Evaluation of bismuth doped La2-xBixNiO4+δ (x = 0, 0.02 and 0.04) as cathode materials for solid oxide fuel cells

Bismuth doped La_2-xBi_xNiO_4+δ (x = 0, 0.02 and 0.04) oxides are investigated as SOFC cathodes. The effects of Bi doping on the phase structure, thermal expansion, electrical conduction behavior as well as electrochemical performance are studied. All the samples exist as a tetragonal Ruddlesden-Popper structure. Bi-doped LBNO-0.02 and LBNO-0.04 have good chemical and thermal compatibility with LSGM electrolyte. The average TEC over 20–900°С was 13.4 × 10^?6 and 14.2 × 10^?6 K^?1 for LBNO-0.02 and LBNO-0.04, respectively. The electrical conductivity was decreasing with the rise of Bi doping content. EIS measurement indicates Bi doping can decrease the ASR values. At 750 °C, the obtained ASR for LBNO-0.04 is 0.18 Ωcm², which is 56% lower than that of the sample without Bi doping, suggesting Bi doping is beneficial to the electrochemical catalytic activity of LBNO cathodes.     

First-Principles Study on the Stability and Electronic Properties of Bi-Doped Sr3Ti2O7

The electronic and crystal structural properties of Bi-doped Sr_3Ti_2O_7are studied using the first principles density functional theory(DFT)based on pseudopotentials basis and plane-wave method.Our results show that the formation energy of Bi doping in Site-1 and Site-2 of Sr_3Ti_2O_7increases with increasing doping concentration.And at the same doping concentration,the formation energy of Bi doping in Site-2 is lower than that in Site-1.The undoped Sr_3Ti_2O_7is found to be an insulator and its Fermi level stays at the top of the valence band.While the Fermi level of the Bi-doped Sr_3Ti_2O_7moves into the bottom of conduction band,the system undergoes an insulator-to-metal phase transition.Furthermore,our calculation results demonstrated that the Fermi level of the Bi-doped Sr_3Ti_2O_7goes deeper into the bottom of conduction band with increasing doping concentration.     

Bi掺杂纳米AgSnO2的耐电弧侵蚀性能研究

AgSnO2在使用过程中温升过高以及抗侵蚀性和抗熔焊性差。采用溶胶-凝胶法制备掺杂Bi元素的纳米复合AgSnO2电接触合金,对合金进行电弧侵蚀试验,通过扫描电镜对合金电弧侵蚀后的形貌、燃弧能量和燃弧时间进行观察和分析。结果发现,与无掺杂的纳米复合AgSnO2合金相比,Bi元素的加入改善了Ag对SnO2的浸润性,避免了因SnO2富集形成绝缘层使接触电阻升高,从而提高触头材料电性能、电寿命,抗熔焊、耐电弧烧损的能力。     

Conductive and transparent Bi-doped ZnO thin films prepared by rf magnetron sputtering

Bi-doped ZnO thin films were grown on glass substrates by ratio frequency (rf) magnetron sputtering technique and followed by annealing at 400 °C for 4 h in vacuum (~ 10^− 1 Pa). The effect of argon pressure on the structural, optical, and electrical properties of the Bi-doped films were investigated. The XRD patterns show that the thin films were highly textured along the c-axis and perpendicular to the surface of the substrate. Some excellent properties, such as high transmittance (about 85%) in visible region, low resistivity value of 1.89 × 10^− 3 W cm and high carrier density of 3.45 × 10²⁰ cm^− 3 were obtained for the film deposited at the argon pressure of 2.0 Pa. The optical band gap of the films was found to increase from 3.08 to 3.29 eV as deposition pressure increased from 1 to 3 Pa. The effects of post-annealing treatments had been considered. In spite of its low conductivity comparing with other TCOs, Bi-doping didn't appreciably affect the optical transparency in the visible range of ZnO thin films.     

Development of high-capacity primary alkaline manganese dioxide/zinc cells consisting of Bi-doping of MnO<Subscript>2</Subscript>

The feasibility of using Bi-doped manganese dioxide as the cathode in a primary alkaline zinc cell is discussed. A Bi-doped MnO₂ cathode material made by the CMD process is examined with respect not only to its discharge in conditioning cycles but also with achievement of practically high voltage on discharge. With suitable composition of the Bi/MnO₂ composite, remarkably high C-rates for discharge and recharge are achieved with little polarization. The Bi–Mn–O compounds with possible structures are also discussed.     

Bi-TiO2纳米管阵列的制备及其光催化性能

以甲基橙光催化降解效率为指标、 Bi（ NO3）3-稀HNO3混合液为电沉积液,利用电化学沉积法探讨铋掺杂二氧化钛纳米管阵列（ Bi-TNTs）的制备条件,通过SEM、 XRD对其结构和形貌进行表征,考察Bi-TNTs光催化降解制糖废水的条件。结果显示,在电压为2.2 V 、0.33 g/L Bi（NO3）3和0.28 mol/L HNO3溶液电沉积4 min条件下制备的Bi-TNTs可以显著提高光催化降解甲基橙及制糖废水的效率。底物pH值对Bi-TNTs光催化活性有较大影响,较强碱性环境中, Bi-TNTs对制糖废水降解率最高,光照25 h制糖废水降解率达到90.24％。     

Electroluminescence properties of PbTe pn junctions fabricated under controlled Te vapor pressures

Electroluminescence properties of PbTe pn junctions grown under various tellurium vapor pressures are investigated. For unintentionally doped pn junctions, the luminescence bands corresponding to D-A pair and band to band transition are observed. The luminescence intensity of the band to band transition has depended on tellurium vapor pressure, which suggests nonradiative transitions through nonstoichiometric defects forming deep levels. For pn junctions with Bi-doped epitaxial layers, only one peak appears at 20∼25 meV below band to band-transition energy, which, probably, shows recombination through impurity levels or impurity band originating from Bi-doping.