Intercalating Nb-based oxides are promising anode compounds for lithiumion batteries since they have both good safety and large capacities.However,the research in this field is still limited.Here,Mo_(3)Nb_(14)O_(44)wi...Intercalating Nb-based oxides are promising anode compounds for lithiumion batteries since they have both good safety and large capacities.However,the research in this field is still limited.Here,Mo_(3)Nb_(14)O_(44)with a large theoretical capacity of 398 mAh g^(–1)(Mo^(64)←→Mo^(4+)and Nb^(5+)←→Nb^(3+))is exploited as a new Nb-based oxide anode compound,and Mo_(3)Nb_(14)O_(44)micron-sized particles(Mo_(3)Nb_(14)O_(44)-M)and Mo3Nb14O44 nanowires(Mo_(3)Nb_(14)O_(44)-N)are demonstrated.Mo3Nb14O44 owns a tetragonal shear ReO_(3)crystal structure(high-symmetric 14 space group)constructed by 4×4×∞(Mo,Nb)O_(6)octahedron blocks linked by Mo O4 tetrahedra,forming an A–B–A layered structure with a large interlayer spacing.This interesting structure allows fast Li+storage within the interlayers and significant intercalation-pseudocapacitive behavior,leading to the high rate performance of Mo_(3)Nb_(14)O_(44)-M/Mo_(3)Nb_(14)O_(44)-N with a large 10 C versus 0.1 C capacity retention percentage of 38.1/54.2%.Mo_(3)Nb_(14)O_(44)-M/Mo_(3)Nb_(14)O_(44)-N further exhibits a safe operating potential of 1.72/1.68 V,large reversible capacity of 323/321 m Ah g^(–1)at 0.1 C,high initial coulombic efficiency of 92.2/90.0%,and good cycling stability with 71.8/75.8%capacity retention after 1000 cycles at10 C.Additionally,a Li Mn_(2)O_(4)/Mo_(3)Nb_(14)O_(44)-N full cell also performs well.Therefore,Mo_(3)Nb_(14)O_(44)holds great promise as a fast-charging,safe,largecapacity,high-efficient,and long-life Li^(+)anode container.展开更多
Four complexes containing the [Re(V)O]3+ core have been prepared by substitution on the precursors RO(citrate)2- and ReO(gluconate)2-. The complex [ReO(MBT)2OH] was obtained by reaction of the direct reduction of ReO4...Four complexes containing the [Re(V)O]3+ core have been prepared by substitution on the precursors RO(citrate)2- and ReO(gluconate)2-. The complex [ReO(MBT)2OH] was obtained by reaction of the direct reduction of ReO4- using sodium borohydride as a reducing agent. Four complexes were character-ized by UV-Vis and IR spectrophotometer, elemental analyses, 1H-and 13C NMR spectroscopy, TG and DFT calculations.展开更多
A [ReO(Imz)(Hyd)(H2O)2OH] complex was successfully synthesized by the ligand exchange method using oxorhenuim citrate and an imidazole /Hydanton mixed ligand system. Geometry optimization of complex has been carried o...A [ReO(Imz)(Hyd)(H2O)2OH] complex was successfully synthesized by the ligand exchange method using oxorhenuim citrate and an imidazole /Hydanton mixed ligand system. Geometry optimization of complex has been carried out using DFT at the B3LYP/LANL2DZ functional in singlet state. B3LYP predicated infrared spectrum of the geometrically optimized structure using the same level of the theory and the same base set showed good agreement with experimentally observed values. The spin allowed singlet-singlet electronic transition of the [ReO(Imz)(Hyd) (H2O)2OH] complex was calculated with time dependent density function theory (TD-DFT) and the UV-Vis spectra has been discussed on this basis. The complex was characterized using microanalysis and IR, UV-Vis, NMR and mass spectroscopic. The technetium tracer [99mTcO(Imz)(Hyd) (H2O)2OH] has also been synthesized by two methods using 99mTc-gluconate as a precursor or;by direct reduction. The radiochemical purity of the complex was over 95% as measured by thin layer chromatography. In vitro studies showed that the complex possessed good stability under physiological conditions. The partition coefficient indicated that the complex hydrophilic and the electrophoresis results showed that the complex cationic. Biodistrbution in mice showed that the complex accumulated in heart uptake of 9.53±3.87 % ID/gm at 5 min and good retention (6.37±1.21) % ID/gm at 60 min. One hour after the injection, the heart/liver, heart/lung and heart/blood radioactivity ratios were 0.46, 1.04 and 0.56, respectively. These findings indicate that the complex might be suitable for myocardial imaging.展开更多
