铝在路易斯酸性1-烯丙基-3甲基米唑氯铝酸离子液体中的低温电沉积(英文)

Lewis acidic 1-allyl-3-methylimidazolium chloroaluminate ionic liquids were used as promising elec-trolytes in the low-temperature electrodeposition of aluminium.Systematic studies on deposition process have been performed by cyclic voltammetry and chronoamperometry.The surface morphology and X-ray diffraction(XRD) patterns of deposits prepared at different experimental conditions were also investigated.It was shown that the nu-cleation density and growth rate of crystallites had a great effect on the structure of aluminium deposited.The crys-tallographic orientation of deposits was mainly influenced by temperature and current density.Smooth,dense and well adherent aluminium coatings were obtained on copper substrates at 10-25 mA?cm?2 and 313.2-353.2 K.More-over,the current efficiency of deposition and purity of aluminium have been significantly improved,demonstrating that the ionic liquids tested have a prospectful potential in electroplating and electrorefining of aluminium.     

两相更新支撑液膜中金属二价镍的迁移行为研究(英文)

A novel disphase supplying supported liquid membrane(DSSLM),containing supplying feed phase and supplying stripping phase for transport behavior of Ni(II),have been studied.The supplying supported feed phase included feed solution and di(2-ethyhexyl) phosphoric acid(HDEHP) as the carrier in kerosene,and supplying stripping phase included HDEHP as the carrier in kerosene and HCl as the stripping agent.The effects of volume ratio of membrane solution to feed solution(O/F),pH,initial concentration of Ni(II) and ionic strength in the feed solution,volume ratio of membrane solution to stripping solution(O/S),concentration of H2SO4 solution,HDEHP concentration in the supplying stripping phase on transport of Ni(II),the advantages of DSSLM compared to the traditional supported liquid membrane(SLM),the system stability,the reuse of membrane solution and the reten-tion of membrane phase were studied.Experimental results indicated that the optimum transport of Ni(II) was ob-tained when H2SO4 concentration was 2.00 mol·L-1,HDEHP concentration was 0.120 mol·L-1,and O/S was 4:1 in the supplying stripping phase,O/F was 1︰10 and pH was 5.20 in the supplying feed phase.The ionic strength in supplying feed phase had no obvious effect on transport of Ni(II).When initial Ni(II) concentration was 2.00×10?4 mol/L,the transport percentage of Ni(II) was up to 93.1 % in 250 min.The kinetic equation was deduced in terms of the law of mass diffusion and the interface chemistry.     

硫化镍精矿超声波辅助氧化浸出特性(英文)

The feasibility of oxidation leaching process of nickel from nickel sulfide ore and the form of different components in the lixivium has been studied at first. The method of leaching nickel sulfide concentration directly by oxidants with existence of ultrasonic has been advanced. The process of leaching nickel from nickel sulfide concentration by using the system of persulfate and silver has been determined. The influence of different factors on the leaching rates of nickel, such as with and without ultrasonic, the concentration of Na2S2O8, liquid-solid ratio and the concentration of AgNO3 have been explored. The results show that: (1) in the oxidative leaching system, nickel can be leached completely as Ni2+ or NiSO4(aq.)from nickel sulfide concentration in theory; (2) the nicopyrite can not exist steadily in the persulfate acid leaching system, but Ni2+can. Meanwhile, sulfur may be existed steadily in the leaching process; (3) nicopyrite with much lower electrostatic potential may be leached earlier than chalcopyrite and sideropyrite; and (4) the overall reaction rate of the leaching process can be enhanced with ultrasonic radiation, but it does not change the mecha-nism of leaching. The more oxidant concentration or higher liquid-solid ratio is, the higher leaching percentage of nickel. The leach-ing percentage of nickel can be increased significantly by adding a small amount of AgNO3 during the leaching processes. Under the same conditions, the higher concentration of AgNO3 is, the higher leaching yields of nickel will be obtained.     

