Preparation of nitrogen-doped nano-TiO2 powders

Light yellow nitrogen-doped nano-TiO2 powders were prepared by directly calcining the mixture of anatase TiO2 powders and guanidine hydrochloride in the muffle furnace at different temperatures. The as-synthesized powders were characterized by XRD, BET, XPS and UV-Vis reflectance spectroscopy. X-ray photoelectron spectroscopy (XPS) results show that N atoms are incorporated into the lattice of TiO2 and the concentration of N is up to 8.3at%. XRD patterns indicate that all the powders are anatase crystalline phase. The UV-visible response and higher absorption in the visible light region can be observed. UV-Vis spectral absorption results show that the synthesized N-doped TiO2 powder calcined at 350°C for 2.5 h, has red-shifted well into visible region up to 700 nm. The photodegradation of methylene blue shows that N-doped TiO2 has high visible light photocatalysis.