Cs4Sn5S12的溶剂热合成与表征

利用溶剂热法合成了硫代锡酸铯Cs4Sn5S12,单晶X-射线衍射结果表明Cs4Sn5S12属正交晶系,Pbca空间群,a=1.4232(4)nm,b=1.3161(4)nm,c=1.6372(5)nm,α=90°,Z=4。化合物Cs4Sn5S12中含有由八面体Sn S6和三角双锥Sn S5连接形成的层状阴离子[Sn5S12]4-∞。[Sn5S12]4-∞结构中有两种类型硫原子:连接六配位锡原子和五配位锡原子的硫原子以及只与两个五配位锡原子相连的硫原子。紫外-可见漫反射光谱表明Cs4Sn5S12为半导体,禁带宽度为2.3 e V。     

尖晶石型纳米CoAl2O4色料水热合成工艺研究

分别以钴、铝的氯化物、硝酸盐和硫酸盐为起始原料,NaOH为沉淀剂,用水热法合成了纳米尖晶石型钴蓝色料。分别研究了填充度、pH值、nCo/nAl、起始原料种类以及浓度等对合成色料物相组成、颗粒大小与形貌和呈色的影响。用XRD、TEM和色度分析对样品进行了表征。结果表明:以浓度分别为0.15 mol/L和0.3 mol/L的CoCl2.6H2O和AlCl3为起始原料,在填充度为70%、pH值为13、nCo/nAl为1/2的条件下,245℃水热培育20 h制得呈色良好的尖晶石型钴蓝色料,颗粒为八面体型,晶型完整,粒径多为100 nm以下。相同条件下,以钴、铝的硫酸盐为起始原料,产物中除CoAl2O4外,还有Co-Al LDHs、γ-AlO(OH)和β-Al(OH)3;以钴、铝的硝酸盐为起始原料,样品呈绿色,颗粒为八面体型CoAl2O4,粒径多为100 nm以上。     

CdWO4纳米晶形貌可控合成

分别以氯化镉、草酸镉、碳酸镉、柠檬酸镉和钨酸钠为原料,在没有采用模板和表面活性剂的条件下,采用水热法可控制备出了钨酸镉纳米颗粒、纳米棒、纳米束和纳米线.利用X射线衍射(XRD)、透射电镜(TEM)、高分辨透射电子显微镜(HRTEM)和选区电子衍射(SAED)对样品进行了表征.结果表明:[WO42-]/[Cd2+]摩尔比、反应时间及先驱体的类型对产物的形貌和尺寸有着重要的影响.     

铁位掺杂对LiFePO4-C性能的影响

本文从体相铁位掺杂出发,以二氧化钛、乙酸镍、乙酸锰、氢氧化镁等为原料,合成LiFe0.9M0.1PO4-C材料,考察了不同掺杂元素对LiFePO4性能的影响。与碳包覆LiFePO4材料相比较,Ti的掺杂使Li+扩散系数提高了两个数量级,达到4.117E-09 cm2.s-1;将材料的振实密度显著提高到了1.62 g/ml;循环30次,容量保持在79.8 mAh/g,保持率达92%。即铁位掺杂Ti的复合材料在高倍率下的性能远远好于未掺杂LiFePO4材料。     

纳米HgMoO4的水热合成与表征

通过多种溶剂或其混合溶剂为水热反应媒介,制备出多种形貌和尺寸的纳米HgMoO4.SEM观察结果显示,当仅以水为水热合成媒介时,所合成的HgMoO4为由许多纳米棒(长～ 750 nm, 宽～150 nm)组成的不规则纺锤状结构.当无水乙醇或聚乙烯醇被引入该合成体系时,产物呈球形花状或蝴蝶结状结构.当进一步引入油酸时,体系则转变成由无数厚～100 nm的薄片形成的花状结构.XRD结果表明,上述溶剂体系所得HgMoO4均为单斜晶系的黑钨矿结构.红外光谱亦进一步证实了其结构.与体相材料相比,所得纳米HgMoO4的荧光发射峰均发生了一定程度的蓝移,体现了纳米材料的量子尺寸效应.     

