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东天山维权银铜矿床中钴矿化发现及成因意义 被引量:12
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作者 李立兴 李厚民 +3 位作者 丁建华 宋哲 孟洁 马玉波 《矿床地质》 CAS CSCD 北大核心 2018年第4期779-797,共19页
新疆东天山地区是中国重要的钴成矿带之一,在多个与基性-超基性岩有关的铜镍硫化物矿床和磁海铁矿床中伴生有中小型钴矿资源。最近,笔者在研究东天山维权矽卡岩型银铜矿床物质组分的过程中,通过显微镜观察、电子探针扫描和成分分析发现... 新疆东天山地区是中国重要的钴成矿带之一,在多个与基性-超基性岩有关的铜镍硫化物矿床和磁海铁矿床中伴生有中小型钴矿资源。最近,笔者在研究东天山维权矽卡岩型银铜矿床物质组分的过程中,通过显微镜观察、电子探针扫描和成分分析发现了独立钴矿物辉砷钴矿,不仅代表了东天山含钴矿床的新类型,而且具有综合利用的前景。文章对维权矿床中铜银钴矿石类型、矿石中辉砷钴矿和其他主要金属矿物的赋存状态进行了研究,划分出铜矿石、铁铜矿石、含银铜钴矿石、银矿石、含钴铁铜矿石和铅银铜矿石6种矿石类型,认为它们可能是铁铜、钴、银3期成矿作用叠加的产物,钴成矿作用为独立的一期中高温热液成矿作用,含钴铁铜矿石是钴成矿作用叠加在铁铜成矿作用之上形成,而含银钴铜矿石是银成矿作用叠加在钴成矿作用之上形成。 展开更多
关键词 地球化学 辉砷钴矿 钴矿 银矿 维权矿床 东天山
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碱促进的钴酸镁催化剂上的氧化亚氮分解(英文) 被引量:9
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作者 Bahaa M. ABU-ZIED 《催化学报》 SCIE EI CAS CSCD 北大核心 2011年第2期264-272,共9页
The direct decomposition of N2O was investigated over a series of magnesium cobaltite catalysts,MgxCo1-xCo2O4(0.0 ≤ x ≤ 1.0) ,which were prepared by the thermal decomposition of stoichiometric amounts of magnesium h... The direct decomposition of N2O was investigated over a series of magnesium cobaltite catalysts,MgxCo1-xCo2O4(0.0 ≤ x ≤ 1.0) ,which were prepared by the thermal decomposition of stoichiometric amounts of magnesium hydroxide and cobalt acetate. The thermal genesis of the different catalysts from their precursors was explored using thermogravimetric analysis,differential thermal analysis,and X-ray diffraction. Texture analysis was carried out using N2 adsorption at -196 °C. We found that all the catalysts that were calcined at 500 °C have a spinel structure. N2O decomposition activity was found to increase with an increase in the spinel structure's magnesium content. The influence of alkali cation promoters(Li,Na,K,and Cs) on the activity of the most active catalyst in the MgxCo1-xCo2O4 series,i.e. MgCo2O4,was also investigated. The sequence of the promotional effect was found to be: un-promoted < Li < Na < Cs < K-promoted catalyst. The reason for the increase in activity for the added alkali cations was electronic in nature. Additionally,the dependence of the activity on the K/Co ratio was also determined. The highest activity was obtained for the catalyst with a K/Co ratio of 0.05. A continuous decrease in activity was obtained for higher K/Co ratios. This decrease in activity was attributed to the elimination of mesoporosity in the catalysts with K/Co ratios > 0.05,based on N2 adsorption and scanning electron microscopy results. 展开更多
关键词 nitrous oxide cobalt oxide magnesium cobaltite SPINEL alkali promotion
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Nickel foam supported Cr-doped NiCo2O4/FeOOH nanoneedle arrays as a high-performance bifunctional electrocatalyst for overall water splitting 被引量:11
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作者 Tengyi Liu Peng Diao 《Nano Research》 SCIE EI CAS CSCD 2020年第12期3299-3309,共11页
Efficient and robust noble-metal-free bifunctional electrocatalysts for overall water splitting(OWS)is of great importance to realize the large-scale hydrogen production.Herein,we report the growth of undoped and Cr-d... Efficient and robust noble-metal-free bifunctional electrocatalysts for overall water splitting(OWS)is of great importance to realize the large-scale hydrogen production.Herein,we report the growth of undoped and Cr-doped NiCo2O4(Cr-NiCo2O4)nanoneedles(NNs)on nickel foam(NF)as bifunctional electrocatalysts for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).We demonstrate that Cr-doping significantly improves activity for HER and OER by increasing