以四水合钼酸铵、六水合硝酸钴和硫脲为原料,采用一步水热法在钛网(TM)上原位构筑了不同阵列结构Co_(9)S_(8)/MoS_(2)@TM催化电极。通过改变原料中钴、钼、硫的物质的量之比来调控Co_(9)S_(8)/MoS_(2)@TM电极的结构。采用SEM、XRD和XPS...以四水合钼酸铵、六水合硝酸钴和硫脲为原料,采用一步水热法在钛网(TM)上原位构筑了不同阵列结构Co_(9)S_(8)/MoS_(2)@TM催化电极。通过改变原料中钴、钼、硫的物质的量之比来调控Co_(9)S_(8)/MoS_(2)@TM电极的结构。采用SEM、XRD和XPS对Co_(9)S_(8)/MoS_(2)@TM进行物相分析和形貌表征,并在1 mol/L KOH电解液中对Co_(9)S_(8)/MoS_(2)@TM的电催化析氧性能进行了研究。结果表明,钴、钼、硫的物质的量之比为10∶14∶600时,制备的Co_(9)S_(8)/MoS_(2)@TM为3D花瓣状阵列结构,且在10 m A/cm^(2)电流密度下过电势为271 m V,塔菲尔斜率为88.5 m V/dec,具有良好的析氧稳定性和耐久性,展现了优异的电化学性能。展开更多
Metal-organic framework(MOF)derived hybrid materials have been developed as an efficient non-noblemetal electrocatalysts for clean energy conversion systems.In this work,a Co-based MOF containing nitrogen and oxygen h...Metal-organic framework(MOF)derived hybrid materials have been developed as an efficient non-noblemetal electrocatalysts for clean energy conversion systems.In this work,a Co-based MOF containing nitrogen and oxygen heteroatoms(Co-NOMOF)mixed with the thiomolybdate[Mo3S(13)]^2- nanoclusters was used to prepare the N,S,O-doped carbon encapsulating Co9S8 and MoS2(Co9S8/MoS2@NSOC)nanocomposite by one-step pyrolysis.The Co9S8/MoS2@NSOC nanocomposite exhibited remarkable catalytic performance for hydrogen evolution reaction(HER)with overpotential of 194 and 233 mV in 1 M KOH and 0.5 M H2SO4 solution under 10 mA cm^-2,respectively,which was ascribed to the multiheteroatom-doped hierarchical porous carbon matrix and the synergistic effect of intrinsic activity of Co9S8 and MoS2.This work provides new opportunity for developing highly efficient non-precious metal electrochemical catalysts.展开更多
近年来,过渡金属硫化物已成为锂离子电池理想的负极材料之一。其中,MoS_2具有的独特二维层状结构使得其能够让Li+在电化学反应中可逆地嵌入和脱出,且拥有较高的理论储锂容量(670 m A·h/g)而受到广泛关注。但MoS_2作为典型的半导体...近年来,过渡金属硫化物已成为锂离子电池理想的负极材料之一。其中,MoS_2具有的独特二维层状结构使得其能够让Li+在电化学反应中可逆地嵌入和脱出,且拥有较高的理论储锂容量(670 m A·h/g)而受到广泛关注。但MoS_2作为典型的半导体材料,电导率低下且在锂离子嵌入-脱出的过程中会发生较大程度的体积收缩膨胀,所以具有较差的倍率性能和循环性能,限制了其商业化的使用。很多研究通过优化MoS_2结构或与其它导电材料复合来克服上述缺陷。Co_9S_8具有较高的电导率,但由于其迟缓的离子传输动力学表现出低的首次库仑效率及较差的循环稳定性,基于此,将MoS_2与Co_9S_8结合利用二者协同效应来提高复合材料的电化学性能。本文采用溶剂热与气相沉积法制备得MoS_2@Co_9S_8蛋黄结构复合材料电极。MoS_2与Co_9S_8均匀分布于整个蛋黄壳结构,这有利于电子和锂离子的快速传输,从而有效地提升了电极的循环性能和倍率性能。其次,蛋黄壳的空穴有效缓解了在充放电过程中的体积膨胀,及其活性位点有效缩短了离子和电子的传输距离,提高了电极反应动力学并获得高比容量。MoS_2@Co_9S_8蛋黄壳复合物的循环性能与倍率性能在同等条件下均高于Co_9S_8和MoS_2,在电流密度为0.2 A/g下循环500圈后,放电容量仍能维持在631.5 m A·h/g。展开更多
A new tetrahydrophenanthrene named henryin A(1) was isolated from the leaves of Chloranthus henryi.Its structure was determined to be(S)-4,6,9-trimethyl-5,6,7,8-tetrahydrophenanthrene-1,2-diol on the basis of IR,MS,1D...A new tetrahydrophenanthrene named henryin A(1) was isolated from the leaves of Chloranthus henryi.Its structure was determined to be(S)-4,6,9-trimethyl-5,6,7,8-tetrahydrophenanthrene-1,2-diol on the basis of IR,MS,1D and 2D NMR spectral.展开更多
In this paper,Co9S8/Ni3S2 nanoflakes(NFs)with sulfur deficiencies were grown in-situ on N-doped graphene nanotubes(NGNTs).They were successfully prepared through electrodeposition followed by hydrogenation treatment,w...In this paper,Co9S8/Ni3S2 nanoflakes(NFs)with sulfur deficiencies were grown in-situ on N-doped graphene nanotubes(NGNTs).They were successfully prepared through electrodeposition followed by hydrogenation treatment,which is able to act as a self-supported electrode for asymmetric supercapacitors(ASCs).Combining the defect-rich active materials with highly