基金supported by National Natural Science Foundation of China(51762014)China Postdoctoral Science Foundation(2019M652316)
文摘Intercalating Nb-based oxides are promising anode compounds for lithiumion batteries since they have both good safety and large capacities.However,the research in this field is still limited.Here,Mo_(3)Nb_(14)O_(44)with a large theoretical capacity of 398 mAh g^(–1)(Mo^(64)←→Mo^(4+)and Nb^(5+)←→Nb^(3+))is exploited as a new Nb-based oxide anode compound,and Mo_(3)Nb_(14)O_(44)micron-sized particles(Mo_(3)Nb_(14)O_(44)-M)and Mo3Nb14O44 nanowires(Mo_(3)Nb_(14)O_(44)-N)are demonstrated.Mo3Nb14O44 owns a tetragonal shear ReO_(3)crystal structure(high-symmetric 14 space group)constructed by 4×4×∞(Mo,Nb)O_(6)octahedron blocks linked by Mo O4 tetrahedra,forming an A–B–A layered structure with a large interlayer spacing.This interesting structure allows fast Li+storage within the interlayers and significant intercalation-pseudocapacitive behavior,leading to the high rate performance of Mo_(3)Nb_(14)O_(44)-M/Mo_(3)Nb_(14)O_(44)-N with a large 10 C versus 0.1 C capacity retention percentage of 38.1/54.2%.Mo_(3)Nb_(14)O_(44)-M/Mo_(3)Nb_(14)O_(44)-N further exhibits a safe operating potential of 1.72/1.68 V,large reversible capacity of 323/321 m Ah g^(–1)at 0.1 C,high initial coulombic efficiency of 92.2/90.0%,and good cycling stability with 71.8/75.8%capacity retention after 1000 cycles at10 C.Additionally,a Li Mn_(2)O_(4)/Mo_(3)Nb_(14)O_(44)-N full cell also performs well.Therefore,Mo_(3)Nb_(14)O_(44)holds great promise as a fast-charging,safe,largecapacity,high-efficient,and long-life Li^(+)anode container.
文摘Four complexes containing the [Re(V)O]3+ core have been prepared by substitution on the precursors RO(citrate)2- and ReO(gluconate)2-. The complex [ReO(MBT)2OH] was obtained by reaction of the direct reduction of ReO4- using sodium borohydride as a reducing agent. Four complexes were character-ized by UV-Vis and IR spectrophotometer, elemental analyses, 1H-and 13C NMR spectroscopy, TG and DFT calculations.
文摘A [ReO(Imz)(Hyd)(H2O)2OH] complex was successfully synthesized by the ligand exchange method using oxorhenuim citrate and an imidazole /Hydanton mixed ligand system. Geometry optimization of complex has been carried out using DFT at the B3LYP/LANL2DZ functional in singlet state. B3LYP predicated infrared spectrum of the geometrically optimized structure using the same level of the theory and the same base set showed good agreement with experimentally observed values. The spin allowed singlet-singlet electronic transition of the [ReO(Imz)(Hyd) (H2O)2OH] complex was calculated with time dependent density function theory (TD-DFT) and the UV-Vis spectra has been discussed on this basis. The complex was characterized using microanalysis and IR, UV-Vis, NMR and mass spectroscopic. The technetium tracer [99mTcO(Imz)(Hyd) (H2O)2OH] has also been synthesized by two methods using 99mTc-gluconate as a precursor or;by direct reduction. The radiochemical purity of the complex was over 95% as measured by thin layer chromatography. In vitro studies showed that the complex possessed good stability under physiological conditions. The partition coefficient indicated that the complex hydrophilic and the electrophoresis results showed that the complex cationic. Biodistrbution in mice showed that the complex accumulated in heart uptake of 9.53±3.87 % ID/gm at 5 min and good retention (6.37±1.21) % ID/gm at 60 min. One hour after the injection, the heart/liver, heart/lung and heart/blood radioactivity ratios were 0.46, 1.04 and 0.56, respectively. These findings indicate that the complex might be suitable for myocardial imaging.
