N-F-codoped TiO2 (NFTO) photocatalysts were synthesized by a simple sol-gel process with tetrabutyl titanate (Ti(OBu)4 ) as the precursor of TiO 2 and ammonium fluoride (NH4 F) as the source of N and F.The syn...N-F-codoped TiO2 (NFTO) photocatalysts were synthesized by a simple sol-gel process with tetrabutyl titanate (Ti(OBu)4 ) as the precursor of TiO 2 and ammonium fluoride (NH4 F) as the source of N and F.The synthesized photocatalysts were investigated by X- ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) and photodegradation reaction tests of 4-chlorophenol under visible light irradiation to understand the relationship between the structure of NFTO catalyst and corresponding photocatalytic activity.The crystal phase and particle size of catalysts were found to be largely affected by the calcination temperature.In addition,N-F-codoping could inhibit phase transition of TiO2 from anatase to rutile.The presence of N and F atoms in the lattice of TiO2 is responsible for the visible light catalytic activity.In UV-Vis DRS tests,the spectrum of NFTO exhibited red shift compared with Degussa P25 and the band gap was reduced to around 2.92 eV.Under optimal calcination temperature and dopant concentration conditions,the NFTO photocatalyst exhibited the highest activity in the photodegradation reaction tests of 4-chlorophenol under visible light irradiation with a degradation rate of 75.84%.Besides,the 5-recycle test showed that NFTO photocatalyst could be reused and its activity kept stable under visible light irradiation.展开更多
First-principles plane-wave pseudopotential calculations are performed to study the geometrical structures, for- mation energies, and electronic and optical properties of Y-doped, N-doped, and (Y, N)-codoped Ti02. T...First-principles plane-wave pseudopotential calculations are performed to study the geometrical structures, for- mation energies, and electronic and optical properties of Y-doped, N-doped, and (Y, N)-codoped Ti02. The calculated results show that Y and N codoping leads to lattice distortion, easier separation of photogenerated electron-hole pairs and band gap narrowing. The optical absorption spectra indicate that an obvious red-shift occurs upon Y and N codoping, which enhances visible-light photocatalytic activity.展开更多
Nanometer SnO2 particles were synthesized by sol-gel dialytic processes and used as a support to prepare CuO supported catalysts via a deposition-precipitation method.The samples were characterized by means of TG-DTA,...Nanometer SnO2 particles were synthesized by sol-gel dialytic processes and used as a support to prepare CuO supported catalysts via a deposition-precipitation method.The samples were characterized by means of TG-DTA,XRD,H2-TPR and XPS.The catalytic activity of the CuO/TiO2-SnO2 catalysts was markedly depended on the loading of CuO,and the optimum CuO loading was 8 wt.%(Tloo=80℃).The CuO/TiO2-SnO2 catalysts exhibited much higher catalytic activity than the CuO/TiO2 and CuO/SnO2 catalysts.H2-TPR result indicated that a large amount of CuO formed the active site for CO oxidation in 8 wt.%CuO/TiO2-SnO2 catalyst.展开更多
Polyaniline(PAn)sensitized nanocrystalline TiO2 composites(TiO2/PAn)were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue(MB).The results showed that PAn was able ...Polyaniline(PAn)sensitized nanocrystalline TiO2 composites(TiO2/PAn)were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue(MB).The results showed that PAn was able to sensitize TiO2 efficiently and the composite photocatalyst could be activated by absorbing both the ultraviolet and visible light(λ:190~800 nm),whereas pure TiO2 absorbed ultraviolet light only(λ〈380 nm).Under the irradiation of natural light,MB could be degraded more efficiently on the TiO2/PAn composites than on the TiO2 Furthermore,it could be easily separated from the solution by simple sedimentation.展开更多
(N,F)-codoped anatase TiO2 nanocrystals with active visible light response were prepared by using a simple sol-gel approach.X-ray photoelectron spectroscopy measurements suggested that the substitutional N and F speci...(N,F)-codoped anatase TiO2 nanocrystals with active visible light response were prepared by using a simple sol-gel approach.X-ray photoelectron spectroscopy measurements suggested that the substitutional N and F species replaced the lattice oxygen atoms in TiO2 nanocrystals.Such nanocrystals showed strong absorption from 400 to 550 nm,which was mainly induced by nitrogen doping.The phase transformation from anatase to rutile was hindered by fluorine doping at high calcination temperatures,which was verified by XRD patterns.The N2 adsorption-desorption isotherms revealed the absence of mesopores in these nanocrystals.The(N,F)-codoped TiO2 nanocrystals showed satisfying photocatalytic activity on the photo-degradation of methylene blue under visible light.展开更多
