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1.
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   

2.
Samples of β-Co2(OH)3Cl and Zn5(OH)8Cl2 · H2O have been prepared and their thermal decomposition studied in air and N2 by DTA and TG up to 1000°C. X-Ray diffraction analysis of the thermal treatment products in air at various temperatures from 100 to 100°C was also carried out. The results obtained made it possible to establish the steps through which the pyrolysis of both compounds proceeds.  相似文献   

3.
The new U(VI) compound, [Ni(H2O)4]3[U(OH,H2O)(UO2)8O12(OH)3], was synthesized by mild hydrothermal reaction of uranyl and nickel nitrates. The crystal-structure was solved in the P-1 space group, a=8.627(2), b=10.566(2), c=12.091(4) Å and α=110.59(1), β=102.96(2), γ=105.50(1)°, R=0.0539 and wR=0.0464 from 3441 unique observed reflections and 151 parameters. The structure of the title compound is built from sheets of uranium polyhedra closely related to that in β-U3O8. Within the sheets [(UO2)(OH)O4] pentagonal bipyramids share equatorial edges to form chains, which are cross-linked by [(UO2)O4] and [UO4(H2O)(OH)] square bipyramids and through hydroxyl groups shared between [(UO2)(OH)O4] pentagonal bipyramids. The sheets are pillared by sharing the apical oxygen atoms of the [(UO2)(OH)O4] pentagonal bipyramids with the oxygen atoms of [NiO2(H2O)4] octahedral units. That builds a three-dimensional framework with water molecules pointing towards the channels. On heating [Ni(H2O)4]3[U(OH,H2O)(UO2)8O12(OH)3] decomposes into NiU3O10.  相似文献   

4.
CdIr(OH)6 and ZnIr(OH)6 were isolated and characterized in the process of synthesizing new ternary oxides of the platinum-group metals by means of thermal decomposition of hydroxide intermediates. Both compounds crystallize with an ordered ReO3-type structure. CdIr(OH)6 is tetragonal with a = 7.86 Å and c = 7.91 Å. It is a magnetically dilute insulator. ZnIr(OH)6 is cubic with a = 7.64 Å. It is an insulator with anomalous magnetic behavior. The cadmium and zinc iridium hexahydroxides decompose at 180 and 170°C, respectively.  相似文献   

5.
The new compound Co3Te2O2(PO4)2(OH)4 was synthesized using hydrothermal techniques. It crystallizes in the monoclinic space group C2/m with the unit cell a=19.4317(10) Å, b=6.0249(3) Å, c=4.7788(2) Å, β=103.139(5)°. The crystal structure is an open framework having chains of edge sharing [Co(1)O6] octahedra. Other building blocks are [TeO3(OH)2], [PO4] and [Co(2)O2(OH)4] connected mainly via corner sharing. The –OH groups protrude into channels in the structure. The magnetic susceptibility measured from 2 to 300 K shows two broad anomalies at around 21 K and 4 K, respectively. The peak at ∼20 K is ascribed to a two-dimensional antiferromagnetic ordering of linear [Co(1)O6] chains coupled by interchain interaction via [PO4] groups in the Co(1) sheets. The second transition at 4 K is ascribed to a second antiferromagnetic ordering of the moments of the Co(2) entities via super–super exchange involving [PO4] and [TeO3(OH)2] groups. This assignment is strongly supported by low-temperature heat capacity measurements indicating an entropy removal within the high-temperature transition of about twice the magnitude of the low-temperature transition.  相似文献   

6.
The chlorofullerene C60Cl6 was demonstrated as a versatile precursor for the synthesis of two isomerically pure fullerenols via tetrabutylammonium bromide promoted reactions with water. Performing the synthesis in wet chlorobenzene produced 1,4-C60(OH)2 as the only isolable product along with substantial amounts of non-functionalized C60. However, the addition of DMSO as a co-solvent altered the reaction pathway, leading to the formation of C60(OH)5Br as the main product. Both isolated compounds were novel and their molecular compositions and structures were confirmed by mass spectrometry and NMR spectroscopy. The fullerenol C60(OH)5Br, which was formed in a moderate yield, represents the first isomerically pure polyhydroxylated fullerene available on a large scale.  相似文献   

