Preparation and Characterization of Tungsten Powder Molten Salt Electrolysis in the Eutectic NaCl-CaCl2-Na2WO4 System

采用NaCl-CaCl2-Na2WO4体系熔盐电解制备金属钨粉，采用x射线衍射法（XRD）及能谱分析（EDS）表征电极产物并采用差热法（DTA）分析体系中发生的前置化学反应．采用循环伏安法和残余电动势法分析阳极过程和过电位变化规律．结果表明：800℃、槽电压2．5V条件下以石墨为电极可以电解制得钨粉，活性物质为电解前置反应产物CaWO4；阳极总反应不可逆，阳极过程为化学反应极化控制．     

In掺杂SnO2/Ti阳极电催化氧化4-硝基苯酚研究

采用凝胶-溶胶法制备了In掺杂SnO2/Ti电极.采用In掺杂SnO2/Ti电极为阳极,Ti为阴极电解4-硝基苯酚,实验了电流密度、电极间距离和废水pH值等对4-硝基苯酚电解去除效果的影响,确定了最佳处理条件.在电流密度为20 mA/cm2,电极间距离为2 cm,废水pH为1以及电解时间为5 h的处理条件下,4-硝基苯酚的电解处理去处率可达到96.2%.并利用HPLC对4-硝基苯酚降解过程中的产物进行了初步分析.     

NaF-K2TiF6-TiO2体系中直接电解制备钛的可行性研究

以NaF-K2 TiF6作为熔盐电解质,TiO2作为溶质,探究直接电解TiO2制备金属钛的可行性.通过对比不同摩尔比NaF-K2 TiF6的初晶温度和TiO2溶解度以选择较为合适的熔盐体系,而后对该体系进行热力学计算、三电极体系循环伏安测试(Mo棒作为工作电极和参比电极,高纯石墨作为对电极)和180min的双电极恒流电解(不锈钢棒作为阴极,石墨作为阳极).结果表明,摩尔比为1.5:1的NaF-K2 TiF6体系可作为电解钛的电解质,TiO2的溶解以化学形式溶解为主,其溶入形式以K2 NaTiOF5为主,以Na2 Ti3 O7为辅.且少量TiO2溶解后会降低熔盐体系的初晶温度.T4+的阴极过程分为两个阶段:TiF62-/TiF63-;Ti3+/Ti.热力学上钛的氧化物优先反应,二氧化钛的还原是逐级进行的.恒流电解阴极产物的钛以小颗粒形式存在并夹杂着一定程度的电解质.     

3-羟基-2-吲哚酮的电化学合成研究

以靛红为原料,采用线性扫描伏安法探讨了电解液组成对电还原过程的影响.实验结果表明:当阴极电解液由硫酸(1.5mol/L)、甲醇(5.0mol/L)和靛红组成,阳极电解液由硫酸(1.0mol/L)溶液组成时,以Cu为工作电极,对靛红电还原起到良好的效果.在此基础上,分别以Cu和Pb为工作电极,进行电解实验,研究了温度、电势和时间等对产物产率和电流效率的影响.优先考虑产率,当工作电极为Cu、电极电势-0.9V(vs.SCE)、电解时间为4h和温度为40℃时,3-羟基-2-吲哚酮的产率为91.1%,电流效率为9.4%;当工作电极为Pb、电极电势-1.1V(vs.SCE)、电解时间为4h和温度为50℃时,产率为89.5%,电流效率为26.1%.这为3-羟基-2-吲哚酮的绿色合成提供了可行的技术参考.     

