EDTA辅助水热法合成硫化铋晶体

以Bi(NO3)3·5H2O和Na2S2O3·5H2O为原料,用乙二胺四乙酸(EDTA)辅助水热法合成了纳米或微米级的Bi2S3晶体(1),其结构、形貌和光谱性能经XRD,FE-SEM和UV-Vis表征。结果表明:溶液的pH对1的形貌有显著的影响,随着pH的增大,1由纳米棒组成的微米球逐渐转变为微米级片状结构;1出现蓝移。     

含镧的Bi2Te3基化合物的溶剂热合成及微观结构

以BiCl3,LaCl3和Te粉为原料,用溶剂热合成法制备了含稀土元素的单相LaxBi4Te6(x≤1)热电材料纳米粉末.研究发现,三元化合物LaxBi4Te6具有与二元Bi2Te3化合物相同的晶体结构和相似的晶格常数。LaxBi4Te6中的La含量随合成温度升高而增加,但与反应时间没有显著关系。LaxBi4Te6合成粉末的颗粒尺寸在30nm左右,并且几乎与反应温度和反应时间没有关系。在120℃合成的粉末基本上为不规则多面体形状,在150℃及以上温度合成的粉末则趋向于薄片状．并存在一些直径在50～80nm之间的纳米管。     

Effect of Electrical Contact on the Performance of Bi2S3 Single Nanowire Photodetectors

Bi₂S₃ single‐crystalline nanowires are synthesized through a hydrothermal method and then fabricated into single nanowire photodetectors. Due to the different contact barrier between the gold electrode and Bi₂S₃ nanowires, two kinds of devices with different electrical contacts are obtained and their photoresponsive properties are investigated. The non‐ohmic contact devices show larger photocurrent gains and shorter response times than those of ohmic contact devices. Furthermore, the influence of a focused laser on the barrier height between gold and Bi₂S₃ is explored in both kinds of devices and shows that laser illumination on the Au?Bi₂S₃ interface can greatly affect the barrier height in non‐ohmic contact devices, while keeping it intact in ohmic contact devices. A model based on the surface photovoltage effect is used to explain this phenomenon.     

反应溶剂对Bi2S3粉体形貌的影响

利用溶剂热法在不同反应溶剂中制备了不同尺寸的Bi2S3纳米管和纳米棒.利用XRD、SEM、TEM、选区电子衍射(SAED)和高分辨透射电镜(HRTEM)对其结构和形貌进行了表征.结果表明,所制备的产物是结晶良好的正交相Bi2S3,反应溶剂的表面张力、粘度大小和反应溶剂中的比例影响纳米粉体的形貌和尺寸.紫外-可见光吸收光谱测量表明,由于尺寸效应所有粉体的吸收谱相对于正交相的Bi2S3块体都出现蓝移.     

From nanoplates to microtubes and microrods: a surfactant-free rolling mechanism for facile fabrication and morphology evolution of Ag2S films

By a simple and facile wet-chemistry technique without any surfactant, various shapes of Ag(2)S crystals--including leaflike pentagonal nanoplates, crinkly nanoscrolls, hexagonal prismlike microtubes, and microrods--were fabricated in situ on a large-area silver-foil surface separately. Detailed experiments revealed that the Ag(2)S nanoplates were formed just by immersing the silver foil in a sulfur/ethanol solution at room temperature and atmospheric pressure, and they subsequently rolled into nanoscrolls and further grew into microtubes and microrods under solvothermal conditions. Inspired by the natural curling of a piece of foliage, we proposed a surfactant-free rolling mechanism to interpret the observed morphological evolution from lamellar to tubular structures. Based on these simple, practical, and green chemical synthetic routes, we can easily synthesize lamellar, scrolled, tubular, and clubbed Ag(2)S crystals by simply adjusting the reaction temperature, pressure, and time. It is very interesting to note that the current rolling process is quite different from the previous reported rolling mechanism that highly depends on the surfactants; we revealed that the lamellar Ag(2)S could be rolled into tubular structures without using any surfactant or other chemical additives, just like the natural rolling process of a piece of foliage. Therefore, this morphology-controlled synthetic route of Ag(2)S crystals may provide new insight into the synthesis of metal sulfide semiconducting micro-/nanocrystals with desired morphologies for further industrial applications. The optical properties of the pentagonal Ag(2)S nanoplates/film were also investigated by UV/Vis and photoluminescence (PL) techniques, which showed large blue-shift of the corresponding UV/Vis and PL spectra.     