7.
CdTe@Cu(OH)2 nanocomposites were synthesized in aqueous solution by a seed-mediated growth approach. The effect of refluxing time and the concentration of Cu2+ on the preparation of these samples were measured using UV-visible absorption and photoluminescence analysis. The emission peak of the synthesized nanocomposites (CdTe@Cu(OH)2) was shifted from 605 (CdTe seed) to 621 nm. The size of CdTe nanoparticles were averaged about 3.22 nm, and the CdTe@Cu(OH)2 nanocomposites were averaged as 5.19 nm. The synthesized CdTe@Cu(OH)2 nanocomposite were characterized with XRD, EDAX, TEM, FT-IR, EPR, and thermal analysis (TG/DTG curves). The results indicate that as-prepared nanoparticles with core/shell structure exhibit interesting optical properties.  相似文献   

8.
When the polycyclic alumosiloxane [Ph2SiO]8[AlO(OH)]4 is allowed to react with either cyclopentadienyl sodium in tetrahydrofuran or with dimethyl zinc in diethyl ether the organic ligands on the metal elements are eliminated as cyclopentadiene or methane and the metals are bonded to oxygen atoms in the alumosiloxane forming [Ph2SiO]8[AlO2(Na)]4 · 5(THF) or [Ph2SiO]8[AlO(OH)]2[AlO2]2[Zn(OH)]2 · 2(OEt2), respectively. X-ray structure determinations reveal that in the sodium derivative the original polycycle rests almost unchanged while in the zinc derivative the inner skeleton is rearranged.  相似文献   

9.
β-Co(OH)2 and Mg(OH)2 nanoplates were synthesized via a facile template-free hydrothermal approach.The different conditions of preparation and catalytic properties of the products were studied and discussed.The products were characterized by X-ray diffraction,transmission electron microscopy,scanning electron microscopy,selected area electron diffraction(SAED),and gas chromatograph.  相似文献   

10.
When the polycyclic alumosiloxane (Ph2SiO)8[AlO(OH)]4, which may be isolated as the diethyl ether adduct (Ph2SiO)8[AlO(OH)]4·4OEt2, is allowed to react with the double N-methylpiperidine (nmp) adduct of monochloroalane, AlH2Cl·2nmp (1) (crystal structure analysis), the polycycle (Ph2SiO)8[AlO(O)0.5]4·2nmp (2) is obtained. Compared to the starting material and apart from the coordinating bases, the compound formally has lost two water molecules. The structure of (Ph2SiO)8[AlO(O)0.5]4·2nmp (2) can be derived from (Ph2SiO)8[AlO(OH)]4 by substituting the central Al4(OH)4 motif through an Al4O2 entity which consists of a central Al2O2 ring coordinated to two further aluminum atoms through almost trigonal planar oxygen atoms. Using tris(ethylene)diamine (ted) as base and reacting it with (Ph2SiO)8[Al(OH)]4, we have been able to isolate and completely characterize an intermediate on the way to these formally condensed alumosiloxane polycycles like in (Ph2SiO)8[AlO(O)0.5]4·2nmp (2). It has the composition (Ph2SiO)8[AlO(O)0.25]4·(OH·ted)2·(OH2·ted) (3) and has, compared to the starting material, the same number of hydrogen, oxygen, aluminum and silicon atoms within the inner molecular framework. Nevertheless, its structure is very different: whereas half of the molecule is structurally similar to (Ph2SiO)8[AlO(OH)]4, with OH-groups forming hydrogen bridges to the nitrogen atoms of ted and connecting two aluminum atoms, the other half contains a unique oxygen atom which is in an almost planar trigonal bonding mode to three aluminum atoms. Furthermore, this part of the molecule has an aluminum atom to which a water molecule is coordinated, one of the hydrogen atoms being involved in hydrogen bonding to a further tris(ethylene)diamine (ted). This structure gives some important insights in the possible mechanism of the “condensation reaction” within (Ph2SiO)8[AlO(OH)]4.  相似文献   

11.
双注-水热法制备高分散氢氧化镁纳米片   总被引:11,自引:0,他引:11       下载免费PDF全文
本工作以氯化镁、氢氧化钠为原料,氯化钠为衬底溶液,探讨了采用双注-水热法制备高分散氢氧化镁纳米片的可行性。结果表明:采用双注方式或提高衬底溶液氯化钠浓度均有利于降低反应体系过饱和度,改善常温产物的结晶性和分散性;对常温合成的氢氧化镁进行水热处理可进一步提高产物的结晶度,形成形貌规则、粒径分布窄、分散良好的氢氧化镁纳米片。  相似文献   

