Ion-Exchange Chromatographic Separation of Anions on Hydrated Bismuth Oxide Impregnated Papers

Abstract

A comparative study of the chromatographic behaviour of anions, iodide, sulphide, phosphate, arsenate, arsenite, vanadate, chroraate, dichromate, thiosulphate, thiocyanate, ferricyanide and ferrocyanide on papers impregnated with hydrated bismuth oxide and untreated Whatman no, 1 papers has been made by employing identical aqueous, non-aqueous and mixed solvent systems. Sharp and compact spots were obtained with impregnated papers whereas the opposite applied to plain papers. Various analytically important binary and ternary separations are reported.     

石榴状单质铋(Bi)球与g-C3N4复合材料表现出超强可见光氧化NO性能

采用一种原位合成工艺制备了具有类石榴结构的金属铋(Bi)单质修饰的g-C3N4复合材料(Bi-CN),并用于可见光氧化NO反应中.金属Bi单质镶嵌在CN层间形成的复合物,由于金属Bi单质显著的表面等离子体共振(SPR)作用可将光吸收范围由紫外光延展至近红外,极大地提高了复合物的光吸收.此外,由于Bi单质存在于复合物界面可产生内建莫特-肖特基效应,从而加快光生载流子的分离与转移.由此,Bi-CN复合物光催化剂展现出超强的光催化去除NO性能.我们提出了类石榴结构的形成以及相应的Bi-CN复合物光催化活性的提高机理.这不仅为高效的金属铋单质改性的g-C3N4基光催化剂提供了一种新的设计方案,也对g-C3N4基光催化的机制理解提出了新的见解.通过X射线衍射、红外光谱和X射线光电子能谱结果发现Bi是以金属单质的形式存在于Bi-CN复合物中,这得益于我们采用了二水合铋酸钠(NaBiO3·2H2O)作为铋前驱体,从而成功避免了氧化态铋的形成.Bi-CN复合物中金属铋单质的存在有诸多优点.首先,金属铋单质具有显著的表面SPR效应,它的引入可大大提高复合物的光吸收能力和太阳光利用率.有研究表明,直径为150–200 nm的铋球能够在紫外-可见漫反射图谱(UV-vis)在λ=500 nm处呈现出典型的SPR峰,但本样品在λ=200–800 nm区间内并未发现该SPR峰.由于铋单质的共振受限于其尺寸大小、颗粒形状和构造环境.本文中球形铋单质的直径约为1μm,其可能发生共振效应的峰位置应超过800 nm,因此未发现相应的SPR峰.其次,金属铋单质分散在CN层表面上构建的肖特基垫垒能够高效地阻止光生电子与空穴的复合,促进了光生载流子的分离与转移,从而提高光氧化NO进程.再者,金属铋单质的介入成功构造了Bi-CN异质结,在可见光照射下NO氧化反应中,Bi-CN复合物活性显著高于CN(22.2%)、CN-EG(36.4%)和Bi(14.1%),其中以10%Bi-CN活性最佳,NO去除率到70.4%,远远超过K插层的g-C3N4、Ag掺杂的g-C3N4和氧化石墨烯修饰的g-C3N4.当复合物中金属铋单质含量超过10%时,其活性明显下降.这是因为大量的金属铋单质积聚在Bi-CN复合物表面上而造成物理堵塞,妨碍了CN吸收可见光,从而降低了其可见光吸收能力;同时导致只会吸收更多的紫外光(λ<280 nm)而不是可见光,因而其可见光催化氧化NO能力下降.     

Die trikline Kristallstruktur von Ag2Bi2S3Cl2: Pseudosymmetrie und Zwillingsbildung

Ruby‐red crystals of Ag₂Bi₂S₃Cl₂ were synthesized from AgCl and Bi₂S₃ by cooling a melt from 770 K to room temperature. X‐ray diffraction on powders and single‐crystals revealed a triclinic crystal structure with special lattice constants (P &1macr; (No. 2), a = 1085.0(2), b = 717.2(1), c = 1137.6(1) pm, α = 89.80(1)?, β = 74.80(1)?, γ = 87.81(1)?). In the structure [Bi^IIIS₃Cl₄] polyhedra form 2[BiS_3/2Cl_4/4]^‐ double‐layers by sharing common faces and edges. The silver(I) cations between the layers are coordinated either octahedrally by sulfide ions or tetrahedrally by sulfide and chloride ions. The deviations from the monoclinic space group P 1 2₁/c 1 are small and induce twinning along [010]. Further pseudosymmetry is based on the stacking of layer packages with the symmetry of the layer group P (2/c) 2₁/c 2/b.     

