采用改进的碳酸盐共沉淀与高温固相法相结合的方法制备出了高倍率性能的锂离子电池正极材料Li[Ni1/3Co1/3Mn1/3]O2,通过X射线衍射(XRD)、扫描电镜(SEM)、循环伏安扫描(CV)、电化学阻抗谱(EIS)和电化学性能测试等手段对材料进行表征.结...采用改进的碳酸盐共沉淀与高温固相法相结合的方法制备出了高倍率性能的锂离子电池正极材料Li[Ni1/3Co1/3Mn1/3]O2,通过X射线衍射(XRD)、扫描电镜(SEM)、循环伏安扫描(CV)、电化学阻抗谱(EIS)和电化学性能测试等手段对材料进行表征.结果表明,该方法制备的材料具有良好的α-Na Fe O2型层状结构(R3m(166)),一次粒径平均大小为157 nm,二次颗粒成球形.同传统碳酸盐制备得到的材料相比,该材料具备良好的倍率性能和循环性能,在2.7-4.3 V电压范围内,0.1C(1.0C=180 m A?g-1)倍率下,首次放电比容量为156.4m Ah?g-1,库仑效率为81.9%.在较高倍率下,即0.5C、5.0C和20C时,其放电比容量分别为136.9、111.3、81.3m Ah?g-1.在1C倍率下100次循环容量保持率为92.9%,高于传统共沉淀法得到的材料(87.0%).展开更多
Compound [Co 3(BTC)(HBTC)(H 2BTC)(C 2H 4O 2) 3]·3(DMF)·6(H 3O) was synthesized under mild conditions and its crystal structure was determined by using single crystal X-ray diffraction. The crystal structure ...Compound [Co 3(BTC)(HBTC)(H 2BTC)(C 2H 4O 2) 3]·3(DMF)·6(H 3O) was synthesized under mild conditions and its crystal structure was determined by using single crystal X-ray diffraction. The crystal structure was solved by direct method and refined by full-matrix least-square method. The crystal is monoclinic and belongs to space group Cc with a=2.645 3(5) nm, b= 1.670 4(3) nm, c=1\^821 6(4) nm, β=128.16(3) °, V=6.329(2) nm 3, Z=2 , D c=20.200 Mg/m 3, M r= 1 314.744, μ=10.274 mm -1, F(000) =38 226, GOF=0.99, R=0.094 1, ωR=0.257 3.展开更多
为探究溶剂对合成有机金属框架化合物的影响机制,采用实验和DFT理论计算相结合的方法,研究溶剂N,N-二甲基甲酰胺(DMF)和N-甲基-2-吡咯烷酮(NMP)对溶剂热法合成有机金属框架材料[Zn4O(BDC)3]8的影响及溶剂与框架间的微观作用机制。粉末X...为探究溶剂对合成有机金属框架化合物的影响机制,采用实验和DFT理论计算相结合的方法,研究溶剂N,N-二甲基甲酰胺(DMF)和N-甲基-2-吡咯烷酮(NMP)对溶剂热法合成有机金属框架材料[Zn4O(BDC)3]8的影响及溶剂与框架间的微观作用机制。粉末X射线衍射(XRD)和扫描电镜(SEM)结果表明,NMP在[Zn4O(BDC)3]8孔道中的吸附力较DMF的弱,NMP分子更容易从框架中脱除;热重(TG)和热重-红外联用(TGA/FT-IR)结果表明,以DMF为溶剂合成的[Zn4O(BDC)3]8的热分解温度和热稳定性较高;氮气等温吸附实验(BET)发现,以NMP为溶剂合成的[Zn4O(BDC)3]8的气体吸附性能更强,兰缪尔比表面积高于用DMF合成的[Zn4O(BDC)3]8。调控介电常数设定溶剂分别为NMP和DMF,用COSMO溶剂化方法对溶剂分子与框架化合物基本结构单元Zn4O(BDC)3间相互作用模型进行几何优化计算,发现溶剂设定为NMP时Zn4O(BDC)3优化结构的总能量较溶剂设定为DMF时的高8.6405 k J/mol,这说明DMF分子与Zn4O(BDC)3间的结合力强于NMP分子的,溶剂化作用降低了Zn与O间的离子性;用DMol3在GGA-BLYP/DN水平计算了DMF、NMP或DEF溶剂分子在[Zn4O(BDC)3]8晶体孔道中的相互作用,与DMF相比,NMP在孔道中能量状态稳定性较差,在能量状态角度上NMP应最容易从框架材料孔道中脱除。研究结果说明NMP更有利于合成性质良好的[Zn4O(BDC)3]8,与DMF相比NMP与框架结构基元间的作用力较弱。展开更多