conductive skeletons,the hybrid electrode N-GNTs@sd-Co9S8/Ni3S2NFs show ultrahigh specific capacity of^304 mA hg^-1 and prominent rate capability(capacity retention ratio of^85%even at 100 Ag^-1),and deliver a long cycling lifespan of^1.9%capacitance loss after 10000 cycles.In addition,an ASC was constructed using the as-synthesized composite electrode as the positive electrode and active carbon(AC)as the negative electrode.The fabricated device shows a high energy density of^45.1 Wh kg^-1 at^3.4 kW kg^-1 and superior cycling stability.This work substantiates a smart strategy to fabricate novel composite electrode materials for next-generation supercapacitors by incorporating riched deficiencies into nanostructures.展开更多
A new jatrophane diterpenoid ester （2S, 3S, 4R, 5R, 7S, 8R, 13R, 15R） - 3, 5, 7, 8, 15- pentaacetoxy-9, 14-dioxojatropha-6（17）, 11E-diene was isolated from the whole plant of Euphorbia turczaninowii Kar. ＆ Kit.. ...A new jatrophane diterpenoid ester （2S, 3S, 4R, 5R, 7S, 8R, 13R, 15R） - 3, 5, 7, 8, 15- pentaacetoxy-9, 14-dioxojatropha-6（17）, 11E-diene was isolated from the whole plant of Euphorbia turczaninowii Kar. ＆ Kit.. Its structure was characterized by spectral analysis and confurmed by X-ray crystallographic analysis.展开更多
A new bicyclic spiroketone was isolated from the bud of Chrysanthemum indicum L. The chemical structure was elucidated as （1R, 9S, 10S）-10-hydroxyl-8 （2＇, 4＇-diynehexylidene）- 9-isovaleryloxy-2, 7-dioxaspiro [5,...A new bicyclic spiroketone was isolated from the bud of Chrysanthemum indicum L. The chemical structure was elucidated as （1R, 9S, 10S）-10-hydroxyl-8 （2＇, 4＇-diynehexylidene）- 9-isovaleryloxy-2, 7-dioxaspiro [5, 4] decane based on the X-ray crystallography.展开更多
A new highly sensitive method for determination of trace silver in waste water with 9,10- dimethylacridinium fluorosulfonate (DAFA)-K_2S_2O_3, system was suggested. In the basic aqueous so- lution, trace of silver (I)...A new highly sensitive method for determination of trace silver in waste water with 9,10- dimethylacridinium fluorosulfonate (DAFA)-K_2S_2O_3, system was suggested. In the basic aqueous so- lution, trace of silver (I) showed strongly catalytic effect on the chemiluminescence system with the pre- sence of 2,2'-bipyridine. The range of the linear relationship between light intensity and concen- tration of silver (I) is 1.0×10^(-3)mol / L to 6.0×10^(-6) mol / L. The detection limit is 8.0×10^(-9)mol / L, and the RSD for 5.0×10^(-8) mol / LAg (I) is 6.5％ (n=13). In the existence of potassium fluoride, the selectivity is higher. Combining the treatment with nitric acid, the method is applied to determine some environmental waste water and the results are similar to atomic absorption spectroscopy.展开更多
A highly active and stable oxygen evolution reaction （OER） electrocatalyst is critical for hydrogen production from water splitting. Herein, three-dimensional Ni3Sa@graphene@Co9S8 （Ni3S2@G@Co9S8）, a sandwich- stru...A highly active and stable oxygen evolution reaction （OER） electrocatalyst is critical for hydrogen production from water splitting. Herein, three-dimensional Ni3Sa@graphene@Co9S8 （Ni3S2@G@Co9S8）, a sandwich- structured OER electro-catalyst, was grown in situ on nickel foam; it afforded an enhanced catalytic performance when highly conductive graphene is introduced as an intermediary for enhancing