Electrodeposition of Copper in a Citrate Bath and Its Application to a Micro-Electro-Mechanical System

Corresponding author. Email: [email protected]; Tel: +86-592-2185957; Fax: +86-592-2181436.[中文文摘]研究并讨论了在新型柠檬酸盐体系铜电沉积工艺中电镀工艺参数对镀层形貌和颗粒尺寸的影响;利用X射线衍射(XRD)和X射线光电子能谱(XPS)表征了镀层的结构和组分存在状态;并将柠檬酸盐体系电沉积铜应用于微机电系统(MEMS)加工工艺.结果表明:在6 g.L-1 Cu2+,pH=7.0-8.5,1-2 A.dm-2,45℃,搅拌条件下可得到结晶细小,表面平整的致密铜镀层;镀层为面心立方多晶结构的单质铜,不含其他杂质.利用MEMS工艺成功制得平面电感,其有效的最大品质因数(Q)为12.75,达到了设计要求.[英文文摘]We investigated the effect of plating parameters on the coating morphology and grain size of copper using a novel citrate bath.The structure and deposit were characterized by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS),respectively.The copper plating bath was applied to a micro-electro-mechanical system(MEMS).Results show that an even and compact copper coating was obtained for the fine grains using plating parameters of 6 g.L-1 Cu2+,pH=7.0-8.5,1-2 A.dm-2,45 ℃,and bath agitation.The deposit consists of pure copper in a fcc polycrystalline structure. A planar inductor was successfully fabricated by MEMS using this bath and its maximum quality factor was 12.75, which satisfies the design requirements.国家自然科学基金(20873114,20833005); 国家重点基础研究发展规划项目(973)(2009CB930703)资

Promotional Effects of Ni and Mg on the Preferential Oxidation of CO over Carbon Nanotube-Supported Pt Catalyst

采用共浸渍法制备了nI和Mg促进的碳纳米管载PT催化剂(PT-nI-Mg/CnT),考察了其对CO优先氧化的催化性能.结果表明,PT,nI和Mg在CnT表面发生了相互作用,可能存在合金纳米粒子,从而显著改善了催化剂CO优先氧化的催化性能.添加适量nI可提高CO的转化率,而加入适量Mg则有助于改善CO2的选择性.当PT,nI和Mg同时负载时,优化后所得的催化剂5%PT-5%nI-5%Mg/CnT在100°C对富H2气体中CO选择氧化的转化率为100%,CO2的选择性为53.7%;该催化剂在140°C下连续反应24H,催化活性稳定.A carbon nanotube-supported Pt catalyst promoted by Ni and Mg(Pt-Ni-Mg/CNT) was prepared by the co-impregnation method for preferential oxidation of CO in H2-rich gas.The results of X-ray diffraction, H2 temperature-programmed reduction, transmission electron microscopy, and energy dispersive spectroscopy indicated that Pt interacted with Ni and Mg on CNT surface and might form alloy nanoparticles to some extents, which in turn markedly improved the catalytic performance of preferential oxidation of CO in H2-rich gas.The results of performance tests showed that CO conversion at low temperatures could be effectively enhanced by adding a proper amount of Ni, while the selectivity was improved by adding a proper amount of Mg.When Ni and Mg were added simultaneously, the 5%Pt-5%Ni-5%Mg/CNT catalyst showed CO conversion of 100% and selectivity for CO2 of 53.7% in a H2-rich stream at 100 °C.The catalytic performance did not change obviously during 24 h of run at 140 °C.国家重点基础研究发展计划(973计划;2009CB939804);福建省科技重大专项前期项目(2009HZ10102

翼反角对高压捕获翼构型高超气动特性的影响

为研究翼反角变化对高压捕获翼构型高超声速气动特性的影响，基于一种双翼面、单支撑、翼身组合布局的高压捕获翼概念构型，以飞行马赫数6，飞行高度30km为计算状态，捕获翼和机体三角翼上/下反角为设计变量，结合均匀试验设计方法、数值模拟方法和Kriging建模方法，探寻了升阻特性、纵向和横航向稳定性随翼反角的变化规律。结果表明，升力、阻力及升阻比随翼反角的变化规律基本一致，且对上反角变化更加敏感；小攻角时，翼面上反会明显降低升阻比，而下反会使升阻比先略微增大后缓慢减小；大攻角时，翼反角对升阻比的影响较小；纵向稳定性主要受三角翼反角的影响，三角翼上反时，纵向稳定性降低，下反时，纵向稳定性基本不变；翼面上/下反都会提高航向稳定性，但下反的效果更明显；翼面上反会提高横向稳定性，下反则降低，但大攻角飞行时，三角翼上反角过大可能会导致横向稳定性降低

Probing electrode/electrolyte interfacial structure in the potential region of hydrogen evolution by Raman spectroscopy

The detailed interfacial structure in the potential region of severe hydrogen evolution, to date, is far from clear due to lack of both experimental data and correlated theoretic models. It has been shown that it is possible to surmount, to some extent, the disturbance of the spectroelectrochemical measurement by strong hydrogen bubbling in the potential region of severe hydrogen evolution by using a surface enhancement effect and a thin-layer cell configuration. Using this approach, we have obtained surface enhanced Raman scattering (SERS) spectra of water at an Ag electrode at very negative potentials at various concentrations of NaClO4. To explain the abnormal reversal of the peak intensity ratio of the bending to the stretching vibration, a preliminary model of the electrode/electrolyte interface is presented. The water molecule is oriented with one hydrogen attached to the surface and the oxygen towards an adsorbed cation which is partially dehydrated owing to the very strong electrostatic force. Raman spectra of hydrogen bound at a Pt electrode in solutions of varying pH from 0 to 14 at potentials of mild hydrogen evolution have also been presented for the first time. The spectra reveal that the Pt-hydrogen interaction is influenced by both the potential and the interfacial structure. These primary studies may initiate more molecular-level research of electrochemical interfaces in the potential region of hydrogen evolution