溶剂热合成球形Cu2ZnSnS4 （CZTS）微粉的研究

本文采用高压溶剂热法合成了铜锌锡硫(CZTS)粉体,采用XRD、SEM测试方法对合成产物的物相、形貌进行了表征。探讨了温度,时间以及表面活性剂等因素对溶剂热合成CZTS粉体形貌、物相和性能的影响。结果表明:高压溶剂热法制备的CZTS目标粉体纯度高,制备周期短,产物形貌为球形的片状集合体。反应进程随着反应温度的升高而加快,随着保温时间的延长而趋于完全。加入部分表面活性剂对团聚现象改善并不明显。     

新型链状化合物Mn3（dap）2（AsS3）2的溶剂热合成与表征

用溶剂热方法合成了一种新型链状化合物Mn3(dap)2(AsS3)2(dap=1,2-丙二胺),通过单晶X-射线衍射技术对其进行了晶体结构分析,该化合物属于单斜晶系,空间群C2/c。晶胞参数a=2.0869(14)nm,b=0.8745(6)nm,c=1.2496(8)nm,β=121.141(10)°,Z=4。标题化合物由两个相对称的[AsS3]3-三角锥与两个对称的过渡金属胺螯合物[Mn(dap)]2+通过共用S原子连接形成{[Mn(dap)]2(AsS3)2}2-原子簇,这些原子簇之间由四配位的Mn1进一步连接,形成沿c轴延伸的{Mn3(dap)2(AsS3)2}n一维链。紫外-可见漫反射光谱研究表明,化合物为宽带半导体,带隙Eg=2.5 eV。同时对该化合物进行了IR、XRD、XPS等表征。     

空心结构NaYF4∶Yb,Er上转换材料的制备

以稀土三氟乙酸盐、氟化钠和三氟乙酸钠为原料通过溶剂热法成功制备出了空心结构的Na YF4∶Yb,Er上转换材料,探索了反应温度、钠离子浓度对产物形貌、晶相及发光性能的影响。利用扫描电镜,透射电镜,X射线衍射和发光光谱对产物的形貌、物相结构及荧光性能进行表征。结果表明,当Na F和Y3+的摩尔比为2.5,220℃溶剂热反应12 h时,可得到空心结构的上转换材料,该结构兼具上转换荧光、载药双重功能。     

微乳液溶剂热法微/纳米Sm2O3的可控合成

采用微乳液溶剂热法,在十六烷基三甲基溴化铵(CTAB)/正辛烷/正丁醇/硝酸钐(碳酸铵)形成的反相微乳液体系中,合成了微/纳米Sm2O3的前驱体.前驱体经800℃焙烧制得了微/纳米Sm2O3.利用X-射线衍射(XRD)、扫描电子显微镜(SEM)对产物的晶形、形貌和尺寸进行了测试与分析,考察了水核比(ω)、反应温度对微/纳米Sm2O3形貌和尺寸的影响,并提出了其可能的形成机理.结果表明:随着ω的增大,微/纳米Sm2O3的形貌由椭球状变为多面体状再变为双鱼尾状;随着反应温度的升高,微/纳米Sm2O3的形貌由鱼骨状变为菱片堆叠状再变为菱片状.     

Mn3O4纳米粒子的合成及表征

以 KMnO4和乙醇为原料,常压下50～60 ℃反应生成前驱物,将此前驱物转移至反应釜中,在190 ℃反应4 h,采用溶剂热法合成Mn3O4纳米粒子.探索了反应温度对产物结晶度及产物在水中分散性的影响.利用X射线衍射仪(XRD)、透射电子显微镜(TEM)、红外吸收光谱(IR)对产物进行表征.结果表明,反应温度为190 ℃时,产物Mn3O4纳米粒子的结晶度最大,在水中分散性最好,为四方晶系,平均粒径在50 nm左右.该方法的突出特点是Mn3O4纳米粒子的合成量大,反应时间短,效率高.     

Synthesis and crystal structure of rare earth selenates Nd(HSeO4)3, Sm(HSeO4)3, and Nd2(SeO4)3 · 5H2O

Single crystals of rare earth (RE) selenates of the compositions Nd(HSeO₄)₃, Sm(HSeO₄)₃, and Nd₂(SeO₄)₃ · 5H₂O are synthesized and studied by X-ray diffraction analysis at T = 297 and 180 K. It is established that Nd and Sm hydrogen selenates are isostructural to one another and to the corresponding hydrogen sulfates. Neodymium selenate pentahydrate is not isostructural to the analogous RE sulfates, although their structural motifs are similar. __________ Translated from Kristallografiya, Vol. 49, No. 5, 2004, pp. 835–840. Original Russian Text Copyright ? 2004 by Zakharov, Troyanov, Kemnitz.     

