表面改性低银铅钙合金阳极工业化试验

对自主研发的低银铅钙合金阳极进行表面改性,于某电解锌厂进行工业化对比试验,并对电积锌的重量和质量进行分析。试验结果表明：经表面改性后的低银铅钙合金阳极电解过程中锌产量明显高于未经处理的阳极,且电积锌更加致密。     

饱和NaCl溶液中钌-钛阳极失效机理研究

采用电化学方法和表面物理方法研究了饱和NaCl溶液中RuO_2-TiO_2阳极(DSA)失去活性的机理.在不同的电解阶段所进行的研究表明:DSA电极的失活是一渐变过程.在此过程中,电极的RuO_2-TiO_2涂层的组成与结构不断变化.而组分Ru的溶解则是导致电极失效的主要原因.研究还表明:Ti组份溶解产生的水化物覆盖在阳极表面以及涂层的裂纹腐蚀也加速了电极的失效.研究中未发现明显的结果足以证实DSA电极发生了钝化.     

IrO_2-SiO_2涂层钛阳极的失效行为研究

为探讨氧化物涂层阳极的失效原因,采用热分解法在不同焙烧温度下制备了60%IrO2-40%SiO2/Ti氧化物阳极,利用扫描电子显微镜(SEM)、能谱分析(EDX)和循环伏安测试(CV)分析了阳极在硫酸溶液的强化电解过程前后表面形貌、涂层组成和电化学性能的变化。结果表明,IrO2-SiO2涂层钛阳极失效的主要原因是钛基体和涂层之间形成了不导电的TiO2层。在强化电解过程中,低焙烧温度制备的阳极活性组分的电化学溶解和涂层的机械脱落促进TiO2层的生长。高焙烧温度制备的阳极中已生成一定量的TiO2,在电解时加速电极的失效。600℃焙烧温度下制备的电极的强化寿命最高。     

铝/铅-碳化钨-氧化铈复合电极的耐腐蚀性能

以1060铝为基体,在由Pb(CH3COO)2 220 g/L,HBF4170 g/L,H3BO314g/L,明胶2g/L,十六烷基三甲基溴化铵0.5～1.0 g/L组成的基础镀液中,电沉积制得Pb-WC-CeO2复合镀层.通过测定其作阳极电解锌时的塔菲尔曲线,研究了WC和CeO2颗粒的质量浓度、电流密度、温度及搅拌速...     

新型不锈钢基PbO2-WC-ZrO2复合电极材料的研制

在不锈钢基体上电沉积PbO2-WC-ZrO2复合镀层。研究了电沉积工艺参数对复合镀层的影响。确定了最佳工艺规范:J=3A/dm2,t=2.5h,θ=25°C,ρ(ZrO2)=40～50g/L,ρ(WC)=30～40g/L。获得了镀层结构均匀、致密,w(ZrO2)=4%～6%,w(WC)=7%～10%的PbO2-ZrO2-WC复合惰性阳极材料。将该阳极材料应用于电积锌其析氧电位为1700mV。新型PbO2-ZrO2-WC复合电极材料满足了惰性阳极材料的要求。     

锌电积用惰性阳极材料的研究现状及发展趋势

综述了锌电积用惰性阳极材料的研究现状,着重阐述了锌电积用惰性阳极材料研究的主要改进方式:新型基体的使用,脉冲电镀和复合电镀技术的运用,梯度惰性阳极的制备,以及表面层掺杂.展望了未来锌电积用惰性阳极材料的发展趋势.     

Pb-Ag-SiC阳极在锌电积中的性能

为制备一种具有更高耐腐蚀性,高催化活性的锌电积阳极,在传统Pb-Ag[w(Ag)=0.25%]阳极表面用SiC进行活化处理得到Pb-Ag-SiC阳极。并通过电化学测试分析了Pb-Ag-SiC阳极在锌电积过程中的性能。阳极极化曲线和塔菲尔曲线的数据分析显示Pb-Ag-SiC阳极与传统Pb-Ag阳极相比具有更好的耐腐蚀性,阳极极化曲线和循环伏安曲线数据分析显示Pb-Ag-SiC阳极与传统Pb-Ag阳极相比具有更高的电催化活性。     

锌电积用惰性阳极材料的研究现状

阐述了国内外铅及铅合金阳极、钛基二氧化铅阳极等锌电积用惰性阳极材料的研究现状,并对未来锌电积用惰性阳极材料的发展趋势进行了展望.     

超声强化电氧化法湿法分解辉钼矿

针对电氧化法湿法分解辉钼精矿电流效率不高、能耗较大的缺点,引入超声波强化浸出过程. 超声场可显著减少电极表面的覆盖物,提高电解电流,促进MoS2分解. 电解时超声波作用方式为每隔15 min发射3 min,在电解电压3.5 V、矿浆液固比10、阳极电流密度700 A/m2、矿浆初始pH 10、电极间距13 mm的条件下,电解电流效率大于100%.     

