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
In this work,a multi-core-shell-structured LiFePO_(4)@Na_(3) V_(2)(PO_(4))_(3)@C(LFP@NVP@C) composite was successfully designed and prepared to address inferior low-temperature performance of LiFePO_(4) cathode for li...In this work,a multi-core-shell-structured LiFePO_(4)@Na_(3) V_(2)(PO_(4))_(3)@C(LFP@NVP@C) composite was successfully designed and prepared to address inferior low-temperature performance of LiFePO_(4) cathode for lithium-ion batteries.Transmission electron microscopy(TEM) confirms the inner NVP and outer carbon layers coexisted on the surface of LFP particle.When evaluated at low-temperature operation,LFP@NVP@C composite exhibits an evidently enhanced electrochemical performance in term of higher capacity and lower polarization,compared with LFP@C.Even at-10℃ with 0.5 C,LFP@NVP@C delivers a discharge capacity of ca.96.9 mAh-g^(-1) and discharge voltage of ca.3.3 V,which is attributed to the beneficial contribution of NVP coating.NAS ICON-structured NVP with an open framework for readily insertion/desertion of Li+ will effectively reduce the polarization for the electrochemical reactions of the designed LFP@NVP@C composite.展开更多
SnO2-Li4Ti5O12 was prepared by sol-gel method using tin tetrachloride,lithium acetate,tetrabutylorthotitanate and aqueous ammonia as starting materials.The composite was characterized by thermogravimertric(TG)analysis...SnO2-Li4Ti5O12 was prepared by sol-gel method using tin tetrachloride,lithium acetate,tetrabutylorthotitanate and aqueous ammonia as starting materials.The composite was characterized by thermogravimertric(TG)analysis and differential thermal analysis(DTA),X-ray diffractometry(XRD)and transmission electron microscopy(TEM)combined with electrochemical tests.The results show that SnO2-Li4Ti5O12 composite derived by sol-gel technique is a nanocomposite with core-shell structure, and the amorphous Li4Ti5O12 layer with 20?40 nm in thickness is coated on the surface of SnO2 particles.Electrochemical tests show that SnO2-Li4Ti5O12 composite delivers a reversible capacity of 688.7 mA·h/g at 0.1C and 93.4%of that is retained after 60 cycles at 0.2C.The amorphous Li4Ti5O12 in composite can accommodate the volume change of SnO2 electrode and prevent the small and active Sn particles from aggregating into larger and inactive Sn clusters during the cycling effectively,and enhance the cycling stability of SnO2 electrode significantly.展开更多
The insulating nature and dissolution of vanadium-based oxides in aqueous electrolytes result in low capacity and lifespan during charge/discharge process, which is unable to meet the demands for the development and a...The insulating nature and dissolution of vanadium-based oxides in aqueous electrolytes result in low capacity and lifespan during charge/discharge process, which is unable to meet the demands for the development and application of high-energy-density aqueous zinc-ion batteries(AZIBs). Herein, a novel V_(2)O_(5-x)@C composite cathode consisting of conductive carbon coatings with abundant oxygen vacancies is specifically designed through plasma-enhanced chemical vapor deposition(PECVD) method. As expected,the ideal microstructure of V_(2)O_(5-x)@C cathode enables large specific surface areas, fast electron/ion diffusion kinetics, and superior interfacial stability, which can realize outstanding cycling stability and electrochemical performance. Consequently, the V_(2)O_(5-x)@C composite cathode delivers a high reversible rate capacity of 130.6 mAh/g at 10 A/g and remains 277.6 mAh/g when returned to 1 A/g. In addition, the Zn//V_(2)O_(5-x)@C full cell can stably cycle for 1000 cycles with a high initial specific capacity of 149.2 m Ah/g,possessing 83.8% capacity retention at 5 A/g. The process of constructing a conductive layer on the surface of cathode materials while increasing oxygen vacancies in the structure through PECVD provides new insight into the design of high-performance cathode materials for AZIBs.展开更多