the conductivity of NNs and allowing more active sites on NNs electrochemically accessible.When amorphous FeOOH is electrodeposited on the surface of Cr-NiCo2O4 NNs,the resulting FeOOH/Cr-NiCo2O4/NF exhibits itself as an excellent bifunctional catalyst for OWS.In the two-electrode cell where FeOOH/Cr-NiCo2O4/NF is used both as cathode and anode for OWS,a cell voltage of only 1.65 V is required to achieve an electrolysis current density of 100 mA·cm^−2.In addition,the catalyst shows a very high stability for OWS,the two-electrode cell can operate at a consist current density of 20 mA·cm^−2 for 10 h OWS with the cell voltage being stable at ca.1.60 V.These results demonstrate that FeOOH/Cr-NiCo2O4/NF possesses an OWS performance superior to most of transition-metal based bifunctional electrocatalysts working in alkaline medium.The excellent bifunctional activity and stability of FeOOH/Cr-NiCo2O4/NF are attributed to the following reasons:(i)The NN structure provides a large specific surface area;(ii)the high conductivity of Cr-NiCo2O4 enables more active centers on the far-end part of NNs to be electrochemically reached;(iii)the deposition of FeOOH supplies additional active sites for OWS. 展开更多
关键词 Cr-doped nickel cobaltite bifunctional electrocatalyst iron oxyhydroxide hydrogen evolution reaction oxygen evolution reaction overall water splitting
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Effect of the addition of rare earths on the activity of alumina supported copper cobaltite in CO oxidation, CH_4 oxidationand NO decomposition 被引量:6
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作者 B.Ivanov I.Spassova +2 位作者 M.Milanova G.Tyuliev M.Khristova 《Journal of Rare Earths》 SCIE EI CAS CSCD 2015年第4期382-390,共9页
The effect of the addition of small amounts of rare earths (Ln=La, Ce, Nd and Gd) to alumina supported copper-cobalt spinel oxide on the catalysts efficiency in CO and CH4 oxidation and in NO decomposition was inves... The effect of the addition of small amounts of rare earths (Ln=La, Ce, Nd and Gd) to alumina supported copper-cobalt spinel oxide on the catalysts efficiency in CO and CH4 oxidation and in NO decomposition was investigated. Samples of Ln/CuCo/AI catalyst were prepared and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic absorption spectroscopy (AAS), scanning electron mieroscopy-energy dispersive spectroscopy (SEM-EDS), H2-temperature-programmed reduc- tion (H2-TPR), electron paramagnetic resonanee (EPR) spectroscopy and low temperature nitrogen adsorption, The results showed that the addition of rare earths changed the surface state of the alumina supported copper-cobalt spinel catalyst. As a result, partial re- duction of copper species was observed as well as migration of these species between the surface and the bulk. The Ln/CuCo/A1 catalysts behaved differently in oxidation and reduction processes. In oxidation processes where oxide structure was important, Ce/CuCo/A1 and Nd/CuCo/A1 were the most active catalysts. The catalyst Ce/CuCo/AI was the most active in the oxidation reactions because of the availability and favorable surface distribution of the redox couples Cu+/Cu2+ and Ce3+/Ce4+. In NO decompostion, Ln-modified catalysts significantly improved the selectivity of the process to N2. 展开更多
关键词 copper cobaltite NO decomposition CO oxidation CH4 oxidation rare earths
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湘东北长沙—平江断裂带关键金属钴的赋存状态与成矿规律 被引量:6
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作者 王智琳 伍杨 +5 位作者 许德如 邹少浩 董国军 彭尔柯 宁钧陶 康博 《黄金科学技术》 CSCD 2020年第6期779-785,共7页