Synthesis and characterization of MxNb4P2O17

A new series of niobium phosphates with the composition of M_xNb₄P₂₁₇17 (M=Li and Na, X=4; M=Zn, Ca, Mg, Sr and Ba, X=2) have been successfully synthesized. The powder X-ray diffraction (XRD) data of these isostructural compounds, was studied The powder Second Harmonic Generation (SHG) effects of these compounds were about twice of that of KH₂PO₄ (KDP).     

钒酸铁纳米棒的制备及光吸收性能研究

以Fe(NO3)3·9H2O和NH4VO3为原料,采用水热法制备了FeVO4纳米棒。采用X射线衍射(XRD),热重分析(TG),X射线光电子能谱(XPS)及场发射扫描电子显微镜(FE-SEM)对样品的物相组成和微观形貌进行了表征。并采用紫外-可见漫反射测试(UV-vis DRS)测定了样品的光吸收性能,DRS结果显示FeVO4纳米棒具有较宽的紫外-可见光吸收范围,结合Tauc方程计算得出FeVO4纳米棒的光学带隙为2.13 eV。光催化降价甲基橙性能测试显示经90 min紫外灯照射,对甲基橙的降解率为93.6%。     

Synthesis and Structural Characterization of K3Th2(PO4)3F2 and RbThPO4F2 as Potential Nuclear Waste Storage Materials

Abstract  

Two new alkali thorium phosphate materials, K₃Th₂(PO₄)₃F₂ and RbThPO₄F₂, were isolated by hydrothermal synthesis at 575 °C. These structures were characterized by single crystal X-ray diffraction using a full-matrix least squares method. The K₃Th₂(PO₄)₃F₂ compound crystallizes in C2/c (No. 15) with a = 15.8179(15) ?, b = 9.8172(8) ?, c = 9.6472(9) ?, β = 121.132(7)°, Z = 4 and R ₁ = 0.0329. This structure contains two large open channels possibly suitable for incorporating radioactive cesium isotopes for waste storage. The RbThPO₄F₂ structure forms in the P2 ₁ /m (No. 11) space group with a = 6.719(4) ?, b = 6.002(3) ?, c = 7.431(5) ?, β = 113.925(19)°, Z = 2 and R ₁ = 0.0359. Unique to this material is a chain of edge sharing thorium with square antiprism coordination environments where fluorine occupies both sites along the edge. Both structures also represent the first occurrences of a fluorinated alkali thorium phosphate material.     

Nanoscale phase separation of CuI-Cu2MoO4 superionic conducting glass studied by analytical transmission electron microscopy

Microstructures of CuI-Cu₂MoO₄ superionic conducting glasses have been studied by analytical transmission electron microscopy equipped with high angle annular detector dark field (HAADF) detector and energy dispersive X-ray spectroscopy (EDS). Structural inhomogeneities of 5-10 nm in size are observed from HAADF images in the glass. Deference of composition between bright and dark contrast regions is clearly confirmed by EDS experiments. The nanoscale phase separation of 5-10 nm in size has been clarified by HAADF and EDS experiments.     

Synthesis of superparamagnetic Mn3O4 nanocrystallites by ultrasonic irradiation

Nanocrystalline Mn₃O₄ has been synthesized by ultrasonic irradiation of Mn acetate solution in water. Analysis of its X-ray diffraction data shows formation of a phase-pure compound with an average particle size of about 15 nm. DC magnetization measurements as a function of temperature and field show a reduced ferrimagnetic transition temperature as compared to those reported for the bulk , and a subsequent observation of superparamagnetic behavior at 40 K. The observed magnetic properties are suggestive of formation of a single domain magnetically ordered Mn₃O₄ nanoparticles below their ferrimagnetic transition temperature.     

Synthesis and X-ray structural investigation of K2(H5O2)[UO2(C2O4)2(HSeO3)]

The synthesis and X-ray diffraction analysis of K₂(H₅O₂)[UO₂(C₂O₄)₂(HSeO₃)] single crystals have been performed. This compound crystallizes in the triclinic system with the unit-cell parameters a = 6.7665(4) ?, b = 8.8850(4) ?, c = 12.3147(7) ?, α = 94.73°, β = 90.16°, γ = 92.11°, sp. gr. P[`1]P\bar 1, Z = 2, and R = 0.019. The basic structural units are island [UO₂(C₂O₄)₂(HSeO₃)]³⁻ groups, which belong to the AB ₂⁰¹ M ¹ crystallochemical group of uranyl complexes (A = UO₂²⁺, B ⁰¹ = C₂O₄²⁻, and M ₁ = HSeO₃⁻). Uraniumcontaining complexes are linked through K⁺ and H₅O₂⁺ ions and via a system of hydrogen bonds with the participation of oxonium hydrogen atoms in this structure.     