Synthesis and Crystal Structure of the Mixed-quadriligand Bismuth Complex [Bi(S_2CNEt_2)_2(NO_3)]·[1,10-Phen]

1 INTRODUCTION Some reports on the syntheses and crystal struc-tures of organotin(IV) dithiocarbamate complexes haveappeared in the previous literatures[1～3], but the bis-muth(Ⅲ) complexes with dithiocarbamate have beenscarcely studied[4]. Due to the n…     

Photocatalysis of Reduction of the Dye Methylene Blue by Bi2S3/CdS Nanocomposites

We have determined the optimal conditions for synthesis of Bi₂S₃/CdS nanocomposites and we have determined their photocatalytic activity in the reaction of reduction of methylene blue as a function of composition. We suggest a possible mechanism for the photocatalytic action of the nanocomposites.     

Synthesis and Crystal Structure of a Puckered Rhombus Grid-like Coordination Polymer with Bridging Ligand Containing Sulfanyl Linker

Introduction The design and construction of metal-organic frameworks (MOFs), obtained by metal-directed self-assembly from labile metal centers and multidentate bridging ligands, is a rapidly developing area of su-pramolecular chemistry.1-3 Besides the aesthetic struc-tural and fascinating functional motifs, they are of in-terest both for understanding the mechanisms of the assembly process and for the host-guest chemistry asso-ciated with their large central cavities.4-13 It has been documen…     

Crystal and electronic structure of Ni3Bi2S2 (parkerite)

The crystal structure of parkerite, Ni₃Bi₂S₂, was studied by single-crystal X-ray diffraction analysis and refined. The single crystal was prepared by the method of chemical transport reactions. The electronic structure of Ni₃Bi₂S₂ was calculated by the extended Hückel and DFT--LMTO--ASA methods. Substantial delocalization of electrons in the vicinity of the Fermi level and the presence of the strong Ni--S and Ni--Bi bonds were revealed. The Ni--Ni bonds are weak, which is in agreement with the X-ray diffraction data.     

Synthesis and Crystal Structure of Bi（Hsal）3（1,10- phenanthroline） （Hsal = O2CC6H4-2-OH）

A new bismuth compound Bi（Hsal）3（1,10-phenanthroline） （Hsal = O2CC6H4-2-OH） has been synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in the triclinic system, space group P1, with a = 10.243（2）, b = 11.905（3）, c = 12.934（3） A, α= 76.780（6）, β= 68.683（6）,γ= 80.930（7）°, V = 1425.6（5） A^3, Dc = 1.865 g/cm^3, Mr = 800.51, F（000） = 780, μ= 6.247 mm^-1, Z = 2, R = 0.0456 and wR = 0.1131 for 5612 observed reflections （I 〉 2σ（I））. In this compound, three salicylate ligands coordinate to the Bi atom through the carboxylate groups to form a four-membered chelate ring, and phenanthroline ligand chelates the metal through two N atoms. The structure of the title compound manifests a possible coordination mode between bismuth subsalicylate and N atom containing amino acid in the biological system.     

Facile Synthesis and Thermoelectric Properties of Self‐assembled Bi2Te3 One‐Dimensional Nanorod Bundles

Self‐assembled Bi₂Te₃ one‐dimensional nanorod bundles have been fabricated by a low‐cost and facile solvothermal method with ethylene diamine tetraacetic acid as an additive. The phase structures and morphologies of the samples were characterized by X‐ray diffraction, scanning electron microscopy, Fourier‐transform infrared spectrometry, and transmission electron microscope measurements. The growth mechanisms have been proposed based on the experimental results. The full thermoelectric properties of the nanorod bundles have been characterized and show a large improvement in the thermal conductivity attributed to phonon scattering of the nanostructures and then enhance the thermoelectric figure of merit. This work is promising for the realization of new types of highly efficient thermoelectric semiconductors by this method.     

Template‐Free Fabrication of Bi2O3 and (BiO)2CO3 Nanotubes and Their Application in Water Treatment

Uniform bismuth oxide (Bi₂O₃) and bismuth subcarbonate ((BiO)₂CO₃) nanotubes were successfully synthesized by a facile solvothermal method without the need for any surfactants or templates. The synergistic effect of ethylene glycol (EG) and urea played a critical role in the formation of the tubular nanostructures. These Bi₂O₃ and (BiO)₂CO₃ nanotubes exhibited excellent Cr^VI‐removal capacity. Bi₂O₃ nanotubes, with a maximum Cr^VI‐removal capacity of 79 mg g^?1, possessed high removal ability in a wide range of pH values (3–11). Moreover, Bi₂O₃ and (BiO)₂CO₃ nanotubes also displayed highly efficient photocatalytic activity for the degradation of RhB under visible‐light irradiation. This work not only demonstrates a new and facile route for the fabrication of Bi₂O₃ and (BiO)₂CO₃ nanotubes, but also provides new promising adsorbents for the removal of heavy‐metal ions and potential photocatalysts for environmental remediation.     

Crystallographic report: Bi(S2CNC5H10)2(NO3)(1,10‐phenanthroline)

The structure of Bi(S₂CNC₅H₁₀)₂(NO₃)(1,10‐Phen) features an eight‐coordinated distorted square antiprismatic geometry around bismuth, defined by an N₂O₂S₄ donor set, with Bi? S distances ranging from 2.641(2) to 2.824(2) Å. Copyright © 2004 John Wiley & Sons, Ltd.     

