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1.
Eight new complexes were synthesized for the first time. The compounds which have the general formula KxH2[PM(OH2)Mo7W2V2O39nH2O(M=Cr3+,Mn2+,Fe3+,Co3+,Ni2+,Cu2+,Zn2+, Cd2+; x=4 or 5) were de-termined by conductance titration and elemental analysis. The analysis of IR, UV, XRD and ESR show that the products hold the Keggin structure and TG-DTA, IR, XRD at various temperatures and water solubility test also give the evidences that the range of pyrolysis temperature is 300~350℃. The study on the substitutional reaction of coordinated water by optical ligand quinine shows that the SN2 nucleophilic substitution occures when Ni is con-tained in the compound and SN1 nucleophilic substitution occures when Cu is contained. These also confirmed that the transitional metals are in the inner sphere of the complexes.  相似文献   

2.
碳酸铝铵热分解制备纳米氧化铝粉体   总被引:12,自引:0,他引:12       下载免费PDF全文
Nanosized alumina powders were prepared from Al(NO3)3·9H2O and (NH4)2CO3 through the synthesis of ammonium aluminium carbonate hydroxide (AACH) and followed by calcination. TG-DTA, XRD, TEM and BET were employed to study the process of AACH thermal decomposition and to characterize the products obtained. The results show that high purity (99.97%) and nanosized spherical α-Al2O3 powders with the diameter of 40~50nm and BET surface area 32.5m2·g-1 can be obtained by calcining AACH at 1150℃ for 1.5h, the sequence of phase transformation during calcination was AACH → amorphous Al2O3 → γ-Al2O3 → α-Al2O3, and the activation energy of AACH decomposition is (115±5)kJ·mol-1.  相似文献   

3.
单分散超细ZnO粉体的制备与表征   总被引:8,自引:0,他引:8  
王金敏  高濂 《无机化学学报》2003,19(11):1249-1252
Monodispersed superfine ZnO powders with particle size of about 200~400nm were successfully prepared by the decompressed distillation process with n-butyl alcohol as the solvent. The starting materials were Zn(NO3)2·6H2O and NH3·H2O. TG-DSC, XRD, TEM and BET surface areas techniques were used to characterize the precursor and as-prepared superfine ZnO powders. In the preparation process of superfine ZnO powders, two techniques including the decompressed distillation with n-butyl alcohol and washing with absolute ethanol were used to avoid agglomeration. It is showed that the decompressed distillation process has a better effect in avoiding ag-glomeration than washing with absolute ethanol. The precursor obtained by the decompressed distillation technique has a lower calcination temperature than the one obtained by washing with absolute ethanol. Zincite phase of ZnO with some impurities was obtained when the precursor was calcined at 200℃ for 2h. After it was calcined at 300℃ for 2h, pure superfine ZnO powder was obtained.  相似文献   

4.
于龙  张校刚 《无机化学学报》2004,20(9):1112-1116
Vanadium oxide/titanate composites nanorods (VOx/ Titanate-CNRs) were synthesized in high yield by using titanate nanotubes as templates and V2O5·nH2O sol as the precursors under hydrothermal conditions (200 ℃, 48 h). Samples were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive analysis by X-ray (EDAX). X-ray diffraction structure determination showed that this new phase had the composition of V3O7·H2O and crystallized with orthorhombic symmetry. SEM and TEM tests showed that the samples were uniform straight rods with the diameter range from around 100 to 300 nm and the length over 10 μm. The chemical compositions of the samples were determined with EDXA. The electrochemical tests of samples (titanates nanotubes, V2O5 and VOx/ Titanate-CNRs) prove that VOx/ Titanate-CNRs exhibit a better electrochemical performance.  相似文献   

5.
 VOSO4 immobilized within nanoreactors of Al-MCM-41 (VO2+/Al-MCM-41) was synthesized and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption, and chemical analysis techniques. The prepared VO2+/Al-MCM-41 successfully catalyzes the oxidation of aryl alkyl sulfides and up to 99% conversion and 90% selectivity for the corresponding sulfoxides were obtained with H2O2 as oxidant in acetonitrile at room temperature in 30 min.  相似文献   