Crystal structure of M4[(UO2)2C2O4(SO4)2(NCS)2] ( M = K+, Rh+) and K4[(UO2)2C2O4(SeO4)2(NCS)2]

Three heteroacidoligand uranyl complexes M ₄[(UO₂)₂C₂O₄(SO₄)₂(NCS)₂] (M = K⁺ (I), Rb⁺ (II)) and K₄[(UO₂)₂C₂O₄(SeO₄)₂(NCS)₂] (III) have been synthesized and their crystal structure has been determined by X-ray diffraction analysis. The compounds I–III are isostructural and crystallized in the monoclinic system, sp. gr. P2₁/c, Z = 2, a = 11.5548(3) ?, b = 7.0847(1) ?, c = 13.5172(3) ?, β = 93.130(1)°, V = 1104.90(4), R = 0.015 (I); a = 11.5854(9) ?, b = 7.3841(6) ?, c = 13.9072(9) ?, β = 95.754(3)°, V = 1183.74(15), R = 0.0235 (II); a = 11.6715(3) ?, b = 7.1418(2) ?, c = 13.8546(1) ?, β = 93.539(1)°, V = 1152.66(5), R = 0.0126 (III). Basic structural units of these crystals are [(UO₂)₂C₂O₄(XO₄)₂(NCS)₂]⁴⁻ chains, which belong to the crystallochemical group A ₂ K ⁰² B ₂² M ₂¹ (A = UO₂²⁺, K ⁰² = C₂O₂₋⁴, B ² = SO₄²⁻ or SeO₄²⁻, M ¹ = NCS⁻) of uranyl complexes. Uranium-containing chains are connected into a 3D framework via a system of electrostatic interactions with potassium or rubidium cations from outer spheres. Original Russian Text ? I.V. Medrish, E.V. Peresypkina, A.V. Virovets, L.B. Serezhkina, 2008, published in Kristallografiya, 2008, Vol. 53, No. 3, pp. 495–498.     

Synthesis, Crystal Structure and Properties of the Binuclear Complex [Sm2(C10H9N2O4)2(C10H8N2O4)2(H2O)4]

Abstract  A novel binuclear Smarium (III) complex with N-(2-propionic acid)-salicyloyl hydrazone (C₁₀H₁₀N₂O₄, H₃L) was prepared and characterized. The crystal structure of [Sm₂(H₂L)₂(HL)₂(H₂O)₄] (1) was determined by X-ray single crystal diffractometry. 1 crystallizes in the monoclinic systerm, space group P2(1)/c, with a = 0.10229(2), c = 31.549(7), b = 0.70599(15) nm, and Z = 4. In the structure, Sm(III) is nine-coordinated by carboxyl O and acyl O atoms and imido N atoms of two ligands (H₂L and HL forms) and O atoms from two water molecules. H₂L and HL act as tridentate ligands which form two stable five-numbered chelating rings sharing one edge in the keto form for each ligand, and the carboxyl groups of two ligands were coordinated via bidentated bridging form. The coordination polyhedron around Sm (III) was described as a monocapped square antiprism. The inter- and intramolecular hydrogen bonds resulted in a three-dimensional network and provided extra stability for the structure. The complex was researched the interaction with calf thymus DNA by electronic absorption titration and emission titration. The results show that the complex is bound to calf thymus DNA mainly by intercalation .The complex also shows good fluorescence property. Index Abstract  The title compound, [Sm₂(H₂L)₂(HL)₂(H₂O)₄] was synthesized by the treatment of N-(2-propionic acid)-salicyloyl hydrazone (C₁₀H₁₀N₂O₄, H₃L) and Sm(NO₃) · 4H₂O and its crystal structure determined. Single crystal X-ray diffraction analysis reveals that Sm (III) is nine-coordinated by carboxyl O and acyl O atoms and imido N atoms of two ligands (H₂L and HL forms) and O atoms from two water molecules. The carboxyl groups of two ligands were coordinated via bidentated bridging form. The coordination polyhedron around Sm (III) was described as a monocapped square antiprism. The inter- and intramolecular hydrogen bonds resulted in a three-dimensional network and provided extra stability for the structure.