Au-Pt/SnO2/GC composite electrode was prepared by self-assembling Au-Pt nanoparticles on SnO2 film, which was deposited on actived glassy carbon （GC）. Atomic force microscopy （AFM） and scanning electron microscopy...Au-Pt/SnO2/GC composite electrode was prepared by self-assembling Au-Pt nanoparticles on SnO2 film, which was deposited on actived glassy carbon （GC）. Atomic force microscopy （AFM） and scanning electron microscopy （SEM） images revealed that dense and uniform Au-Pt particles with 25-nm diameter were dispersed on SnO2 film. X-ray photoelectron spectroscopy （XPS） results proved that there was an interaction between Au-Pt nanoparticles and SnO2 support. Electrochemical experiments showed that Au-Pt/SnOz/GC composite electrode had a good electrocatalytic activity to the oxidation of methanol展开更多
All-solid-state electrolytes are exceedingly attractive because of the outstanding inherent safety and energy density compared to liquid electrolytes.Whereas,it is still formidable to simultaneously design solid elect...All-solid-state electrolytes are exceedingly attractive because of the outstanding inherent safety and energy density compared to liquid electrolytes.Whereas,it is still formidable to simultaneously design solid electrolytes with favorable electrode/electrolyte interface compatibility and high ionic conductivity in a simple and scalable manner.Hence,the oxygen-vacancy-rich Gd-doped SnO_(2) nanotubes(GDS NTs)are innovatively prepared and applied to the electrolyte of all-solid-state lithium metal batteries for the first time.The addition of GDS NTs can validly construct long-range co ntinuous ion transport networks in the poly(ethylene oxide)(PEO)-based system and greatly improve the mechanical properties of the electrolyte.Compared to the PEO-based electrolyte,the composite electrolyte displays a higher lithium ion conductivity of 2.41×10^(-4) S cm^(-1) at 30℃,a higher lithium ion transference number up to 0.62 and a wider electrochemical window of 5 V at 50℃.In addition,the composite electrolyte manifests outstanding compatibility with high-voltage LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811)cathode,LiFePO4 cathode and lithium metal anode.The assembled Li/Li symmetric battery exhibits stable Li plating/stripping cycling performance,which can cycle steadily for 1500 h at a capacity of 0.3 mA h cm^(-2).And Li/LiFePO4 battery still maintains a high capacity of 131.54 mA h g^(-1) at 0.5C after 800 cycles,which has a superior capacity retention rate of 93.2%.The obtained novel composite electrolyte has promising application prospects in the field of all-solid-state lithium metal cells.展开更多
Composite nanoporous electrode SnO2/TiO2 was fabricated for the dye sensitized solar cell (DSSC) with N3 (Cis-Ru). After introducing of TiO2, the open-circuit photovoltage (Voc) was higher than that of the pure SnO2 ...Composite nanoporous electrode SnO2/TiO2 was fabricated for the dye sensitized solar cell (DSSC) with N3 (Cis-Ru). After introducing of TiO2, the open-circuit photovoltage (Voc) was higher than that of the pure SnO2 electrode, while short-circuit photocurrent (Isc) was varied with the ratio of the TiO2. Appropriate content of the TiO2 can be beneficial to the efficiency of the solar cell, and it gives negative impact on the composite electrode when the content of TiO2 is higher.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
TiO 2 nanoparticles were obtained from industrial TiOSO 4 by hydrolysis method. SnO 2/TiO 2 and SnO 2-TiO 2 composite powders were prepared by stepwise precipitation method and coating method, respectively. The phase ...TiO 2 nanoparticles were obtained from industrial TiOSO 4 by hydrolysis method. SnO 2/TiO 2 and SnO 2-TiO 2 composite powders were prepared by stepwise precipitation method and coating method, respectively. The phase transformation of TiO 2 and the effect of composite mode of SnO 2 on phase transformation of TiO 2 have been investigated by TG-DTA and XRD. The phase transform of pure TiO 2 from anatase to rutile begins at 750 ℃ and the presence of SnO 2 markedly reduces the transform temperature: for coated SnO 2-TiO 2 composite with ω(SnO 2)=20% it was 400 ℃. The SnO 2/TiO 2 composite prepared by precipitation method and followed by calcination at 400 ℃ for 30 min possesses 55% rutile TiO 2. The formation of SnO 2-TiO 2 solid- solution occurrs mainly due to the substitution of Ti 4+ crystal lattice sites by Sn 4+ ions of SnO 2.展开更多
