共查询到20条相似文献，搜索用时 484 毫秒
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介绍Ni-S电极的制备,以及电镀时间、电镀电流密度、镀层中硫含量、镀液PH值、镀液温度等对Ni-S合金电极的活性的影响。 相似文献
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以高熵合金(Al Cr Nb Si Ti V)为靶材,Ar为工作气体,N2为反应气体,利用反应式直流磁控溅镀在硅晶片和车削刀具上制备高熵合氮化薄膜,探讨不同溅镀沉积时间对(Al Cr Nb Si Ti V)氮化物薄膜表层微结构及机械性质的影响。沉积薄膜中所有元素的相对原子浓度与高熵合金靶材相当。氮化物薄膜组织均匀、致密地附着于基材,薄膜表面为颗粒状组织。随着溅镀时间的增加,显示薄膜表面晶粒变大,薄膜沉积速率下降。应用高熵合金(Al Cr Nb Si Ti V) N氮化物薄膜镀层刀具干式切削S45C中碳钢圆柱工件时,工件表面的粗糙度和刀具的侧面磨损显著降低。研究显示镀层可有效提升刀具切削效率,延长刀具使用寿命,溅镀时间30 min时,车削刀具的切削性能最佳。 相似文献
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以电化学沉积法在玻碳电极上修饰纳米金颗粒,以修饰后的电极作为工作电极,用于同位镀铋膜法连续测定水中铅的含量。在含铋的溶液中,采用示差脉冲溶出伏安法测定铅离子的浓度,考察电解液pH值、富集电位、富集时间及铋膜浓度对溶出峰的影响,优化出最佳实验条件。在优化的实验条件下,金属离子浓度和峰电流有较好的线性关系,结果表明,本法测定结果准确度,灵敏度较高,重现性良好,可实现水中微量重金属离子的快速测定。 相似文献
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99A型光亮镀铜工艺具有电流效率高,沉积速度快,光亮电流密度范围宽,镀层光亮性能好,机械性能优良等特点。采用该工艺能够降低镀铜层孔隙率,提高铝件镀银的防腐能力。 相似文献
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用蒙脱土制备了蒙脱土/SnO_2/染料(靛蓝胭脂红)化学修饰电极.循环伏安图表明,有机染料分子可以持留在蒙脱上膜中,并显示出电化学活性.用蒙脱土制备的化学修饰电极(CME)可以很大地改进电极反应的稳定性.电活性物在蒙脱土膜中的电化学行为是受扩散控制的.测得扩散系数的数量级为10~(-10)cm~2/s.所制得的蒙脱土/SnO_2/染料化学修饰电极对抗坏血酸的电化学氧化显示电催化作用,使它的氧化电位降低了100mV. 相似文献
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目前,实现对细胞神经递质释放过程的高时空分辨实时监测,仍存在诸多挑战。近些年来,通过发展不同的电化学检测技术实现了对细胞胞吐(exocytosis)释放以及细胞内部囊泡的定量化分析;一些研究使用这些技术,进行了细胞释放模式的探究。通过在电极表面修饰小分子或者调控电极尺寸,可实现高分辨率和高灵敏度的监测。文章重点介绍了神经递质电化学检测的机理、微米电极以及纳米电极检测技术的发展,对电化学传感与成像技术的联用进行了评述,并对电化学传感检测技术未来发展方向进行了展望。在此基础上,文章综合各种不同监测技术的优点,提出构建纳米电极与成像以及其他检测手段的联用技术,以大幅提高纳米电极在神经递质检测方面的能力。 相似文献
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Chao Wang Yanxiao Ning Haibo Huang Shiwen Li Chuanhai Xiao Qi Chen Li Peng Shuainan Guo Yifan Li Conghui Liu Zhong-Shuai Wu Xianfeng Li Liwei Chen Chao Gao Chuan Wu Qiang Fu 《国家科学评论(英文版)》2021,8(3)
Surface and interface play critical roles in energy storage devices, calling for operando characterization techniques to probe the electrified surfaces/interfaces. In this work, surface science methodology, including electron spectroscopy and scanning probe microscopy, has been successfully applied to visualize electrochemical processes at operating electrode surfaces in an Al/graphite model battery. Intercalation of anions together with cations is directly observed in the surface region of a graphite electrode with tens of nanometers thickness, the concentration of which is one order higher than that in bulk. An intercalation pseudocapacitance mechanism and a double specific capacity in the electrode surface region are expected based on the super-dense intercalants and anion/cation co-intercalation, which are in sharp contrast to the battery-like mechanism in the electrode bulk. The distinct electrochemical mechanism at the electrode surface is verified by performance tests of real battery devices, showing that a surface-dominant, nanometer-thick graphite cathode outperforms a bulk-dominant, micrometer-thick graphite cathode. Our findings highlight the important surface effect of working electrodes in charge storage systems. 相似文献
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Summary In order to understand the mechanism of fauling of electrode surfaces ofin vivo electrochemical sensors used for monitoring whole blood, the investigations on protein adsorption on the membrane surfaces
were undertaken. Using an oxygen sensor, the protein adsorption studies were carried out on two different polymeric surfaces-teflon
(PTFE) and polyurethane (PU)-using Scanning Electron Microscopy and Fourier Transform Infrared Spectrophotometry. Investigations
