The effect of Lanthanum content,calcinating temperature and calcinating time on the photocatalytic activity of Lanthanum doping TiO 2 was investigated.The study showed that samples treated under higher temperature and...The effect of Lanthanum content,calcinating temperature and calcinating time on the photocatalytic activity of Lanthanum doping TiO 2 was investigated.The study showed that samples treated under higher temperature and longer calcinating time exhibited higher photocatalytic activity.The X ray diffraction pattern revealed that the lattice of those samples was highly expanded.It is suggested that the highly distorted crystal lattice may be involved in producing more ways by which the hole was captured.Thus,the photocatalytic activity of samples treated under higher temperature and longer time was promoted.展开更多
A composite photocatalyst （La/TiO2/Fe3O4） with a lanthanum doped TiO2 （La/TiO2） shell and a magnetite core was prepared by coating photoactive La/TiO2 onto a magnetic Fe3O4 core. The morphological, structural, and...A composite photocatalyst （La/TiO2/Fe3O4） with a lanthanum doped TiO2 （La/TiO2） shell and a magnetite core was prepared by coating photoactive La/TiO2 onto a magnetic Fe3O4 core. The morphological, structural, and optical properties of as-prepared samples were charac-terized by transmission electron microscopy （TEM）, X-ray diffraction （XRD） and UV-vis absorption spectroscopy. The effect of lanthanum content on the photocatalytic properties was studied, and the result revealed that 0.15 mol% La/TiO2/Fe3O4 exhibited the highest photoactiv-ity. The photocatalytic properties of the prepared photocatalyst under UV and visible light were investigated in aqueous solution using methyl orange （MO） as a target pollutant. The results showed that the prepared photocatalyst was activated by visible light and used as an ef-fective catalyst in photooxidation reactions. In addition, the possibility of cyclic usage of the prepared photocatalyst was also confirmed. Moreover, La/TiO2 was tightly bound to Fe3O4 and could be easily recovered from the medium by a simple magnetic process.展开更多
Using solid-state synthesis method,a series of samples of lanthanum doped Li1-xLaxFePO4(x=0.0025,0.005,0.0075,0.01) were prepared.Each cathode structural and electrochemical properties were investigated using X-ray di...Using solid-state synthesis method,a series of samples of lanthanum doped Li1-xLaxFePO4(x=0.0025,0.005,0.0075,0.01) were prepared.Each cathode structural and electrochemical properties were investigated using X-ray diffractometry(XRD),scanning electron microscopy(SEM),electrochemical impedance spectroscopy(EIS) and charge/discharge cycling.Nanopowders material with single-phase could be obtained.The reversible capacity could be drastically improved by the introduction of La.The optimum cells with Li0.99La0....展开更多
Powders of spinel LiLaxMn2-xO4 were successfully synthesized by the ultrasonic-assisted sol-gel （UASG） method. The structure and properties of LiLaxMn2-xO4 were examined by X-ray diffraction （XRD）, Fourier transfo...Powders of spinel LiLaxMn2-xO4 were successfully synthesized by the ultrasonic-assisted sol-gel （UASG） method. The structure and properties of LiLaxMn2-xO4 were examined by X-ray diffraction （XRD）, Fourier transform infrared （FT-IR） spectroscopy, scanning electronic microscopy （SEM）, galvanostatic charge-discharge test, and cyclic voltammetry （CV）. XRD results show that the La^3＋ can partially reptace Mn^3＋ in the spinel and the doped materials with La^3＋ have a larger lattice constant compared with pristine LiMn2O4. FT-IR indicates that the absorption peak of Mn^3＋-O and Mn^4＋- O bonds has a red and blue shift with the increase of doping lanthanum in LiLaxMn2-xO4, respectively. The charge-discharge test exhibits that the initial discharge capacity of LiLaxMn2-xO4 drops off, and the capacity retention increases gradually at C/5 discharge rate with the increase of doping lanthanum, and LiLa0.01Mn1.99O4 has a higher discharge capacity and a better cycling performance at 1C discharge rate. CV reveals that the doping La^3＋ is beneficial to the reversible extraction and intercalation of Li^＋ ions.展开更多
文摘The effect of Lanthanum content,calcinating temperature and calcinating time on the photocatalytic activity of Lanthanum doping TiO 2 was investigated.The study showed that samples treated under higher temperature and longer calcinating time exhibited higher photocatalytic activity.The X ray diffraction pattern revealed that the lattice of those samples was highly expanded.It is suggested that the highly distorted crystal lattice may be involved in producing more ways by which the hole was captured.Thus,the photocatalytic activity of samples treated under higher temperature and longer time was promoted.
