采用优化的静电纺丝方法结合控制热解法制备出一维Co_3O_4/C纳米纤维,前驱纳米纤维均匀光滑,其纤维直径大约为200 nm左右,经退火处理后Co_3O_4颗粒镶嵌于碳纤维中。通过X射线衍射(XRD)表征,发现该Co_3O_4结晶完整且无杂质。室温下用蓝...采用优化的静电纺丝方法结合控制热解法制备出一维Co_3O_4/C纳米纤维,前驱纳米纤维均匀光滑,其纤维直径大约为200 nm左右,经退火处理后Co_3O_4颗粒镶嵌于碳纤维中。通过X射线衍射(XRD)表征,发现该Co_3O_4结晶完整且无杂质。室温下用蓝电电池测试系统(CT2001A)测试其倍率性能和循环性能,首次放电比容量高达1314. 5 m Ah·g^(-1)。分别以0. 1 C、0. 5 C、1 C、2 C、5 C、10 C、15 C和0. 1 C的倍率进行充放电测试,其对应比容量分别为633 m Ah·g^(-1)、535 m Ah·g^(-1)、398 m Ah·g^(-1)、252 m Ah·g^(-1)、157 m Ah·g^(-1)、86 m Ah·g^(-1)、49 m Ah·g^(-1)和643 m Ah·g^(-1),表现出良好的倍率性能。在倍率为0. 5 C下测试其循环性能,50次循环后充电比容量为494 m Ah·g^(-1),容量保持率为88. 2%; 200次循环后比容量仍能达到300 m Ah·g^(-1),显示出优异的循环性能。这一优异的电化学性能归因于一维CNF网状结构的抗应力缓冲作用。展开更多
Three-dimensional （3D） hierarchical Co3O4 microcrystal with radial dendritic morphologies was prepared through hydrothermal reactions followed by subsequent annealing treatment. Structural and morphological characte...Three-dimensional （3D） hierarchical Co3O4 microcrystal with radial dendritic morphologies was prepared through hydrothermal reactions followed by subsequent annealing treatment. Structural and morphological characterizations were performed by X-ray diffraction, scan-ning electron microscopy and transmission electron microscopy. The gas sensing properties of the as-obtained microcrystal were investigated at 110 oC, which revealed that the 3D hierarchical porous Co3O4 microcrystal exhibited high sensitivity to ammonia, as well as a short response time of 10 s. The response characteristic indicates that the sensor has a good stability and reversibility. Detections of toxic and flammable gases, such as ethanol, acetone and benzene were also carried out at a relative low temperature. The results indicate that such hierarchical Co3O4 microcrystal would be a potential material in the field of gas sensing.展开更多
基金supported by the National Natural Science Foundation of China (Grants No.21103013,21473014)the Natural Science Foundation of Shanxi Province (Grant No.2016JM5082)Student′s Platform for Innovation and Entrepreneurship Training Program (Grants No. 201810710113, 201910710469)~~
文摘采用优化的静电纺丝方法结合控制热解法制备出一维Co_3O_4/C纳米纤维,前驱纳米纤维均匀光滑,其纤维直径大约为200 nm左右,经退火处理后Co_3O_4颗粒镶嵌于碳纤维中。通过X射线衍射(XRD)表征,发现该Co_3O_4结晶完整且无杂质。室温下用蓝电电池测试系统(CT2001A)测试其倍率性能和循环性能,首次放电比容量高达1314. 5 m Ah·g^(-1)。分别以0. 1 C、0. 5 C、1 C、2 C、5 C、10 C、15 C和0. 1 C的倍率进行充放电测试,其对应比容量分别为633 m Ah·g^(-1)、535 m Ah·g^(-1)、398 m Ah·g^(-1)、252 m Ah·g^(-1)、157 m Ah·g^(-1)、86 m Ah·g^(-1)、49 m Ah·g^(-1)和643 m Ah·g^(-1),表现出良好的倍率性能。在倍率为0. 5 C下测试其循环性能,50次循环后充电比容量为494 m Ah·g^(-1),容量保持率为88. 2%; 200次循环后比容量仍能达到300 m Ah·g^(-1),显示出优异的循环性能。这一优异的电化学性能归因于一维CNF网状结构的抗应力缓冲作用。
基金ACKNOWLEDGMENTS This work was supported by the 211 project of Anhui University, the National Natural Science Foundation of China （No.11374013, No.61290301, No.51072001, No.51272001, and No.51272003）, Anhui Provincial Natural Science Fund （No.l1040606M49）, Higher Educational Natural Science Foundation of Anhui Province （No.KJ2012A007）, and the PhD Start-up Fund of Anhui University （No.33190209）. Ming-zai Wu thanks Dr. Fan-li Meng and Miss Hui-hua Li from the Institute of Intelligent Machines, CAS for the help with gas sensing experiment.
文摘Three-dimensional （3D） hierarchical Co3O4 microcrystal with radial dendritic morphologies was prepared through hydrothermal reactions followed by subsequent annealing treatment. Structural and morphological characterizations were performed by X-ray diffraction, scan-ning electron microscopy and transmission electron microscopy. The gas sensing properties of the as-obtained microcrystal were investigated at 110 oC, which revealed that the 3D hierarchical porous Co3O4 microcrystal exhibited high sensitivity to ammonia, as well as a short response time of 10 s. The response characteristic indicates that the sensor has a good stability and reversibility. Detections of toxic and flammable gases, such as ethanol, acetone and benzene were also carried out at a relative low temperature. The results indicate that such hierarchical Co3O4 microcrystal would be a potential material in the field of gas sensing.
