SnO2-glaze composites were prepared by Sb-doped SnO2 and SiO2-CaO-Al2O3-B2O3 glaze. The composites changed from an electrical insulator to a conductor as the SnO2 content increased from Owt% to 90 wt% . The complex im...SnO2-glaze composites were prepared by Sb-doped SnO2 and SiO2-CaO-Al2O3-B2O3 glaze. The composites changed from an electrical insulator to a conductor as the SnO2 content increased from Owt% to 90 wt% . The complex impedance spectra of the fabricated composites were investigated in the frequency range of 100Hz-40 MHz and three kinds of typical shape of complex impedance spectra were recorded and analyzed. The ,spectrum is quite close to the model of conduction via nonohmic contactiug when the SnO2 content is relatively low, In high loading region, the spectrum shows the conduction pattern through ohmic contact chains . In the moderate loading region, the model is a mixture of the above two models. Equivalent circuit of the composite changes from resistor-capacitor circuit to resistor-inductor circuit as the content of SnO2 increases.展开更多
Europium doped ZnO/SnO2 nanocomposite phosphors were synthesized via room temperature co-precipitation method. In this work structural changes, optical properties and the associated photoluminescence response were inv...Europium doped ZnO/SnO2 nanocomposite phosphors were synthesized via room temperature co-precipitation method. In this work structural changes, optical properties and the associated photoluminescence response were investigated for different compositions of ZnO and SnO2 activated with Eu3＋ ions. The prepared samples were systematically characterized by means of X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, field emission scanning electron microscopy for obtaining the structural information about the prepared materials. Diffuse reflectance （DR） UV-Vis spectrometer and photoluminescence （PL） spectroscopy technique were employed for studying the optical properties of prepared materials. XRD results confirmed the presence of both phases, hexagonal ZnO as well as tetragonal SnO2 simultaneously and further using Debye Scherrer＇s and Hall-Williamson relations, crystallite size were estimated and it was found to be in the range of 8-14 nm. The FTIR studies revealed the presence of different stretching and bending modes of Zn-O and Sn-O with an additional stretching and bending vibration of absorbed water （O-H） molecules. FESEM images suggested that the particle size lied in the range of 50 to 70 nm, which were almost spherical in shapes. A long range multi colour emission from blue to red region was observed for the 320 nm excitation wavelength. The observed emission involved sharp emission due to 5D0→7F1 transition that corresponded to the magnetic dipole transition. The study showed that the Eu3＋ doped nanocomposite was more suitable material than singly Eu3＋ doped ZnO and Eu3＋ doped SnO2 with enhanced opto-eleetronic and luminescence properties and potential applications in display devices.展开更多
The nanosized binary mixed oxides of Zn/Sn had been prepared by the fractional homogeneous precipitation route using urea as the latent precipitant under boiling reflux condition The samples prepared with the differen...The nanosized binary mixed oxides of Zn/Sn had been prepared by the fractional homogeneous precipitation route using urea as the latent precipitant under boiling reflux condition The samples prepared with the different initial concentrations of urea or calcined at different temperatures had been investigated by X-ray diffration （XRD） or transmission electron microscopy （TEM）. The calcination temperature had obvious effect on the phase composition and the crystal size of the samples attained, and the precipitant concentration also had obvious effect on the oxide particles size and the production rate of ZnO.展开更多
[Zn(CH3COO)2 + PVP]/[C2H5O)4Si + PVP]/[SnCl4 + PVP]/[Ti(OC4H9)4 + CH3COOH + PVP] precursor composite fibers have been fabricated through self-made electrospinning equipment via electrospinning tech-nique. ZnO/SiO2/SnO...[Zn(CH3COO)2 + PVP]/[C2H5O)4Si + PVP]/[SnCl4 + PVP]/[Ti(OC4H9)4 + CH3COOH + PVP] precursor composite fibers have been fabricated through self-made electrospinning equipment via electrospinning tech-nique. ZnO/SiO2/SnO2/TiO2 composite nanofibers were obtained by calcination of the relevant precursor composite fibers. The samples were characterized by thermogravimetric-differential thermal analysis (TG-DTA), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and Scanning electron microscopy (SEM). TG-DTA analysis reveals that solvents, organic compounds and inorganic in the precursor composite fibers are decomposed and volatilized totally, and the mass of the samples kept constant when sintering temperature was above 900?C, and the total mass loss percentage is 88%. XRD results show that the precursor composite fibers are amorphous in structure, and pure phase ZnO/SiO2/SnO2/TiO2 com-posite nanofibers are obtained by calcination of the relevant precursor composite fibers. FTIR analysis manifests that pure inorganic oxides are formed. SEM analysis indicates that the width of the precursor composite fibers is ca. 1.485 ± 0.043 μm. The width of the ZnO/SiO2/SnO2/TiO2 composite nanofibers is ca. 1145.098 ± 68.093 nm.展开更多
基金Funded by Guangdong Provincal Natural Science Foundation(No.05006564) and Science &Technology Programof GuangdongProvince(No.2004B10301007)
文摘SnO2-glaze composites were prepared by Sb-doped SnO2 and SiO2-CaO-Al2O3-B2O3 glaze. The composites changed from an electrical insulator to a conductor as the SnO2 content increased from Owt% to 90 wt% . The complex impedance spectra of the fabricated composites were investigated in the frequency range of 100Hz-40 MHz and three kinds of typical shape of complex impedance spectra were recorded and analyzed. The ,spectrum is quite close to the model of conduction via nonohmic contactiug when the SnO2 content is relatively low, In high loading region, the spectrum shows the conduction pattern through ohmic contact chains . In the moderate loading region, the model is a mixture of the above two models. Equivalent circuit of the composite changes from resistor-capacitor circuit to resistor-inductor circuit as the content of SnO2 increases.
