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1.
本文研究了[Co(NH_3)_4CO_3]Cl、[Co(en)_2CO_3]C1分别与NH_4SCN在100℃发生的固相取代反应.[Co(NH_3)_4CO_3]Cl与NH_4SCN反应生成trans-[Co(NH_3)_4(NCS)_2]~+;[Co(en)_2CO_3]Cl与NH_4SCN反应先生成cis-[Co(en)_2(NCS)_2]~+,然后转化成trans-(Co(en)_2(NCS)_2]~+。采用气相色谱、红外光谱、X粉末衍射和核磁共振法对相应反应体系及其产物进行了测试,推测反应按S_(N~2)机理进行。  相似文献   

2.
外掺Y2O3对镍氢电池正极高温性能的影响   总被引:8,自引:2,他引:8  
研究了外掺Y2O3对镍氢电池镍正极高温性能的影响. 通常镍正极在高温下放电比容量会骤然降低, 为了提高其高温性能, 进行了球型Ni(OH)2外掺不同比例Y2O3的实验, 对压制的镍电极在不同温度下的充放电情况进行了细致的研究. 研究发现外掺Y2O3的球型Ni(OH)2电极比普通球型Ni(OH)2电极的放电比容量在高温下要高出很多, 在0.2 C充放电情况下外掺1%是最佳比例, 它比普通球型Ni(OH)2电极的放电比容量要高出35%以上, 在1 C充放电情况下外掺0.2%是最佳比例, 它比普通球型Ni(OH)2电极的放电比容量要高出15%以上. 同时对外掺Y2O3提高镍正极放电比容量的原因也进行了初步探讨.  相似文献   

3.
银氨溶液中的溶质是[Ag(NH3)2]OH吗   总被引:2,自引:1,他引:1  
杨洪雷 《化学教育》2008,29(6):67-68
先从理论上证明了教材中所给的配制方法配制出来的银氨溶液中的溶质不是[Ag(NH3)2]OH而是[Ag(NH3)2]NO3,然后又利用对照实验对这一结论进行了实验验证。  相似文献   

4.
本文通过气相色谱逸出气体分析(EGA)法,配合红外光谱、X-射线粉末衍射等手段,研究了氢气氛中阴离子盐KY(Y=Cl,Br,I,CN,SCN)对配合物[Co(NH_3)_4CO_3]Cl热分解的影响,用Coats-Redfern方法计算了固相反应放出CO_2的动力学参数,得到的活化能值随外加阴离子的不同而有下列顺序:CN~->Cl~->Br~->Г>SCN~-,反应机理均为成核生长机理(F_1).  相似文献   

5.
陆宝仪  赖艳艳  李红 《电化学》2009,15(1):67-73
采用修饰单壁碳纳米管(SWNT、SWNT-COOH或SWNT-OH)及多壁碳纳米管(MWNT、MWNT-COOH或MWNT-OH)的石墨电极研究配位阴离子[Fe(CN)6]3-和配位阳离子[Co(phen)3]3+的电化学行为与吸附性能,借助[Co(phen)3]3+在碳纳米管(CNT)的强吸附特性制备[Co(phen)3]3+/CNT/C修饰电极,以其应用于6-MP的分析检测.结果表明:1)在CNT修饰电极上[Fe(CN)6]3-/4-呈现很好的氧化还原可逆性,而[Co(phen)3]3+则显示明显的吸附控制特征.2)[Co(phen)3]3+在多壁碳纳米管修饰电极上的吸附量较单壁碳纳米管大,但经羧基化或羟基化后,吸附量减小,而且在羧基化表面的吸附量较羟基化的大.3)[Co(phen)3]3+与6-MP间存在明显的相互作用,其配位产物的还原峰电流与6-MP浓度呈线性关系.  相似文献   

6.
球型Ni(OH)2表面包覆Y(OH)3及其高温充放电性能   总被引:4,自引:0,他引:4  
应用共沉淀的方法在球型Ni(OH)2的表面包覆了一层Y(OH)3,并研究了包覆不同含钇量后的球型Ni(OH)2的高温充放电性能。研究结果表明:包覆Y(OH)3的球型Ni(OH)2具有良好的高温充放电性能。其中1C充放电条件下,包覆量为0.3%的Ni(OH)2较好,0.2C充放电条件下,包覆量为1%的Ni(OH)2较好。  相似文献   

7.
为了同时改善固相共沉积法合成的α-Ni0.8Co0.05Al0.15(OH)2.15-2y(CO3)y·xH2O的常、高温充放电性能,样品经混合掺杂不同比率的La2O3,Sm2O3,Y2O3,Lu2O3以及La2O3+Y2O3后,作为模拟MH/Ni电池的正极材料,在不同温度下由恒流充放电和循环伏安测定其电化学性能.结果表明:复合掺加0.5%La2O3+1.0%Y2O3(质量分数),在0.5C和5C充放电下,30℃时可分别提高样品的放电比容量3.3%和4.7%,60℃时可分别提高17.4%和19.9%.同时也改善了高温放电电位.  相似文献   