近年来,我国在湘东北长沙—平江断裂带东侧的井冲—北山一带的钴资源找矿勘查取得了较大进展,相继发现了井冲铜钴多金属矿床(中型)、横洞钴铜矿床(中型)和大岩金钴矿化点等热液脉型钴独立/共生矿床(点)。通过系统分析长沙—平江断裂带... 近年来,我国在湘东北长沙—平江断裂带东侧的井冲—北山一带的钴资源找矿勘查取得了较大进展,相继发现了井冲铜钴多金属矿床(中型)、横洞钴铜矿床(中型)和大岩金钴矿化点等热液脉型钴独立/共生矿床(点)。通过系统分析长沙—平江断裂带钴的成矿特征和控矿因素,在识别不同成矿阶段的基础上,总结了钴的主要产出形式和赋存状态。结果表明:与毒砂共生的细粒黄铁矿中钴含量高达13.48%,明显高于其他类型的黄铁矿中的钴含量(最高仅为1.06%),据此提出细粒黄铁矿+毒砂矿物组合可作为长沙—平江钴矿带寻找高品位钴矿的直接矿物标志。结合含钴矿物的类型、分布与丰度,提出了初步的选冶建议。 展开更多
关键词 关键金属钴 黄铁矿 毒砂 辉砷钴矿 长沙—平江断裂带 赋存状态 湘东北
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Ni-doped ZnCo2O4 atomic layers to boost the selectivity in solar-driven reduction of CO2 被引量:3
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作者 Katong Liu Xiaodong Li +5 位作者 Liang Liang Ju Wu Xingchen Jiao Jiaqi Xu Yongfu Sun Yi Xie 《Nano Research》 SCIE EI CAS CSCD 2018年第6期2897-2908,共12页
Regulating the selectivity of CO2 photoreduction is particularly challenging. Herein, we propose ideal models of atomic layers with/without element doping to investigate the effect of doping engineering to tune the se... Regulating the selectivity of CO2 photoreduction is particularly challenging. Herein, we propose ideal models of atomic layers with/without element doping to investigate the effect of doping engineering to tune the selectivity of CO2 photoreduction. Prototypical ZnCo2O4 atomic layers with/without Ni-doping were first synthesized. Density functional theory calculations reveal that introducing Ni atoms creates several new energy levels and increases the density-of-states at the conduction band minimum. Synchrotron radiation photoemission spectroscopy demonstrates that the band structures are suitable for CO2 photoreduction, while the surface photovoltage spectra demonstrate that Ni doping increases the carrier separation efficiency. In situ diffuse reflectance Fourier transform infrared spectra disclose that the CO2^- radical is the main intermediate, while temperature-programed desorption curves reveal that the ZnCo2O4 atomic layers with/without Ni doping favor the respective CO and CH4 desorption. The Ni-doped ZnCo2O4 atomic layers exhibit a 3.5-time higher CO selectivity than the ZnCo2O4 atomic layers. This work establishes a clear correlation between elemental doping and selectivity regulation for CO2 photoreduction, opening new possibilities for tailoring solar-driven photocatalytic behaviors. 展开更多
关键词 atomic layers Ni-doped zinc cobaltite selectivity of CO2 reduction
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Structural,magnetic and electrical characterization of the La_(0.7)Ca_(0.3)Co_(1–x)Mn_xO_3(x=0,0.7 and 1) compounds prepared by a simple method 被引量:3
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作者 M.Eshraghi P.Kameli +2 位作者 F.Khalili M.H.Ehsani H.Salamati 《Journal of Rare Earths》 SCIE EI CAS CSCD 2014年第10期965-972,共8页
Structural, magnetic and electrical properties of the La0.7Ca0.3Co1–xMnxO3(x=0, 0.7 and 1) samples prepared by a simple method were systematically studied and it was found that the crystal structure was transformed... Structural, magnetic and electrical properties of the La0.7Ca0.3Co1–xMnxO3(x=0, 0.7 and 1) samples prepared by a simple method were systematically studied and it was found that the crystal structure was transformed from rhombohedral for La0.7Ca0.3CoO3(LCCO) and La0.7Ca0.3Co0.3Mn0.7O3(LCCMO) samples to orthorhombic for La0.7Ca0.3MnO3(LCMO) sample. The AC magnetic susceptibility measurements showed that LCCO sample underwent a transition from paramagnetic(PM) to ferromagnetic(FM) phase at Curie temperature, TC^155 K and below Curie temperature, the glassy ferromagnetism nature was observed. In LCCMO sample,clear evidence of spin glass(SG) state was observed at low temperature. PM-FM phase transition at about TC^260 K and long range FM order at low temperatures were observed in LCMO sample. Both the LCCO and LCCMO samples exhibited insulating behavior in the whole range of measuring temperature whereas the LCMO sample underwent a clear metal-insulator(MI) transition at about TMI^263 K, corresponding to Curie temperature. Metallic region of ρ(T) curve of the LCMO sample was fitted to the model of electron-electron and electron-magnon scattering. The charge carrier transport behavior in all the samples was compared based on polaronic models. 展开更多
