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1.
Via a simple glycine-assisted hydrothermal route, large-scale 3D hierarchical Zn3(OH)2V2O7·2H2O microspheres have been fabricated. Their purity, crystalline phase, morphologies and thermal stability were characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), Fourier transform IR (FTIR), scanning electron microscopy (SEM) and thermogravimetry-differential scanning calorimetry (TG-DSC). The SEM results indicate that the microspheres are self-assembled by numerous nanoflakes with mean thickness of 100 nm. Some factors influencing the morphologies of the Zn3(OH)2V2O7·2H2O micro-/nanostructures have been systematically investigated, as well as quantity of glycine and the reaction time. The possible mechanism of the crystal growth and assembled procedure were also proposed. The as-prepared Zn3(OH)2V2O7·2H2O can be transformed into Zn3(VO4)2 with the similar morphologies by calcination in air at 600 °C. Furthermore, the photoluminescent properties of both Zn3(OH)2V2O7·2H2O and Zn3(VO4)2 were studied and exhibited different spectra. 相似文献
2.
《晶体工程》2000,3(4):237-250
Two novel materials, [HMTA-H··H2O] [HMTA-CH2OH] [H3V10O28[Na(H2O)4}]·4H2O, 1 and [Na2(H2O)10][H3V10O28[Na(H2O)2}]·3H2O, 2 containing decavanadate clusters interconnected through hydrated sodium cations forming 1D molecular chains and 2D molecular arrays have been self-assembled from acidified, aqueous vanadate solution in the presence of organic bases, hexamethylenetetramine and 1,3,5-triazine respectively. 相似文献
3.
《Materials Research Bulletin》1987,22(11):1483-1491
Single crystal of [Y(H2O)3]2 (C6Br2O4)3·6H2O and [Y(H2O)3]2 (C6Cl2O4)3·6.6H2O were grown in aqueous silicagel. The compounds are in principle isostructural. In Y chloranilate one additional water site is occupied as verified by X-ray single crystal structure analysis. Y3+ is nine-coordinated by three water molecules and six oxygen atoms of the bischelating (C6X2O4)2− ions (XCl, Br). The coordination polyhedron is an only slightly distorted tri-capped trigonal prism. The connection of Y3+ with the dianions leads to infinite, corrugated layers. The layer stacking yields cage-like cavities in which water molecules are accomodated. Hydrogen bonds interlink adjacent layers. Further hydrogen bonds involve the entrapped water molecules. DSC measurements indicated a complicated dehydration process which caused right at the start destruction of the single crystals. 相似文献
4.
Three-dimensional Zn3V2O7(OH)2·2H2O microspheres have been successfully synthesized by a simple and facile liquid phase precipitation method without using any surfactants or additives. The as-prepared microspheres were constructed by two-dimensional nanosheets, which interconnected with each other through self-assembly. The influences of the aging time, reaction temperature, and pH value on the morphologies of the products were systematically investigated. Moreover, three-dimensional Zn3(VO4)2 microspheres could be formed through calcination of the Zn3V2O7(OH)2·2H2O precursor. The obtained Zn3V2O7(OH)2·2H2O and Zn3(VO4)2 microspheres were further investigated as the anode materials of lithium-ion batteries. Electrochemical measurements showed that the Zn3V2O7(OH)2·2H2O and Zn3(VO4)2 microspheres exhibited high discharge capacity and good cycle stability, indicating potential anode candidates in advanced rechargeable lithium-ion batteries. It should be noted that this is the first report on the Zn3V2O7(OH)2·2H2O and Zn3(VO4)2 three-dimensional microspheres as anode materials in lithium-ion batteries. The present work will greatly expand the range of anode choices and could assist long-term endeavors in developing high capacity anode materials for lithium-ion batteries. 相似文献
5.
Inorganic Materials - Magnesium double phosphates, MgHPO4·3H2O and MgKPO4·6H2O, isostructural with the minerals newberyite and struvite-K have been synthesized in powder form via... 相似文献
6.
Xiaoyun Hao Shanzhong Li Junyan Gong Lizhen Ren Juanjuan Ma 《Particulate Science and Technology》2018,36(6):689-694
A simple one-step process has been used to synthesize novel Fe5(PO4)4(OH)3?·?2H2O hollow octahedra in a mixed solvent of diethylene glycol (DEG) and H2O. The x-1ray diffraction (XRD) and scanning electron microscopy (SEM) have been provided for the characterizations of the nanostructures. The shape of the as-obtained products could be controlled by adjusting the volume ratio of DEG and H2O in the solvothermal process. The possible formation mechanism was proposed based2 on nucleation and the Ostwald ripening process as well as the soft-template function of DEG. In addition, the study herein demonstrated that the hollow octahedra exhibit excellent capability for the adsorption of salmon sperm DNA and would have great application potentials in DNA separation. 相似文献
7.