碳毡基体电活性铁氰化镍电极电控离子交换连续分离Cs~+(英文)

Nickel hexacyanoferrate (NiHCF) film was synthesized on porous three-dimensional carbon felt (PTCF) substrate by repetitious batch chemical depositions, and the NiHCF/PTCF electrode was used as electrochemically switched ion exchange (ESIX) electrode in a packed bed for continuous separation for cesium ions. The morphologies of the prepared electrodes were characterized by scanning electron microscopy and the effects of solution concentration on the ion-exchange capacity of the electrodes were investigated by cyclic voltammetry technique. Cycling stability and long-term storage stability of NiHCF/PTCF electrodes were also studied. The NiHCF/PTCF electrodes with excellent ion-exchange ability were used to assemble a diaphragm-isolated ESIX reactor for cesium separation. Continuous separation of cesium and regeneration of NiHCF/PTCF electrode based on the diaphragm-isolated reactor were performed in a laboratory-scale two-electrode system.     

303.15 K下氯化钙和氯化铵盐的溶解对甲醇+苯混合物焓的影响(英文)

The effect of two dissolved inorganic salts, cadmium chloride CdCl2 and ammonium chloride NH4Cl, on the excess enthalpy of mixing (HE) of the binary system methanol + benzene measured at 303.15 K using an isothermal displacement calorimeter with vapor space is investigated in the present work. Compared to the salt-free system, a decreasing trend in the endothermicity of HE values is significant with the addition of CdCl2 salt but the decrease in the HE values is insignificantly smaller with the addition of NH4Cl salt. The experimental values of the enthalpy of mixing are fitted into a Redlich-Kister equation and the deviations in the val-ues and the parameters are reported. The importance of the solute-solvent interactions and the solvent-solvent interactions are dem-onstrated from the increasing excess enthalpy of mixing values in the positive direction with the increase of salt concentration.     

电沉积法制备固态染料敏化太阳能电池(英文)

本文采用一步电化学沉积的方法在导电玻璃上先后沉积了ZnO/染料复合薄膜以及CuSCN薄层,实现仅以电沉积法制备结构为ZnO/染料/CuSCN的固态染料敏化太阳能电池,电池的光电转换效率达到0.1%。在电沉积CuSCN前,脱附电沉积制备的ZnO/染料复合薄膜中的染料以形成多孔ZnO薄膜,然后通过染料再吸附得到染料敏化ZnO纳晶多孔薄膜。在电沉积过程中,ZnO和CuSCN的晶体尺寸、晶体取向和膜层形貌都可以进行比较精准的控制。探讨了影响沉积薄膜形貌和光电转换效率的因素,如旋转圆盘电极的旋转速度、电沉积温度以及染料敏化剂的选择。本文报道的低温电沉积制备全固态太阳能电池的方法为制备柔性染料敏化太阳能电池提供了一种新的思路。     

添加剂EDTA对氢氧化镁反应结晶过程的影响(英文)

The effects of additive ethylenediaminetetraacetic acid (EDTA) on crystallization process were investigated by the induc-tion time of MgSO4-NaOH system. Nucleation and growth rates, growth mechanism and particle size distribution of magne-sium hydroxide precipitation were involved with. The induction time in unseeded and seeded precipitation of magnesium hydroxide with and without additive EDTA was measured. The conductivity method was used to determine the induction period. Theoretical relations of the induction time and supersaturation ratio for different growth mechanisms and a combined analysis on the induction time were applied to determine nucleation and growth rates. The growth mechanism of magnesium hydroxide precipitation was dis-closed by analyzing the experimental data with and without additive. The analysis on induction time indicated that additive EDTA had a significant influence on both nucleation and growth of magnesium hydroxide precipitation. The mechanism underlying the effect of EDTA on crystal growth was 2-dimension nucleation-mediated growth model.     

镍钨合金电沉积伏安特性和初期行为的研究

镍钨合金镀层由于其高的硬度、耐磨及耐蚀性而被作为代铬镀层用于金属表面处理。为进一步探讨镍钨合金的电沉积机理,采用循环环伏安法和电位阶跃法研究了玻碳电极上镍钨电沉积的循环伏安特性和初期行为。电沉积过程中,钨酸根被还原成中间价态的氧化物。     

指甲花萃取物对镍从瓦特镀液中电沉积的影响(英文)