关键词 cobaltite spin glass MANGANITES rare earths
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东昆仑驼路沟矿床中钴成矿过程的矿物学示踪 被引量:4
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作者 王智琳 张凯 +2 位作者 许德如 邹少浩 王宇非 《黄金科学技术》 CSCD 2023年第2期175-189,共15页
东昆仑是我国西部重要的金、铜、铁、钴、镍多金属成矿带,其中,驼路沟钴(金)矿床是西北地区发现的首例大型独立钴矿床,目前关于该矿床中钴的成矿过程尚存在争议。在详细野外地质调查和岩(矿)相学观察的基础上,结合EPMA和EBSD分析,将驼... 东昆仑是我国西部重要的金、铜、铁、钴、镍多金属成矿带,其中,驼路沟钴(金)矿床是西北地区发现的首例大型独立钴矿床,目前关于该矿床中钴的成矿过程尚存在争议。在详细野外地质调查和岩(矿)相学观察的基础上,结合EPMA和EBSD分析,将驼路沟钴成矿过程划分为喷流沉积期和叠加改造期,喷流沉积期形成了细粒富钴黄铁矿(PyⅠ),叠加改造期包括细粒富钴黄铁矿(PyⅡ)+辉砷钴矿—辉砷镍矿+硫镍钴矿+磁黄铁矿+少量黄铜矿阶段和半自形—他形粗粒贫钴黄铁矿(PyⅢ)+自然金阶段。其中,PyⅠ中钴含量为0.03%~4.86%,PyⅡ中钴含量为0.38%~2.74%,PyⅢ中钴含量为0.03%~0.58%,流体耦合的溶解再沉淀机制是黄铁矿复杂环带的重要形成机制。上述矿物学研究表明:钴在驼路沟矿床中以独立矿物和富钴黄铁矿2种形式赋存,喷流沉积成矿作用和后期构造变形叠加改造作用是驼路沟矿床中钴富集成矿的2个重要过程。 展开更多
关键词 黄铁矿 辉砷钴矿 富集成矿 驼路沟矿床 东昆仑成矿带
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Covalency competition induced selective bond breakage and surface reconstruction in manganese cobaltite towards enhanced electrochemical charge storage 被引量:1
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作者 Peng Gao Pei Tang +7 位作者 Ying Mo Peitao Xiao Wang Zhou Shi Chen Hongliang Dong Ziwei Li Chaohe Xu Jilei Liu 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第5期909-918,共10页
Manganese cobaltite(MnCo_(2)_(4))is a promising electrode material because of its attractive redox chemistry and excellent charge storage capability.Our previous work demonstrated that the octahedrally-coordinated Mn ... Manganese cobaltite(MnCo_(2)_(4))is a promising electrode material because of its attractive redox chemistry and excellent charge storage capability.Our previous work demonstrated that the octahedrally-coordinated Mn are prone to react with the hydroxyl ions in alkaline electrolyte upon electrochemical cycling and separates on the surface of spinel to reconstruct into d-MnO_(2) nanosheets irreversibly,thus results in a change of the reaction mechanism with Kþion intercalation.However,the low capacity has greatly limited its practical application.Herein,we found that the tetrahedrally-coordinated Co_(2) þions were leached when MnCo_(2)_(4) was equilibrated in 1 mol L^(-1) HCl solution,leading to the formation of layered CoOOH on MnCo_(2)_(4) surface which is originated from the covalency competition induced selective breakage of the CoT–O bond in CoT–O–CoO and subsequent rearrangement of free Co_(6) octahedra.The as-formed CoOOH is stable upon cycling in alkaline electrolyte,exhibits conversion reaction mechanism with facile proton diffusion and is free of massive structural evolution,thus enables utilization of the bulk electrode material and realizes enhanced specific capacity as well as facilitated charge transfer and ion diffusion.In general,our work not only offers a feasible approach to deliberate modification of MnCo_(2)_(4)'s surface structure,but also provides an in-depth understanding of its charge storage mechanism,which enables rational design of the spinel oxides with promising charge storage properties. 展开更多
关键词 Manganese cobaltite Tetrahedrally-coordinated Co^(2+)leaching Selective bond breakage Surface reconstruction Charge storage mechanisms