The interaction between β-K 4H 3 [SiW 9O 37(CpTi) 3]·11H 2O and DNA was investigated by agarose gel electrophoresis. The results suggest that β-K 4H 3[SiW 9O 37(CpTi) 3]·11H 2O can degrade the genomic DNA....The interaction between β-K 4H 3 [SiW 9O 37(CpTi) 3]·11H 2O and DNA was investigated by agarose gel electrophoresis. The results suggest that β-K 4H 3[SiW 9O 37(CpTi) 3]·11H 2O can degrade the genomic DNA. The treatment of plasmid DNA with β-K 4H 3 [SiW 9O 37(CpTi) 3]·11H 2O resulted in a fast moving band in front of the three normal conformations(super coiled DNA, linear DNA and relaxed circular DNA) in agarose gel electrophoresis . These results indicate that this chemical material may have the ability to specifically cleavage DNA or to alter conformation of DNA molecules.展开更多
A novel porous coordination polymer [La(C8H6NO2)3]n was synthesized by hydrothermal reaction of flexible ligands 3 (3 pyridyl)acrylate and La(NO3)3· 6H2O. The structure was characterized by elemental analysis, IR...A novel porous coordination polymer [La(C8H6NO2)3]n was synthesized by hydrothermal reaction of flexible ligands 3 (3 pyridyl)acrylate and La(NO3)3· 6H2O. The structure was characterized by elemental analysis, IR spectroscopy and X ray single crystal diffraction. X ray single crystal analysis reveals the structure consists of [La(C8H6NO2)3]n. It crystallizes in monoclinic crystal system with space group P2(1)/c. Crystallographic date: a=0. 7889(3)nm, b=2.5916(9)nm, c=1.1489(4)nm, α =90.00° , β =95.219(6)° , γ =90.00° , V=2.3393(15)nm3, Z=4, Dc=1.656g· cm- 3, μ =1.871mm- 1, F(000)=1152, R1=0.0328, wR2=0.0522. CCDC: 211700.展开更多
文摘采用改进的碳酸盐共沉淀与高温固相法相结合的方法制备出了高倍率性能的锂离子电池正极材料Li[Ni1/3Co1/3Mn1/3]O2,通过X射线衍射(XRD)、扫描电镜(SEM)、循环伏安扫描(CV)、电化学阻抗谱(EIS)和电化学性能测试等手段对材料进行表征.结果表明,该方法制备的材料具有良好的α-Na Fe O2型层状结构(R3m(166)),一次粒径平均大小为157 nm,二次颗粒成球形.同传统碳酸盐制备得到的材料相比,该材料具备良好的倍率性能和循环性能,在2.7-4.3 V电压范围内,0.1C(1.0C=180 m A?g-1)倍率下,首次放电比容量为156.4m Ah?g-1,库仑效率为81.9%.在较高倍率下,即0.5C、5.0C和20C时,其放电比容量分别为136.9、111.3、81.3m Ah?g-1.在1C倍率下100次循环容量保持率为92.9%,高于传统共沉淀法得到的材料(87.0%).