Ag/SnO2,as a promising and environment-friendly electrical contact material,is widely applied in low-voltage apparatus.But the properties of Ag/SnO2 composites is difficult to improve due to the poor distribution phas...Ag/SnO2,as a promising and environment-friendly electrical contact material,is widely applied in low-voltage apparatus.But the properties of Ag/SnO2 composites is difficult to improve due to the poor distribution phases and difficult component design.In this work,the Ag/SnO2 composites are prepared by selective laser melting.To get better performance,Ag/SnO2 composites with different energy density were studied.The microstructure was observed by field emission scanning electron microscope.In addition,reinforced SnO2 phase was characterized by X-ray diffraction and transmission electron microscope.The results indicated that the microstructure,relative density and hardness of are influenced by energy density,while Ag/SnO2 composites with homogeneous microstructure,high relative density,higher hardness and lower electrical resistivity can be obtained by proper energy density(E?68 J/mm^3).展开更多
We report a composite material with the high tribological performance,which consists of onedimensional SnO2 nanotubes(ST)and a high molecular weight poly(vinylidene fluoride)(PVDF)matrix in terms of nano-impregnation....We report a composite material with the high tribological performance,which consists of onedimensional SnO2 nanotubes(ST)and a high molecular weight poly(vinylidene fluoride)(PVDF)matrix in terms of nano-impregnation.Dissolution of PVDF in N,N-dimethylformamide(DMF)resulted in a facile penetration of PVDF into the inner hollow voids of ST,leading to the close contact.Interaction between PVDF and ST results in a beneficial effect on the chain arrangement of PVDF,providing anα-phase with better tribological property.Upon ST incorporation,the friction coefficient decreased by 85.0%to 0.408,and the specific wear rate decreased by 69.1%to 0.412,demonstrating the pivotal role of ST as a self-lubricating material due to a large interactive area and PVDF chain rearrangement.展开更多
We synthesized SnO2/NiO composite oxides by microwave-assisted liquid phase deposition to improve their surface physico-chemical properties and gas-sensing selectivity,and we investigated how the molar ratio of Ni^2+t...We synthesized SnO2/NiO composite oxides by microwave-assisted liquid phase deposition to improve their surface physico-chemical properties and gas-sensing selectivity,and we investigated how the molar ratio of Ni^2+to Sn^4+and the microwave power affected their gas-sensing performance.The microstructure,surface physico-chemical states,and morphology of the samples were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,and scanning electron microscopy,respectively.Nitrogen adsorption-desorption isotherms were used to characterize the specific surface areas of the samples.Our results showed that microwave-assisted liquid phase deposition increased the surface-adsorbed oxygen content and the specific surface area of the SnO2/NiO composite oxide from about 22to 120m2/g.When the molar ratio of Ni^2+to Sn^4+was 0.1,the gas response to 1000ppm ethanol gas reached 84.7at a lower working voltage of 3.5V.However,the optimum working voltages for methanol and acetone gas were 4.5and 4.0V,respectively.Thus,a new method was found to improve the selectivity of the gas sensor.Moreover,at a working voltage of 4.0V,the gas response of a SnO2/NiO gas sensor synthesized by microwave-assisted liquid phase deposition with the optimum radiation power of 450W to 1000ppm acetone gas was 49.7,twice that of a sensor synthesized by traditional liquid phase deposition.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financially supported by the National Natural Science Foundation of China(No.51902036)the Natural Science Foundation of Chongqing Science&Technology Commission(No.cstc2019jcyj-msxm1407)+5 种基金the Natural Science Foundation of Chongqing Technology and Business University(No.1952009)the Science and Technology Research Program of Chongqing Municipal Education Commission(Nos.KJQN201900826 and KJQN201800808)the Venture&Innovation Support Program for Chongqing Overseas Returnees(No.CX2018129)the Innovation Group of New Technologies for Industrial Pollution Control of Chongqing Education Commission(No.CXQT19023)the Engineering and Physical Sciences Research Council(EPSRC)(No.EP/S032886/1)the Key Disciplines of Chemical Engineering and Technology in Chongqing Colleges and Universities during the 13th Five Year Plan。