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西藏南木林县浦桑果铜多金属矿床矿石矿物特征及钴、镍元素赋存状态研究 被引量:5
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作者 杨海锐 钟康惠 +3 位作者 多吉 普布次仁 高一鸣 崔晓亮 《地球学报》 EI CAS CSCD 北大核心 2012年第4期624-632,共9页
西藏冈底斯成矿带南木林县浦桑果铜多金属矿床是新发现的大型铜多金属矿床,该矿床以品位高,成矿元素复杂为其特征。本文应用野外地质编录、显微镜鉴定、电子探针等手段对浦桑果矿床矿石矿物特征以及Co、Ni元素赋存状态进行了研究。矿石... 西藏冈底斯成矿带南木林县浦桑果铜多金属矿床是新发现的大型铜多金属矿床,该矿床以品位高,成矿元素复杂为其特征。本文应用野外地质编录、显微镜鉴定、电子探针等手段对浦桑果矿床矿石矿物特征以及Co、Ni元素赋存状态进行了研究。矿石矿物主要由黄铜矿、方铅矿、闪锌矿、铜蓝等组成。矿石中的有用元素除了铜、铅锌、银外,钴、镍元素是伴生有益组分,矿石中主要Co-Ni元素独立矿物为镍辉砷钴矿。通过电子探针分析,Co元素含量平均为17.87%,Ni元素含量平均12.66%,Co-Ni元素同时以类质同象置换铁的形式赋存于金属硫化物中,黄铜矿平均含Co0.04%、Ni0.08%,黄铁矿平均含Co0.40%、Ni0.20%,闪锌矿平均含Co0.14%、Ni0.06%,磁黄铁矿平均含Co0.79%、Ni0.18%等。Co-Ni元素作为重要的伴生矿产,对提高矿床综合利用价值,丰富青藏高原矿床类型,指导找矿工作部署具有重要的意义。 展开更多
关键词 西藏 冈底斯 浦桑果 矿石矿物特征 Co—Ni元素赋存状态 镍辉砷钴矿
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非洲某硫化铜钴矿选矿综合回收技术研究 被引量:5
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作者 叶岳华 孙志健 +2 位作者 袁喜振 王立刚 姚松 《有色金属(选矿部分)》 CAS 北大核心 2021年第2期83-87,共5页
非洲某铜钴矿原矿含铜2.11%,钴0.090%,其中的钴品位较低,难以有效回收,且含钴矿物嵌布粒度不均匀,与黄铜矿、黄铁矿共生关系复杂,严重影响选矿过程中含钴矿物的综合回收。根据原矿性质,采用“铜钴依次优先”浮选工艺流程,结合使用高效... 非洲某铜钴矿原矿含铜2.11%,钴0.090%,其中的钴品位较低,难以有效回收,且含钴矿物嵌布粒度不均匀,与黄铜矿、黄铁矿共生关系复杂,严重影响选矿过程中含钴矿物的综合回收。根据原矿性质,采用“铜钴依次优先”浮选工艺流程,结合使用高效选择性捕收剂BKAP,实现了铜、钴资源的综合回收,实验室所得铜精矿铜品位35.08%,铜回收率93.42%;钴精矿钴品位2.27%,钴回收率51.82%。 展开更多
关键词 硫化铜钴矿 黄铜矿 硫铜钴矿 优先浮选 综合回收
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Electronic Structures and Chemical Bonds of Cobaltite and Ni-Doped 被引量:2
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作者 闵新民 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2005年第3期48-51,共4页
The relation among electronic structure, chemical bond and thermoelectric property of Ca3 Co2 O6 and Ni-doped was studied by density function theory and discrete variation method(DFT-DVM). The results indicate that ... The relation among electronic structure, chemical bond and thermoelectric property of Ca3 Co2 O6 and Ni-doped was studied by density function theory and discrete variation method(DFT-DVM). The results indicate that the highest valence band( HVB )attd the lowest conduction band( LCB ) are mainly attribuled to Co3d, Ni3d and O2p atomic orbitals. The property of a semiconductor is shown from the gap between HVB and LCB. The gap of Ni-doped one is less than that of Ca3 Co2 O6. The non-metal bond or ceramic characteristic of Ni-doped one is weaker than that of Ca3 Co2 O6, but the metal characteristics of Ni-doped one are stronger than those of Ca3 Co2 O6. The thermoelectric property should be improved by adding Ni element into the system of Ca3 Co2 O6 . 展开更多
关键词 cobaltite Ni- doped electronic structure chemical bond thermoelectric property
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Electronic Structure and Thermoelectric Properties of Ca_3Co_4O_9 被引量:2
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作者 闵新民 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2006年第1期13-15,共3页
The relation among electronic structure, chemical bond and thermoelectric property of Ca3 Co4 O9 was studied using density function and discrete variation method (DFT-DVM). The gap between the highest valence band ... The relation among electronic structure, chemical bond and thermoelectric property of Ca3 Co4 O9 was studied using density function and discrete variation method (DFT-DVM). The gap between the highest valence band (HVB) and the lowest conduction band (LCB) shows a semiconducting property. Ca3 Co4 O9 consists of CoO2 and Ca2 CoO3 two layers. The HVB and LCB near Fermi level are only mainly from O( 2 ) 2p and Co (2) 3d in Ca2 CoO3 layer. Therefore, the semiconducting or thermoelectric property of Ca3 Co4 O9 should be mainly from Ca2 CoO3 layer, but it seems to have no direct relation to the CoO2 layer, which is consistent with that binary oxides hardly have a thermoelectric property, but trinary oxide compounds have quite a good thermoelectric property. The covalent and ionic bonds of Ca2 CoO3 layer are both weaker than those of CoO2 layer. Ca plays the role of connections between CoO2 and Ca2 CoO3 layers in Ca3 Co4 O9, decrease the ionic and covalent bond strength, and improve the thermoelectric property. 展开更多
