A material with the formula ZrMgMo_(3)O_(12) having negative thermal expansion is presented and characterized.It is shown that ZrMgMo_(3)O_(12) crystallizes in an orthorhombic symmetry with space group Pnma(62)or Pna2...A material with the formula ZrMgMo_(3)O_(12) having negative thermal expansion is presented and characterized.It is shown that ZrMgMo_(3)O_(12) crystallizes in an orthorhombic symmetry with space group Pnma(62)or Pna21(33)and exhibits negative thermal expansion in a large temperature range(αl=-3.8×10^(-6) K^(-1) from 300 K to 1000 K by x-ray diffraction andαl=-3.73×10^(-6) K^(-1) from 295 K to 775 K by dilatometer).ZrMgMo_(3)O_(12) remains the orthorhombic structure without phase transition or decomposition at least from 123 K to 1200 K and is not hygroscopic.These properties make it an excellent material with negative thermal expansion for a variety of applications.展开更多
We described the preparation of copper oxide composite nanofibers doped with carbon nanotubes （CuO/C-NFs） or nickel oxide（CuO/NiO-NFs） by electrospinning for direct glucose determination. The interest in exploring...We described the preparation of copper oxide composite nanofibers doped with carbon nanotubes （CuO/C-NFs） or nickel oxide（CuO/NiO-NFs） by electrospinning for direct glucose determination. The interest in exploring practical CuO/C-NFs and CuO/NiO-NFs electrode materials for sensor application was fascinated by the possibility of promoting electron transfer for kinetically unfavorable glucose oxidation reactions at a lower overpo- tential and thus improving the selectivity of the electrode for glucose in electroanalysis. The morphologies of CuO/C-NFs and CuO/NiO-NFs were characterized by scanning electron microscopy（SEM） and X-ray powder diffraction（XRD）. The electrocatalytic performances of glucose were evaluated in detail by cyclic voltammetry（CV） and chronoamperometry. Facile charge transport, enhanced current response（at a lower overpotential of ＋0.35 V）, improved stability and selectivity, as well as excellent resistance towards electrode fouling were observed at CuO/ C-NFs electrode in direct glucose electroanalysis. These merits are attributed to the highly porous three-dimensional network film structure of CuO/C-NFs electrode materials and the potential synergic catalytic effect of CuO and carbon nanotubes in composite nanofibers. This study may provide a new insight into metal oxide-based composite nanofibers obtained via electrospinning for fabricating novel and high performance sensors and devices.展开更多
基金Supported by the National Science Foundation of China(Nos 10974183,11104252)the Ministry of Education of China(No 20114101110003)+1 种基金the Fund for Science&Technology Innovation Team of Zhengzhou(No 112PCXTD337)the Postdoctoral Research Sponsorship in Henan Province(No 2011002).
文摘A material with the formula ZrMgMo_(3)O_(12) having negative thermal expansion is presented and characterized.It is shown that ZrMgMo_(3)O_(12) crystallizes in an orthorhombic symmetry with space group Pnma(62)or Pna21(33)and exhibits negative thermal expansion in a large temperature range(αl=-3.8×10^(-6) K^(-1) from 300 K to 1000 K by x-ray diffraction andαl=-3.73×10^(-6) K^(-1) from 295 K to 775 K by dilatometer).ZrMgMo_(3)O_(12) remains the orthorhombic structure without phase transition or decomposition at least from 123 K to 1200 K and is not hygroscopic.These properties make it an excellent material with negative thermal expansion for a variety of applications.
基金Supported by the National Natural Science Foundation of China（Nos. 21075048, 20543003）.
文摘We described the preparation of copper oxide composite nanofibers doped with carbon nanotubes （CuO/C-NFs） or nickel oxide（CuO/NiO-NFs） by electrospinning for direct glucose determination. The interest in exploring practical CuO/C-NFs and CuO/NiO-NFs electrode materials for sensor application was fascinated by the possibility of promoting electron transfer for kinetically unfavorable glucose oxidation reactions at a lower overpo- tential and thus improving the selectivity of the electrode for glucose in electroanalysis. The morphologies of CuO/C-NFs and CuO/NiO-NFs were characterized by scanning electron microscopy（SEM） and X-ray powder diffraction（XRD）. The electrocatalytic performances of glucose were evaluated in detail by cyclic voltammetry（CV） and chronoamperometry. Facile charge transport, enhanced current response（at a lower overpotential of ＋0.35 V）, improved stability and selectivity, as well as excellent resistance towards electrode fouling were observed at CuO/ C-NFs electrode in direct glucose electroanalysis. These merits are attributed to the highly porous three-dimensional network film structure of CuO/C-NFs electrode materials and the potential synergic catalytic effect of CuO and carbon nanotubes in composite nanofibers. This study may provide a new insight into metal oxide-based composite nanofibers obtained via electrospinning for fabricating novel and high performance sensors and devices.