the electron transfer rate and stability. Serving as a free-standing electrocatalytic electrode, Ni3S2@G@Co9S8 presents excellent electrocatalytic activities for OER： A low onset overpotential （2 mA·cm^-2 at 174 mV）, large anode current density （10 mA·cm^-2 at an overpotential of 210 mV）, low Tafel slope （66 mV·dec^-1）, and predominant durability of over 96 h （releasing a current density of N 14 mA·cm^-2 with a low and constant overpotential of 215 mV） in a 1 M KOH solution. This work provides a promising, cost-efficient electrocatalyst and sheds new light on improving the electrochemical performance of composites through enhancing the electron transfer rate and stability by introducing graphene as an intermediary.展开更多
文摘以四水合钼酸铵、六水合硝酸钴和硫脲为原料,采用一步水热法在钛网(TM)上原位构筑了不同阵列结构Co_(9)S_(8)/MoS_(2)@TM催化电极。通过改变原料中钴、钼、硫的物质的量之比来调控Co_(9)S_(8)/MoS_(2)@TM电极的结构。采用SEM、XRD和XPS对Co_(9)S_(8)/MoS_(2)@TM进行物相分析和形貌表征,并在1 mol/L KOH电解液中对Co_(9)S_(8)/MoS_(2)@TM的电催化析氧性能进行了研究。结果表明,钴、钼、硫的物质的量之比为10∶14∶600时,制备的Co_(9)S_(8)/MoS_(2)@TM为3D花瓣状阵列结构,且在10 m A/cm^(2)电流密度下过电势为271 m V,塔菲尔斜率为88.5 m V/dec,具有良好的析氧稳定性和耐久性,展现了优异的电化学性能。
基金supported by the National Science Fund for Distinguished Young Scholars (No. 21825106)National Natural Science Foundation of China (No. 21671175)+2 种基金Program for Science & Technology Innovation Talents in Universities of Henan Province (No. 164100510005)Key Scientific Research Project Plan in Colleges and Universities of Henan Province (No. 16A150045)Program for Innovative Research Team (in Science and Technology) in Universities of Henan Province (No. 19IRTSTHN022).
文摘Metal-organic framework(MOF)derived hybrid materials have been developed as an efficient non-noblemetal electrocatalysts for clean energy conversion systems.In this work,a Co-based MOF containing nitrogen and oxygen heteroatoms(Co-NOMOF)mixed with the thiomolybdate[Mo3S(13)]^2- nanoclusters was used to prepare the N,S,O-doped carbon encapsulating Co9S8 and MoS2(Co9S8/MoS2@NSOC)nanocomposite by one-step pyrolysis.The Co9S8/MoS2@NSOC nanocomposite exhibited remarkable catalytic performance for hydrogen evolution reaction(HER)with overpotential of 194 and 233 mV in 1 M KOH and 0.5 M H2SO4 solution under 10 mA cm^-2,respectively,which was ascribed to the multiheteroatom-doped hierarchical porous carbon matrix and the synergistic effect of intrinsic activity of Co9S8 and MoS2.This work provides new opportunity for developing highly efficient non-precious metal electrochemical catalysts.
文摘近年来,过渡金属硫化物已成为锂离子电池理想的负极材料之一。其中,MoS_2具有的独特二维层状结构使得其能够让Li+在电化学反应中可逆地嵌入和脱出,且拥有较高的理论储锂容量(670 m A·h/g)而受到广泛关注。但MoS_2作为典型的半导体材料,电导率低下且在锂离子嵌入-脱出的过程中会发生较大程度的体积收缩膨胀,所以具有较差的倍率性能和循环性能,限制了其商业化的使用。很多研究通过优化MoS_2结构或与其它导电材料复合来克服上述缺陷。Co_9S_8具有较高的电导率,但由于其迟缓的离子传输动力学表现出低的首次库仑效率及较差的循环稳定性,基于此,将MoS_2与Co_9S_8结合利用二者协同效应来提高复合材料的电化学性能。本文采用溶剂热与气相沉积法制备得MoS_2@Co_9S_8蛋黄结构复合材料电极。MoS_2与Co_9S_8均匀分布于整个蛋黄壳结构,这有利于电子和锂离子的快速传输,从而有效地提升了电极的循环性能和倍率性能。其次,蛋黄壳的空穴有效缓解了在充放电过程中的体积膨胀,及其活性位点有效缩短了离子和电子的传输距离,提高了电极反应动力学并获得高比容量。MoS_2@Co_9S_8蛋黄壳复合物的循环性能与倍率性能在同等条件下均高于Co_9S_8和MoS_2,在电流密度为0.2 A/g下循环500圈后,放电容量仍能维持在631.5 m A·h/g。
基金the National Natural Science Foundation of China(No.20462004) for financial support
文摘A new tetrahydrophenanthrene named henryin A(1) was isolated from the leaves of Chloranthus henryi.Its structure was determined to be(S)-4,6,9-trimethyl-5,6,7,8-tetrahydrophenanthrene-1,2-diol on the basis of IR,MS,1D and 2D NMR spectral.
