共查询到18条相似文献,搜索用时 656 毫秒
1.
2.
3.
苯基硫脲对6063铝合金表面化学镀镍层电化学性能的影响 总被引:1,自引:0,他引:1
采用极化曲线及交流阻抗技术研究了不同浓度的苯基硫脲(稳定剂)对6063铝合金表面镍层的电化学性能的影响。极化曲线结果表明,镀液中加入苯基硫脲后的镀镍层比基体铝合金具有更正的腐蚀电位(Ecorr)、小孔(点)腐蚀电位(Epit)及更低的腐蚀电流(icorr)。为了解释镍层的电化学性能,建立了等效电路模型,并拟合出了表面电阻(Rcoat)及电容(Qcoat),电荷转移电阻(Rct)及双电层电容(Qdl)等腐蚀参数。交流阻抗研究结果表明,加入6~10 mg/L苯基硫脲后的镀镍层具有较高的表面电阻(Rcoat)、电荷转移电阻(Rct)及较低的表面电容与双电层电容(Qcoat与Qdl)。镀镍层的交流阻抗谱及极化曲线的测试结果表明,制备的镀层具有较好的耐腐蚀性能,并且相互吻合。采用扫描电子显微镜及能谱对化学镀镍层的表面形貌及成份进行了分析。结果显示,表面处于较均匀的状态,磷元素的质量分数超过10%。 相似文献
4.
5.
化学镀镍—高磷合金的微观结构及晶化行为研究 总被引:12,自引:0,他引:12
采用混合络合剂在酸性体系中进行化学镀镍-高磷合金,并用原子力显微镜(AFM),透射电镜(TEM)、差热分析(DSC)、X射线衍射(XRD)等技术研究所得到的化学镀镍-高磷合金的微观结构和晶化行为。结果表明,化学镀镍-高磷合金具有胞状结构的微观形貌,镀态时呈典型的非晶态结构,300℃以下对热非常。镀层在343.8℃开始晶化,400℃时完全转化成亚稳用Ni5P2,440.4 ℃,时进一步转变成稳定的Ni和Ni3P相其晶化行为同从碱性乙二胺镀液中得到的高磷化学镀镍层有明显的差异。 相似文献
6.
在强碱性溶液中低电压低电流条件下在W基底上经阳极氧化得到致密WO3层,而后在酸性条件下在WO3表面经光辅助电化学还原沉积镍,所获得的复合电极具有优异的光电化学氧化水的活性和稳定性.SEM,EDX,XPS和TEM等表征表明复合电极中具有体心立方结构的W基底经阳极氧化形成了具有单斜结构的WO3层,表面修饰的镍物种以Ni(OH)2形式存在.光电化学实验表明WO3层对可见光具有良好的光响应,表面修饰镍后,光电氧化水的起始电位显著降低,电极的稳定性也得以提高. 相似文献
7.
采用多孔阳极氧化铝模板(AAO)结合直流电化学沉积法, 通过一种新的两步法合成一维铜(核)-镍(壳)纳米结构. 首先制备铜纳米线, 然后对AAO进行扩孔, 利用铜纳米线和AAO孔壁之间的间隙,沉积镍纳米线/纳米管. 通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对其结构和形貌进行表征分析, 所得结果验证了这种方法的可行性. 以腺嘌呤为探针分子研究此种纳米结构的表面增强拉曼散射(SERS)效应, 结果表明, 这种一维纳米材料是一种潜在的SERS活性基底, 拓宽了过渡金属在SERS中的应用. 相似文献
8.
9.
