A series of nanometer TiO2 photocatalysts co-doped respectively with rare earth Er^3＋-Ce^3＋ and La^3＋-Fe^3＋ were prepared by sol-gel method,and the photocatalytic activity under ultra-violet light was evaluated by...A series of nanometer TiO2 photocatalysts co-doped respectively with rare earth Er^3＋-Ce^3＋ and La^3＋-Fe^3＋ were prepared by sol-gel method,and the photocatalytic activity under ultra-violet light was evaluated by photocatalytic degradation of methyl blue.The crystallographic forms,particles size,and morphology were characterized by XRD and TEM.The results showed that the optimum heat temperature of co-doped TiO2 was 550 ℃,and the co-doped TiO2 kept anatase.The anatase crystal had the average size of 20 nm.The co-doping caused red-shift of the UV-Vis absorption spectra and enhanced the absorption of light.Compared with the spectrum of pure TiO2 photocatalysts,the red-shift of Er^3＋-Ce^3＋ co-doping and La^3＋-Fe^3＋ co-doping catalysts was 53 nm and 34 nm,respectively.Optimal co-doping amount for Er^3＋-Ce^3＋ was n（Er^3＋）：n（TiO2）=0.1%,n（Ce^3＋）：（TiO2）= 0.05% and La^3＋-Fe^3＋ was n（La^3＋）：n（TiO2）=0.05%,n（Fe^3＋）：（TiO2）=0.5%.Under the condition the photocatalysis properties of the samples can be enhanced.It was found that the catalytic activity correlated well with the ratio.The degradation rate of methyl blue examined at two hour of the reaction was 92.37%,and the better photocatalysis properties than the non-doped TiO2 were obtained.The co-doped photocatalyst on methyl blue degradation follows the apparent first-order kinetics.展开更多
TiO2 powder and TiO2 thin film on the surface of glazed ceramic tile were prepared by sol-gel method.The influences of different doping Cr3+ concentration on the photocatalytic activity of TiO2 were discussed, UV-visi...TiO2 powder and TiO2 thin film on the surface of glazed ceramic tile were prepared by sol-gel method.The influences of different doping Cr3+ concentration on the photocatalytic activity of TiO2 were discussed, UV-visible and X-ray diffraction analysis were used to test the performance of TiO2 powder and film. The results indicate that photocatalytic activity of doping Cr3+-TiO2 thin film is higher than that of powder, and the interaction between Cr3+-doped and substrate can greatly enhance the photocatalytic activity. The results of X-ray diffraction and photoabsorption show that the Cr3+ -doped energy level in TiO2 is 0. 62 eV high from the top of valence band, which belongs to the type of deep energy level doping. On the basis of the semiconductor energy level theory and Cr3+ dopant energy level, the semiconductor energy level model of Cr3+ in TiO2 powder and thin film were established, and the doping mechanisms of Cr3+-doped in TiO2 powder and thin film were analyzed.展开更多
基金Funded by the 11th Five-Year National Key Technology R&D Program(No.2008BAC41B00)
文摘A series of nanometer TiO2 photocatalysts co-doped respectively with rare earth Er^3＋-Ce^3＋ and La^3＋-Fe^3＋ were prepared by sol-gel method,and the photocatalytic activity under ultra-violet light was evaluated by photocatalytic degradation of methyl blue.The crystallographic forms,particles size,and morphology were characterized by XRD and TEM.The results showed that the optimum heat temperature of co-doped TiO2 was 550 ℃,and the co-doped TiO2 kept anatase.The anatase crystal had the average size of 20 nm.The co-doping caused red-shift of the UV-Vis absorption spectra and enhanced the absorption of light.Compared with the spectrum of pure TiO2 photocatalysts,the red-shift of Er^3＋-Ce^3＋ co-doping and La^3＋-Fe^3＋ co-doping catalysts was 53 nm and 34 nm,respectively.Optimal co-doping amount for Er^3＋-Ce^3＋ was n（Er^3＋）：n（TiO2）=0.1%,n（Ce^3＋）：（TiO2）= 0.05% and La^3＋-Fe^3＋ was n（La^3＋）：n（TiO2）=0.05%,n（Fe^3＋）：（TiO2）=0.5%.Under the condition the photocatalysis properties of the samples can be enhanced.It was found that the catalytic activity correlated well with the ratio.The degradation rate of methyl blue examined at two hour of the reaction was 92.37%,and the better photocatalysis properties than the non-doped TiO2 were obtained.The co-doped photocatalyst on methyl blue degradation follows the apparent first-order kinetics.
基金Project (20466001) supported by the National Natural Science Foundation of China
文摘TiO2 powder and TiO2 thin film on the surface of glazed ceramic tile were prepared by sol-gel method.The influences of different doping Cr3+ concentration on the photocatalytic activity of TiO2 were discussed, UV-visible and X-ray diffraction analysis were used to test the performance of TiO2 powder and film. The results indicate that photocatalytic activity of doping Cr3+-TiO2 thin film is higher than that of powder, and the interaction between Cr3+-doped and substrate can greatly enhance the photocatalytic activity. The results of X-ray diffraction and photoabsorption show that the Cr3+ -doped energy level in TiO2 is 0. 62 eV high from the top of valence band, which belongs to the type of deep energy level doping. On the basis of the semiconductor energy level theory and Cr3+ dopant energy level, the semiconductor energy level model of Cr3+ in TiO2 powder and thin film were established, and the doping mechanisms of Cr3+-doped in TiO2 powder and thin film were analyzed.