Zr-doped-TiO2 loaded glass fiber(ZT/GF) composite photocatalysts with different Zr/Ti ratios were prepared with a sol–gel process. Zr4+can replace Ti4+in the TiO2 lattice, which is conducive to forming the anatas...Zr-doped-TiO2 loaded glass fiber(ZT/GF) composite photocatalysts with different Zr/Ti ratios were prepared with a sol–gel process. Zr4+can replace Ti4+in the TiO2 lattice, which is conducive to forming the anatase phase and reducing the calcination temperature. The glass fiber carrier was responsible for better dispersion and loading of Zr-doped-TiO2 particles, improving the applicability of the Zr-doped-TiO2. The ZT/GF photocatalysts were characterized by X-ray diffraction(XRD), scanning electron microscope(SEM), Fourier transform infrared spectroscopy(FT-IR), ultraviolet–visible spectroscopy(UV–vis) and Barrett–Joyner–Halenda(BJH). The performance of photocatalysts with different loading was evaluated in formaldehyde degradation under visible light at room temperature. ZT/GF0.2exhibited the highest activity, with a formaldehyde removal rate as high as 95.14% being observed, which is better than that of the photocatalyst particles alone. The stability of the catalyst was also tested, and ZT/GF exhibited excellent catalytic performance with 94.38%removal efficiency, even after seven uses.展开更多
A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sens...A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sensitive to pH change. Diffuse reflectance spectra (DRS) revealed that the electronic change in TiO2 did not occur by the addition of AC. Results of SEM and XRD suggested that better TiO2 distribution can be achieved when optimal AC content was adopted. The performance of the prepared TiO2/5AC catalyst revealed great practical potential in wastewater treatment field.展开更多
基金supported by the Scienceand Technology Project of Education Commission of Chongqing of China(No.KJ110709)the Key Science Project of Ministry of Education of China(No.2008119)+1 种基金the Colleges and Universities Innovation Team Project of Chongqing of China(No.KJTD201020)the Scienceand Technology Project of Engineering Research Centre for Waste Oil,Ministry of Education of China(No.FYKJ2009012)
摘要N-F-codoped TiO2 (NFTO) photocatalysts were synthesized by a simple sol-gel process with tetrabutyl titanate (Ti(OBu)4 ) as the precursor of TiO 2 and ammonium fluoride (NH4 F) as the source of N and F.The synthesized photocatalysts were investigated by X- ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) and photodegradation reaction tests of 4-chlorophenol under visible light irradiation to understand the relationship between the structure of NFTO catalyst and corresponding photocatalytic activity.The crystal phase and particle size of catalysts were found to be largely affected by the calcination temperature.In addition,N-F-codoping could inhibit phase transition of TiO2 from anatase to rutile.The presence of N and F atoms in the lattice of TiO2 is responsible for the visible light catalytic activity.In UV-Vis DRS tests,the spectrum of NFTO exhibited red shift compared with Degussa P25 and the band gap was reduced to around 2.92 eV.Under optimal calcination temperature and dopant concentration conditions,the NFTO photocatalyst exhibited the highest activity in the photodegradation reaction tests of 4-chlorophenol under visible light irradiation with a degradation rate of 75.84%.Besides,the 5-recycle test showed that NFTO photocatalyst could be reused and its activity kept stable under visible light irradiation.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10647008, 50971099, and 21176199)the Research Fund for the Doctoral Program of Higher Education, China (Grant Nos. 20096101110017 and 20096101110013)+1 种基金the Key Project of the Natural Science Foundation of Shaanxi Province, China (Grant Nos. 2010JZ002 and 2011JM1001)the Graduate Innovation Fund of Northwest University, China (Grant No. 10YZZ38)
摘要First-principles plane-wave pseudopotential calculations are performed to study the geometrical structures, for- mation energies, and electronic and optical properties of Y-doped, N-doped, and (Y, N)-codoped Ti02. The calculated results show that Y and N codoping leads to lattice distortion, easier separation of photogenerated electron-hole pairs and band gap narrowing. The optical absorption spectra indicate that an obvious red-shift occurs upon Y and N codoping, which enhances visible-light photocatalytic activity.
