The rare earth doped TiO（2） was prepared and characterized with Nd,Ho and Y as the doping agents,which have obvious absorption in visible light area.The particle size of the glomeration was about 200-400 nm.TiO2 sen...The rare earth doped TiO（2） was prepared and characterized with Nd,Ho and Y as the doping agents,which have obvious absorption in visible light area.The particle size of the glomeration was about 200-400 nm.TiO2 sensor performed a significant change in resistance when exposed to methanol vapor.By comparison,the Nd,Ho and Yb doped TiO2 sensors exhibited a response of 2.22,4.05 and 3.78,and lowered response and recovery times of 91,56 and 67 s,respectively.The Ho doped TiO2 showed the best methanolsensing properties,which exhibited high selectivity and response to methanol compared with the other tested vapors.In concentration of 0-10 ppm,the sensor exhibited excellent stability for detecting methanol at various concentrations.展开更多
Rare earth（Y, La and Nd） doped TiO2 thin films were prepared on glass slides by sol-gel method. The photocatalytic decomposition of methylene blue in aqueous solution was used as a probe reaction to evaluate their p...Rare earth（Y, La and Nd） doped TiO2 thin films were prepared on glass slides by sol-gel method. The photocatalytic decomposition of methylene blue in aqueous solution was used as a probe reaction to evaluate their photocatalytic activities. The effects of hydroxyl groups on hydrophilic and photocatalytic activities were investigated by means of techniques such as X-ray diffraction（XRD）, atomic force microscopy（AFM）, Fourier transform infrared（FTIR）, optical contact angle, UV-Visible spectroscopy and VIS spectroscopy. The results showed that an appropriate doping of rare earth could cause the TiO2 lattice distortion, inhibited phase transition from anatase to rutile, accelerated surface hydroxylation and produced more hydroxyl groups, which resulted in a denser surface and smaller grains（40–60 nm）, and a significant improvement in the hydrophilicity and photoreactivity of TiO2 thin films. The optimal content of rare earth was between 0.1 wt.% and 0.3 wt.%. Moreover, the modification mechanism of rare earth doping was also discussed.展开更多
The density of states （DOS） of 17 kinds of rare earths （RE） doped rutile TiO2 was by using first-principles density functional theory （DFT） calculation. The band gap widths of RE doped futile TiO2 were important...The density of states （DOS） of 17 kinds of rare earths （RE） doped rutile TiO2 was by using first-principles density functional theory （DFT） calculation. The band gap widths of RE doped futile TiO2 were important factors for altering their absorbing wavelengths. The results show that RE ions could obviously reduce the band gap widths and form of energy of ruffle TiO2 except Lu, Y, Yb and Sc, and the order of absorbing wavelengths of RE doped ruffle TiO2 were the same as that of the results of calculation. The ratio of RE dopant was another important factor for the photo catalytic ＇activity of RE doped rutile TiO2, and there was an optimal ratio of dopant. There was a constant for predigesting the calculation difficulty, respectively, which were 0.5mol.% and 100 mol^-1 under supposition. The band gap widths of RE doped rutile TiOz by DFT calculation were much larger than that by experiment. Finally, by transferring the calculation values to experiment values, it could be found and predicted that RE enlarged obviously the absorbing wavelengh of ruffle TiO2. In addition, the degree of RE ions edging out the Ti atom using the parameters of RE dements was computed.展开更多
This review focused on rare-earth elements containing inorganic semiconductor photocatalysts for efficient solar energy conversion. We also summarized the recent progress in the modification of the transition metal ox...This review focused on rare-earth elements containing inorganic semiconductor photocatalysts for efficient solar energy conversion. We also summarized the recent progress in the modification of the transition metal oxides and mixed oxides with rare earth ions. In the first section, we surveyed a variety of rare-earth elements modified TiO2 photocatalysts. Attributed to the modifica-tion with rare-earth elements, phase transformation of TiO2 from anatase to rutile was inhibited. Furthermore, the light-absorbing property of the TiO2 modified with rare-earth elements was also enhanced. In the second section, we summarized the effects of rare-earth elements on the modification of transition metal mixed oxides. It was believed that the corner-shared octahedral units in the form of networks, chains and slabs within the mixed oxide lattice were essential for the enhancement of the photocatalytic activity. In the last section, the strategy for the design of NIR or IR response upconversion composite photocatalysts was also discussed.展开更多
The iso-electric point of different rare earths （La, Ce, Y） doped anatase TiO2 was set out, and three organisms with different sur- face electrical properties （methylene blue trihydrate-positive electricity, methyl...The iso-electric point of different rare earths （La, Ce, Y） doped anatase TiO2 was set out, and three organisms with different sur- face electrical properties （methylene blue trihydrate-positive electricity, methyl orange-negative electricity, methyl red-neutral electricity） were selected as photodegradable models. The result showed that the photocatalytic activity of 0.5wt.%Y ions doped anatase TiO2 was better than those of the others. The relationship between Zeta （ξ） potential and the photocatalytic activity of different RE doped anatase TiO2 were also investigated. The Y-doped anatase TiO2 was found with the special two iso-electric points and three ξ potential values.展开更多
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
基金Funded by National Natural Science Foundation of China(No.51672196)
文摘The rare earth doped TiO（2） was prepared and characterized with Nd,Ho and Y as the doping agents,which have obvious absorption in visible light area.The particle size of the glomeration was about 200-400 nm.TiO2 sensor performed a significant change in resistance when exposed to methanol vapor.By comparison,the Nd,Ho and Yb doped TiO2 sensors exhibited a response of 2.22,4.05 and 3.78,and lowered response and recovery times of 91,56 and 67 s,respectively.The Ho doped TiO2 showed the best methanolsensing properties,which exhibited high selectivity and response to methanol compared with the other tested vapors.In concentration of 0-10 ppm,the sensor exhibited excellent stability for detecting methanol at various concentrations.