文摘Compound [Co 3(BTC)(HBTC)(H 2BTC)(C 2H 4O 2) 3]·3(DMF)·6(H 3O) was synthesized under mild conditions and its crystal structure was determined by using single crystal X-ray diffraction. The crystal structure was solved by direct method and refined by full-matrix least-square method. The crystal is monoclinic and belongs to space group Cc with a=2.645 3(5) nm, b= 1.670 4(3) nm, c=1\^821 6(4) nm, β=128.16(3) °, V=6.329(2) nm 3, Z=2 , D c=20.200 Mg/m 3, M r= 1 314.744, μ=10.274 mm -1, F(000) =38 226, GOF=0.99, R=0.094 1, ωR=0.257 3.
基金Project(51104185)supported by the National Natural Science Foundation of ChinaProject(2010QZZD003)supported by the Key Project of Central South University of Fundamental Research Funds for the Central Universities of China
文摘为探究溶剂对合成有机金属框架化合物的影响机制,采用实验和DFT理论计算相结合的方法,研究溶剂N,N-二甲基甲酰胺(DMF)和N-甲基-2-吡咯烷酮(NMP)对溶剂热法合成有机金属框架材料[Zn4O(BDC)3]8的影响及溶剂与框架间的微观作用机制。粉末X射线衍射(XRD)和扫描电镜(SEM)结果表明,NMP在[Zn4O(BDC)3]8孔道中的吸附力较DMF的弱,NMP分子更容易从框架中脱除;热重(TG)和热重-红外联用(TGA/FT-IR)结果表明,以DMF为溶剂合成的[Zn4O(BDC)3]8的热分解温度和热稳定性较高;氮气等温吸附实验(BET)发现,以NMP为溶剂合成的[Zn4O(BDC)3]8的气体吸附性能更强,兰缪尔比表面积高于用DMF合成的[Zn4O(BDC)3]8。调控介电常数设定溶剂分别为NMP和DMF,用COSMO溶剂化方法对溶剂分子与框架化合物基本结构单元Zn4O(BDC)3间相互作用模型进行几何优化计算,发现溶剂设定为NMP时Zn4O(BDC)3优化结构的总能量较溶剂设定为DMF时的高8.6405 k J/mol,这说明DMF分子与Zn4O(BDC)3间的结合力强于NMP分子的,溶剂化作用降低了Zn与O间的离子性;用DMol3在GGA-BLYP/DN水平计算了DMF、NMP或DEF溶剂分子在[Zn4O(BDC)3]8晶体孔道中的相互作用,与DMF相比,NMP在孔道中能量状态稳定性较差,在能量状态角度上NMP应最容易从框架材料孔道中脱除。研究结果说明NMP更有利于合成性质良好的[Zn4O(BDC)3]8,与DMF相比NMP与框架结构基元间的作用力较弱。
文摘The interaction between β-K 4H 3 [SiW 9O 37(CpTi) 3]·11H 2O and DNA was investigated by agarose gel electrophoresis. The results suggest that β-K 4H 3[SiW 9O 37(CpTi) 3]·11H 2O can degrade the genomic DNA. The treatment of plasmid DNA with β-K 4H 3 [SiW 9O 37(CpTi) 3]·11H 2O resulted in a fast moving band in front of the three normal conformations(super coiled DNA, linear DNA and relaxed circular DNA) in agarose gel electrophoresis . These results indicate that this chemical material may have the ability to specifically cleavage DNA or to alter conformation of DNA molecules.
文摘A novel porous coordination polymer [La(C8H6NO2)3]n was synthesized by hydrothermal reaction of flexible ligands 3 (3 pyridyl)acrylate and La(NO3)3· 6H2O. The structure was characterized by elemental analysis, IR spectroscopy and X ray single crystal diffraction. X ray single crystal analysis reveals the structure consists of [La(C8H6NO2)3]n. It crystallizes in monoclinic crystal system with space group P2(1)/c. Crystallographic date: a=0. 7889(3)nm, b=2.5916(9)nm, c=1.1489(4)nm, α =90.00° , β =95.219(6)° , γ =90.00° , V=2.3393(15)nm3, Z=4, Dc=1.656g· cm- 3, μ =1.871mm- 1, F(000)=1152, R1=0.0328, wR2=0.0522. CCDC: 211700.