基金supported by ISM research scholars funding by Government of India
文摘Europium doped ZnO/SnO2 nanocomposite phosphors were synthesized via room temperature co-precipitation method. In this work structural changes, optical properties and the associated photoluminescence response were investigated for different compositions of ZnO and SnO2 activated with Eu3＋ ions. The prepared samples were systematically characterized by means of X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, field emission scanning electron microscopy for obtaining the structural information about the prepared materials. Diffuse reflectance （DR） UV-Vis spectrometer and photoluminescence （PL） spectroscopy technique were employed for studying the optical properties of prepared materials. XRD results confirmed the presence of both phases, hexagonal ZnO as well as tetragonal SnO2 simultaneously and further using Debye Scherrer＇s and Hall-Williamson relations, crystallite size were estimated and it was found to be in the range of 8-14 nm. The FTIR studies revealed the presence of different stretching and bending modes of Zn-O and Sn-O with an additional stretching and bending vibration of absorbed water （O-H） molecules. FESEM images suggested that the particle size lied in the range of 50 to 70 nm, which were almost spherical in shapes. A long range multi colour emission from blue to red region was observed for the 320 nm excitation wavelength. The observed emission involved sharp emission due to 5D0→7F1 transition that corresponded to the magnetic dipole transition. The study showed that the Eu3＋ doped nanocomposite was more suitable material than singly Eu3＋ doped ZnO and Eu3＋ doped SnO2 with enhanced opto-eleetronic and luminescence properties and potential applications in display devices.
基金Acknowledgments： This work was supported by the National Natural Science Foundation of China （No. 20673042）, the Natural Science Foundation of Anhui Provincial Education Committee （No. K12007B014）, the Natural Science Foundation of Anhui Province （No. 070415211）, China Postdoctoral Science Foundation （No. 2004036511）, the Laboratory Open Foundation of Green Materials Chemistry （No. KLSF（I）09）, and the Laboratory Open Foundation of Guangdong Public Laboratory of Environmental Science and Technology. The authors thank Mr. LUO S. M., Mr. CHEN D. Z., and Mr. TAO Q. for their assistance.
文摘The nanosized binary mixed oxides of Zn/Sn had been prepared by the fractional homogeneous precipitation route using urea as the latent precipitant under boiling reflux condition The samples prepared with the different initial concentrations of urea or calcined at different temperatures had been investigated by X-ray diffration （XRD） or transmission electron microscopy （TEM）. The calcination temperature had obvious effect on the phase composition and the crystal size of the samples attained, and the precipitant concentration also had obvious effect on the oxide particles size and the production rate of ZnO.
文摘[Zn(CH3COO)2 + PVP]/[C2H5O)4Si + PVP]/[SnCl4 + PVP]/[Ti(OC4H9)4 + CH3COOH + PVP] precursor composite fibers have been fabricated through self-made electrospinning equipment via electrospinning tech-nique. ZnO/SiO2/SnO2/TiO2 composite nanofibers were obtained by calcination of the relevant precursor composite fibers. The samples were characterized by thermogravimetric-differential thermal analysis (TG-DTA), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and Scanning electron microscopy (SEM). TG-DTA analysis reveals that solvents, organic compounds and inorganic in the precursor composite fibers are decomposed and volatilized totally, and the mass of the samples kept constant when sintering temperature was above 900?C, and the total mass loss percentage is 88%. XRD results show that the precursor composite fibers are amorphous in structure, and pure phase ZnO/SiO2/SnO2/TiO2 com-posite nanofibers are obtained by calcination of the relevant precursor composite fibers. FTIR analysis manifests that pure inorganic oxides are formed. SEM analysis indicates that the width of the precursor composite fibers is ca. 1.485 ± 0.043 μm. The width of the ZnO/SiO2/SnO2/TiO2 composite nanofibers is ca. 1145.098 ± 68.093 nm.
