电沉积Ni81.32Mo18.68非晶/纳米晶镀层的晶化动力学

在碱式碳酸镍为主的盐溶液中用电沉积法制备出含Mo原子分数为18.68%的Ni-Mo合金镀层. X射线衍射(XRD)表明该镀层为非晶/纳米晶混合结构; 用差示扫描量热法(DSC)对这种非晶/纳米晶混合结构的合金进行了晶化动力学研究, 测得其晶化激活能(E)为3.84×105 kJ·mol-1; 晶化开始温度约为440 ℃, 与非晶态结构Ni-Mo合金镀层相比, 晶化温度提高了约13 ℃. 热处理过程发现, 非晶/纳米晶混合结构镀层中少量纳米晶的存在阻止了非晶态相转变的可能性, 提高了混合结构镀层的热稳定性和晶化温度; 镀层在450 ℃热处理过程中有新相产生, 其不仅提高了镀层的密实度, 同时也阻止了非晶态相的转变, 提高了镀层的热稳定性.     

电沉积Ni81.32Mo18.68非晶/纳米晶镀层的晶化动力学

在碱式碳酸镍为主的盐溶液中用电沉积法制备出含Mo原子分数为18.68%的Ni-Mo合金镀层.X射线衍射(XRD)表明该镀层为非晶/纳米晶混合结构;用差示扫描量热法(DSC)对这种非晶/纳米晶混合结构的合金进行了晶化动力学研究,测得其晶化激活能(E)为3.84x105 kJ·mol-1;晶化开始温度约为440℃,与非晶态结构Ni-Mo合金镀层相比,晶化温度提高了约13℃.热处理过程发现,非晶/纳米晶混合结构镀层中少量纳米晶的存在阻止了非晶态相转变的可能性,提高了混合结构镀层的热稳定性和晶化温度;镀层在450℃热处理过程中有新相产生,其不仅提高了镀层的密实度,同时也阻止了非晶态相的转变,提高了镀层的热稳定性.     

电沉积纳米锌层的研究

采用XRD研究和场发射电镜(FEG＿TEM)电沉积锌镀层纳米改性,分别观察并分析纳米镀锌层的结晶形态及其晶粒尺寸,根据镀层极化曲线和中性盐雾试验测定,结果表明,纳米镀锌层的抗腐蚀性能优于其它镀层.     

(110)晶面全择优取向Cu镀层的制备及其条件优化

研究了添加剂聚乙二醇(PEG)、氯离子(Cl－)和电流密度对Cu的电沉积过程的影响, 着重探讨了制备(110)晶面全择优取向Cu镀层的电沉积条件及其形成机理. 循环伏安(CV)结果表明, PEG阻化Cu的电沉积, Cl－加快Cu的电沉积速率. XRD实验结果表明, PEG和Cl－在一定浓度范围有利于(110)晶面择优取向; 这两种不同特性的添加剂的协同作用可以制得(110)晶面全择优取向的较薄的Cu镀层; 所制备的全择优Cu镀层较稳定. 全择优取向Cu镀层形成的机理在于PEG和Cl－吸附过程联合起作用, 在不同晶粒的不同晶面进行选择吸附, 改变了晶面的生长速率及晶粒的快生长方向.     

氧化锌纳米棒/云母复合粉体的合成、表征及红外发射性能

采用液相沉积法制备了氧化锌(ZnO)纳米棒负载云母复合粉体,其合成工艺分为:(1)云母粉体表面沉积ZnO纳米粒子,并经煅烧制得表面晶种化的云母粉体;(2)以七水硫酸锌(ZnSO4·7H2O)为前驱体,乙醇胺和氨水为络合剂,制得液相沉积前驱体溶液,并在晶种化的云母粉体表面沉积ZnO纳米棒。利用X-射线衍射(XRD)、ζ电位仪、扫描电子显微镜(SEM)以及红外发射率测试仪对氧化锌/云母复合粉体进行了测试与表征。结果表明,云母分散于乙醇水体积比为1∶1的混合溶液中,其表面带负电(-37 mV),而ZnO粒子表面则带正电(16 mV);两种粒子混合时,可通过静电引力实现ZnO纳米粒子在云母表面沉积;随着云母表面ZnO纳米棒沉积密度的增大,复合粉体在8~14μm波段内的红外发射率逐渐增大,从0.800增加至0.863;对比棒状ZnO球体,结构单元聚集状态的变化对最终红外发射性能的影响不大。     