铝基β-PbO2-WC-TiO2复合电极材料的研制

用电沉积法在铝/导电涂层/α-PbO2上制备了[3-PbO2-WC-TiO2复合电极材料,最佳工艺条件为:Pb(NO3)2250g/L,HNO3 15 g/L,WC 40g/L,TiO2 50g/L,温度50℃,电流密度3.0A/dm2,电沉积时间5 h.与传统Pb-1%Ag阳极相比,该新型复合电极可使电积锌时的槽电压降低,电流效率提高.     

Electrocatalytic oxidation of methanol on Cu modified polyaniline electrode in alkaline medium

Electrolytically deposited Cu on polyaniline film covered Pt substrate (Cu/PANI/Pt) is used as anode for the electrooxidation of methanol in alkaline medium. The electrochemical behavior and electrocatalytic activity of the electrode were characterized using cyclic voltammetry, impedance spectroscopy, chronomethods, rotating disc voltammetry and polarization studies. The morphology and composition of the modified film were obtained using SEM and EDAX techniques. The electrooxidation of methanol in NaOH is found to be more efficient on Cu/PANI/Pt than on bare Cu (Cu), electrodeposited Cu on Cu (Cu/Cu) and electrodeposited Cu on Pt (Cu/Pt) substrates. Partial chemical displacement of dispersed Cu on PANI with Pt or Pd further improved its performance towards methanol oxidation.     

Influence of microstructure on the capacitive performance of polyaniline/carbon nanotube array composite electrodes

A series of polyaniline/carbon nanotube array (PANI/CNTA) composite electrodes are prepared by electrodeposition of PANI onto CNTA electrodes by 100-500 cyclic voltammetry (CV) cycles, with the aim to investigate the influence of microstructure on the capacitive performance of PANI/CNTA composites. The morphology of PANI/CNTA composites varies remarkably with the CV cycles of electrodeposition. The optimum condition is obtained for the PANI/CNTA composite prepared by 100 CV cycles, corresponding to the highest specific capacitance, best rate performance, and longest cycle life, which are much better than that of activated carbon fiber cloth, the PANI electrodeposited on stainless steel substrate, and CNTA electrode. The forming process of the microstructure and its influence on the capacitive performance of PANI/CNTA composites are presented in this paper.     

石墨烯/聚苯胺复合阳极的制备及在MFC中的应用

采用化学氧化还原法制备高纯度石墨烯（GR）,利用电化学修饰法得到石墨烯/聚苯胺（GR/PANI）膜阳极,采用红外光谱（FI-IR）、X射线衍射（XRD）、场发射扫描电镜（FESEM）对所制备复合电极进行了表征,采用循环伏安法（CV）、交流阻抗法（EIS）考察了复合电极的电化学性能。将GR/PANI膜阳极应用于固定床微生物燃料电池（MFC）,考察了电池的产电性能。均匀地附着在石墨烯表面,GR/PANI膜电极具有良好可逆性,其电阻小、导电性良好。GR/PANI膜阳极应用于MFC,最大功率密度和开路电压分别为230.2 mW·m^-2和834.6 mV,比未修饰阳极的最大功率密度和开路电压分别提高了110.6%和34.8%,GR/PANI膜阳极的表观内阻也由未修饰阳极的843.2Ω降低为469.4 Ω,且电池启动时间大大缩短,产电稳定性增强。结果表明,GR/PANI复合物是一种优良的电极材料,GR/PANI膜阳极MFC具有良好的产电性能。     

硫酸溶液中Ti/SnO2+Sb2O3/PbO2阳极在电解过程中的结构变化及失活行为

引　言有机电化学合成以电子作为试剂代替重金属盐氧化剂和严重污染环境的硫化碱等化学还原剂 ,合成过程可在常压、常温或较低温度下进行 ,因此是2 1世纪“绿色化学”研究开发的一个重要领域 .在有机电化学合成的工业开发中 ,得到具有优良性能的电极材料是电有机合成工业化中需     

Electrical conductivity and mechanical properties of polyaniline/natural rubber composite fibers

Electrically conducting elastomer fibers based on natural rubber (NR) and up to 10% w/w polyaniline (PANI) in its emeraldine base (EB) form were fabricated by a wet spinning process. The resulting fibers at various PANI contents were doped by immersion in aqueous HCl solution, which converted the PANI to the electrically conductive emeraldine salt (ES) form. The morphology of the composite fibers was studied by scanning electron microscopy (SEM). PANI particles were inhomogeneously distributed in the NR matrix. The electrical conductivity of the fibers increased with the increasing PANI‐ES content and leveled off at a value of around 10^?3 S/cm at PANI‐ES concentration of 5% w/w. The fibers retained most of their elasticity upon doping, while the tenacity was somewhat reduced. Gratifyingly, the electrical conductivity of the new elastomer fibers was preserved upon elongational deformation, even if strains as large as 600% were applied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Thermal dynamic processing of polyaniline with dodecylbenzene sulfonic acid