基金supported by the National Natural Science Foundation of China(Grant Nos.51672144,51572137,51702181)the Key Research and Development Program of Shandong Province(Grant No.2019GGX102055)+3 种基金the Natural Science Foundation of Shandong Province(Grant Nos.ZR2017BB013,ZR2019BEM042)the Higher Educational Science and Technology Program of Shandong Province(Grant Nos.J17KA014,J18KA001,J18KA033)the Taishan Scholars Program of Shandong Province(Grant No.201511034)the Overseas Taishan Scholars Program。
文摘In this paper,Co9S8/Ni3S2 nanoflakes(NFs)with sulfur deficiencies were grown in-situ on N-doped graphene nanotubes(NGNTs).They were successfully prepared through electrodeposition followed by hydrogenation treatment,which is able to act as a self-supported electrode for asymmetric supercapacitors(ASCs).Combining the defect-rich active materials with highly conductive skeletons,the hybrid electrode N-GNTs@sd-Co9S8/Ni3S2NFs show ultrahigh specific capacity of^304 mA hg^-1 and prominent rate capability(capacity retention ratio of^85%even at 100 Ag^-1),and deliver a long cycling lifespan of^1.9%capacitance loss after 10000 cycles.In addition,an ASC was constructed using the as-synthesized composite electrode as the positive electrode and active carbon(AC)as the negative electrode.The fabricated device shows a high energy density of^45.1 Wh kg^-1 at^3.4 kW kg^-1 and superior cycling stability.This work substantiates a smart strategy to fabricate novel composite electrode materials for next-generation supercapacitors by incorporating riched deficiencies into nanostructures.
文摘A new jatrophane diterpenoid ester （2S, 3S, 4R, 5R, 7S, 8R, 13R, 15R） - 3, 5, 7, 8, 15- pentaacetoxy-9, 14-dioxojatropha-6（17）, 11E-diene was isolated from the whole plant of Euphorbia turczaninowii Kar. ＆ Kit.. Its structure was characterized by spectral analysis and confurmed by X-ray crystallographic analysis.
文摘A new bicyclic spiroketone was isolated from the bud of Chrysanthemum indicum L. The chemical structure was elucidated as （1R, 9S, 10S）-10-hydroxyl-8 （2＇, 4＇-diynehexylidene）- 9-isovaleryloxy-2, 7-dioxaspiro [5, 4] decane based on the X-ray crystallography.
文摘A new highly sensitive method for determination of trace silver in waste water with 9,10- dimethylacridinium fluorosulfonate (DAFA)-K_2S_2O_3, system was suggested. In the basic aqueous so- lution, trace of silver (I) showed strongly catalytic effect on the chemiluminescence system with the pre- sence of 2,2'-bipyridine. The range of the linear relationship between light intensity and concen- tration of silver (I) is 1.0×10^(-3)mol / L to 6.0×10^(-6) mol / L. The detection limit is 8.0×10^(-9)mol / L, and the RSD for 5.0×10^(-8) mol / LAg (I) is 6.5％ (n=13). In the existence of potassium fluoride, the selectivity is higher. Combining the treatment with nitric acid, the method is applied to determine some environmental waste water and the results are similar to atomic absorption spectroscopy.
基金The work was supported by the National Natural Science Foundation of China （NSFC） （Nos. 61525402 and 5161101159）, Key University Science Research Project of Jiangsu Province （No. 15KJA430006）, QingLan Project, National Postdoctoral Program for Innovative Talents （No. BX201600072）, China Postdoctoral Science Foundation （No. 2016M601792）.
文摘A highly active and stable oxygen evolution reaction （OER） electrocatalyst is critical for hydrogen production from water splitting. Herein, three-dimensional Ni3Sa@graphene@Co9S8 （Ni3S2@G@Co9S8）, a sandwich- structured OER electro-catalyst, was grown in situ on nickel foam; it afforded an enhanced catalytic performance when highly conductive graphene is introduced as an intermediary for enhancing the electron transfer rate and stability. Serving as a free-standing electrocatalytic electrode, Ni3S2@G@Co9S8 presents excellent electrocatalytic activities for OER： A low onset overpotential （2 mA·cm^-2 at 174 mV）, large anode current density （10 mA·cm^-2 at an overpotential of 210 mV）, low Tafel slope （66 mV·dec^-1）, and predominant durability of over 96 h （releasing a current density of N 14 mA·cm^-2 with a low and constant overpotential of 215 mV） in a 1 M KOH solution. This work provides a promising, cost-efficient electrocatalyst and sheds new light on improving the electrochemical performance of composites through enhancing the electron transfer rate and stability by introducing graphene as an intermediary.