Synthesis,Structural Characterization,and Cation Transport of Tripotassium Pentabismuth Arsenate K3Bi5(AsO4)6

During the exploration of the K₂O-Bi₂O ₃ -As₂O₅ system, single crystals of a new arsenate of trivalent bismuth, K₃Bi₅(AsO₄) ₆, were isolated by solid state reaction at 600°C. The title compound crystallizes in the monoclinic system, space group C2/c (N°15) with a = 18.257(2) Å, b = 7.260(1) Å, c = 20.130(4) Å, β = 119.86(1)°, and Z = 4. Its structure consists of a three-dimensional framework made up of AsO₄ tetrahedra and BiO₆ and BiO₇ polyhedra sharing edges and corners, delimiting cavities wherein K⁺ ions reside. This compound exhibits a potassium ion conductivity but with rather low conductivity value.     

New Dimeric Selenidoarsenate(Ⅲ): Solvothermal Synthesis and Crystal Structure of [Co(en)3]2As2Se5

A new selenidoarsenate [Co(en)3]2As2Se5 1 (en = ethylenediamine) was synthesized by a reaction of AsCl3, COCl2·6H2O and Se in en under mild solvothermal conditions, and the structure was determined by single-crystal X-ray diffraction. 1 crystallizes in the orthorhombic system, space group Pbca with a = 15.5092(12), b = 11.5756(9), c = 17.8138(14) (A), V= 3198.1(4)(A)3, Mr = 1023.12, Z = 4, Dc = 2.125 g/cm3,μ = 8.807 mm-1, F(000) = 1976, S = 1.171, the final R =0.0591 and wR = 0.1067 for 3170 observed reflections with I ＞ 2σ(Ⅰ). 1 consists of isolated dimeric[As2Se5]4- anion constructed by two comer-sharing AsSe3 trigonal pyramids and transition metal [Co(en)3]2+ cations. The optical absorption property and thermal stability of 1 are reported.     

New Dimeric Selenidoarsenate(III):Solvothermal Synthesis and Crystal Structure of [Co(en)_3]_2As_2Se_5

1 INTRODUCTION The mild solvothermal synthesis with the presence of a structure-directing agent is proved to be a versa- tile route for the preparation of chalcogenidometa- lates of the heavier group (14 and 15) elements[1～3]. Templated by the transition metal complex cations, a large number of chalcogenidoantimonates containing transition metal complex ions have been synthesized by solvothermal method, such as Mn2(en)2Sb2S5[4], [Co(en)3]CoSb4S8[5], [M(en)3]Sb2S4 (M = Co, Ni)[6], [N…     

Synthesis of Bi2O3 and Bi4(SiO4)3 Thin Films by the Sol-Gel Method

Bi2O3 thin films were prepared by dipping silica slides in ethanolic solutions of tris(2,2-6,6-tetramethylheptane-3, 5-dionato)bismuth(III) [Bi(dpm)3] [1] and heating in air at temperatures 500°C. Bi4(SiO4)3 homogeneous thin films were obtained from the reaction of the bismuth oxide coating with the silica glass substrate at temperatures higher than 700°C. For heat treatments at temperatures between 600°C and 700°C, Bi2SiO5 coatings were obtained. The composition and microstructure evolution of the films were determined by Secondary Ion-Mass Spectrometry (SIMS), X-Ray Photoelectron Spectroscopy (XPS) and Glancing Angle X-Ray Diffraction (GA-XRD). The synthesis procedure was reproducible and allowed the control of the Bi2O3 phase composition. Moreover, the thin film annealing parameters were correlated with the formation of bismuth silicates, among which Bi4(SiO4)3 (BSO) is very appealing for the production of fast light-output scintillators [2].     

Sb2S3 with various nanostructures: controllable synthesis, formation mechanism, and electrochemical performance toward lithium storage

The size- and shape-controlled synthesis of Sb(2)S(3) nanostructures has been successfully realized by a facile hydrothermal route. A range of dimensional nanostructures, such as one-dimensional nanorods, two-dimensional nanowire bundles, three dimensional sheaf-like superstructures, dumbbell-shaped superstructures, and urchin-like microspheres, could be obtained through introducing different organic complex reagents or ionic liquids to the reaction system. The formation mechanisms of various Sb(2)S(3) nanostructures have been rationally proposed based on the crystal structure and the nature of the complex reagents and the ionic liquid. The effects of experimental parameters on the final product are also discussed in detail. In addition, electrochemical measurements demonstrate that the as-synthesized Sb(2)S(3) nanostructures have higher initial Li intercalation capacity and excellent cyclic performances, which indicates that the as-synthesized Sb(2)S(3) nanostructures could have potential applications in commercial batteries.