电生H2O2协同电解絮凝法处理餐饮废水实验研究

采用电生H2O2协同电解絮凝法处理餐饮废水，研究了废水初始浓度、电解时间、电压、电极材料、pH等因素对降解餐饮废水的影响．结果表明，进水CODCr在1200mg／L以内、pH值为中性的餐饮废水，在10V电压、电磁搅拌、曝气条件下，电解15min后，COD去除率在80％以上．该法利用了铝阳极反应生成的絮凝剂Al(OH)3和阴极上电合成的H2O2对有机物的去除作用，同时阳极产生的H^ 与阴极产生的OH^-中和又促进了两极的反应，使有机物降解更彻底．     

电解法生产过硫酸铵的研究

以电合成对氨基苯酚的副产品—硫酸铵为原料,在自制的箱式电化学反应器中,采用钛基镀铂电极为阳极,铅锑合金电极为阴极,Nafion 427阳离子交换膜为隔膜,电解制备过硫酸铵.以电流效率及产率为优化目标,考察了多种因素对电解反应的影响.所得到的优化条件为:副产物硫酸铵中对氨基苯酚含量小于0.05%,初始浓度为36.5%,阳极添加剂为0.06%的聚磷酸铵,电解温度15℃,电流密度10000 A.m-2,通电量72.48 A.h.在此较佳条件下进行了5批次的重复电解实验,电流效率均高于80%,产率均高于55%.产物经结晶、分离、干燥,可得到质量分数99.5%以上的过硫酸铵产品.     

醋酸-醋酐体系中 Mn(Ⅱ)在石墨阳极上的氧化

采用稳态极化曲线、恒电流电解和恒电势电解等多种电化学方法研究了醋酸－醋酐体系中Ｍｎ（Ⅱ）在石墨阳极上的阳极氧化过程结果表明,Ｍｎ（Ⅱ）氧化成Ｍｎ（Ⅲ）的电极过程具有前置转化反应控制的动力学规律,溶液中的Ｍｎ（ＯＡｃ）２浓度、ＫＯＡｃ浓度、电解温度、电流密度、阳极电势、电极面积与溶液体积比都不同程度地影响阳极电流效率及Ｍｎ（Ⅱ）生成Ｍｎ（Ⅲ）的转化率     

碱性介质中对苯二胺在铂微电极上的电化学聚合研究

采用循环伏安法,比较了酸性、中性和碱性介质下对苯二胺(p-PD)在铂微电极上的电化学聚合的异同,并探讨扫描速度、底物浓度等因素对p-PD在碱性体系下的电化学聚合行为的影响.结果表明,只有碱性介质才能得到吸附于电极的高分子膜;铂电极上p-PD的氧化反应为不可逆过程;在20~100 mV/s的扫描速率范围内,阳极峰电流与扫描速度的1/2次方成线性关系,表明该电极反应受扩散控制.     

辣根过氧化酶催化H_2O_2氧化邻苯二胺反应产物的循环伏安法研究

用辣根过氧化物酶催化H2O2氧化邻苯二胺制备了酶促反应产物。经高效液相色谱法、紫外 可见光谱法和红外光谱法测定分析,产物为 2, 3 -二氨基吩嗪。用金圆盘电极循环伏安法和金超微盘电极循环伏安法对 2, 3- 二氨基吩嗪在B R缓冲溶液中的电还原性质进行了研究,求得电极反应电子转移数和参与电极反应H+的反应级数均为 2。2,3- 二氨基吩嗪在电极上经历了H+eH+e的两步一电子过程,生成产物 2, 3 -二氨基- 5, 10 -二氢吩嗪。     

高能绿色环保高铁电池材料K2FeO4的制备

提出了一种电解-电渗方法制备高铁酸钾正极材料的方法,并采用铬酸盐法和XRD法对高铁酸钾的含量和结构进行测定分析.考察了制备过程中电流密度、电解温度和电解时间对K2FeO4产率的影响.结果表明,以白口铸铁为阳极,在20℃,6.5 mA/cm2电流密度下电解8 h,可得到纯度为98%的K2FeO4晶体.     

