通过机械混合法将Si和TiO2复合合成锂离子电池复合负极材料。采用XRD、SEM和电化学测试等手段对复合材料进行一系列表征和测试,考察了不同TiO2复合量对Si负极材料性能的影响。结果表明:复合后材料的首次库仑效率明显提高,循环性能也有...通过机械混合法将Si和TiO2复合合成锂离子电池复合负极材料。采用XRD、SEM和电化学测试等手段对复合材料进行一系列表征和测试,考察了不同TiO2复合量对Si负极材料性能的影响。结果表明:复合后材料的首次库仑效率明显提高,循环性能也有明显的改善。当Si与TiO2质量比为1∶1时,电极材料的首次放电比容量为2 099.0m Ah/g,首次库仑效率为78.7%,0.5 A/g电流密度下首次放电比容量为1 112.1 m Ah/g,循环50次后比容量保持在480.4 m Ah/g。展开更多
TiO2 supports doped with different amounts of Si were prepared by a sol-gel method, and 1 wt% vanadia （V2O5） loaded on Si-doped TiO2 was obtained by an impregnation method. The mole ratio of Si/Ti was 0.2, NOx conve...TiO2 supports doped with different amounts of Si were prepared by a sol-gel method, and 1 wt% vanadia （V2O5） loaded on Si-doped TiO2 was obtained by an impregnation method. The mole ratio of Si/Ti was 0.2, NOx conversion exceeds 94% at 300℃ and GHSV of 41,324 hr-1 , which is about 20% higher than pure V2O5/TiO2 . The catalysts were characterized by XRD, BET, TEM, FT-IR, NH3-TPD, XPS, H2-TPR, Raman and in situ DRIFTS. The results of FT-IR and XPS indicated that Si was doped into the TiO2 lattice successfully and a solid solution was obtained. V2O5 active component could be dispersed well on the support with the increasing of surface area of the catalyst, which was confirmed by Raman and XRD results. Above all, the numbers of acid sites （especially the Br nsted-acid） and oxidation properties were enhanced for Si-doped V2O5/TiO2 catalysts, which improved the deNOx catalytic activity.展开更多
Highly ordered TiO_2 nanotube arrays(NTAs) on Si substrate possess broad applications due to its high surfaceto-volume ratio and novel functionalities, however, there are still some challenges on facile synthesis. Her...Highly ordered TiO_2 nanotube arrays(NTAs) on Si substrate possess broad applications due to its high surfaceto-volume ratio and novel functionalities, however, there are still some challenges on facile synthesis. Here, we report a simple and cost-effective high-field(90–180V) anodization method to grow highly ordered TiO_2 NTAs on Si substrate,and investigate the effect of anodization time, voltage, and fluoride content on the formation of TiO_2 NTAs. The current density–time curves, recorded during anodization processes, can be used to determine the optimum anodization time. It is found that the growth rate of TiO_2 NTAs is improved significantly under high field, which is nearly 8 times faster than that under low fields(40–60 V). The length and growth rate of the nanotubes are further increased with the increase of fluoride content in the electrolyte.展开更多
文摘通过机械混合法将Si和TiO2复合合成锂离子电池复合负极材料。采用XRD、SEM和电化学测试等手段对复合材料进行一系列表征和测试,考察了不同TiO2复合量对Si负极材料性能的影响。结果表明:复合后材料的首次库仑效率明显提高,循环性能也有明显的改善。当Si与TiO2质量比为1∶1时,电极材料的首次放电比容量为2 099.0m Ah/g,首次库仑效率为78.7%,0.5 A/g电流密度下首次放电比容量为1 112.1 m Ah/g,循环50次后比容量保持在480.4 m Ah/g。
基金supported by the National Natural Science Foundation of China (No. 51078185, U1162119)the research fund of Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province (No. AE201001)the research fund for the Doctoral Program of Higher Education of China (No.20113219110009)
文摘TiO2 supports doped with different amounts of Si were prepared by a sol-gel method, and 1 wt% vanadia （V2O5） loaded on Si-doped TiO2 was obtained by an impregnation method. The mole ratio of Si/Ti was 0.2, NOx conversion exceeds 94% at 300℃ and GHSV of 41,324 hr-1 , which is about 20% higher than pure V2O5/TiO2 . The catalysts were characterized by XRD, BET, TEM, FT-IR, NH3-TPD, XPS, H2-TPR, Raman and in situ DRIFTS. The results of FT-IR and XPS indicated that Si was doped into the TiO2 lattice successfully and a solid solution was obtained. V2O5 active component could be dispersed well on the support with the increasing of surface area of the catalyst, which was confirmed by Raman and XRD results. Above all, the numbers of acid sites （especially the Br nsted-acid） and oxidation properties were enhanced for Si-doped V2O5/TiO2 catalysts, which improved the deNOx catalytic activity.
基金supported by National 863 Program 2011AA050518the Natural Science Foundation of China(Grant Nos.11174197,11574203,and 61234005)
文摘Highly ordered TiO_2 nanotube arrays(NTAs) on Si substrate possess broad applications due to its high surfaceto-volume ratio and novel functionalities, however, there are still some challenges on facile synthesis. Here, we report a simple and cost-effective high-field(90–180V) anodization method to grow highly ordered TiO_2 NTAs on Si substrate,and investigate the effect of anodization time, voltage, and fluoride content on the formation of TiO_2 NTAs. The current density–time curves, recorded during anodization processes, can be used to determine the optimum anodization time. It is found that the growth rate of TiO_2 NTAs is improved significantly under high field, which is nearly 8 times faster than that under low fields(40–60 V). The length and growth rate of the nanotubes are further increased with the increase of fluoride content in the electrolyte.