关键词 cobaltite electronic structure chemical bond thermoelectric property
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Facile synthesis of samarium and cerium doped double perovskite cobaltite with enhanced dielectric response
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作者 Yasir Abbas M.Kamran M.Anis-ur-Rehman 《Journal of Rare Earths》 SCIE EI CAS CSCD 2024年第7期1317-1327,I0005,共12页
The investigation of Sm-Ce doping on structure,conduction,and dielectric response of Bi_(2)Ca_(2-2x)Sm_(x)CexCoO_(6)(x=0.000,0.025,0.050,0.075)(BCSCCO)are presented.All the specimens were synthesized by a facile synth... The investigation of Sm-Ce doping on structure,conduction,and dielectric response of Bi_(2)Ca_(2-2x)Sm_(x)CexCoO_(6)(x=0.000,0.025,0.050,0.075)(BCSCCO)are presented.All the specimens were synthesized by a facile synthesis technique named the co-precipitation route.X-ray diffraction(XRD)reveals that BCSCCO crystallizes into one phase with space group P21/m.The crystallite size,dislocation density,lattice parameters,lattice strain,unit cell volume,and bulk density were determined using XRD data.The structural properties of Bi_(2)Ca_(2)CoO_(6)were examined using calculations based on the density functional theory.Theoretical and experimental values discrepancy is less than 1%.A scanning electron microscope was used for performing a microstructural analysis.The SEM images demonstrate the homogeneous distribution of grains with a range of sizes(0.054-0.090μm).The alternating current(ac)conductivity,dielectric permittivity,and tangent loss were also studied as a function of frequency(20 Hz-3 MHz)at different temperatures(100-500℃).All synthesized samples were examined using non-linear Debye's function to determine their spreading factor and relaxation time.The specimen with the lowest crystallite size(∼23 nm)exhibits a high dielectric permittivity(∼3.80×10^(6)).The conduction mechanism was examined in the studied samples with the use of Jonscher's power law.The power law indicates that the BCSCCO(x=0.000,0.025)follows correlated barrier hopping,whereas the x=0.050 and 0.075 compositions follow non-overlapping polaron tunneling.The studied specimen Bi_(2)Ca_(1.9)0Sm_(0.05)0Ce_(0.05)_(0)CoO_(6)with the highest density(∼5.65 g/cm^(3))displays a high electrical conductivity(∼46.1 S/cm).These findings correspond to those published for ceramics made from calcium cobaltite using solid-state reactions(5.0-26.0 S/cm). 展开更多
关键词 Bismuth calcium samarium cerium cobaltite (BCSCCO) Spreading factor Conduction mechanism Rare earths
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Structural engineering of cathodes for improved Zn-ion batteries 被引量:4
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作者 Jiajia Huang Yuying Li +9 位作者 Ruikuan Xie Jianwei Li Zhihong Tian Guoliang Chai Yanwu Zhang Feili Lai Guanjie He Chuntai Liu Tianxi Liu Dan J.L.Brett 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第7期147-155,共9页