reveal that even a single protein like albumin or fibrinogen tend to adhere to the sensor membrane surface and influences
the electrochemical characteristics of the sensor. The influence is more significant, in the case of PTFE membrane. 相似文献
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酸度计是一种电化学分析仪器,由电极和电计组成。主要用于测量水溶液的PH值,其广泛应用于工业、食品、农业、医疗、科研及环保等行业,酸度计的维护保养及故障排除在各行业中存在一些值得大家引起重视的共性问题,在使用中若能合理维护保养电极、正确操作电计,不仅能提供测量数据准确可靠,还对仪器的寿命也是有影响;对于酸度计在使用中出现的常见故障能够自行解决的,不但使仪器免遭不应有的损坏,更重要的是不影响正常工作。文章针对酸度计的常见故障提出解决办法及如何对酸度计进行正确的维护保养。 相似文献
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用蒙脱石与Ｎａｆｉｏｎ制备了阳离子染料中性红化学修饰电极（ＣＭＥ）．两种ＣＭＥ在支持电解质溶液中有相似的循环伏安行为．蒙脱石ＣＭＥ的峰电流随膜厚增加而增加，而ＮａｆｉｏｎＣＭＥ的峰电流随膜厚增加有所降低．阳离子染料在蒙脱石膜内的扩散系数比在Ｎａｆｉｏｎ膜中的扩散系数大一个数量级．阴离子电活性物以及不同的制备方法对两种ＣＭＥ的电化学响应有不同的影响．两种ＣＭＥ在性质上的差异反映了两种膜的微结构与通透性等方面的差别．蒙脱石用作制备化学修饰电极的表面层材料有一定吸引力． 相似文献
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Electrochemistry is a promising tool for microfluidic systems because it is relatively inexpensive, structures are simple to fabricate, and it is straight-forward to interface electronically. While most widely used in microfluidics for chemical detection or as the transduction mechanism for molecular probes, electrochemical methods can also be used to efficiently alter the chemical composition of small (typically <100 nl) microfluidic volumes in a manner that improves or enables subsequent measurements and sample processing steps. Here, solvent (H2O) electrolysis is performed quantitatively at a microchannel Pt band electrode to increase microchannel pH. The change in microchannel pH is simultaneously tracked at a downstream electrode by monitoring changes in the i-V characteristics of the proton-coupled electro-oxidation of hydroquinone, thus providing real-time measurement of the protonated forms of hydroquinone from which the pH can be determined in a straightforward manner. Relative peak heights for protonated and deprotonated hydroquinone forms are in good agreement with expected pH changes by measured electrolysis rates, demonstrating that solvent electrolysis can be used to provide tunable, quantitative pH control within a microchannel. 相似文献
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The development of widely applicable point-of-care sensing and diagnostic devices can benefit from simple and inexpensive fabrication techniques that expedite the design, testing, and implementation of lab-on-a-chip devices. In particular, electrodes integrated within microfluidic devices enable the use of electrochemical techniques for the label-free detection of relevant analytes. This work presents a novel, simple, and cost-effective bench-top approach for the integration of high surface area three-dimensional structured electrodes fabricated on polystyrene (PS) within poly(dimethylsiloxane) (PDMS)-based microfluidics. Optimization of PS-PDMS bonding results in integrated devices that perform well under pressure and fluidic flow stress. Furthermore, the fabrication and bonding processes are shown to have no effect on sensing electrode performance. Finally, the on-chip sensing capabilities of a three-electrode electrochemical cell are demonstrated with a model redox compound, where the high surface area structured electrodes exhibit ultra-high sensitivity. We propose that the developed approach can significantly expedite and reduce the cost of fabrication of sensing devices where arrays of functionalized electrodes can be used for point-of-care analysis and diagnostics. 相似文献