三维多孔Sn-Zn合金电极助力Zn的均匀沉积/剥离

通过在化学镀构建的三维多孔铜上电沉积锡-锌(Sn-Zn)合金, 构筑了孔径为5 μm左右的三维多孔 Sn-Zn合金电极(3D Sn-Zn), 对其形貌、 结构和性能进行了表征和测定. 结果表明, 该电极拥有高稳定性和适宜孔径的三维多孔结构, 可降低局部电流密度, 提供均匀的电场分布, 缓解了由于锌的不均匀生长而造成的粗大枝晶; 合金镀层中的Sn元素不仅可以增大析氢过电位, 增强电极的防腐蚀性能, 还可降低锌的形核势垒, 为锌的沉积提供丰富的形核位点, 促进锌在电极表面的均匀沉积, 减少枝晶的形成. 采用3D Sn-Zn电极组装的对称电池, 在0.5 mA/cm² 下可稳定循环超过1200 h, 电压滞后仅为21.3 mV; 而采用锌片(2D Zn)组装的对称电池电压滞后达到了99.2 mV, 且在循环300 h后开始出现剧烈的电压波动. 使用3D Sn-Zn电极组装的全电池在 1.8 A/g电流密度下可稳定循环2000次.     

一种简单组装纳米沸石粒子层的方法及其二次法成膜研究

使用一种简单、新颖的纳米沸石晶体自组装方法, 以γ-氨丙基三甲氧基硅烷(AP-TMS)为偶联剂, 成功地实现了纳米A型沸石粒子在多孔不锈钢、陶瓷以及单晶硅表面的沉积组装, 获得了覆盖度高的续、均匀的沸石粒子层. 组装过程在合成釜内分为载体功能化和晶种化两步. 以该沸石粒子层为晶种二次法成膜, 形成了交织生长的连续、均匀的沸石膜, 并用含少量水的苯甲醛混合液评价了微型膜的渗透蒸发性能, 水-苯甲醛分离系数超过10 000以上. 考察了使用γ-氨丙基三甲氧基硅烷(AP-TMS)、γ-氯丙基三甲氧基硅烷(CP-TMS)和γ-巯丙基三甲氧基硅烷(SP-TMS)三种不同偶联剂时, 纳米A型沸石晶体在多孔不锈钢、陶瓷以及单晶硅表面的自组装效果. 研究发现, 使用CP-TMS作为偶联剂时, 只在不锈钢载体上形成较为连续的粒子层, 而使用SP-TMS作为偶联剂时, 在三种载体上纳米A型沸石粒子均不能沉积形成粒子层. 对偶联剂的作用和粒子组装机制进行了讨论和预测.     

1-4丁炔二醇和乙二胺对离子液体电沉积Cu的影响(英文)

研究了1-4丁炔二醇和乙二胺作为添加剂对在离子液体1-甲基-3-甲基咪唑三氟甲磺酸盐中电沉积Cu的影响。紫外可见光吸收光谱结果表明,当采用1-4丁炔二醇作为添加剂时,1-4丁炔二醇吸附在工作电极表面且未与溶液中的Cu2+形成配合物。扫描电镜测试结果表明由于1-4丁炔二醇与离子液体的正离子的竞争吸附使得Cu的沉积电势发生正移并使镀层表面更加均匀平整。当采用乙二胺作为添加剂时,紫外可见光吸收光谱和循环伏安测试结果表明乙二胺与溶液中的Cu2+离子形成带有正电荷的络合离子使得Cu的沉积电势发生正移,扫描电镜和原子力显微镜测试结果表明得到了更加均匀的镀层。当同时加入1-4丁炔二醇和乙二胺时,Cu的沉积电势仍然发生正移并得到具有纳米粒径的镀层。     

非晶态Ni-W/ZrO2复合镀层的制备、热处理及腐蚀行为

在镍钨合金电解液中, 通过搅拌使二氧化锆固体微粒悬浮, 电沉积制备Ni-W/ZrO2复合镀层. 研究结果表明, 二氧化锆粒子影响复合镀层的电沉积、表面形貌、结构、热处理过程和抗腐蚀性能; 与Ni-W合金的电沉积过程相比, 复合镀层中的W含量和电流效率均降低; 在400 ℃处理1 h后, 嵌入Ni-W本体中的ZrO2粒子脱落, W向镀层表面富集. 扫描电子显微镜(SEM)结果显示, 复合镀层呈现团粒状形态, 无裂纹. 差示扫描量热(DSC)分析结合X射线(XRD)衍射实验指出, Ni-W/ZrO2复合镀层为非晶态结构. 复合镀层的显微硬度较纳米晶Ni-W合金的高; 热处理后, 复合镀层的显微硬度和在3%氯化钠溶液中的抗腐蚀行为显著增强.     

