非晶钛酸铋的晶化过程

利用差热分析、X射线衍射和透射电子显微镜等技术对溶胶-凝胶法合成的凝胶的晶化过程进行了分析，实验结果表明，Bi₄Ti₃O₁₂非晶凝胶晶化过程经历了四个过程：首先在433℃先形成了Bi₂O₃和TiO₂亚稳相，然后在488℃时TiO₂亚稳相与Bi₂O₃反应形成Bi，Ti复合氧化物亚稳相Bi₂T 关键词： 钛酸铋 铁电材料 溶胶凝胶 非晶 晶化过程     

掺铒重金属氧氟硅铋酸盐玻璃的光谱性质

研究了重金属氧氟硅铋酸盐玻璃 (50-x)SiO2 xBi2O3 50PbF2(x=0, 3, 5, 8, 10, 13, 15 mol%)中Er3+离子的吸收光谱、荧光光谱、荧光半高宽、荧光 寿命和热稳定性能.应用Judd Ofelt理论计算了玻璃的强度参数Ωt(t=2,4,6)，应用 McCumber计算了能级4I13/2→4I15/2跃迁的受激发射截面. 结果发现荧光半高宽与Ω6有较大联系，Ω6越大，荧光半高宽越宽.对Er3+ 关键词： 重金属氧氟硅铋酸盐玻璃 光谱性质 Er3+离子 Judd Ofelt参数     

Bismuth triflate catalyzed conjugate addition of indoles to α,β-enones

Reaction of indoles with electron deficient olefins under the influence of bismuth triflate has been studied at ambient temperature and affords the corresponding 3-alkylated indoles in excellent yields.     

Crystal structure of tetrakisdiphenylammonium hexadecachlorotetrabismuthate(III)

[(C₆H₅)₂NH₂]₄ ⁺[Bi₄Cl₁₆]^4– crystallizes in the triclinic space group witha=11.835(2),b=12.393(2),c=12.625(3)Å, =108.37(3), =108.69(3), =96.00(3)° andD _c=2.135 g cm^–3 forZ=1. The [Bi₄Cl₁₆]^4– anion is a centrosymmetric cluster of four distorted edge-sharing BiCl₆ octahedra. The ranges of the Bi–Cl bonds are 2.484(4)–2.606(3)Å for Bi–Cl(terminal), 2.691(3)–2.956(4)Å for Bi-Cl(µ₂), and 2.960(3)–3.120(4)Å for Bi-Cl(µ₃). The cations and anions are held in place by weak hydrogen bonds.     

The Narrowest Band Gap Ever Observed in Molecular Ferroelectrics: Hexane‐1,6‐diammonium Pentaiodobismuth(III)

Narrow band gaps and excellent ferroelectricity are intrinsically paradoxical in ferroelectrics as the leakage current caused by an increase in the number of thermally excited carriers will lead to a deterioration of ferroelectricity. A new molecular ferroelectric, hexane‐1,6‐diammonium pentaiodobismuth (HDA‐BiI₅), was now developed through band gap engineering of organic–inorganic hybrid materials. It features an intrinsic band gap of 1.89 eV, and thus represents the first molecular ferroelectric with a band gap of less than 2.0 eV. Simultaneously, low‐temperature solution processing was successfully applied to fabricate high‐quality ferroelectric thin films based on HDA‐BiI₅, for which high‐precision controllable domain flips were realized. Owing to its narrow band gap and excellent ferroelectricity, HDA‐BiI₅ can be considered as a milestone in the exploitation of molecular ferroelectrics, with promising applications in high‐density data storage and photovoltaic conversion.     

Deep‐Level Defect Enhanced Photothermal Performance of Bismuth Sulfide–Gold Heterojunction Nanorods for Photothermal Therapy of Cancer Guided by Computed Tomography Imaging

Bismuth sulfide (Bi₂S₃) nanomaterials are emerging as a promising theranostic platform for computed tomography imaging and photothermal therapy of cancer. Herein, the photothermal properties of Bi₂S₃ nanorods (NRs) were unveiled to intensely correlate to their intrinsic deep‐level defects (DLDs) that potentially could work as electron–hole nonradiative recombination centers to promote phonon production, ultimately leading to photothermal performance. Bi₂S₃‐Au heterojunction NRs were designed to hold more significant DLD properties, exhibiting more potent photothermal performance than Bi₂S₃ NRs. Under 808 nm laser irradiation, Bi₂S₃‐Au NRs could trigger higher cellular heat shock protein 70 expression and more apoptotic cells than Bi₂S₃ NRs, and caused severe cell death and tumor growth inhibition, showing great potential for photothermal therapy of cancer guided by computed tomography imaging.     

Controllable Synthesis of Few‐Layer Bismuth Subcarbonate by Electrochemical Exfoliation for Enhanced CO2 Reduction Performance

Two‐dimensional (2D) engineering of materials has been recently explored to enhance the performance of electrocatalysts by reducing their dimensionality and introducing more catalytically active ones. In this work, controllable synthesis of few‐layer bismuth subcarbonate nanosheets has been achieved via an electrochemical exfoliation method. These nanosheets catalyse CO₂ reduction to formate with high faradaic efficiency and high current density at a low overpotential owing to the 2D structure and co‐existence of bismuth subcarbonate and bismuth metal under catalytic turnover conditions. Two underlying fast electron transfer processes revealed by Fourier‐transformed alternating current voltammetry (FTacV) are attributed to CO₂ reduction at bismuth subcarbonate and bismuth metal. FTacV results also suggest that protonation of CO₂^.? is the rate determining step for bismuth catalysed CO₂ reduction.     

Investigation of synthesis and microstructure of bismuth titanates with TiO<Subscript>2</Subscript> rich compositions

Preliminary examinations regarding formation of bismuth titanates in a part of Bi₂O₃—TiO₂ system rich with TiO₂ have been carried out. Bismuth titanates have been synthesized from mixtures of Bi₂O₃ and TiO₂ (anatase) by the conventional solid-state method at the temperatures ranged from 1273 to 1473 K. Differential thermal analysis (DTA), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) have been used to study the formation of bismuth titanates. The following compounds have been achieved: Bi₄Ti₃O₁₂, Bi₂Ti₂O₇ and Bi₂Ti₄O₁₁. Existence of controversial bismuth titanate of formula Bi₂Ti₃O₉ in the Bi₂O₃—TiO₂ system has not been confirmed.