天然高分子壳聚糖(CS)与聚乙烯醇(PVA)共混后存在强烈的氢键作用能够促进二者相容,形成互穿网络(IPN)结构的CS/PVA二元共混膜。 通过傅里叶红外(FT-IR)和强力测试对共混膜结构及拉伸强力性能进行了表征。 利用掺杂少量氯化钯的CS与PVA共混液的成膜性能,在涤纶织物表面预制一层具有自催化活性的薄膜,并对经过处理后的涤纶织物进行化学镀镍研究。 采用扫描电子显微镜(SEM)、热重分析(TG)、电磁屏蔽效能测试和水洗牢度测试,分别对织物表面形貌、热稳定性、电磁屏蔽性能和结合牢度进行测试。 结果表明,CS与PVA共混液处理后的涤纶织物,经化学镀镍能获得表面均匀致密、导电性优良、与织物结合力良好的镀层。 相似文献
10.
p型硅片上激光诱导局部化学沉镍 总被引:1,自引:0,他引:1
在以肼为还原剂的碱性化学镀镍溶液中实现p型单晶硅片上激光诱导微区化学沉镍,讨论了激光能量、照射时间对镍沉积层的影响,使用SEM、AES和RBS等方面对镀层的形貌、性质进行了分析。激光诱导化学沉积得到了均匀致密、结合力好的纯镍镀层。镀层与基体间具有Schottky接触特性。 相似文献
11.
Electroless Deposition of Nickel Nanowire and Nanotube Arrays as Supports for Pt-Pd Catalyst for Ethanol Electrooxidation 下载免费PDF全文
Nickel nanowire and nanotube arrays as supports for Pt-Pd catalyst were prepared by electroless deposition with anodic aluminum oxide template. Pt-Pd composite catalyst was deposited on the arrays by displacement reaction. SEM images show that the nickel nanowires have an average diameter of 100 nm and the nickel nanotubes have an average inner diameter of 200 nm. EDS scanning reveals that elemental Pt and Pd disperse uniformly on the arrays. Cyclic voltammetry study indicates that the nickel nanotube array loaded with Pt-Pd possesses a higher electrochemical activity for ethanol oxidation than the nickel nanowire array with Pt-Pd. 相似文献
12.
用重量法测定了卤离子对化学沉积镍速度的影响.并借助电化学方法研究了卤离子对镍的化学沉积过程的极化曲线和稳定电位的影响.探讨了卤离子加速和稳定化学沉积镍的机理 相似文献
13.
Ming‐Qiu Wang Jun Yan Shi‐Guo Du Sheng‐Hao Meng 《Surface and interface analysis : SIA》2013,45(13):1899-1902
A novel and facile activation process for electroless nickel deposition was developed. The semi‐interpenetrating polymer network hydrogel biofilm was used to functionalize the inert poly(vinyl chloride) (PVC) surface, and then Cu nanoparticles, which can initial the subsequent electroless nickel deposition successfully seeded on the functionalized‐PVC surface. The samples were characterized by scanning electron microscopy, X‐ray photoelectron spectroscopy, X‐ray diffraction, and transmission electron microscopy. The results show that the hydrogel film provided the PVC surface with amino groups and Cu nanoparticles of 20–50 nm in size could be functioned as the catalytic nuclei for the subsequent electroless metal deposition on PVC plastic. It can be concluded that the novel Cu activation was effective for the nickel deposition on PVC surface, because of more chemisorption sites for Cu nanoparticles generated on PVC surface. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
14.
研究无电镀镍镀层加入钻石微粒或PTFE微粒的均匀分散相 ,所得之复合镀层在 3.5%NaCl水溶液中的电化学分析 ,浸渍试验与临雾试验 ,皆显示复合镀层之耐蚀性低于不含微粒之无电镀镍镀层 .由SEM ,AES ,XRD ,EPMA分析镀层微观组成 ,复合镀层之磷含量分布呈差异性变化 ,磷量较多区域为微阴极 ,磷量较少区域为微阳极 ,复合镀层存在众多微电池组合 ,容易引起电化学伽凡尼腐蚀 ,造成复合镀层耐蚀性降低 ,当镀层微粒含量增加时 ,微粒的惰性保护效果超过微电池效应 ,复合镀层的耐蚀性质才能提高 相似文献
15.