8.
用化学共沉淀法合成了A l掺杂N i(OH)2,用XRD表征了合成样品的结构特征:研究了合成样品的循环伏安性能,以及用A l掺杂N i(OH)2为正极活性物质的Zn/N i试验电池的充放电性能。研究结果表明:所合成的A l掺杂N i(OH)2为具有α-型晶体结构的材料,A l掺杂N i(OH)2具有优良的电化学可逆性、良好的充放电性能和较好的电化学循环性能;A l掺杂N i(OH)2作为正极活性物质的Zn/N i试验电池等250次充放电循环容量保持率130.1%,最高放电比容量为420.5mAh/g。  相似文献   

9.
本文深入研究了过放电对锂离子电池性能的影响,并进行了机理研究。结果表明,过放会导致电池鼓胀,且使电池的再充放电性能恶化。这可以被解释为:作为负极集流体的铜箔,在电池发生深度放电的时候会发生氧化,并且在再充电的过程中在负极发生还原,形成一层铜膜,因而大大降低了电池效率,并且SEI膜由于发生过量的锂离子脱出而发生分解和重整,释放出的二氧化碳等气体导致电池发生鼓胀。本文通过实验表明,向LiCoO2正极中加入20%的Li(Ni1/3Co1/3Mn1/3)O2时,可以提高电池的过放性能,即可以使电池的气胀现象消失,且电池鼓胀率显著降低,再充放电能力也显著得到提高。  相似文献   

10.
11.
We reported the effects of annealing temperatures on microstructure and electrochemical properties of perovskite-type oxide LaFeO3 prepared by stearic acid combustion method. X-Ray diffraction(XRD) patterns show that the annealed LaFeO3 powder has orthorhombic structure. Scanning electron microscopy(SEM) and transmission electron microscopy(TEM) images show the presence of homogeneously dispersed, less aggregated, and small crystals(30-40 nm) at annealing temperatures of 500 and 600℃. However, as the annealing temperature was increased to 700 and 800℃, the crystals began to combine with each other and grew into further larger crystals(90-100 nm). The electrochemical performance of the annealed oxides was measured at 60℃ using chronopotentiometry, poten-tiodynamic polarization, and cyclic voltammetry. As the annealing temperature increased, the discharge capacity and anti-corrosion ability of the oxide electrode first increased and then decreased, reaching the optimum values at 600℃, with a maximum discharge capacity of 563 mA·h/g. The better electrochemical performance of LaFeO3 annealed at 600℃ could be ascribed to their smaller and more homogeneous crystals.  相似文献   

12.
The new transition metal oxo‐thiostannate {[Ni(cyclen)]6[Sn6S12O2(OH)6]} · 2(ClO4) · 19H2O ( 1 ) was prepared under hydrothermal conditions using Na4SnS4 · 14H2O and [Ni(cyclen)](ClO4)2 as reactants. In the crystal structure the rare [Sn6S12O2(OH)6]10– anion is observed, which is composed of SnS2O(OH)3 and SnS4O2 octahedra, and SnS4 tetrahedra sharing edges and corners. The anion is expanded by six Ni2+ centered complexes via Ni–S and Ni–OH bonds. The photocatalytic properties for the visible light driven hydrogen evolution reaction shows that 26.6 mmol · g–1 H2 were evolved after 3 h.  相似文献   

13.
设计和合成结构新颖的聚合物太阳能电池给体材料是有机电子学的热点研究领域. 首先利用二噻吩取代的苯并二噻吩(DBDT)作为富电子结构单元, 吡咯并吡咯二酮(DPP)作为缺电子单元构筑了一种新的聚合物太阳能电池电子给体材料(PDBDTDPP), 然后以[6,6]-苯基-C61-丁酸甲酯(PC61BM)作为电子受体, 借助密度泛函理论(DFT)方法结合不相干的Marcus-Hush电荷传输模型, 系统研究了PC61BM-DBDTDPPn=1,2,3,∞体系的分子结构、电子性质、光吸收性质、电荷转移的内重组能和外重组能、激子结合能、电荷传输积分、给体-受体界面上激子分离和电荷复合速率等性质, 并利用线性回归方法分析了聚合物重复单元与其光伏性质的关系. 结果表明, 该聚合物具有较好的平面结构, 低的最高占据分子轨道(HOMO)能级, 在紫外-可见区具有宽且强的光学吸收、较大的激子束缚能(1.365 eV), 小的激子分离内重组能(0.152 eV)和电荷复合内重组能(0.314 eV). 在给体-受体界面上, 激子分离速率高达1.073×1014 s-1, 而电荷复合速率仅为1.797×108 s-1. 相比较而言, 激子分离速率比电荷复合速率高约6个数量级, 表明在给体-受体界面上, 光生激子具有很高的分离效率. 总之, 研究证明PDBDTDPP是一个非常有前途的聚合物太阳能电池给体材料, 值得实验上进一步合成及器件化研究. 理论研究不仅有助于更深入理解有机化合物结构与其光学、电子性质之间的关系, 还可以为合理设计聚合物太阳能电池给体材料提供有价值的参考.  相似文献   

