytic activity of P-doped TiO2 xerogels compared to pure TiO2 could be explained by its high surface area and small TiO2-anatase crystallite size. From these results, it was proved by using three different models that phosphorus intrinsically influences the photocatalytic activity.