6.
The layered trivanadate, LiV3O8, was prepared by sol-gel method with LiOH, V2O5 and H2O2 as initial reagents. The materials at different heat treatment conditions were characterized by XRD and TG-DTA. Their electrochemical behaviors were studied by galvanostatic charge-discharge and cyclic voltammetry. The results show that LiV3O8 prepared by sintering at 300 ℃ for 16 h has higher capacity, and its initial discharge capacity is 333.1 mAh·g-1, and maintains a discharge capacity of 302.8 mAh·g-1 after 10 cycles at 0.2 C and the voltage range of 1.8~4.0 V.  相似文献   

7.
草酸盐共沉淀法制备Y1.84La0.16O3纳米粉体   总被引:1,自引:0,他引:1  
唐在峰  丁君  杨秋红  徐军 《无机化学学报》2006,22(10):1871-1873
Nanopowder of Y1.84La0.16O3 was prepared by oxalate co-precipitation method. The powder was characterized by TG-DTA, XRD and TEM. The results show that the precursor is Re2(NO3)2(C2O4)2·2H2O (Re=Y, La), and the Y1.84La0.16O3 nanopowders produced by calcining the precursor at 1 000 ℃ for 4 h are 20~40 nm spherical particles and well dispersed. The powders were with high sintering activity and could be fabricated to transparent ceramic without additive at 1 450~1 550 ℃ in H2 atmosphere for 3 hours. The total transmission of the transparent ceramic could reach 80%.  相似文献   

8.
A binuclear vanadium complex NH4[(VO)22-O)(nta)2][Eu(H2O)9] was synthesized by reaction of NH3VO3, nitrilotriacetic acid and EuCl3 in one aqueous solution. The crystal X-ray analysis shows that the complex contains one binuclear vanadium anion [(VO)22-O)(nta)2]4- and one [Eu(H2O)9]3+ cation. The molecules are built up to a three-dimensional supramolecular structure through hydrogen bonding. CCDC: 238716.  相似文献   

9.
The vanadates of LiNi1-xMxVO4(M=Fe,Co,Ni) containing VO4 tetrahedrons were synthesized by soft chemical method through a new mild liquid route. The samples sintered at 450℃ for 3h and at 650℃ for 3h are named for LT-LiNiVO4 and for MT-LiNi1-xMxVO4 respectively. All of the products were measured by X-ray diffraction, IR and Raman spectra respectively. In comparison with IR spectra of V2O5 and NiO, the LT-LiNiVO4 has a strong and broad IR absorption band of VO4 tetrahedrons located at 600~850cm-1 with three small splitting peaks corresponding to the asymmetry stretching vibrations of V-O bonds. The results of IR and Raman spectra for MT-LiNi1-xMxVO4 show that the cations of Ni2+, Co2+, Fe2+ have the influences on the frequency shifts of the V-O vibrations.  相似文献   

10.
A new complex bis[(N-salicylidene-N′-aminoethanol)dioxovandium(Ⅴ)], [V(Ⅴ)O2(SALAE)]2, was synthesized by the reaction of salicylaldehyde and aminoethanol with vanadyl sulfate. It was characterized by elemental analysis, IR and X-ray single crystal diffraction analysis. The crystal of the title complex (C18H20N2O8V2, Mr = 494.24) belongs to monoclinic, space group P21/c with the following crystallographic parameters: a= 1.7966(6) nm, b= 0.7587(3) nm, c= 2.1539(7) nm, β = 92.551 (6) °, V= 2.9329 (17) nm3, Z= 6, Dc= 1.679 g·cm-3, μ(Mo) = 1.006 mm-1, F(000) =1512, and final R1 = 0.0563, wR2= 0.1243 for observed reflections 2861(I> 2σ(I)). The complex is a bis(μ-oxo)-bridged V(Ⅴ) schiff base dimer formed by two dioxovandium units, V(Ⅴ) is six-coordinated and forms a distorted octahedral structure. The thermal decomposition for the complex was studied by TG-DTG curves and the apparent activation energy was obtained by the Kissinger formula. CCDC: 211147.  相似文献   