12.
Dense thin nanostructured films of cadmium sulfide CdS obtained by chemical deposition from aqueous solutions are strongly bound to a substrate due to the formation of cadmium hydroxide Cd(OH)2 in the system. By X-ray reflectometry and grazing incidence diffraction it is found that at the beginning of the deposition a dense Cd(OH)2/SiO2 layer is produced on the surface of a silicon or glass substrate. This layer is formed through the atomic-layer adsorption of crystalline 1–3 nm thick Cd(OH)2 film by the oxygencontaining substrate surface. During sulfidation of this cadmium-containing substrate layer, a surface nucleation layer of CdS/Cd(OH)2/SiO2 forms, which provides the growth, denseness, and strong adhesion to the substrate of nanostructured CdS film with a disordered structure. According to the obtained experimental data, a “hydroxide scheme” of film deposition is confirmed and refined, and the stages of CdS nanofilm formation are determined.  相似文献   

13.
王非  塔娜  李勇  申文杰 《催化学报》2014,35(3):437-443
通过调节溶液的pH值,在水热条件下合成出长径比为2-45的La(OH)3纳米棒. 对水热合成过程中间体的结构演变分析,发现高碱度有利于小尺寸晶核的形成,La(OH)3晶体结构的各向异性导致这些晶种沿着C轴方向生长,进而形成纳米棒结构. 将La(OH)3纳米棒前驱体于773 K焙烧可以得到长径比为2-20的La2O2CO3纳米棒. 随着长径比的增加,La2O2CO3纳米棒暴露的(110)晶面逐渐增加,La3+-O2-碱性位的数目也从0.08增加到0.24 mmol/g. 因此,在Claisen-Schmidt缩合反应中,La2O2CO3纳米棒催化剂上的反应速率随着长径比的增加而逐渐增大.  相似文献   

14.
近几年来,氢氧化镁作为一种无机阻燃剂由于其具有制备条件相对温和,生产工艺简单且产品与自然环境友好等特点,在研究及生产活动方面备受关注且得到了长足的发展[1~4].目前采用氢氧化钠法进行反应一水热制备高分散阻燃级氢氧化镁的工艺路线已经比较成熟[5~8].然而,不利的是,氢氧化钠偏高的价格导致了产品的制造成本较高.而采用石灰法制备氢氧化镁阻燃剂具有价格低廉的特点,引起了人们的关注.  相似文献   

15.
Syntheses and single-crystal X-ray diffraction studies have been completed on two cycloruthenapentadienyl (CO)6Ru2L2 derivatives, with L = CH2OHC = CCH2OH and C2H5C=CCH2CH2OH respectively. Crystal data are as follows: for [(CO)3RuC4(CH2OH)4]Ru(CO)3·H2O, P21/c, a 13.72(1), b 9.501(4), c 14.86(1) Å, β 101.10(6)°, Rw = 0.052 for 1911 reflections; for [(CO)3RuC4(CH2CH2OH)2(C2H5)2]Ru(CO)3, P21/c, a 9.191(3), b 16.732(4), c 14.903(3) Å, β 113.61(4)°, Rw = 0.042 for 2865 reflections. Both compounds are built up from binuclear units, each unit being regarded as a Ru(CO)3 fragment π-bonded to a cycloruthenapentadienyl ring. The molecular parameters are compared with those of known cyclometallapentadienyl complexes of transition metals. The presence of a semi-bridging CO group is discussed.  相似文献   

16.
A new three-dimensional open-framework gallophosphate: [H3N(CH2)2NH3]1/2·[Ga5 (PO4)4(OH)4] has been prepared by hydro(solvo)thermal synthesis in presence of ethylenediamine (en) as structure-directing agent. Its structure was determined by means of single-crystal X-ray diffraction analysis with the following crystal data: monoclinic space group C2/m, a=10.1604(9) Å, b=12.0085(15) Å, c=7.1892(7) Å, β=90.797(6)°, V=877.08(16) Å3, Z=2, R1=0.0264, wR2=0.0764. The total numbers of measured reflections and unique reflections were 3508 and 1300, respectively. It is built up from a new secondary building unit (SBU) Ga4P4O20(OH)4, in which Ga atoms exhibit distorted trigonal bipyramidal coordination and P atoms are in tetrahedral coordination. The SBU Ga4P4O20(OH)4 are linked into a layer by bridge oxygen atoms. The GaO4(OH)2 octahedra link the layers into a three-dimentional framework. Diprotonated ethylenediamine was found in the channel of the framework. The material was characterized by IR spectroscopy, 1H NMR spectra, thermogravimetric and differential thermal analyses and elemental analysis.  相似文献   

