Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, sha...Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, shape, and ionic conductivity of these samples. The results show that the range of solid solution formation is in 0< x ≤0 09, in which the conductivity of these samples raises with the increasing amount of RE 2O 3 (RE=Pr, Nd, Sm, Gd) added, and the diameter of the powders is about 100 nm. Compared with the conventional solid state reaction, the sol gel method needs low temperature and presents high ionic conductivity.展开更多
Eu2+, Dy3+-doped SrAl2O4 was prepared by a hydrothermal reaction through the process of calcination at lower temperature. The physicochemical properties of the SrAl2O4: Eu2+, Dy3+ phosphor were characterized and compa...Eu2+, Dy3+-doped SrAl2O4 was prepared by a hydrothermal reaction through the process of calcination at lower temperature. The physicochemical properties of the SrAl2O4: Eu2+, Dy3+ phosphor were characterized and compared to those of the SrAl2O4: Eu2+, Dy3+ prepared by sol-gel method. The photocatalytic properties of the SrAl2O4: Eu2+, Dy3+ were evaluated in photocatalytic water decomposition for hydrogen production. The SrAl2O4: Eu2+, Dy3+ prepared by hydrothermal reaction exhibited excellent phosphor properties which were similar with that prepared by sol-gel method. Its photocatalytic activity for hydrogen evolution was higher than that of TiO2 photocatalyst.展开更多
Tungsten （VI） oxide （WO3） nanomaterials were synthesized by a sol-gel method using WC16 and C2HsOH as precursors followed by calcination or hydrothermal treatment. X-Ray diffraction （XRD）, scanning electron micr...Tungsten （VI） oxide （WO3） nanomaterials were synthesized by a sol-gel method using WC16 and C2HsOH as precursors followed by calcination or hydrothermal treatment. X-Ray diffraction （XRD）, scanning electron microscopy （SEM） and high resolution transmission electron microscopy （HRTEM） equipped with energy dispersive X-ray spectroscopy （EDX） were used to characterize the structure and morphology of the materials. There were significant differences between the WO3 materials that were calcinated and those that were subjected to a hydrothermal process. The XRD results revealed that calcination temperatures of 300℃and 400℃ gave hexagonal structures and temperatures of 500℃ and 600℃ gave monoclinic structures. The SEM images showed that an increase in calcination temperature led to a decrease in the WO3 powder particle size. The TEM analysis showed that several nanoparticles agglomerated to form bigger clusters. The hydrothermal process produced hexagonal structures for holding times of 12, 16, and 20 h and monoclinic structures for a holding time of 24 h. The SEM results showed transparent rectangular panicles which according to the TEM results originated from the aggregation of several nanotubes.展开更多
文摘Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, shape, and ionic conductivity of these samples. The results show that the range of solid solution formation is in 0< x ≤0 09, in which the conductivity of these samples raises with the increasing amount of RE 2O 3 (RE=Pr, Nd, Sm, Gd) added, and the diameter of the powders is about 100 nm. Compared with the conventional solid state reaction, the sol gel method needs low temperature and presents high ionic conductivity.
文摘Eu2+, Dy3+-doped SrAl2O4 was prepared by a hydrothermal reaction through the process of calcination at lower temperature. The physicochemical properties of the SrAl2O4: Eu2+, Dy3+ phosphor were characterized and compared to those of the SrAl2O4: Eu2+, Dy3+ prepared by sol-gel method. The photocatalytic properties of the SrAl2O4: Eu2+, Dy3+ were evaluated in photocatalytic water decomposition for hydrogen production. The SrAl2O4: Eu2+, Dy3+ prepared by hydrothermal reaction exhibited excellent phosphor properties which were similar with that prepared by sol-gel method. Its photocatalytic activity for hydrogen evolution was higher than that of TiO2 photocatalyst.
文摘Tungsten （VI） oxide （WO3） nanomaterials were synthesized by a sol-gel method using WC16 and C2HsOH as precursors followed by calcination or hydrothermal treatment. X-Ray diffraction （XRD）, scanning electron microscopy （SEM） and high resolution transmission electron microscopy （HRTEM） equipped with energy dispersive X-ray spectroscopy （EDX） were used to characterize the structure and morphology of the materials. There were significant differences between the WO3 materials that were calcinated and those that were subjected to a hydrothermal process. The XRD results revealed that calcination temperatures of 300℃and 400℃ gave hexagonal structures and temperatures of 500℃ and 600℃ gave monoclinic structures. The SEM images showed that an increase in calcination temperature led to a decrease in the WO3 powder particle size. The TEM analysis showed that several nanoparticles agglomerated to form bigger clusters. The hydrothermal process produced hexagonal structures for holding times of 12, 16, and 20 h and monoclinic structures for a holding time of 24 h. The SEM results showed transparent rectangular panicles which according to the TEM results originated from the aggregation of several nanotubes.