基金support forthis work from the Ministry of Science and Technology of China (No.2009CB426301)Chinese Academy of Sciences(No. KZCX2-YW-JS405)the National Natural Science Foundation of China (No.40925011)
文摘A composite photocatalyst （La/TiO2/Fe3O4） with a lanthanum doped TiO2 （La/TiO2） shell and a magnetite core was prepared by coating photoactive La/TiO2 onto a magnetic Fe3O4 core. The morphological, structural, and optical properties of as-prepared samples were charac-terized by transmission electron microscopy （TEM）, X-ray diffraction （XRD） and UV-vis absorption spectroscopy. The effect of lanthanum content on the photocatalytic properties was studied, and the result revealed that 0.15 mol% La/TiO2/Fe3O4 exhibited the highest photoactiv-ity. The photocatalytic properties of the prepared photocatalyst under UV and visible light were investigated in aqueous solution using methyl orange （MO） as a target pollutant. The results showed that the prepared photocatalyst was activated by visible light and used as an ef-fective catalyst in photooxidation reactions. In addition, the possibility of cyclic usage of the prepared photocatalyst was also confirmed. Moreover, La/TiO2 was tightly bound to Fe3O4 and could be easily recovered from the medium by a simple magnetic process.
基金supported by Priority Research item in Application Foundation Research Plan of Hebei(09963910D)the State Key Laboratory of New Ceramics and Fine Processing (Tsinghua University) Open Project Fund (KF0710,KF0802)+2 种基金Natural Science Research Guiding Project of Hebei Education Department (Z2008408)Ningxia National Science Foundation (NZ0843)Science and Technology Research and Development Guiding Plan of Qinhuangdao City (22,200901A003)
文摘Using solid-state synthesis method,a series of samples of lanthanum doped Li1-xLaxFePO4(x=0.0025,0.005,0.0075,0.01) were prepared.Each cathode structural and electrochemical properties were investigated using X-ray diffractometry(XRD),scanning electron microscopy(SEM),electrochemical impedance spectroscopy(EIS) and charge/discharge cycling.Nanopowders material with single-phase could be obtained.The reversible capacity could be drastically improved by the introduction of La.The optimum cells with Li0.99La0....
文摘Powders of spinel LiLaxMn2-xO4 were successfully synthesized by the ultrasonic-assisted sol-gel （UASG） method. The structure and properties of LiLaxMn2-xO4 were examined by X-ray diffraction （XRD）, Fourier transform infrared （FT-IR） spectroscopy, scanning electronic microscopy （SEM）, galvanostatic charge-discharge test, and cyclic voltammetry （CV）. XRD results show that the La^3＋ can partially reptace Mn^3＋ in the spinel and the doped materials with La^3＋ have a larger lattice constant compared with pristine LiMn2O4. FT-IR indicates that the absorption peak of Mn^3＋-O and Mn^4＋- O bonds has a red and blue shift with the increase of doping lanthanum in LiLaxMn2-xO4, respectively. The charge-discharge test exhibits that the initial discharge capacity of LiLaxMn2-xO4 drops off, and the capacity retention increases gradually at C/5 discharge rate with the increase of doping lanthanum, and LiLa0.01Mn1.99O4 has a higher discharge capacity and a better cycling performance at 1C discharge rate. CV reveals that the doping La^3＋ is beneficial to the reversible extraction and intercalation of Li^＋ ions.