采用赫尔槽试验、分散能力测定法、扫描电镜、X射线衍射、能谱分析、硬度测量及交流阻抗谱,研究指甲花萃取物(主要成分为2-羟基-1,4-萘醌)对镍从瓦特镀液中电沉积(以低碳钢为基体)的影响。在温度40~50°C和pH4.5~5.0的条件下,从含60mL/L指甲花萃取物的瓦特镀镍液中得到的镀层具有良好的耐蚀性和硬度。指甲花萃取物作为瓦特镀镍液的添加剂,极大地提高了镀液的分散能力和电流效率。在最佳指甲花萃取物浓度下所得的镀镍层为晶态,结晶细致。     

氨基磺酸盐体系复合电沉积镍-钴-氧化钇工艺的正交优化

通过正交试验对超声波辅助复合电沉积Ni–Co–Y₂O₃工艺进行优化,得到最佳镀液组成和工艺参数为:Ni(NH₂SO₃)2·4H₂O100 g/L,Co(SO₃NH₂)2·4H₂O 20 g/L,H₃BO₃ 40 g/L,纳米Y₂O₃ 3.0 g/L,p H 4.2,温度40°C,电流密度5 A/dm²,超声波功率300 W,时间1.25 h。在最优工艺下所得Ni–Co–Y₂O₃复合镀层细致、平整,含0.98%(质量分数)的Y₂O₃颗粒,显微硬度为538.85 HV,耐磨性较优。     

室温型熔盐镀锡的研究

在测定了室温型SnCl2 BPC熔盐的物理、电化学性质的基础上 ,进行了镀锡的研究。结果表明 ,SnCl2 BPC熔盐可用于Sn的电镀 ;熔盐的组成影响电流效率与镀层的形貌 ,5 0 .0mol%SnCl2 熔盐可得到平整光亮的锡镀层。     

Electrodeposition of magnesium from the eutectic LiCl–KCl melt

Electrodeposition of magnesium in the eutectic LiCl--KCl mixture (58--42 mol%) containing different MgCl₂ concentrations was studied using tungsten as cathode material. The temperature was varied above and below the melting point of magnesium (983 K). Electrochemical techniques such as cyclic voltammetry, chronopotentiometry and chronoamperometry were employed in order to characterise the system and study nucleation and growth of the magnesium phase. With all the electrochemical techniques above mentioned, macroscopic growth of the solid magnesium deposit was observed. Liquid magnesium deposits were found to grow without giving rise to a significant increase in surface area. This may be related to lithium co-deposition and formation of Li--Mg liquid solution and the differences in interfacial properties of the cathodic deposits obtained in each case. The deposition of lithium on pre-deposited magnesium leads to the formation of Li--Mg solid alloys or to a liquid Li--Mg solution at temperatures below or above the melting point of magnesium, respectively. The diffusion coefficient of magnesium ions was determined by different electrochemical techniques. The values obtained showed the effect of macroscopic growth of the deposit in the case of solid magnesium deposits.     

温度对金属镍电沉积中枝晶分形生长的影响

将分形几何与电化学原理相结合,通过改进的有限扩散凝聚模型(diffusion-limited aggregation,DLA),采用基于Microsoft Visual C 6.0编程,模拟温度对点电极电沉积结果的影响.以环形金属镍为阳极,石墨为阴极,用自行设计的试验设备研究了不同温度时金属镍二维电沉积生长的行为特性,并与模拟结果进行比较.结果表明:在保持电压恒定的条件下,温度对点电极电沉积的影响与采用DLA模型模拟所得的结果具有相似性,表明利用DLA模型模拟的结果对枝晶电沉积的试验研究具有很好的指导意义.     

金属镍电沉积中枝晶分形生长的研究

将分形几何与电化学原理相结合,通过改进的有限扩散凝聚模型(diffusion-limited aggregation,DLA),采用基于Microsoft Visual C 6.0的Open GL编程,对点电极为阴极进行二维电沉积时沉积产物的形貌进行了模拟.以环形金属镍为阳极,石墨为阴极,用自行设计的试验设备制备了二维的金属镍枝晶以验证模拟结果.结果表明,在保持电压恒定的条件下,镍沉积层的形貌特征为具有分形结构的枝晶,这与采用DLA模型模拟所得的二维枝晶形貌具有相似性,表明该模型对枝晶电沉积的实验研究具有很好的指导意义.     