非晶态Ni-W／ZrO2复合镀层的制备、热处理及腐蚀行为

在镍钨合金电解液中,通过搅拌使二氧化锆固体微粒悬浮,电沉积制备Ni-W/ZrO2复合镀层.研究结果表明,二氧化锆粒子影响复合镀层的电沉积、表面形貌、结构、热处理过程和抗腐蚀性能;与Ni-W合金的电沉积过程相比,复合镀层中的W含量和电流效率均降低;在400℃处理1 h后,嵌入Ni-W本体中的ZrO2粒子脱落,W向镀层表面富集.扫描电子显微镜(SEM)结果显示,复合镀层呈现团粒状形态,无裂纹.差示扫描量热(DSC)分析结合X射线(XRD)衍射实验指出,Ni-W/ZrO2复合镀层为非晶态结构.复合镀层的显微硬度较纳米晶Ni-W合金的高;热处理后,复合镀层的显微硬度和在3%氯化钠溶液中的抗腐蚀行为显著增强.     

Electrodeposition of nanocrystalline zinc from acidic sulfate solutions containing thiourea and benzalacetone as additives

Nanocrystalline zinc coatings were produced by pulse electrodeposition in acid sulfate bath containing thiourea and benzalacetone additives and characterized by X-ray diffraction and scanning electron microscopy techniques. The influence of benzalacetone concentration and pulse peak current density on the grain size and crystallographic orientation of zinc deposits was investigated. Zinc electrodeposited from additive-free solutions or with one of the two additives is not composed of nanosized crystals. The mixture additives of thiourea and benzalacetone give rise to the formation of particle-like nanocrystalline zinc with a (10ī1) random orientation. A change in peak current density from 2 to 1 A/cm² only increases the grain size from 60 to 62 nm.     

Influence of pulse parameters on nanocrystalline zinc coatings electrodeposited from acidic sulfate electrolyte

The influence of pulse electrodeposition parameters (i.e., current-on time, current-off time and peak current density) on the grain size and orientation of zinc deposits was investigated in acidic sulfate electrolyte. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses indicate that the pulse parameters play an important role in the grain refinement of nanocrystalline zinc coatings. As varying peak current density (1–2 A/cm²), current-on time (1–6 ms) and current-off time (4–18 ms), nanocrystalline zinc coatings are produced in the grain range 60 to 35 nm. The pulse parameters have a slight influence on the orientation of nanocrystalline zinc coatings. Published in Russian in Elektrokhimiya, 2009, vol. 45, No. 3, pp. 310–315. The article is published in the original.     

纳米光亮镀锌层的结构研究

用正电子湮没技术、X射线衍射技术和透射电子显微镜研究了氯化钾酸性纳米光亮镀锌层的晶体结构.结果表明,该纳米光亮镀锌层是一种介于晶态与非晶态之间的镀层结构,镀层中存在的有机物夹杂和渗氢以及纳米锌微晶中大量的界面原子使镀层具有很高的缺陷浓度,而且有机物夹杂和渗氢主要分布在纳米微晶的界面组元中.     

Nanostructural analysis of mirror-bright zinc coatings

The zinc coatings electrode posited from solution containing dextrin/salicyl aldehyde mixture are examined by the scanning tunneling microscopy (STM). It is shown that mirror brightness of these zinc deposits is associated with flat and mutually parallel hexagonal zinc crystals which are smooth at the atomic level. The mechanism of zinc electrodeposition with these additives is examined by the use of a possibility of STM soft-ware measurements based on root-mean-square roughness analysis of metal surfaces and known as scaling analysis. It is proposed that the zinc growth in the presence of these additives follows the Edwards-Wilkinson model. Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 10, pp. 1245–1251. The text was submitted by the authors in English.     

Electrochemical reduction of O2 in 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid containing Zn2+ cations: deposition of non-polar oriented ZnO nanocrystalline films

The influence of the Zn(2+) concentration and temperature on the electrochemical reduction of O(2) in a solution of zinc bis(trifluoromethanesulfonyl)imide (Zn(TFSI)(2)) salt in 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR(14)TFSI) ionic liquid is presented. ZnO nanocrystalline films were then electrodeposited, under enhanced O(2) reduction, at temperatures in the 75-150 °C range. Their morphology, chemical composition, structural and optical properties were analyzed. In contrast to the polar-oriented ZnO usually obtained from aqueous and conventional solvent based electrolytes, nanocrystalline films oriented along non-polar directions, (11 ?10) and (11 ?20), were obtained from this ionic liquid electrolyte. A significant content of carbon was detected in the films, pointing to the active participation and crucial effect of pyrrolidinium cation (and/or byproducts) during the electrodeposition. The films showed semiconducting behavior with an optical gap between 3.43 and 3.53 eV as measured by optical transmittance. Their room temperature photoluminescence spectra exhibited two different bands centered at ～3.4 and ～2.2 eV. The intensity ratio between both bands was found to depend on the deposition temperature. This work demonstrates the great potential of ionic liquids based electrolytes for the electrodeposition of ZnO nanocrystalline thin films with innovative microstructural and optoelectronic properties.     