Surface enhanced Raman scattering from bare cobalt electrode surfaces

Surface enhanced Raman spectra (SERS) of adsorbed species from a bare cobalt (Co) bulk electrode were observed for the first time with confocal Raman microscopy. A combined AFM, Raman and electrochemical study shows that a proper roughening procedure is vitally important for obtaining good-quality surface Raman spectra from the Co electrode. The surface enhancement factor ranges from 2 to 3 orders of magnitude, depending critically on the surface roughening procedure. The present study provides a bright prospect for the wide investigation of systems of practical application

Preparation of nano-structured platinum electrode surfaces by electrochemical methods and its properties

The nano-sized constant potential roughened platinum (CPRPt) and constant current roughened platinum (CCRPt) electrode-surfaces have been prepared successfully by oxidation-reduction-cycle method. Many regularly shaped triangle-cones of the size of 10 similar to 30 nm were observed on the CPRPt electrode surface by the scan electron microscopy (SEM) technology. The electro-oxidation of methanol on the nano-CPRPt and the CCRPt electrode-surfaces was used to investigate the performances with the results of the peak current density 1.35 and 2.50 times greater than those of smooth Pt respectively. The in situ Raman spectra of these two kinds of electrode-surfaces indicated their high surface enhanced Raman spectrum (SERS) effects for pyridine adsorption. The CPRPt electrode surface has extraordinarily enhanced effect for adsorption-dissociation of small organic molecules. The mechanism of SERS on these platinum electrode-surfaces has been also discussed

不断创新的电化学研究方法（厦门大学电化学研究工作简介之二）

不断创新的电化学研究方法（厦门大学电化学研究工作简介之二）林仲华，罗瑾，田中群，孙世刚，林昌健，毛秉伟，杨勇，林华水执笔（固体表面物理化学国家重点实验室，厦门大学化学系，厦门３６１００５）１历史的回顾与自然科学的其它分支学科一样，电化学科学的建立和纵..

Application of Copper Electrochemical Deposition for the Metallization of Micropores

According to established routes for the microporous metallization of printed circuit boards (PCB), electroless copper plating using glyoxylic acid as a reducing agent and copper electroplating in a citrate bath were used for microporous metallization with PCB distributing micropores as a template. The results show that electroless copper plating using glyoxylic acid as a reducing agent and copper electroplating in a citrate bath can be successfully applied to the microporous metallization of PCB. After an electric conducting treatment of the micropores by electroless copper plating the copper deposited as fine grains and attached to the inner walls of the micropores. The copper deposit was also found in the loose grain arrangement and the leak plating area. Immediately after thickening treatment by copper electroplating, the resistance toward the copper coating of the inner wall decreased notably. The ratio of the copper electroplating rates at the inner and outer micropores was found to be 0.8:1.0. The copper electrodeposit fully covered the surface of the inner wall including the leak plating area, which means that the electroplated copper grains have a certain sideway growing ability. The copper coating on the inner wall was continuous, compact, and adhesive. This coating highly enhanced the conductivity of the interconnected PCB.National Natural Science Foundation of China[20873114, 20833005, 21021002]; National Key Basic Research Program of China[2009CB930703

Promotional Effects of Ni and Mg on the Preferential Oxidation of CO over Carbon Nanotube-Supported Pt Catalyst

A carbon nanotube-supported Pt catalyst promoted by Ni and Mg (Pt-Ni-Mg/CNT) was prepared by the co-impregnation method for preferential oxidation of CO in H-2-rich gas. The results of X-ray diffraction, H-2 temperature-programmed reduction, transmission electron microscopy, and energy dispersive spectroscopy indicated that Pt interacted with Ni and Mg on CNT surface and might form alloy nanoparticles to some extents, which in turn markedly improved the catalytic performance of preferential oxidation of CO in H-2-rich gas. The results of performance tests showed that CO conversion at low temperatures could be effectively enhanced by adding a proper amount of Ni, while the selectivity was improved by adding a proper amount of Mg. When Ni and Mg were added simultaneously, the 5%Pt-5%Ni-5%Mg/CNT catalyst showed CO conversion of 100% and selectivity for CO2 of 53.7% in a H-2-rich stream at 100 degrees C. The catalytic performance did not change obviously during 24 h of ran at 140 degrees C

Revealing the molecular structure of single-molecule junctions in different conductance states by fishing-mode tip-enhanced Raman spectroscopy

The conductance of single-molecule junctions may be governed by the structure of the molecule in the gap or by the way it bonds with the leads, and the information contained in a Raman spectrum is ideal for examining both. Here we demonstrate that molecule-to-surface bonding may be characterized during electron transport by 'fishing-mode' tip-enhanced Raman spectroscopy (FM-TERS). This technique allows mutually verifiable single-molecule conductance and Raman signals with single-molecule contributions to be acquired simultaneously at room temperature. Density functional theory calculations reveal that the most significant spectral change seen for a gold-4,4′-bipyridine-gold junction results from the deformation of the pyridine ring in contact with the drain electrode at high voltage, and these calculations suggest that a stronger bonding interaction between the molecule and the drain may account for the nonlinear dependence of conductance on bias voltage. FM-TERS will lead to a better understanding of electron-transport processes in molecular junctions