Electrodeposition Behaviour of Cadmium Telluride from 1-ethyl-3-methylimidazolium Chloride Tetrafluoroborate Ionic Liquid

Voltammetry at a glassy carbon electrode was used to study the electrochemical deposition of Cd–Te from the Lewis basic 1-ethyl-3-methylimidazolium chloride/tetrafluoroborate air-stable room temperature ionic liquid between 80 °C and 140 °C. Deposition of tellurium alone occurs through a four-electron reduction of Te(iv) to Te which could be further reduced to Te(-ii) at a more negative potential. The Cd–Te electrodeposits could be obtained by the underpotential deposition (UPD) of Cd on the deposited Te. The UPD of Cd on Te was, however, limited by a slow charge transfer rate. Samples of Cd–Te electrodeposits were prepared on tungsten and titanium substrates and characterized by energy dispersive spectroscope (EDS), scanning electron microscope (SEM), and X-ray powder diffraction (XRD). The results showed that an excess amount of Cd(ii) was required in order to prepare CdTe codeposits with a Cd/Te atomic ratio approached 1/1. The deposit composition was independent of the deposition potential within the Cd UPD range. Raising the deposition temperature increased the UPD rate of Cd and promoted the formation polycrystalline CdTe.     

Electrodeposition of aluminum from molten AlCl3–NaCl–KCl mixture

Electrochemical deposition of aluminum from basic and acidic molten NaCl-KCl-AlCl₃ mixture on a graphite electrode at 140 °C was studied by voltammetry, chronopotentiometry and constant current deposition. The deposition of aluminum was found to proceed via a nucleation/growth mechanism in basic melt, while it was found to be diffusion controlled in acidic melt. The diffusion coefficient calculated for Al₂Cl⁻ ₇ ions in acidic melt by voltammetry was in agreement with the deductions of voltammetry. The morphology of the aluminum deposits was examined using a metallographic microscope and by SEM. It was shown that, depending on the current density (c.d.) and AlCl₃ concentration (acidic or basic melt) different aluminum morphologies were evident but a silver-bright, compact, and very stable metallic form of aluminum deposit was obtained in acidic melt with KI addition as surfactant.     

低温熔盐法合成铁酸镧纳米粉体

文章首次以低温熔盐法在合成LaFeO3纳米粉体,用X射线衍射仪(XRD)和透射电子显微镜(TEM)等测试手段对材料的结构、粒径进行了分析和表征;并探讨了不同煅烧温度、不同硝酸锂添加量条件下对铁酸镧粉体结晶情况等的影响。     

电沉积制备镍箔的SEM形貌和抗拉强度

研究了电沉积法制取镍箔的实验条件,并对不同条件下得到的镍箔表面、断面SEM形貌以及抗拉强度进行了分析. 结果表明,动态条件下电沉积镍箔,能够显著提高其极限电流密度,此时SEM形貌显示沿电沉积箔的厚度增长方向,纯镍箔的晶粒逐渐增大. 加入5 g/L糖精能够有效地细化晶粒,并使镍箔表面更加光亮,其抗拉强度也有所提高.     

超重力场电沉积镍箔及其机械性能

在超重力条件下电沉积镍箔,考察了超重力对镍箔沉积的电流效率、槽电压和单位能量消耗的影响,并对所制镍箔的表面形貌和晶体结构及机械性能进行了表征. 结果表明,随着重力系数G和沉积电流密度的增加,镍箔晶粒有细化的趋势. 所得镍箔抗拉强度由常重力(G=1)时的933 MPa增加到G=443时的1190 MPa,硬度则由224 Hv增加到375 Hv. 超重力条件下(G=111),随着沉积电流密度由0.1 A/cm2增加至0.4 A/cm2,镍箔的抗拉强度和硬度分别由1054 MPa和285 Hv增加为1121 MPa和331 Hv.     

脉冲电沉积纳米晶镍镀层的织构与硬度

采用脉冲电沉积方法在304不锈钢表面制备出具有不同织构的纳米晶镍镀层。采用X射线衍射仪对镀镍层的结构进行了表征,并用超显微微米压痕仪测量了镀镍层的硬度。结果表明:随着电镀时间的延长,镀镍层的晶粒尺寸变化不大,约为(14±2)nm;择优晶面由(111)向(200)转变;硬度由6070 MPa降至3 750 MPa。织构的变化显著影响镀镍层的硬度,随着织构系数TC(111)的降低,镀镍层的硬度逐渐下降。