Effect of HCO3^- concentration on CO2 corrosion in oil and gas fields

The effect of HCO3^- concentration on CO2 corrosion was investigated by polarization measurement of potentiodynamic scans and weight-loss method, Under the conditions of high pressure and high temperature, the corrosion rate of steel X65 decreased with the increase of HCO3^- concentration, while pH of solution increased. SEM, EDS, and XRD results of the corrosion scales indir cated that the typical FeCO3 crystallite was found at low HCO3^- concentration but Ca（Fe,Mg）（CO3）2 was found at high HCO3^- con- centration. Ca^2＋ and Mg^2＋ are precipitated preferential to Fe^2＋ at high pH value. Potentiodynamic polarization curves showed that the cathodic current density decreases with the increase of HCO3^- concentration at low HCO3^- concentration. When the HCO3^- concentration reaches 0.126 mol/L, increasing HCO3^- concentration promotes cathodic reactions. Anodic behavior is an active process at low HCO3^- concentration and the anodic current density decreases with the increase of HCO3^- concentration. An evident active-passive behavior is exhibited in anodic process at 0.126 mol/L HCO3^-.     

ZnFe_2O_4纳米粒子磁共振成像性能研究

采用多元醇法制备了粒径约为6nm的ZnFe2O4纳米粒子,通过表面修饰得到了稳定的ZnFe2O4纳米粒子水相分散液。用X-射线粉末衍射仪(XRD)、透射电子显微镜(TEM)、动态光散射仪(DLS)、磁性能测量系统(MPMS)、磁共振分析仪等手段对样品进行表征。结果表明,所制备纳米粒子磁共振成像性能良好。     

Pressureless reactive sintering mechanism of nanocrystalline Bi2O3-Y2O3 solid electrolyte

The nanocrystalline Bi2O3-Y2O3 solid electrolyte material was synthesized by pressureless reactive sintering process with Bi2O3 and Y2O3 nano mixed powder as raw materials, which was prepared by a chemical coprecipitation process. The study on the behavior of nano δ-Bi2O3 formation and its grain growth showed that the solid solution reaction of Y2O3 and β-Bi2O3 to form δ-Bi2O3occurs mainly in the initial stage of sintering process, and nano δ-Bi2O3 crystal grains grow approximately following the rule of paracurve ((D-D0)2=K.t) during sintering process. After sintered at 600℃ for 2 h, the samples could reach above 96% in relative density and have dense microstructure with few remaining pores, the δ-Bi2O3 grains are less than 100 nm in size.     

Fabrication and characterization of highly ordered Ni0.5Zn0.5Fe2O4 nanowire/tube arrays by sol-gel template method

Highly ordered nanowire/tube arrays of Ni0.5Zn0.5Fe2O4 were fabricated by the sol-gel method in the pores of anodic alu- mina membrane (AAM). Whether nanowires or nanotubes were fabricated depends on immersion time. The immersion time was 15-40 s for nanotubes and over 60 s for nanowires. The topography and crystalline structure of the nanowire arrays were character- ized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). It was found that the length and diameter of the Ni0.5Zn0.5Fe2O4 nanowires are related to the thickness of the AAM and the diameter of the pores. The results indicated that the Ni0.5Zn0.5Fe2O4 nanowires are uniform and parallel to each other.     

Zn还原法制多晶硅副产物ZnCl_2的电解回收

Zn还原法制多晶硅会产生大量的ZnCl2副产物,在不添加其他辅助电解质情况下,成功利用ZnCl2熔盐制备出了Zn,纯度可达70.74%,验收了工艺的可行性。结果表明,在400～550℃范围内,随着电解温度的升高,熔盐电导率逐渐升高,有利于电解反应。但是继续升高温度至700℃时,ZnCl2蒸气压迅速上升到63.204kPa,挥发造成损失十分严重,且易堵塞出气管,反应温度控制在550℃左右较合适。另外,此工艺由于受ZnCl2本身属性的约束,离产业化还有一定距离。     

Growth characterization of anodic film on AZ91D magnesium alloy in an electrolyte of Na2SiO3 and KF