K[(NpO2)(SiO3OH)]·H2O (I) and K[(PuO2)(SiO3OH)]·H2O (II) were prepared by hydrothermal synthesis at 120°C, and their IR and near-IR spectra were measured. The unit cell parameters of the compounds were determined from powder X-ray patterns [a = 7.068(1), b = 7.064(2), c = 6.640(1) Å. = 106.68(1)°, V = 317.6 Å3 (I); a = 7.102(1), b = 7.100(2), c = 6.637(1) Å, = 107.62(1)°, V = 318.9 Å3 (II)]. These compounds are isostructural with potassium boltwoodite K[(UO2)(SiO3OH)]·H2O. 相似文献
8.
NaMg(H2O)2[BP2O8]·H2O was prepared by hydrothermal synthesis and was characterized by X-ray powder difraction and IR method. The title compound was synthesized from MgCl2·6H2O, NaBO3·4H2O, and (NH4)2HPO4 with variable molar ratios using hydrothermal method by heating at 165 °C for 3 days. The X-ray powder diffraction data was indexed in hexagonal system, the unit cell parameters were found to be as a = 9.428, c = 15.82 Å, Z = 4 and the space group is P6122. It is isostructural with MlMll(H2O)[BP2O8] type compounds where Ml = Na, K; Mll = Mg, Mn, Fe, Co, Ni and Zn. In addition NH4Mg(H2O)2[BP2O8]·H2O was also synthesized the first time in this research. Its unit cell parameters and hkl values were in good agreement with the sodium magnesium compound. The unit cell parameters are a = 9.529, c = 15.736 Å. The indexed X-ray powder diffraction data of both compounds which were not reported in the literature is presented in this work. The IR data of NaMg(H2O)2[BP2O8]·H2O is also reported. 相似文献
9.
《晶体工程》1999,2(4):251-264
The influence of concentration of water and metal salt in the reaction between Cd(NO3)2·4H2O and 4,4′–bipyridine in MeOH has been studied and three compounds namely, T-shaped [Cd(bpy)1.5(NO3)2]·3H2O, 1 square grid [Cd(bpy)2(H2O)2](NO3)2 4H2O, 2 and one dimensional linear polymer, [Cd(bpy)(H2O)2(NO3)2], 3 were isolated quantitatively in this process. Compound 1 forms in MeOH at high dilution of the metal salt (5.0 mg/mL or less) and for the metal-to-ligand ratio 1:(1.5–2.0). Compound 2 forms exclusively in the concentration range, 17–33% for water in MeOH by volume and 12–28 mg/mL for the metal salt of the solution. Outside these limits, mixtures of 2 and 3 were isolated. For 1:1 ratio of metal salt to bpy, the linear polymer, 3 was obtained in major quantity and its formation was found to be independent of concentration of water or the metal salt. Compounds 1 and 2 have been characterized by X-ray crystallography. On heating all the compounds decompose through a common intermediate [Cd(bpy)(NO3)2] and finally to CdO as monitored by TG. 相似文献
10.
《Materials Science & Technology》2013,29(8):968-974
AbstractThe influence of long term soft milling of a mixture of (1) Mg(OH)2 and α-Fe2O3 and (2) Mg(OH)2 and Fe(OH)3 powders in a planetary ball mill on the reaction synthesis of nanosized MgFe2O4 ferrites was studied. Soft mechanochemical reaction leading to formation of the MgFe2O4 spinel phase was followed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and magnetisation measurements. The spinel phase formation was first observed after 5 h of milling and its formation was completed after 15 h in case (2). The synthesised MgFe2O4 ferrite had a nanocrystalline structure with a crystallite size of about 10 and 15 nm respectively for cases (1) and (2). Measurements after 15 h of milling show magnetisation values of 15·23 and 10·14 J T–1 kg–1 respectively for cases (1) and (2). 相似文献
11.
Precipitation of salts M3[NpO4(OH)2]·nH2O (M = Na, K, Rb, Cs) from concentrated alkali solutions at low temperatures (about ?10°C) was studied. From solutions with [OH?] > 9.5 M, these compounds are isolated as coarse black crystals in high yield without impurity of other phases. The K, Rb, and Cs salts crystallize in the form of the previously studied compounds K3[NpO4(OH)2]·2H2O and M3[NpO4(OH)2]·3H2O (M = Rb, Cs). In the case of Na, a new hydrate Na3[NpO4(OH)2]·6H2O was obtained, and its crystal structure was determined. Crystals of the hexahydrate consist of centrosymmetrical tetragonal-bipyramidal anions [NpO4(OH)2]3?, crystallographically independent Na(1) and Na(2) cations, and water molecules. The coordination surrounding of the Np atom is characterized by noticeable difference (Δ = 0.0203 Å) in the Np-O bond lengths in the equatorial plane of the bipyramid. The [NpO4(OH)2]3? anions are combined with the Na(2) cations to form infinite chains [Na(2)NpO4(OH)2(H2O)2]2? in such a manner that the lateral edges of the anion are simultaneously the lateral edges of the Na(2) coordination polyhedron. Incorporation of one of the two crystallographically independent O atoms of the NpO4 group into the Na(2) coordination surrounding is responsible for a noticeable difference in the Np-O bond lengths in the equator of the [NpO4(OH)2]3? anion. The types of hydrogen bonding in the structures of Na3[NpO4(OH)2]·nH2O (n = 0, 2, 4, 6) are compared. 相似文献
12.