基金supported by the National Natural Science Foundation of China(20771061 and 20871071)the 973 Program(2005CB623607)Science and Technology Commission Foundation of Tianjin(08JCYBJC00100 and 09JCYBJC03600)
摘要Nanometer SnO2 particles were synthesized by sol-gel dialytic processes and used as a support to prepare CuO supported catalysts via a deposition-precipitation method.The samples were characterized by means of TG-DTA,XRD,H2-TPR and XPS.The catalytic activity of the CuO/TiO2-SnO2 catalysts was markedly depended on the loading of CuO,and the optimum CuO loading was 8 wt.%(Tloo=80℃).The CuO/TiO2-SnO2 catalysts exhibited much higher catalytic activity than the CuO/TiO2 and CuO/SnO2 catalysts.H2-TPR result indicated that a large amount of CuO formed the active site for CO oxidation in 8 wt.%CuO/TiO2-SnO2 catalyst.
摘要Polyaniline(PAn)sensitized nanocrystalline TiO2 composites(TiO2/PAn)were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue(MB).The results showed that PAn was able to sensitize TiO2 efficiently and the composite photocatalyst could be activated by absorbing both the ultraviolet and visible light(λ:190~800 nm),whereas pure TiO2 absorbed ultraviolet light only(λ〈380 nm).Under the irradiation of natural light,MB could be degraded more efficiently on the TiO2/PAn composites than on the TiO2 Furthermore,it could be easily separated from the solution by simple sedimentation.
基金supported by the Excellent Young Teachers Program of MOEKey Project of Shanghai Science and Technology Committee(No.06DZ05025),China
摘要(N,F)-codoped anatase TiO2 nanocrystals with active visible light response were prepared by using a simple sol-gel approach.X-ray photoelectron spectroscopy measurements suggested that the substitutional N and F species replaced the lattice oxygen atoms in TiO2 nanocrystals.Such nanocrystals showed strong absorption from 400 to 550 nm,which was mainly induced by nitrogen doping.The phase transformation from anatase to rutile was hindered by fluorine doping at high calcination temperatures,which was verified by XRD patterns.The N2 adsorption-desorption isotherms revealed the absence of mesopores in these nanocrystals.The(N,F)-codoped TiO2 nanocrystals showed satisfying photocatalytic activity on the photo-degradation of methylene blue under visible light.
基金financially supported by the Project of Science and Technology Department of Jiangsu Province (BE2016769)the Natural Science Foundation of China (No. 51608261)+2 种基金Six talent peaks project in Jiangsu Province (2016)Open fund by Jiangsu Engineering Technology Research Center of Environmental Cleaning Materials (KFK1503)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
摘要Zr-doped-TiO2 loaded glass fiber(ZT/GF) composite photocatalysts with different Zr/Ti ratios were prepared with a sol–gel process. Zr4+can replace Ti4+in the TiO2 lattice, which is conducive to forming the anatase phase and reducing the calcination temperature. The glass fiber carrier was responsible for better dispersion and loading of Zr-doped-TiO2 particles, improving the applicability of the Zr-doped-TiO2. The ZT/GF photocatalysts were characterized by X-ray diffraction(XRD), scanning electron microscope(SEM), Fourier transform infrared spectroscopy(FT-IR), ultraviolet–visible spectroscopy(UV–vis) and Barrett–Joyner–Halenda(BJH). The performance of photocatalysts with different loading was evaluated in formaldehyde degradation under visible light at room temperature. ZT/GF0.2exhibited the highest activity, with a formaldehyde removal rate as high as 95.14% being observed, which is better than that of the photocatalyst particles alone. The stability of the catalyst was also tested, and ZT/GF exhibited excellent catalytic performance with 94.38%removal efficiency, even after seven uses.
基金This project was financially supported by Specialized Research Fund for the Doctoral Program of Higher Education (No. 20050225006)the National Natural Science Foundation of China (No. 30400339).
摘要A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sensitive to pH change. Diffuse reflectance spectra (DRS) revealed that the electronic change in TiO2 did not occur by the addition of AC. Results of SEM and XRD suggested that better TiO2 distribution can be achieved when optimal AC content was adopted. The performance of the prepared TiO2/5AC catalyst revealed great practical potential in wastewater treatment field.