17.
The iridium(I) complex [Ir(CO2Me)(CO)2(PPh3)2] undergoes a transesterification reaction with the alcohols CH2C(R)CH2OH (R = H, Me), MeCCCH2CH2OH, and HOCH2CH2OH to afford the complexes
[Ir(CO2CH2CH2CMe)(CO)2(PPh3)2] and [Ir(CO2CH2CH2OH)(CO)2(PPh3)2], respectively. In contrast the acetylenic alcohol HCCCH2CH2OH gives [Ir(CCCH2CH2OH)(CO)PPh3)2]. Some reactions of the new complexes are described.  相似文献   

18.
Two new hydrated borates, Zn8[(BO3)3O2(OH)3] and Pb[B5O8(OH)]·1.5H2O, have been prepared by hydrothermal reactions at 170 °C. Single-crystal X-ray structural analyses showed that Zn8[(BO3)3O2(OH)3] crystallizes in a non-centrosymmetric space group R32 with a=8.006(2) Å, c=17.751(2) Å, Z=3 and Pb[B5O8(OH)]·1.5H2O in a triclinic space group P1¯ with a=6.656(2) Å, b=6.714(2) Å, c=10.701(2) Å, α=99.07(2)°, β=93.67(2)°, γ=118.87(1)°, Z=2. Zn8[(BO3)3O2(OH)3] represents a new structure type in which Zn-centered tetrahedra are connected via common vertices leading to helical ribbons 1[Zn8O15(OH)3]17− that pack side by side and are further condensed through sharing oxygen atoms to form a three-dimensional 3[Zn8O11(OH)3]9− framework. The boron atoms are incorporated into the channels in the framework to complete the final structure. Pb[B5O8(OH)]·1.5H2O is a layered compound containing double ring [B5O8(OH)]2− building units that share exocyclic oxygen atoms to form a two-dimensional layer. Symmetry-center-related layers are stacked along the c-axis and held together by interlayer Pb2+ ions and water molecules via electrostatic and hydrogen bonding interactions. The IR spectra further confirmed the existence of both triangular BO3 and OH groups in Zn8[(BO3)3O2(OH)3], and BO3, BO4, OH groups as well as guest water molecules in Pb[B5O8(OH)]·1.5H2O.  相似文献   

19.
Flower-like Ni(OH)2 nanoarchitectures have been synthesized through a one-step mild hydrothermal reaction with the aid of ethylenediamine in NiCl2 aqueous solution. The flower with the size of several micrometers in diameter is composed of the ultra-thin nanosheets of several nanometers in thickness. It was found the ethylenediamine is vital to the formation of the flower-like nanoarchitectures. The influence of the concentration of the ethylenediamine and the reaction temperature on the formation of the flowers was analyzed and the formation mechanism of the flowers was proposed. Such flower-like β-Ni(OH)2 nanoarchitectures will find potential applications in the fields, such as electrode, or will be used as a starting material to produce NiO, which is widely used in the magnetic, catalysts, sensor and electrochromic devices.  相似文献   

20.
A novel compound, [HN(C2H4)3N][(VO)2(HPO3)2(OH)(H2O)]·H2O, was hydrothermally synthesized and characterized by single crystal X-ray diffraction. This compound crystallizes in the monoclinic system with the space group C2/c and cell parameters a=11.0753(3) Å, b=17.8265(6) Å, c=16.5229(5) Å, and β=92.362(2)°. The structure of the compound consists of vanadium phosphite layers which are built up from the infinite one-dimensional chains of [(VO)(H2O)(HPO3)2]2− of octahedral VO5(H2O) and pseudo pyramidal [HPO3], and bridging binuclear fragments of [VO(OH)]2. Thermogravimetric analysis and magnetic susceptibility data for this compound are given.  相似文献   

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