Cobalt vanadium oxide hydroxide hydrate (Co3(OH)2V2O7·nH2O) nanosheets are successfully synthesized by a simple hydrothermal method. The composition of Co3(OH)2V2O7·nH2O is studied by thermal gravity (TG) analysis in N2 atmosphere and subsequent X-ray powder diffraction (XRD) characterization of the sample obtained via annealing Co3(OH)2V2O7·nH2O nanosheets in N2 atmosphere at 800 °C for 6 h. The results indicate that there are 1.7 water molecules in a Co3(OH)2V2O7·nH2O molecular formula. Electrochemical properties of Co3(OH)2V2O7·1.7H2O nanosheets as negative electrode of lithium ion batteries are studied by conventional charge/discharge test, which show an initial capacity of 730 mAh g?1 with steady plateau near 0.9 V at a current density of 0.05 mA cm?2. 相似文献
13.
A new oxalate complex, Na4(NpO2)2(C2O4)3·6H2O, with the Np:C2O4 ratio of 2:3 was synthesized and studied by single crystal X-ray diffraction. In the crystal, the NpO 2 + cations and oxalate anions are bound in open networks [(NpO2)2(C2O4)3] n 4n- parallel to the bc plane. The Na(1) cations are accommodated in large voids of the neptunyl oxalate networks with the formation of crimped mixed-cation layers of the composition [Na2(NpO2)2(C2O4)3] n 2n- . The negative charge of the layers is compensated by the Na(2) cations arranged between the layers. The Np atoms have a pentagonal bipyramidal coordination surrounding with the equatorial plane formed by the oxygen atoms of three oxalate anions. The structure contains tridentate-bridging and tetradentate-bridging oxalate anions. 相似文献
14.
L. B. Serezhkina A. V. Vologzhanina A. G. Verevkin V. N. Serezhkin 《Radiochemistry》2011,53(4):354-357
An X-ray diffraction study of Rb[UO2(SeO4)F]·H2O (I) was performed. The compound crystallizes in the rhombic system with the following unit cell parameters: a = 8.4753(6), b = 13.5234(9), c = 13.5296(9) Å, space group Pnma, Z = 8, V = 1550.7(2) Å3; R = 0.0248. The principal structural units of crystals of I are [UO2(SeO4)F]? layers belonging to crystal-chemical group AT3M2 (A = UO 2 2+ , T3 = SeO 4 2? , M2 = F?) of uranyl complexes. The uranium-containing layered units are combined via electrostatic interaction with Rb cations and via a system of hydrogen bonds involving outer-sphere water molecules. 相似文献
15.
The structure of NH4[(NpO2)3(C2H5COO)4(H2O)]·3H2O was studied by single crystal X-ray diffraction. The single crystals were prepared by hydrothermal synthesis. In the structure, there are three crystallographically independent Np atoms with different equatorial surrounding. All of them have CN 7; the coordination polyhedron is a distorted pentagonal bipyramid. Each NpO 2 + cation is bonded to four other cations, acting simultaneously as a bidentate ligand and a coordination center for two other dioxocations. The cation-cation interactions result in formation of trigonal-hexagonal cationic networks. 相似文献
16.
A. V. Savchenkov A. V. Vologzhanina L. B. Serezhkina D. V. Pushkin V. N. Serezhkin 《Radiochemistry》2013,55(5):466-471
Synthesis and the results of IR and single crystal X-ray diffraction study of Na4(UO2)4(i-C4H9COO)11·(NO3)·3H2O are reported. The crystals are monoclinic; the unit cell parameters at 100 K are as follows: a = 13.697(2), b = 20.285(3), c = 15.991(3) Å, β = 103.760(3)°, space group P21, Z = 2, R = 0.0650. The uraniumcontaining structural units are mononuclear moieties [UO2(i-C4H9COO)3]? and [UO2(NO3)(i-C4H9COO)2]?, belonging to crystal-chemical group AB 3 01 (A = UO 2 2+ , B01 = i-C4H9COO? and NO 3 ? ) of uranyl complexes. The IR data are consistent with the results of the single crystal X-ray diffraction study. The influence of the carboxylate ligand volume on the structure of Na[UO2L3]·nH2O crystals (L = acetate, n-butyrate, isovalerate ion) is analyzed. 相似文献
17.