To attain an intrinsically conductive and processible polymer, polyaniline (PANI)/dodecylbenzene sulfonic acid (DBSA) blends of several compositions were processed at various elevated temperatures in a Brabender plastograph. The blends' temperatures during processing, as affected by the blends' composition and initial process temperature, were monitored. Accordingly, the process includes the following main stages: heating the blend, exothermic PANI-DBSA doping reaction accompanied by a paste to a solidlike transition, and plasticization of the resulting PANI/DBSA complex by the excess DBSA. Composition analysis of the process products sampled at the various stages showed that the initial blends, prior to their thermal processing, already consisted of partially doped PANI particles, having a core/shell structure; the core consists of PANI_base and the shell of PANI(DBSA)_0.32 complex. In addition, at the paste-to-solidlike transition, the doping reaction is completed; further mixing does not affect the complex composition, but results in conductivity reduction. The morphology of the blends sampled at the various processing stages was studied by electron microscopy. From the conductivity and processibility point of view, optimal PANI/DBSA blend composition and processing temperature were identified. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2199–2208, 1997     

铜镉渣酸浸液旋流电积提铜对比分析

针对湿法炼锌副产物铜镉渣氧化酸浸液成分特点,采用旋流电积工艺回收其中的金属铜。研究了不同旋流电积工艺对电积过程中相关技术参数及杂质离子迁移规律的影响,并对不同电积工艺的优缺点进行了对比分析。结果表明：一段旋流电积可使溶液中铜离子浓度从44.14g/L降低到1.42g/L,而分段旋流电积可使溶液中终点铜离子浓度从1.42g/L继续降低至0.5g/L以下,溶液中铜离子在阴极上的电沉积率可从96.78%提高到99.20%,阴极电流效率可从90.52%提高到98.49%。当溶液中铜离子浓度降低到10g/L左右及以下时,杂质离子在阴极与铜发生共沉积现象逐渐明显,分段旋流电积得到的阴极铜产品光泽度及形貌质量较一段电积更好。与一段旋流电积工艺相比,分段旋流电积工艺具有电流效率高、能耗低、产品质量好等优点。     

Effects of WC addition on the erosion behavior of high-velocity oxygen fuel sprayed AlCoCrFeNi high-entropy alloy coatings

In this study, AlCoCrFeNi (H1), AlCoCrFeNi+25 wt%WC-10Co (H2), and AlCoCrFeNi+50 wt%WC-10Co (H3) high-entropy alloy (HEA)/tungsten carbide (WC) composite coatings were deposited onto 316 stainless steel substrates by applying the high-velocity oxygen fuel spraying technology. The phase, layered microstructure, microhardness, and erosion behavior of the coatings were analyzed by performing X-ray diffractometry, scanning electron microscope/energy dispersive spectrometry, Vickers microhardness testing, and slurry erosion testing. The effects of WC addition on the erosion behavior and mechanism of the coatings at different flow velocities were investigated. The deposited coatings were compacted and adhered well to the substrate. The AlCoCrFeNi coating was composed of BCC and FCC phases. The porosity of the H1, H2 and H3 coatings were 0.24%, 0.33% and 0.45%, respectively, and were less than 1%. The microhardness of the HEA/WC composite coatings was positively correlated with WC content. The volume loss and rate of volume loss of the coatings decreased with the addition of WC. The erosion mechanism of the AlCoCrFeNi coating was typical ductile wear, with a small amount of interlayer peeling. Furrows, cuttings, and plastic deformation caused by low grazing angles contributed to the failure of the AlCoCrFeNi coating. In the HEA/WC composite coatings, WC protected the HEA from more severe plastic deformation by second-phase strengthening, and the main erosion mechanism of WC was gradual brittle detachment caused by high-grazing-angle erosion in which craters, cracks, and massive spalling were responsible for the erosion process.     

Effect of WC mass fraction on the microstructure and friction properties of WC/Ni60 laser cladding layer of brake discs

Laser cladding Ni-based composite coating has significant advantages in improving the surface properties of QT500-7. WC/Ni60 composite powders with different WC mass fractions were cladded on the surface of QT500-7. The microstructure and tribological properties of the cladding layer were studied on the basis of optimizing process parameters. The study found that the surface morphology appeared bright white area, bright gray area, dark gray area, and black area. With the increase of WC mass fraction, the types of the cladding layer from bottom to top are gradually enriched, and the types of W-containing carbides produced are also increasing. Meanwhile, the hardness, corrosion resistance, and tribological properties are significantly improved.     

Effect of sub-layer temperature during HFCVD process on morphology and corrosion behavior of tungsten carbide coating

WC coating was deposited on the polished and cleaned 316L stainless steel by Hot Filament Chemical Vapor Deposition (HFCVD) technique at 400°C and 500°C. Field Emission Gun Scanning Electron Microscope (FEG-SEM) was used to study the corrosion morphology of the WC coatings. Energy dispersive spectroscopy (EDS) was used to analyze the chemical composition of the coatings. Coating porosity was measured by immersion in water. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were used to study the corrosion behavior of the coating in the solution of 1 mol/L H₂SO₄. Results showed that the WC coatings have a honeycomb microstructure where its porosity was increased at higher temperature of the sub-layer. Also, the WC coating significantly increases the corrosion resistance of 316L stainless steel. And increasing the sub-layer temperature in the HFCVD method reduces the corrosion resistance of the WC coating. Corrosion morphology was indicative of pitting corrosion of the WC coating.