SnO2 nanofibers were synthesized by electrospinning and modified with Co3O4 via impregnation in this work. Chemical composition and morphology of the nanofibers were system- atically characterized, and their gas sensi...SnO2 nanofibers were synthesized by electrospinning and modified with Co3O4 via impregnation in this work. Chemical composition and morphology of the nanofibers were system- atically characterized, and their gas sensing properties were investigated. Results showed that Co3O4 modification significantly enhanced the sensing performance of SnO2 nanofibers to ethanol gas. For a sample with 1.2 mol% Co3O4, the response to 100 ppm ethanol was 38.0 at 300 ℃, about 6.7 times larger than that of SnO2 nanofibers. In addition, the response/recovery time was also greatly reduced. A power-law dependence of the sensor response on the ethanol concentration as well as excellent ethanol selectivity was observed for the Co3O4/SnO2 sensor. The enhanced ethanol sensing performance may be attributed to the formation of p-n heterojunctions between the two oxides.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
为改善SnO_2-Fe_2O_3的电化学性能,通过一步水热法合成SnO_2-Fe_2O_3/rGO纳米复合材料,采用XRD、SEM、电化学工作站和蓝电电池测试系统,研究rGO加入量对SnO_2-Fe_2O_3/rGO复合材料的结构和电化学性能的影响.结果表明:rGO的掺入能很好地...为改善SnO_2-Fe_2O_3的电化学性能,通过一步水热法合成SnO_2-Fe_2O_3/rGO纳米复合材料,采用XRD、SEM、电化学工作站和蓝电电池测试系统,研究rGO加入量对SnO_2-Fe_2O_3/rGO复合材料的结构和电化学性能的影响.结果表明:rGO的掺入能很好地提高SnO_2-Fe_2O_3循环稳定性和倍率性能;对于SnO_2-Fe_2O_3/rGO50复合材料,在160 m A/g的电流密度下,100次循环后,放电比容量仍然保持596.9 m Ah/g,库仑效率为98%;即使在1 A/g的电流密度下,依然有366.6 m Ah/g的平均放电比容量.展开更多
Although SnO_2-based nanomaterials used to be considered as being extraordinarily versatile for application to nanosensors,microelectronic devices, lithium-ion batteries, supercapacitors and other devices, the functio...Although SnO_2-based nanomaterials used to be considered as being extraordinarily versatile for application to nanosensors,microelectronic devices, lithium-ion batteries, supercapacitors and other devices, the functionalities of SnO_2-based nanomaterials are severely limited by their intrinsic vulnerabilities. Facile electrospinning was used to prepare SnO_2 nanofibers coated with a protective carbon layer. The mechanical properties of individual core-shell-structured SnO_2@C nanofibers were investigated by atomic force microscopy and the finite element method. The elastic moduli of the carbon-coated SnO_2 nanofibers remarkably increased, suggesting that coating SnO_2 nanofibers with carbon could be an effective method of improving their mechanical properties.展开更多
基金This work was supported by the National Natural Science Foundation of China （No.U1432108） and the Fundamental Research Funds for the Central Universities （No.WK2320000034）.
文摘SnO2 nanofibers were synthesized by electrospinning and modified with Co3O4 via impregnation in this work. Chemical composition and morphology of the nanofibers were system- atically characterized, and their gas sensing properties were investigated. Results showed that Co3O4 modification significantly enhanced the sensing performance of SnO2 nanofibers to ethanol gas. For a sample with 1.2 mol% Co3O4, the response to 100 ppm ethanol was 38.0 at 300 ℃, about 6.7 times larger than that of SnO2 nanofibers. In addition, the response/recovery time was also greatly reduced. A power-law dependence of the sensor response on the ethanol concentration as well as excellent ethanol selectivity was observed for the Co3O4/SnO2 sensor. The enhanced ethanol sensing performance may be attributed to the formation of p-n heterojunctions between the two oxides.
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.
文摘为改善SnO_2-Fe_2O_3的电化学性能,通过一步水热法合成SnO_2-Fe_2O_3/rGO纳米复合材料,采用XRD、SEM、电化学工作站和蓝电电池测试系统,研究rGO加入量对SnO_2-Fe_2O_3/rGO复合材料的结构和电化学性能的影响.结果表明:rGO的掺入能很好地提高SnO_2-Fe_2O_3循环稳定性和倍率性能;对于SnO_2-Fe_2O_3/rGO50复合材料,在160 m A/g的电流密度下,100次循环后,放电比容量仍然保持596.9 m Ah/g,库仑效率为98%;即使在1 A/g的电流密度下,依然有366.6 m Ah/g的平均放电比容量.
基金supported by the National Natural Science Foundation of China(Grant Nos.51401176,51002128)the Scientific Research Foundation of the Hunan Provincial Education Department(Grant No.17A205)the Natural Science Foundation of Hunan Province(Grant No.2018JJ2393,2018JJ2394)
文摘Although SnO_2-based nanomaterials used to be considered as being extraordinarily versatile for application to nanosensors,microelectronic devices, lithium-ion batteries, supercapacitors and other devices, the functionalities of SnO_2-based nanomaterials are severely limited by their intrinsic vulnerabilities. Facile electrospinning was used to prepare SnO_2 nanofibers coated with a protective carbon layer. The mechanical properties of individual core-shell-structured SnO_2@C nanofibers were investigated by atomic force microscopy and the finite element method. The elastic moduli of the carbon-coated SnO_2 nanofibers remarkably increased, suggesting that coating SnO_2 nanofibers with carbon could be an effective method of improving their mechanical properties.