文摘In this work,a multi-core-shell-structured LiFePO_(4)@Na_(3) V_(2)(PO_(4))_(3)@C(LFP@NVP@C) composite was successfully designed and prepared to address inferior low-temperature performance of LiFePO_(4) cathode for lithium-ion batteries.Transmission electron microscopy(TEM) confirms the inner NVP and outer carbon layers coexisted on the surface of LFP particle.When evaluated at low-temperature operation,LFP@NVP@C composite exhibits an evidently enhanced electrochemical performance in term of higher capacity and lower polarization,compared with LFP@C.Even at-10℃ with 0.5 C,LFP@NVP@C delivers a discharge capacity of ca.96.9 mAh-g^(-1) and discharge voltage of ca.3.3 V,which is attributed to the beneficial contribution of NVP coating.NAS ICON-structured NVP with an open framework for readily insertion/desertion of Li+ will effectively reduce the polarization for the electrochemical reactions of the designed LFP@NVP@C composite.
基金Project(20873054)supported by the National Natural Science Foundation of ChinaProject(2005037700)supported by Postdoctoral Science Foundation of China+2 种基金Project(07JJ3014)supported by Hunan Provincial Natural Science Foundation of ChinaProject(07A058)supported by Scientific Research Fund of Hunan Provincial Education DepartmentProject(2004107)supported by Postdoctoral Science Foundation of Central South University
文摘SnO2-Li4Ti5O12 was prepared by sol-gel method using tin tetrachloride,lithium acetate,tetrabutylorthotitanate and aqueous ammonia as starting materials.The composite was characterized by thermogravimertric(TG)analysis and differential thermal analysis(DTA),X-ray diffractometry(XRD)and transmission electron microscopy(TEM)combined with electrochemical tests.The results show that SnO2-Li4Ti5O12 composite derived by sol-gel technique is a nanocomposite with core-shell structure, and the amorphous Li4Ti5O12 layer with 20?40 nm in thickness is coated on the surface of SnO2 particles.Electrochemical tests show that SnO2-Li4Ti5O12 composite delivers a reversible capacity of 688.7 mA·h/g at 0.1C and 93.4%of that is retained after 60 cycles at 0.2C.The amorphous Li4Ti5O12 in composite can accommodate the volume change of SnO2 electrode and prevent the small and active Sn particles from aggregating into larger and inactive Sn clusters during the cycling effectively,and enhance the cycling stability of SnO2 electrode significantly.
基金financially supported by the National Natural Science Foundation of China (No. 52377222)Natural Science Foundation of Hunan Province (No. 2023JJ20064)。
文摘The insulating nature and dissolution of vanadium-based oxides in aqueous electrolytes result in low capacity and lifespan during charge/discharge process, which is unable to meet the demands for the development and application of high-energy-density aqueous zinc-ion batteries(AZIBs). Herein, a novel V_(2)O_(5-x)@C composite cathode consisting of conductive carbon coatings with abundant oxygen vacancies is specifically designed through plasma-enhanced chemical vapor deposition(PECVD) method. As expected,the ideal microstructure of V_(2)O_(5-x)@C cathode enables large specific surface areas, fast electron/ion diffusion kinetics, and superior interfacial stability, which can realize outstanding cycling stability and electrochemical performance. Consequently, the V_(2)O_(5-x)@C composite cathode delivers a high reversible rate capacity of 130.6 mAh/g at 10 A/g and remains 277.6 mAh/g when returned to 1 A/g. In addition, the Zn//V_(2)O_(5-x)@C full cell can stably cycle for 1000 cycles with a high initial specific capacity of 149.2 m Ah/g,possessing 83.8% capacity retention at 5 A/g. The process of constructing a conductive layer on the surface of cathode materials while increasing oxygen vacancies in the structure through PECVD provides new insight into the design of high-performance cathode materials for AZIBs.