11.
Two iron(Ⅱ) complexes [Fe(tpdoen)](FeCl4)Cl (2, tpdoen=N,N-bis(2-pyridylmethoxyethyl)-N-(2-pyridylmethyl)amine) and [Fe(tpdoen)](ClO4)2 (3) with an N4O2 ligand containing two potentially π-coordinate oxygen atoms were synthesized as functional models of non-heme iron oxygenases. The X-ray crystal structure analysis corroborated that complex 3 possesses a significantly distorted six-coordinate pseudooctahedral configuration, in which all six heteroatoms (N4O2) coordinate to the iron center. The catalytic property of complex 3 for alkane oxidation were explored using H2O2, TBHP and mCPBA as oxidants in the presence of excess substrates under mild conditions. When cyclohexane oxidation process was monitored by UV-Vis spectra using H2O2 as oxidant at 0 ℃, a short-life band appeared at ca. 550 nm, which is attributed to the in-situ Fe(Ⅲ)-OOH species. CCDC: 607630.  相似文献   

12.
纳米晶氧化镍的制备及表征   总被引:5,自引:0,他引:5  
Nano-NiO powder was prepared by thermal decomposition of the precursor of NiC2O4·2H2O obtained via Ni(NO3)2·6H2O and H2C2O4·2H2O reacting in ethanol solvent. IR and TGA-DTA indicate physisorption and chem- isorption ethanol co-exist in the precursor. XRD suggests the obtained cubic NiO is stable below 700 ℃. TEM shows the as-calcined NiO at 400 ℃ for 2 hours was of narrow distribution, weak agglomeration and small particle size (average 8 nm). The reason for weak agglomeration was explained.  相似文献   

13.
LiAlO2细粉料的制备及反应机理研究   总被引:4,自引:0,他引:4       下载免费PDF全文
As a functional inorganic material, LiAlO2 was focused on widely, especially in the field of tritium breeder of fusion reactor. In this article, the proper reaction conditions and mechanism to synthesis the γ-LiAlO2 by solid state method are considered. In the experiments, it has been found that the phase of β- and γ-LiAlO2 are only produced by the reaction of LiOH and Al2O3, while the α- and γ-LiAlO2 can be obtained by the reaction of Li2CO3 and Al2O3. As compared with Li2CO3 and Al2O3 reacted at 900~1000℃ for the preparation of γ-LiAlO2, the γ-LiAlO2 can also be made by the reaction of LiOH and Al2O3 at some more lower temperatures that is due to the bulk diffuse mech-anism. But the former can get better crystal and have smaller particles for the mechanism of surface fast reaction. As a result, the sub-micron γ-LiAlO2 powders with the diameter less than 0.3μm are obtained.  相似文献   

14.
Vanadium sesquioxide (V2O3) nanopowder was successfully prepared by the solid phase reaction of the mixture of vanadyl hydroxide (VO(OH)2) and ammonium chloride (NH4Cl) at 500 ℃. The as-obtained samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). V2O3 nanoparticles were well dispersed and displayed sphere-like particles with diameters in the range of 30~50 nm.  相似文献   

15.
温广  张朋 《无机化学学报》2005,21(10):1535-1540
Temperature-programmed reduction (H2-TPR) was employed to quantitatively characterize the active oxygen species generated from a high Fe-loading Fe/ZSM-5 catalyst exposed to N2O at 250 ℃. [Fe-O-Fe]2+ dimer was determined as the active iron complex for N2O decomposition to produce the active oxygen. Reduction of Fe3+ to Fe2+ by H2 in the dimer and removal of OH- groups from Fe2+ dimer by heating Fe/ZSM-5 to 700 ℃ were the prerequisites for the formation of this active Fe complex. A linear correlation with a slope of 1.0 between the amount of [Fe-O-Fe]2+ and that of active oxygen species was observed. Maximum amount of active oxygen species can be generated by reducing Fe/ZSM-5 catalyst with H2 at the temperatures over 500 ℃ and then heating the resulting product in Ar to 700 ℃, followed by N2O exposure at 250 ℃. The ratio of the total number of oxygen atoms (Ode) deposited by interaction of [Fe-O-Fe]2+ with N2O to the amount of [Fe-O-Fe]2+ was 2. However, not all the deposited oxygen atoms were active oxygen (Oa); the ratio of Oa and Ode was 0.5. The iron dimer complex composing active oxygen is a five-atom ion [Fe2O3]2+; the most probable structure is as follows:  相似文献   

