Study On Preparation Of Anatase Titanium Dioxide At Low Temperatures

The TiO₂ nanoparticlers with a smaller size have been prepared by the sol-gel method in water bath at a lower temperature.The TiO₂ nanoparticles were characterized by means of X-ray diffractiometer?XRD?,X-ray photoelectron spectroscopy?XPS?,transmission electron microscopy?TEM?,specific surface area analysis?SSA?and UV-visible diffuse reflectance spectroscope?UV–Vis DRS?.Results showed that the TiO₂ nanoparticles had primarily the anatase phase and mesoporous structure;the average size of the nanoparticles was ca.5 nm,the average size of the mesopores was ca.3.6 nm,the specific surface area and the banding energy of the as-prepared TiO₂ samples were ca.208.7 m²·g^-1,and 3.06 eV respectivlely.There are only three elements of C,O,and Ti existing on thesurface of the TiO2 nanoparticles.The photocatalytic activity of the as-prepared TiO2samples have been investigated by evaluationg the degradation of methyl orange under UV,solar and visible light irradiation.The results showed that the photocatalytic activity of Nano-TiO₂ was significantly higher than that of the commercial TiO₂?P25?.However,the photocatalytic activity of the TiO₂ nanoparticles after calcined at 400?greatly decreased,while their average particle size and specific surface area are ca.10 nm and 100 m²·g^-1,respectively.The carbon self-doped TiO2 nanoparticles?C-TiO2?were prepared by the sol-gel method without using external carbon precursors and calcinating at a lower temperature.The C-TiO₂ nanoparticles were characterized by means of X-ray diffractiometer?XRD?,X-ray photoelectron spectroscopy?XPS?,transmission electron microscopy?TEM?,specific surface area?SSA?and UV-visible diffuse reflectance spectroscope?UV–Vis DRS?.Results showed that the TiO₂ nanoparticles had primarily the anatase phase and mesoporous structure,the average size of the TiO₂ nanoparticles was ca.7 nm,the average size of the mesopores was ca.2.7 nm,and the specific surface area and banding energy were about 216.7 m²·g^-1 and 2.8 eV respectively.The photocatalytic activity of the C-TiO₂samples have been investigated by evaluationg the degradation of methyl orange under visible light irradiation.The results show that the photocatalytic activity of the C-TiO₂nanoparticles was significantly higher than that the commercial TiO₂?P25?.The photocatalytic activites of the C-TiO₂ nanoparticles irradiated under visible light for a long time showed that the photocatalytic stability of C-TiO2 was excellent.