基金supported by the High-Tech Research and Development Program of China (No. 2007AA03Z219)the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality, and the Beijing Natural Science Foundation (No. 207001)
文摘Au-Pt/SnO2/GC composite electrode was prepared by self-assembling Au-Pt nanoparticles on SnO2 film, which was deposited on actived glassy carbon （GC）. Atomic force microscopy （AFM） and scanning electron microscopy （SEM） images revealed that dense and uniform Au-Pt particles with 25-nm diameter were dispersed on SnO2 film. X-ray photoelectron spectroscopy （XPS） results proved that there was an interaction between Au-Pt nanoparticles and SnO2 support. Electrochemical experiments showed that Au-Pt/SnOz/GC composite electrode had a good electrocatalytic activity to the oxidation of methanol
基金supported by the National Natural Science Foundation of China(52203066,51973157,61904123,51873152)the Tianjin Natural Science Foundation(18JCQNJC02900)+3 种基金the Science and Technology Plans of Tianjin(19PTSYJC00010)the Tianjin Research Innovation Project for Postgraduate Students(2021YJSB234)the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(2018KJ196)State Key Laboratory of Membrane and Membrane Separation,Tiangong University。
文摘All-solid-state electrolytes are exceedingly attractive because of the outstanding inherent safety and energy density compared to liquid electrolytes.Whereas,it is still formidable to simultaneously design solid electrolytes with favorable electrode/electrolyte interface compatibility and high ionic conductivity in a simple and scalable manner.Hence,the oxygen-vacancy-rich Gd-doped SnO_(2) nanotubes(GDS NTs)are innovatively prepared and applied to the electrolyte of all-solid-state lithium metal batteries for the first time.The addition of GDS NTs can validly construct long-range co ntinuous ion transport networks in the poly(ethylene oxide)(PEO)-based system and greatly improve the mechanical properties of the electrolyte.Compared to the PEO-based electrolyte,the composite electrolyte displays a higher lithium ion conductivity of 2.41×10^(-4) S cm^(-1) at 30℃,a higher lithium ion transference number up to 0.62 and a wider electrochemical window of 5 V at 50℃.In addition,the composite electrolyte manifests outstanding compatibility with high-voltage LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811)cathode,LiFePO4 cathode and lithium metal anode.The assembled Li/Li symmetric battery exhibits stable Li plating/stripping cycling performance,which can cycle steadily for 1500 h at a capacity of 0.3 mA h cm^(-2).And Li/LiFePO4 battery still maintains a high capacity of 131.54 mA h g^(-1) at 0.5C after 800 cycles,which has a superior capacity retention rate of 93.2%.The obtained novel composite electrolyte has promising application prospects in the field of all-solid-state lithium metal cells.
文摘Composite nanoporous electrode SnO2/TiO2 was fabricated for the dye sensitized solar cell (DSSC) with N3 (Cis-Ru). After introducing of TiO2, the open-circuit photovoltage (Voc) was higher than that of the pure SnO2 electrode, while short-circuit photocurrent (Isc) was varied with the ratio of the TiO2. Appropriate content of the TiO2 can be beneficial to the efficiency of the solar cell, and it gives negative impact on the composite electrode when the content of TiO2 is higher.
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.
