A new microcell or microreactor for material surface investigations at large current densities
A new microcell or microreactor for material surface investigations at large current densities
复制标题
用于大电流密度下材料表面研究的新型微池或微反应器
DOI：
10.1016/j.electacta.2004.01.068
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发表时间：
2004
影响因子：
6.6
通讯作者：
J. Deconinck
中科院分区：
文献类型：
--
作者：
M. Lohrengel;C. Rosenkranz;I. Klüppel;A. Moehring;H. Bettermann;B.Van den Bossche;J. Deconinck
基于毛细管的液滴池在微米范围内的微电化学表面分析中得到了很好的应用。恒电位3电极排列允许所有常见的技术，如循环伏安法，阻抗谱和电位阶跃的电流瞬变。一个限制因素是固定的电解质，这意味着积累的产品或耗尽的离析物，特别是在较大的电流密度。反应产物如气体（O2或H2的气泡）或沉淀物阻塞毛细管。在较大电流密度下的工艺需要移动的电解质。例如金属的脉冲沉积、局部腐蚀和电化学加工（ECM），这意味着在高达100 A/cm 2的电流密度下的阳极溶解。一个新的概念被开发出来，基于由带有隔板的玻璃管制成的毛细管。因此，我们采用了两个分开的通道，一个通道用作电解质入口，另一个通道用作出口。其中一个通道包括作为对电极的细金线。一个特殊的齿轮泵以高达70米/秒的速度在毛细管口移动电解液。在这些条件下，电流密度> 100 A/cm 2成为可能。ECM等溶解过程通常需要对产品进行鉴定，通过在电解质出口处添加紫外-可见光谱仪的流通式微量比色皿，这成为可能。
The capillary-based droplet cell is well established in microelectrochemical surface analysis down to the μm range. The potentiostatic 3-electrode arrangement allows all common techniques like cyclovoltammetry, impedance spectroscopy and current transients of potential steps. A limiting factor was the immobile electrolyte, which meant an accumulation of products or depletion of educts, especially at larger current densities. Reaction products like gases (bubbles of O2or H2) or precipitates blocked the capillary. Processes at larger current densities require a moving electrolyte. Examples are pulse deposition of metals, local corrosion and electrochemical machining (ECM), which means an anodic dissolution at current densities up to 100A/cm2. A new concept was developed, based on capillaries made of glass tubes with a partition. Accordingly, we employed two separated channels, one channel is used as an electrolyte inlet, the other as the outlet. One of the channels includes a thin gold wire as a counter electrode. A special gear pump moves the electrolyte with velocities up to 70m/s in the mouth of the capillary. Current densities >100A/cm2become possible under these conditions. Dissolution processes like ECM normally require an identification of the products, which became possible by adding a flow-through micro cuvette of an UV-Vis spectrometer at the electrolyte outlet.