基金Project supported by the National Natural Science Foundation of China(51162022,21201098)Jiangxi Provincial Education Department(GJJ14126)
文摘Rare earth（Y, La and Nd） doped TiO2 thin films were prepared on glass slides by sol-gel method. The photocatalytic decomposition of methylene blue in aqueous solution was used as a probe reaction to evaluate their photocatalytic activities. The effects of hydroxyl groups on hydrophilic and photocatalytic activities were investigated by means of techniques such as X-ray diffraction（XRD）, atomic force microscopy（AFM）, Fourier transform infrared（FTIR）, optical contact angle, UV-Visible spectroscopy and VIS spectroscopy. The results showed that an appropriate doping of rare earth could cause the TiO2 lattice distortion, inhibited phase transition from anatase to rutile, accelerated surface hydroxylation and produced more hydroxyl groups, which resulted in a denser surface and smaller grains（40–60 nm）, and a significant improvement in the hydrophilicity and photoreactivity of TiO2 thin films. The optimal content of rare earth was between 0.1 wt.% and 0.3 wt.%. Moreover, the modification mechanism of rare earth doping was also discussed.
基金supported by the Education Commission of Sichuan Province of China (2006A099)the National Defense Basic Research Foundation of China (A3120080126)
文摘The density of states （DOS） of 17 kinds of rare earths （RE） doped rutile TiO2 was by using first-principles density functional theory （DFT） calculation. The band gap widths of RE doped futile TiO2 were important factors for altering their absorbing wavelengths. The results show that RE ions could obviously reduce the band gap widths and form of energy of ruffle TiO2 except Lu, Y, Yb and Sc, and the order of absorbing wavelengths of RE doped ruffle TiO2 were the same as that of the results of calculation. The ratio of RE dopant was another important factor for the photo catalytic ＇activity of RE doped rutile TiO2, and there was an optimal ratio of dopant. There was a constant for predigesting the calculation difficulty, respectively, which were 0.5mol.% and 100 mol^-1 under supposition. The band gap widths of RE doped rutile TiOz by DFT calculation were much larger than that by experiment. Finally, by transferring the calculation values to experiment values, it could be found and predicted that RE enlarged obviously the absorbing wavelengh of ruffle TiO2. In addition, the degree of RE ions edging out the Ti atom using the parameters of RE dements was computed.
基金Project supported by the National Natural Science Foundation of China(21271055,21471040)
文摘This review focused on rare-earth elements containing inorganic semiconductor photocatalysts for efficient solar energy conversion. We also summarized the recent progress in the modification of the transition metal oxides and mixed oxides with rare earth ions. In the first section, we surveyed a variety of rare-earth elements modified TiO2 photocatalysts. Attributed to the modifica-tion with rare-earth elements, phase transformation of TiO2 from anatase to rutile was inhibited. Furthermore, the light-absorbing property of the TiO2 modified with rare-earth elements was also enhanced. In the second section, we summarized the effects of rare-earth elements on the modification of transition metal mixed oxides. It was believed that the corner-shared octahedral units in the form of networks, chains and slabs within the mixed oxide lattice were essential for the enhancement of the photocatalytic activity. In the last section, the strategy for the design of NIR or IR response upconversion composite photocatalysts was also discussed.
基金Education Commission of Sichuan Province of China (2006A099)
文摘The iso-electric point of different rare earths （La, Ce, Y） doped anatase TiO2 was set out, and three organisms with different sur- face electrical properties （methylene blue trihydrate-positive electricity, methyl orange-negative electricity, methyl red-neutral electricity） were selected as photodegradable models. The result showed that the photocatalytic activity of 0.5wt.%Y ions doped anatase TiO2 was better than those of the others. The relationship between Zeta （ξ） potential and the photocatalytic activity of different RE doped anatase TiO2 were also investigated. The Y-doped anatase TiO2 was found with the special two iso-electric points and three ξ potential values.
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.