铂修饰光阴极及其在纳晶太阳能电池中的应用

分别用真空镀膜法、热分解法和电化学法制备了铂金修饰导电玻璃,并以此作为光阴极组装了染料敏化纳晶TiO₂太阳能电池.用SEM观察了铂金修饰导电玻璃表面形貌,发现用真空镀膜法制备的铂金膜结构缺陷多、不均匀,存在较多的污点.用热分解法制备的铂金膜具有多孔状结构,但存在较多的有机物分解的残留物.用电镀法制备的铂金膜结构均匀、排列规则、缺陷少、污染少.测定了所制备铂金膜的电阻,结果表明由电镀法所制得的铂金膜电阻最小,用热解法和真空镀膜法制得的铂金膜电阻较大.测定了DSSC电池的光电性能,发现用电镀法制得的铂金膜的催化性能最好,大大提高了DSSC电池的性能;其次是热分解法,由真空镀膜法制备的铂金膜对电池的性能没有多大改善.     

Effects of organic additives on zinc electrodeposition at iron electrodes studied by EQCM and in situ STM

Effects of organic additives, such as benzoic acid (BA) and poly(ethylene glycol)s (PEGs), on the initial stage of the zinc electrodeposition have been investigated at iron electrodes using cyclic voltammetry, electrochemical quartz crystal microbalance measurements and in situ electrochemical scanning tunneling microscopy in an acidic zinc chloride solution in efforts to gain a molecular-level understanding of their roles. BA is adsorbed strongly at the sites of more negative potentials on the electrode, although it is randomly adsorbed on the iron surface at around an open circuit potential. Its role seems to control the deposition rate at the dendritic sites by blocking the active surface via adsorption. On the contrary, PEGs are adsorbed more or less evenly with a well-ordered structure on the iron surface and appear to desorb in the underpotential deposition region of zinc ions, which helps inhibit proton reduction by effectively blocking the electrode surface.     

Electrodeposition of lustrous zinc coatings from sulfate electrolyte

The electrodeposition of lustrous zinc coatings from a sulfate electrolyte containing ZnSO₄, Na₂SO₄, buffer additives, and 2-butyne-1,4 diol was studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 8, 2004, pp. 1284–1288.Original Russian Text Copyright © 2004 by Medvedev, Makrushin.     

Electrodeposition of Al,Zn, and Pt on silver-coated textile fibres from ionic liquids

In the present paper, we report on the electrodeposition of aluminium, zinc and platinum on silver-coated textile fibres from ionic liquids. For electrodeposition of Al, the 60:40 mol% mixture of AlCl₃/1-ethyl-3-methylimidazolium chloride ([EMIm]Cl) and 1.7 M AlCl₃ in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([Py_1,4]TFSA) were employed. It was observed that microcrystalline aluminium was electrodeposited on the textile fibres in 60:40 mol% AlCl₃/[EMIm]Cl. The deposited Al layers either on single fibres or on textile assemblies are well adherent and uniform. An adherent, homogeneous and nanocrystalline Al layer was obtained on the silver-coated textile samples from 1.7 M AlCl₃/[Py_1,4]TFSA at 75 °C. The obtained Al layers from 60:40 mol% AlCl₃/[EMIm]Cl on the textile fibres exhibit a good corrosion resistance in an aqueous iodide/iodine electrolyte. Furthermore, we obtain Al microtubes from the investigated ionic liquids after dissolving the textile fibres. In addition, zinc electrodeposition was carried out on the textile samples from 60:40 mol% ZnCl₂/[EMIm]Cl at 80 °C. The electrodeposition of platinum on the textiles was done from 50 mM PtCl₂ in 1-butyl-1-methylpyrrolidinium dicyanamide ([Py_1,4]DCA).     

Influence of pulse plating conditions on the structure and properties of pure and composite nickel nanocrystalline coatings

An additive-free Watts type bath containing micron- and nano-SiC particles (1 μm and 20 nm respectively), as well as ultrafine-WC particles (200 nm), was used for the production of pure Ni and nickel matrix composite electrocoatings under both direct and pulse current conditions. Moreover, nickel nanocrystalline deposits were obtained from a Watts type bath containing small amounts of 2-butyne-1,4-diol, in order to investigate the combined advantages of additives and pulse technique on the properties of the deposits. The influence of the variable electrolysis parameters, the particle size and the organic additive concentration on the surface morphology, the structure and properties of the deposits were discussed. It has been proved that the application of pulse electrodeposition affects drastically the structural characteristics and properties of the deposits and under well-defined conditions could lead to the preparation of nanostructured materials with improved mechanical properties. Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 6, pp. 802–811. The text was submitted by the authors in English.