Liuqing Yang Liyun Cao Jie Fei Haibo Ouyang Cuiyan Li 《Materials at High Temperatures》2013,30(3):283-287
Antioxidant modification for C/C composites by in situ hydrothermal synthesise at 140 °C of a 4ZnO·B2O3·H2O crystallite coating has been successfully achieved. The influence of hydrothermal time on the phase composition, microstructure of the as-prepared Zn4B2O7·H2O (4ZnO·B2O3·H2O), and its antioxidant modification for C/C composites were investigated. Samples were characterised by XRD, SEM, isothermal oxidation test and TG-DSC. Results show that, 4ZnO·B2O3·H2O crystalline coating is achieved on the surface of C/C composites after the hydrothermal treatment at 140 °C for time in the range of 2–12 h. A smooth and crack-free 4ZnO·B2O3·H2O layer can be obtained when the hydrothermal time reaches 8 h. Isothermal oxidation test demonstrates that the oxidation resistance of C/C composites is improved. The as-modified composites exhibit only 1.52 g·cm?2 weight loss after oxidation at 600 °C for 15 h, while the non-modified one shows a 6.57 g·cm?2 weight loss after only 10 h oxidation. For the uncoated C/C composite the oxidation rate is approximately linear with time (non-protective oxidation), thus at 15 h exposure one can estimate the mass loss to be 6.57 g·cm?2 after 10 h for direct comparison with the coated samples. 相似文献
18.
19.
L. B. Serezhkina A. V. Vologzhanina M. O. Karasev V. N. Serezhkin 《Radiochemistry》2011,53(2):142-145
The compound Cs3[UO2(CH3COO)3]2(NCS)·H2O (I) was synthesized and studied by IR spectroscopy and single crystal X-ray diffraction. Compound I crystallizes in the monoclinic system with the following unit cell parameters: a = 7.8286(9), b = 19.892(2), c = 20.050(2) Å, β = 94.527(2)°, space group P21/c, Z = 4, R = 0.0387. The uranium-containing structural units in crystals of I are mononuclear complexes [UO2(CH3COO)3]? belonging to crystal-chemical group AB 3 01 (A = UO 2 2+ , B01 = CH3COO?) of uranyl complexes. 相似文献
20.
The crystal structure of (NpO2)2(OOC)2C6H4·4H2O [rhombic cell: a = 15.937(3), b = 26.922(5), c = 8.020(2) Å, space group Pbcn, Z = 8, V = 3441.0(12) Å3, d
calc = 2.988 g cm-
3, CAD4, MoK
, graphite monochromator, 2934 independent reflections; R
1 = 0.0352, wR
2 = 0.0951] was studied. The structure consists of NpO2
+ cations, H4C6(COO)2
2
- anions, and molecules of coordinated and crystallization water. The crystal lattice involves neutral layers [(NpO2)2(OOC)2C6H4(H2O)3]
n
parallel to the {101} plane. The dioxocations in these layers are bonded to each other to form cationic networks [the Np···Np distance is 3.911(1)-4.202(1) Å]. The coordination polyhedra of Np(1) and Np(2) are pentagonal bipyramids (CN 7). The point group of the neptunyl(V) groups is close to D
h. These groups are bidentate ligands in the cation-cation interaction. The Np = O bond lengths are 1.852(6) [Np(1)-O(1)], 1.849(7) [Np(1)-O(2)], 1.845(7) [Np(2)-O(3)], and 1.841(7) Å [Np(2)-O(4)]; the O = Np = O bond angles are 178.6(3)° [O(2)-Np(1)-O(1)] and 177.4(3)° [O(3)-Np(2)-O(4)]. The equatorial plane of the Np(1) bipyramid consists of two oxygen atoms of adjacent Np(2)O2
+ dioxocations, two water molecules, and a single oxygen atom of the phthalate anion. The equatorial plane of the Np(2) bipyramid consists of two oxygen atoms of adjacent Np(1)O2
+ dioxocations, two oxygen atom of the phthalate anion, and a single water molecule. The bond lengths in the equatorial plane of the bipyramid lie in the following ranges: Np-Oyl 2.373(7)-2.437(7) Å (average 2.397 Å) , Np-Ophth 2.360(7)-2.474(7) Å (average 2.431 Å), and Np-Owater 2.534(8)-2.558(9) Å (average 2.544 Å). The phthalate anions are tridentate bridging ligands binding neptunium atoms only within a single cationic network. 相似文献