Promotion Effect of Bismuth on Nickel Electrodeposition and Its Electrocatalysis to Glucose Oxidation

Metallic Bi and Ni were co‐deposited onto the surface of glass carbon electrode (GCE) from the electrolyte solution containing their respective nitrate to fabricate a Bi/Ni alloy modified GCE (Bi/Ni‐GCE). The purpose is to study the influence of Bi³⁺ on the deposition of Ni and that of deposited Bi on the electrocatalytic performance of Ni to glucose in alkali solution. The results show that both redox signal of Ni(OH)₂/NiOOH and Ni(OH)₂/NiOOH mediated electrocatalysis to glucose is remarkably increased in the presence of Bi. It seems that there is a synergistic effect between Bi and Ni on each other’s redox electrochemistry. It’s possible that the firstly deposited Bi on GCE surface helps to the following nucleation and growth of Ni, leading to the deposition of more metallic Ni on GCE surface. An extremely attractive feature of Bi/Ni‐GCE is reflected by the fast response time to the electrocatalytic oxidation of glucose. The electrode nearly responses immediately after glucose is added and it reaches a steady‐state level within only 2 seconds, demonstrating a good electrocatalytic property of Bi/Ni‐GCE. The calibration plot is linear over the wide concentration range of 0–5.8 mM with a sensitivity of 33.96 µA/mM and a correlation coefficient of 0.9985. The detection limit of the glucose was found to be 0.59 µM at a signal‐to‐noise ratio of 3. The fabricated Bi/Ni‐GCE was successfully employed to analyze the glucose level in blood samples, exhibiting high accuracy, strong resistance against inference and good reliability in the practical applications.     

Effect of B-site isovalent doping on electrical and ferroelectric properties of lead free bismuth titanate ceramics

In the present work, zirconium modified bismuth titanate ceramics have been studied as potential lead-free ferroelectric materials over a broad temperature range (RT – 800 °C). Polycrystalline samples of Bi₄Ti_3−xZr_xO₁₂ (x=0.2, 0.4, 0.6) (BZrT) with high electrical resistivity were prepared using the solution combustion technique. The effect of Zr doping on the crystalline structure, ferroelectric properties and electrical conduction characteristics of BZrT ceramics were explored. Addition of zirconium to bismuth titanate enhances its dielectric constant and reduces the loss factor as it introduces orthorhombic distortion in bismuth titanate lattice which is exhibited by the growth along (0010) lattice plane. Activation energy due to relaxation is found to be greater than that due to conduction thus confirming that electrical conduction in these ceramics is not due to relaxation of dipoles. Remanent polarization of the doped samples increases as the Zirconium content increases.     

Evidence for pinning by (Sr,Ca)2CuOy particles in partial-melting processed bulk Bi2Sr2CaCu2O8+δ ceramics

Flux distributions of partial-melting processed Bi₂Sr₂CaCu₂O_8+δ ceramics are obtained using magneto-optic imaging. In remanent states (μ₀H_a=0 T), large amounts of trapped flux are observed along (Sr,Ca)₂CuO_y particles embedded in the Bi₂Sr₂CaCu₂O_8+δ matrix. Despite the relatively large size of these particles (up to 30 μm), the pinning effect is similar to that of Y₂BaCuO₅ particles in melt-processed YBa₂Cu₃O_7−δ. Furthermore, we discuss how the pinning capability of non-superconducting particles of different sizes and densities will show up in magneto-optic images.     

Effect of film thickness on interface and electric properties of BiFeO3 thin films

Bismuth ferrite (BFO) thin films were fabricated by RF-magnetron sputtering deposition method on Pt/Ti/SiO₂/Si(1 0 0) substrate. The effect of the thickness of BFO films varying from 85 to 280 nm on electrical properties was investigated. Saturated coercive fields were found to increase with the BFO film thickness. The dielectric constant of BFO thin films measured at 1 kHz decreased with decreasing thickness from 98 to 86, while tangent losses increased from 0.013 to 0.021. The presence of bismuth oxide at the interface between BFO films and Pt bottom electrodes was responsible for the high leakage currents in thin BFO thin films as was demonstrated by X-ray diffraction, grazing-incident X-ray diffraction, and secondary ion mass spectroscopy analysis.     

模糊正交法用于石墨炉探针原子化测定铋条件的研究

模糊正交法是通过把正交试验结果模糊化,然后用模糊数学的理论和方法来处理实验数据。与常规正交设计相比,能在同样实验工作量的情况下获得更多的信息。本文采用模糊正交法对元素Bi的测定条件进行优化,并将其同常规正交设计方差分析的结果进行了比较,并提出一个综合评价参数,对建立的分析方法进行了综合评价。     

Synthese und Strukturen neuer Ringverbindungen des Bismuts mit Tris(trimethylsilyl)silyl und ‐stannylresten – [(Me3Si)3Si]4Bi4 und [(Me3Si)3Sn]6Bi8

Synthesis and Structures of Novel Ring Compounds of Bismuth with Tris(trimethylsilyl)silyl and ‐stannyl Substituents – [(Me₃Si)₃Si]₄Bi₄ and [(Me₃Si)₃Sn]₆Bi₈ A bicyclo[3.3.0]octane‐like core consisting of eight bismuth atoms is found in the novel octabismuthane Bi₈[Sn(SiMe₃)₃]₆. It is prepared like Bi₄[Si(SiMe₃)₃]₄ by reduction of BiBr₃ with Li(thf)₃E(SiMe₃)₃ (E = Si, Sn) together with (Me₃Si)₆E₂. Both bismuth ring compounds have been characterized by single crystal X‐ray crystallography.