酸性化学镀镍中次亚磷酸钠阳极氧化行为的研究 总被引:3,自引:0,他引:3
采用线性电位扫描和交流阻抗法研究了酸性化学镀镍过程中还原剂次亚磷酸钠的阳极氧化行为。结果表明,次亚磷酸钠的氧化是一个复杂的电化学过程,其阳极氧化行为受本身浓度、溶液温度、阳极扫描速度以及Ni^2+的影响,在其氧化反应之前可能存在异相界面转化步骤,该步骤成为整个氧化过程的控制步骤。 相似文献
16.
G. Veera Babu M. Palaniappa M. Jayalakshmi K. Balasubramanian 《Journal of Solid State Electrochemistry》2007,11(12):1705-1712
Graphite particles were coated with Ni–P by electroless deposition using a conventional bath consisting of a nickel salt and
hypophosphite. After 15 min of electroless deposition, the graphite particles were covered with 10 wt% nickel and 0.7–1.0 wt%
phosphorus as analysed by wet chemical method. Surface morphology was studied by scanning electron microscopy (SEM). Electrochemical
characterisation for the catalytic activity was done by cyclic voltammetry. Pure Ni powder and electroless Ni–P coated on
graphite were used as catalysts for the electro-oxidation of dextrose (1.8 × 10−3 to 4.5 × 10−3 M) in 0.1 M KOH solution. Comparative studies revealed that electroless Ni–P coated on graphite particles acted as a better
catalyst than pure Ni powder for catalytic reaction. 相似文献
17.
利用循环伏安法和红外漫反射光谱法研究化学镀镍过程中丙酸的作用机理. 不同丙酸浓度下的循环伏安曲线表明,丙酸能同时促进Ni2+的还原和H2PO-2的氧化.根据丙酸分别与NaH2PO2和NiSO4共存时镍基体上吸附物的红外漫反射光谱变化,推断丙酸是通过与NaH2PO2和Ni2+形成表面络合物来促进化学沉积的. 丙酸能与NaH2PO2形成分子间氢键,促使P-H键断裂并生成·PHO-2中间物,从而提高H2PO-2的氧化速度; 同时,丙酸以其-OCO-官能团与Ni2+生成桥式配合物,有利于加速Ni2+的沉积. H2PO-2氧化速度的提高有助于磷的沉积,从而增大了化学镀层中的磷含量. 相似文献
18.
Evaluation of the corrosion resistance of electroless Ni-P and Ni-P composite coatings by electrochemical impedance spectroscopy 总被引:4,自引:0,他引:4
J. Balaraju T. Sankara Narayanan S. Seshadri 《Journal of Solid State Electrochemistry》2001,5(5):334-338
Electroless Ni-P composite coatings have gained a good deal of popularity and acceptance in recent years as they provide
considerable improvement of desirable qualities such as hardness, wear, abrasion resistance, etc. The disagreement among researchers
on the corrosion behaviour of these coatings warrants a thorough investigation. Among the various techniques available for
the determination of corrosion resistance, electrochemical impedance spectroscopy (EIS) is considered to be superior as it
provides not only an assessment of the corrosion resistance of different deposits but also enables the mechanistic pathway
by which the deposits become corroded to be determined. The present investigation focuses on the evaluation of the corrosion
resistance of electroless Ni-P and Ni-P-Si3N4, Ni-P-CeO2 and Ni-P-TiO2 composite coatings produced using an acidic hypophosphite-reduced electroless nickel bath, using EIS. The study makes evident
that the same fundamental reaction is occurring on all the coatings of the present study but over a different effective area
in each case. The charge transfer resistance of electroless Ni-P and Ni-P composite deposits are in the range 32,253–90,700 Ω cm2, whereas the capacitances of these coatings are in the range 11–17 μF/cm2. The improved corrosion resistance obtained for electroless Ni-P and Ni-P composite coatings is due to the enrichment of
phosphorus on the electrode surface, which enables the preferential hydrolysis of phosphorus over that of nickel. The better
corrosion resistance obtained for electroless Ni-P composite coatings can be ascribed to the decrease in the effective metallic
area prone to corrosion. Among the three electroless Ni-P composite coatings, the corrosion resistance is in the following
order: Ni-P-CeO2=Ni-P-Si3N4>Ni-P-TiO2.
Electronic Publication 相似文献