文摘TiO 2 nanoparticles were obtained from industrial TiOSO 4 by hydrolysis method. SnO 2/TiO 2 and SnO 2-TiO 2 composite powders were prepared by stepwise precipitation method and coating method, respectively. The phase transformation of TiO 2 and the effect of composite mode of SnO 2 on phase transformation of TiO 2 have been investigated by TG-DTA and XRD. The phase transform of pure TiO 2 from anatase to rutile begins at 750 ℃ and the presence of SnO 2 markedly reduces the transform temperature: for coated SnO 2-TiO 2 composite with ω(SnO 2)=20% it was 400 ℃. The SnO 2/TiO 2 composite prepared by precipitation method and followed by calcination at 400 ℃ for 30 min possesses 55% rutile TiO 2. The formation of SnO 2-TiO 2 solid- solution occurrs mainly due to the substitution of Ti 4+ crystal lattice sites by Sn 4+ ions of SnO 2.
基金sponsored by the Natural Science Foundation of China (Grant nos. 51775208)the Hubei Science Fund for Distinguished Young Scholars (No. 0216110085)+2 种基金the National Key Research and Development Program “Additive Manufacturing and Laser Manufacturing”(No. 2016YFB1100101)Wuhan Morning Light Plan of Youth Science and Technology (No. 0216110066)the Academic frontier youth team at Huazhong University of Science and Technology (HUST)
文摘Ag/SnO2,as a promising and environment-friendly electrical contact material,is widely applied in low-voltage apparatus.But the properties of Ag/SnO2 composites is difficult to improve due to the poor distribution phases and difficult component design.In this work,the Ag/SnO2 composites are prepared by selective laser melting.To get better performance,Ag/SnO2 composites with different energy density were studied.The microstructure was observed by field emission scanning electron microscope.In addition,reinforced SnO2 phase was characterized by X-ray diffraction and transmission electron microscope.The results indicated that the microstructure,relative density and hardness of are influenced by energy density,while Ag/SnO2 composites with homogeneous microstructure,high relative density,higher hardness and lower electrical resistivity can be obtained by proper energy density(E?68 J/mm^3).
基金supported financially by a grant from the National Research Foundation(NRF)of South Koreafunded by the Ministry of Science,ICT and Future Planning(Nos.NRF-2017R1A4A1014569 and NRF-2018M3A7B4071535).
文摘We report a composite material with the high tribological performance,which consists of onedimensional SnO2 nanotubes(ST)and a high molecular weight poly(vinylidene fluoride)(PVDF)matrix in terms of nano-impregnation.Dissolution of PVDF in N,N-dimethylformamide(DMF)resulted in a facile penetration of PVDF into the inner hollow voids of ST,leading to the close contact.Interaction between PVDF and ST results in a beneficial effect on the chain arrangement of PVDF,providing anα-phase with better tribological property.Upon ST incorporation,the friction coefficient decreased by 85.0%to 0.408,and the specific wear rate decreased by 69.1%to 0.412,demonstrating the pivotal role of ST as a self-lubricating material due to a large interactive area and PVDF chain rearrangement.
基金Shandong Province Natural Science Foundation of China (Grant No.ZR2015EL009).
文摘We synthesized SnO2/NiO composite oxides by microwave-assisted liquid phase deposition to improve their surface physico-chemical properties and gas-sensing selectivity,and we investigated how the molar ratio of Ni^2+to Sn^4+and the microwave power affected their gas-sensing performance.The microstructure,surface physico-chemical states,and morphology of the samples were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,and scanning electron microscopy,respectively.Nitrogen adsorption-desorption isotherms were used to characterize the specific surface areas of the samples.Our results showed that microwave-assisted liquid phase deposition increased the surface-adsorbed oxygen content and the specific surface area of the SnO2/NiO composite oxide from about 22to 120m2/g.When the molar ratio of Ni^2+to Sn^4+was 0.1,the gas response to 1000ppm ethanol gas reached 84.7at a lower working voltage of 3.5V.However,the optimum working voltages for methanol and acetone gas were 4.5and 4.0V,respectively.Thus,a new method was found to improve the selectivity of the gas sensor.Moreover,at a working voltage of 4.0V,the gas response of a SnO2/NiO gas sensor synthesized by microwave-assisted liquid phase deposition with the optimum radiation power of 450W to 1000ppm acetone gas was 49.7,twice that of a sensor synthesized by traditional liquid phase deposition.