16.
磷酸盐直接共沉淀法制备K0.6Sr0.7Zr4P6O24纳米粉末   总被引:3,自引:0,他引:3  
Nanometer K0.6Sr0.7Zr4P6O24 (KSZP)powders were synthesized from KNO3, Sr(NO3)2, NH4H2PO4 and ZrOCl2·8H2O by direct co-precipitation method. The as-prepared precipitates and KSZP powders were characterized by thermal analysis, XRD, particle-size analyzer and SEM measurements. The results showed that the precipitates could be heat-treated at near 580 ℃ and 900 ℃, and the crystallization of the KSZP powder product depends on treatment temperature. It was non-crystalline after dried at 80 ℃, became incomplete crystalline KSZP after heat-treated at 900 ℃ and was single-phase KSZP after calcined at 1 380 ℃. The mean particle size and particle-size distribution of KSZP powder after heat-treated at 900 ℃ were smaller and narrower than those after dried at 80 ℃ and calcined at 1 380 ℃, and were 62 nm and 40~100 nm, respectively. The particle shape of the powder after heat-treatment was spheric, and the reuniting or agglomeration was found. Phosphate direct co-precipitation was more suitable than phosphate converse co-precipitation to synthesize nanometer single-phase KSZP powder and the sintered body with the nanometer powder possesses better integral sintering properties.  相似文献   

17.
预氧化固气法合成LiNiO2的研究   总被引:1,自引:0,他引:1  
LiNiO2 was prepared by reaction of stoichiometric amounts of thoroughly-mixed LiOH·H2O and preoxidation nanometer-scale Ni3O2(OH)4 powders in O2 at the temperature of 700℃ for 6h. The products were tested by XRD, XPS, SEM and electrochemistry methods. It was shown that product was LiNiO2 single-phase, and the valence of nickel was +3; the average size of it was 40nm; its initial charge specific capacity is 168mAh·g-1 and the coulomb efficiency is 90%; the second charge specific capacity is 160mAh·g-1 and the coulomb efficiency is 96%.  相似文献   

18.
二氧化钒和三氧化二钒研究进展   总被引:7,自引:0,他引:7       下载免费PDF全文
VO2和V2O3是优异的光、电、磁热敏材料,在多种技术领域中具有广阔的应用前景,已成为国内外新颖功能材料研究的热点之一。本文综述了VO2和V2O3的粉体、陶瓷和薄膜的研究进展,并对相关问题进行讨论。  相似文献   

19.
Mg and Al alkoxide complex was synthesized in a cell without battery separator by electrochemical dissolution of aluminum for 6 h and magnesium for 1.8 h at 45 ℃ in ethanol solution of 0.04 mol·dm-3 (Bu4N)Br with a current density of 100 mA·cm-2. IR and Raman spectroscopy were used to characterize the structure of the precursor of MgAl2O4. The results show that the current efficiency attains 98.4% and the precursor is MgAl2(OCH2CH3)5(acac)3. The acac- group-containing precursor could prevent it from agglomeration. The xerogel was obtained by drying in vacuum for 24 h and hydrolysis under pH≈8.5 of the precursor, which was heated at 350 ℃ for 2 h to obtain the nano-MgAl2O4 powder. XRD and TEM were used to investigate the structure of nano-MgAl2O4. The result suggests that the xerogel with an average particle size of 10 nm and the Nano-sized Spinel MgAl2O4 Particle of 12 nm thus obtained are with high purity.  相似文献   

20.
A hydrothermal reaction of NaVO3, Ce(NO3)3, H3BO3, 2,2′-bipyridine and water in a molar of 1∶2∶3∶2∶333 gives a yellow crystal [(C10H8N2)2VO2](H2BO3)·3H2O. It crystallizes in a triclinic with space group P1 and unit cell parameters a=0.6643(1)nm, b=1.1794(2)nm, c=1.4822(3)nm, α=101.39(3)°, β=101.59(3)°, γ=97.15(3)°, Z=2, Dc=1.542g·cm-3, μ=0.508mm-1, F(000)=528, R1=0.0736, wR2=0.1998,Goof=1.071. X-ray crystallographic study showed that the VN4O2 octahedron unit is distorted, in which the V1 atom is coordinated by two terminal O1 and O2 atoms, and N1, N2, N3 and N4 atoms from two 2,2′-bipy ligands. The hydrogen bonding are observed between 2,2′-bipy and adjacent terminal oxygen atom. It is noteworthy that π-π stacking interaction between adjacent 2,2′-bipy groups plays an significant role in stabilization of the structure of crystal. CCDC: 194327.  相似文献   

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