Anodization of AZ91D magnesium alloy in the electrolyte solution of 0.5 mol/L of sodium silicate and 1.0 mol/L of potassium fluoride was investigated. The anodic films were characterized using optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The corrosion resistance of the various anodized alloys was evaluated by a fast corrosion test using the solution of hydrochloric acid and potassium dichromate. The results showed that the addition of KF resulted in the presence of NaF in the anodic film. The thickness of the anodic film formed under a constant current density of 20 mA/cm2 for 16 min at 60℃ exceeded 100 μm. The growth of the anodic film could be divided into three stages based on the anodizing time; the growth rate was much faster during stage Ⅱ than in stages Ⅰ and Ⅲ. The anodic film exhibited the highest corrosion resistance for the AZ91 alloy,which is attributed to the fact that the anodization was maintained until the end of stage Ⅱ.     

均相沉淀法合成Gd2O2S:Dy3+荧光粉的光致发光

采用Gd2O3、Dy2O3、H2SO4和尿素为实验原料,通过均相沉淀法合成了Gd2O2S:Dy3+荧光粉。利用X射线衍射(XRD)、场发射扫描电子显微镜(FE-SEM)和光致发光(PL)光谱对合成的粉体进行了表征。XRD分析表明:前驱体在氢气气氛下900℃煅烧2h能转化成单相的Gd2O2S粉体。FE-SEM观察显示:Gd2O2S粉体形貌为近球形,平均粒度大小为300～500nm。PL光谱分析表明:在270nm紫外光激发下,Gd2O2S:Dy3+荧光粉的主次发射峰分别位于579和488nm,分别归属于Dy3+的4F9/2→6 H13/2和4F9/2→6 H15/2跃迁,这两个跃迁均具有e单指数衰减行为。Dy3+的猝灭摩尔分数是1%,(Gd0.99,Dy0.01)2O2S荧光粉的色坐标和色温分别为(0.308,0.379,0.313)和6 464K。     

Fe/Al_2O_3纳米复合材料的结构和磁性

采用溶胶-凝胶法制备了复合材料Fe2O3/Al2O3,将其在氢气中还原得到了纳米复合材料Fe/Al2O3。利用X-ray衍射、Mssbauer效应和振动样品磁强计对样品的结构和性质进行了研究,结果表明,Fe2O3含量对样品的还原过程及结构和性质有明显的影响。随Fe2O3含量的增加,还原后样品中α-Fe的晶粒尺寸变大,样品的比饱和磁化强度增加,矫顽力减小。Mssbauer效应结果显示,在一些样品中存在超顺磁现象和FeAl2O4相。     

从铅阳极泥中制备纳米三氧化二锑粉体的研究

以铅电解精炼过程中的副产物——铅阳极为原料，通过加入碳粉，使铅阳极泥中的高价锑还原成三氧化二锑；在低压下，用直接蒸发冷凝的方法制备了纳米三氧化二锑。此方法无需对铅阳极泥中所含其它成份进行分离，生产成本低。经XRD分析，产品为立方晶型三氧化二锑。SEM分析表明，产品为球形；粒度分布测定表明：平均粒度为66nm，标准差（GSD）为1．67，粒度分布均匀；化学分析表明，产品中所舍三氧化二锑大于97．5％。     

Effect of TiB2 content on resistance to sodium penetration of TiB2／C cathode composites for aluminium electrolysis

TiB2/C cathode composites with various contents of TiB2 were prepared and their characterizations were observed and compared. The expansion of samples due to sodium and bath penetration was tested with a modified laboratory Rapoport apparatus and the appearances of the cut sections of specimens after electrolysis were studied.The results show that the mass of TiB2/C cathode composites with mass fraction of TiB2 less than 70% appreciably increases, but that of the composites with mass fraction of TiB2 more than 70% decreases slightly after being baked.The resistance to sodium and bath penetration of TiB2/C cathode composites increases with the increase of TiB2 content, especially in the composites with high TiB2 content. TiB2/C cathode composites have high resistance to the penetration of sodium and bath as well as good wettability by molten aluminum, and keep integrality and have little change of appearance after electrolysis, which indicates that TiB2/C cathode composites can be used as inert wettable cathode for aluminum electrolysis.