14.
A novel series of substituted [1,2,4]triazolo[4′,3′:1,2]pyrimido[4,5‐c ]benzo[f ]isoquinolin‐14(10H )‐one was synthesized from the reaction of hydrazonoyl chlorides with pyrimidine thione derivative or via oxidative cyclization of 3‐(2‐substituted‐benzylidene‐hydrazinyl)‐7,8‐dihydrobenzo[f ]pyrimido[4,5‐c ]isoquinolin‐1(2H )‐one. Also, some polyhetero‐cyclic ring systems were prepared through the reaction of 2‐dimethylaminomethylene‐3,4‐dihydro‐2H‐naphthalen‐1‐one and heterocyclic amines. The biological activity of some new products was evaluated, and the results obtained revealed that compounds 10e , 13a , and 18 showed excellent activities against the most bacteria and fungi species used.  相似文献   

15.
采用溶胶-凝胶技术制备了新多金属氧酸盐[Bu4N][Ni(pph3)2]PW11O39(Bu为四丁基,pph为苯基磷)有机-无机杂化材料修饰电极,该修饰电极不仅保持了本体溶液的电化学和电催化性质,而且还具有很好的稳定性与灵敏度.研究表明,优选条件下修饰电极在pH=4.5的缓冲溶液中,其催化电流与NO2-浓度在6.0×10-6~1×10-3mol/L范围内呈良好的线性关系,对不同基质环境水样的加标回收率为97%~102%,方法的检出限为1.0×10-7mol/L,对1.0×10-4mol/L NO2-平行测定10次的相对标准偏差(RSD)为1.96%.  相似文献   

16.
A series of new nickel(II) perchlorate complexes containing an α-diimine(enR) and the anion of a β-dione (1,3-ketoenol or 1,3-ketoester, βH) was prepared and characterized. The composition and the overall structure of the new chelates depend on ligand concentration, on steric and electronic effects induced by substituents within the ligands and the ability of the perchlorate group to coordinate. The IR and electronic excitation spectra of [Ni(enR)2β]ClO4 and [Ni(enR)β(O2ClO2)] indicate, in conjunction with other physicochemical measurements, bidentate coordination of the ligands and replacement of the (O,O′) perchlorato group by basic solvents. The structure of the new chelates was further supported by an X-ray structure analysis of [Ni(ncup)2Etacet]ClO4, where ncup denotes neocuproine and Etacet the anion of the ethyl acetoacetate (orthorhombic, space group Pc21n, a = 14.087(5), b = 14.713(5) and c = 15.952(5) Å, Z = 4). The coordination sphere of nickel is a distorted octahedron, arised from the chromophore NiN4O2, in which the base is favored by three neocuproine nitrogens and one Etacet oxygen. The apical sites are occupied by the remaining oxygen and nitrogen atoms, one from Etacet and one from neocuproine respectively.  相似文献   

17.
用荧光光谱法研究了在生理条件下,3-对氯苯基-2-(4-叔丁基苯氧基)-3’-氧环己烷并噻吩并[2,3-d]嘧啶-4(3H)-酮(PTP)与牛血清白蛋白(BSA)的相互作用。实验表明,PTP主要以静态猝灭方式使BSA荧光强度显著降低。计算了不同温度下二者的结合常数和结合位点数,并根据热力学参数确定了PTP与BSA之间的作用力主要为氢键或范德华力。根据Frster非辐射能量转移机理,测定了PTP与BSA相互结合时的作用距离,并用同步荧光技术讨论了其衍生物对BSA构象的影响。  相似文献   

18.
Among the numerous reduced bandgap polymers currently being developed, poly[3‐(4‐octylphenyl)thiophene)]s (POPT) may present attractive properties for organic solar cells due to its facile preparation and improved absorption with respect to poly(3‐hexylthiophene). This article appraises methods of preparation, including the use of diphenyl ether as a reaction medium, and discusses the effects of variations in molar masses, from about 3200 to 65,000 g mol?1 and regioregularity on its optoelectronic properties. The photovoltaic properties of POPT with [6,6]‐phenyl C61 butyric acid methyl ester (PCBM) in bulk heterojunction devices are also discussed in the light of morphological variations, as indicated by atomic force microscopy characterizations. With an initial screening of conditions, namely POPT:PCBM ratios and deposition solvent, a power conversion efficiency of 1.58% was obtained using a relatively high molar mass POPT sample. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012  相似文献   

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