Aqueous zinc-ion batteries(ZIBs) are attracting considerable attention because of their low cost,high safety and abundant anode material resources.However,the major challenge faced by aqueous ZIBs is the lack of stabl... Aqueous zinc-ion batteries(ZIBs) are attracting considerable attention because of their low cost,high safety and abundant anode material resources.However,the major challenge faced by aqueous ZIBs is the lack of stable and high capacity cathode materials due to their complicated reaction mechanism and slow Zn-ion transport kinetics.This study reports a unique 3 D ’flower-like’ zinc cobaltite(ZnCo_(2)O_(4-x)) with enriched oxygen vacancies as a new cathode material for aqueous ZIBs.Computational calculations reveal that the presence of oxygen vacancies significantly enhances the electronic conductivity and accelerates Zn^(2+) diffusion by providing enlarged channels.The as-fabricated batteries present an impressive specific capacity of 148.3 mAh g^(-1) at the current density of 0.05 A g^(-1),high energy(2.8 Wh kg^(-1)) and power densities(27.2 W kg^(-1)) based on the whole device,which outperform most of the reported aqueous ZIBs.Moreover,a flexible solid-state pouch cell was demonstrated,which delivers an extremely stable capacity under bending states.This work demonstrates that the performance of Zn-ion storage can be effectively enhanced by tailoring the atomic structure of cathode materials,guiding the development of low-cost and eco-friendly energy storage materials. 展开更多
关键词 Zinc cobaltite Oxygen vacancies Aqueous zinc-ion batteries Flexible solid-state pouch cell
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Ca_3Co_2O_6及其掺镍体系的电子结构计算 被引量:1
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作者 闵新民 朱磊 邢学玲 《计算物理》 CSCD 北大核心 2004年第3期373-376,共4页
 用离散变分密度泛函方法(DFT DVM)计算了钴酸盐Ca3Co2O6及其掺镍体系,讨论了电子结构,化学键等与热电性能之间的关系.结果表明,价带和导带主要由Co3d,Ni3d和O2p原子轨道贡献.价带和导带之间的能隙宽度表现出了半导体电子结构特征,且...  用离散变分密度泛函方法(DFT DVM)计算了钴酸盐Ca3Co2O6及其掺镍体系,讨论了电子结构,化学键等与热电性能之间的关系.结果表明,价带和导带主要由Co3d,Ni3d和O2p原子轨道贡献.价带和导带之间的能隙宽度表现出了半导体电子结构特征,且掺镍体系的能隙比不掺镍体系窄.掺镍体系的共价键和离子键都比不掺镍体系弱.由此得到,掺镍后体系的热电性能将有所改善. 展开更多
关键词 钴酸盐 电子结构 化学键 热电性能 离散变分密度泛函法 热电材料
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Effect of Substitution Degree and the Calcination Temperature on the N<sub>2</sub>O Decomposition over Zinc Cobaltite Catalysts 被引量:1
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作者 B. M. Abu-Zied S. A. Soliman S. E. Abdellah 《Modern Research in Catalysis》 2017年第1期47-64,共18页
In this paper, a series of zinc cobaltite catalysts with the general formula Znx-Co1-xCo2O4 (x = 0.25, 0.50, 0.75 and 1.0) has been prepared using the co-precipitation method. Thermal analyzes (TGA and DTA) were used ... In this paper, a series of zinc cobaltite catalysts with the general formula Znx-Co1-xCo2O4 (x = 0.25, 0.50, 0.75 and 1.0) has been prepared using the co-precipitation method. Thermal analyzes (TGA and DTA) were used to follow up the thermal events accompanying the heat treatment of the parent mixture. Based on these results, the various parent mixtures were calcined at 500℃. The obtained solid catalysts were characterized by using XRD, FT-IR and N2-adsorption. The catalytic decomposition of N2O to N2 and O2 was carried out on the zinc-cobaltite catalysts. It was found that partial replacement of Co2+ by Zn2+ in Co3O4 spinel oxide led to a significant improvement in their N2O decomposition activity. Moreover, the catalytic activity was found to be depended on the calcination temperature utilized. 展开更多
关键词 Greenhouse Gases Nitrous OXIDE N2O DECOMPOSITION Znx-Co1-xCo2O4 ZINC cobaltite Spinel OXIDE
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NiCo2O4 decorated PANI–CNTs composites as supercapacitive electrode materials 被引量:1
