Study On The Synthesis And Photocatalysis Of Nano-TiO₂

Nano-TiO2photocatalyst was synthesized by the hydrothermal method. N-TiO2was synthesized by the simple solid chemistry method. The samples were characterized by XRD, JV-vis diffuse reflectance spectroscopy, FT-IR spectroscopy, TEM, SEM, BET and EELS. Then, Cr (VI) and MB were selected as target pollutants to evaluate photocatalytic activity of samples.The main contents and results of research were composed of three parts:Frist, nano-TiO2photocatalyst synthesized using the hydrothermal method was anatase (?)hase. The TiO2-350possessed nanotubes. As the temperature of calcinations rising, the nanotubes structure were destroyed, and tured into nanorods and nanoparticles structure. As he same time, the BET specific surface area of nano-TiO2gradually became smaller.Second, nano-TiO2photocatalyst could reduce Cr(Ⅵ) to Cr(Ⅲ) under UV irradiation. The influence of the calcination temperature, pH and loading cocatalyst was studied. The results indicated to that TiO2-550show the higher photocatalytic activity. The acidic condition contributed to the reduction of Cr(Ⅵ), and reduction rate of Cr(Ⅵ) was95%at (?)H=1. The photocatalytic activity of nano-TiO2loaded with cocatalyst had little effect, but the photocatalytic activity of p-n junction composite catalyst composed of NiO, Fe2O3, CO2O3ind nano-TiO2had been improved, and NiO-TiO2had the highest photocatalytic activity.Third, g-C3N4as a nitrogen precursors reacted with titanic acid to form N-TiO2by the solid chemistry method. The temperature played an important in this reaction. N-TiO2was prepared at temperatures above550℃and g-C3N4/TiO2was obtained at temperatures below550℃. MB was elected as a photodegrading goal to evaluate photocatalytic activity of g-C3N4, TiO2-500, g-C3N4/TiO2-500and N-TiO2-550. Our results indicated that N-TiO2displayed higher photocatalytic activity under visible light and UV light.