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作者 Gunjana Chaudhary Ashok K.Sharma +3 位作者 Preetam Bhardwaj Kamal Kant Indu Kaushal Ajay K.Mishra 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第1期175-181,共7页
Hierarchical Ni CoO/PANI/CNTs hybrid composites were designed and fabricated having a layer of Ni CoOon the surface of PANI encapsulated CNTs with different morphologies. Physicochemical attributes of the synthesized ... Hierarchical Ni CoO/PANI/CNTs hybrid composites were designed and fabricated having a layer of Ni CoOon the surface of PANI encapsulated CNTs with different morphologies. Physicochemical attributes of the synthesized composites were examined by FTIR, UV–visible and X-ray diffraction(XRD)techniques. Morphological aspects were evaluated by field-emission scanning microscopy(FESEM),electron diffraction spectroscopy(EDS), high resolution transmission electron microscopy(HRTEM) and selected area electron diffraction(SAED) studies. Electrochemical measurements revealed an improved specific capacitance of 2250 F/g at a scan rate of 5 m V/s and 2000 F/g at a current density of 1 A/g with good rate capability using a three-electrode system. These enhanced features are achieved from the well designed nanostructure and the synergistic contributions of individual components in the electrode material. 展开更多
关键词 POLYANILINE Carbon nanotubes Nickel cobaltite SUPERCAPACITOR
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Electric properties of La_(0.8)Sr_(0.2)CoO_3 nanoceramics
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作者 A.Chuchmaa R.J.Wiglusz +3 位作者 B.Macalik P.Guchowski B.Mazurek W.Strek 《Journal of Rare Earths》 SCIE EI CAS CSCD 2009年第4期646-650,共5页
The electric measurements were carried out for La0.8Sr0.2CoO3 nanoceramics by using impedance spectroscopy methods. The resistance of sample was practically independent of frequency in measurement range. Its dependenc... The electric measurements were carried out for La0.8Sr0.2CoO3 nanoceramics by using impedance spectroscopy methods. The resistance of sample was practically independent of frequency in measurement range. Its dependence on reciprocal temperature showed quite complicated mechanism of conduction. The most striking property of investigated sample was its resistance decreasing with increasing applied polarization. 展开更多
关键词 PEROVSKITE lanthanum strontium cobaltite hopping conductivity impedance spectroscopy rare earths
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Synthesis and Thermoelectric Properties of Ca_(2.6)Nd_ ( 0.4)Co_4O_9 Compound
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作者 车平 张艳 +3 位作者 薄其兵 冯静 王静平 孟健 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第1期165-167,共3页
The layered cobaltite Ca 2.6Nd 0.4Co 4O 9 was synthesized by the solid-state reaction. Their crystal structure was determined by the X-ray powder diffraction and CELL program. The prepared Ca 2.6Nd 0.4Co... The layered cobaltite Ca 2.6Nd 0.4Co 4O 9 was synthesized by the solid-state reaction. Their crystal structure was determined by the X-ray powder diffraction and CELL program. The prepared Ca 2.6Nd 0.4Co 4O 9 compound has the monoclinic symmetry. The electrical conductivity and Seebeck coefficient were measured from room temperature to 700 ℃ in air. Both the properties increase while rising temperature. The thermoelectric power of Ca 2.6Nd 0.4Co 4O 9 is about 242 4 μV·K -1. The results imply a promising way to enhance the thermoelectric properties of the layered cobaltite oxides by optimizing their composition and microstructure. 展开更多
关键词 inorganic chemistry thermoelectric property layered cobaltite Seebeck coefficient Ca 2.6Nd 0.4Co 4O 9 compound rare earths
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