HEDP镀铜体系中铜阳极的电化学溶解行为

通过循环伏安、阳极极化曲线等方法研究了羟基乙叉二膦酸(HEDP)镀铜液中铜阳极的电化学行为,分析了不同阳极材料的溶解行为差异及对镀层质量的影响.结果表明,溶液环境的改变会显著影响铜阳极溶解的电化学行为,HEDP体系中加入23CO?可促进铜阳极的溶解及提高Cu还原电势;在HEDP镀铜液中,铜的阳极溶解过程主要包括Cu2O的形成、Cu2+的溶出、浓差极化阻滞溶解、Cu(OH)2和CuCO3的生成及氧气的析出.HEDP镀铜体系中,磷铜阳极反应活性低,表面易钝化;电解铜阳极的溶解过快,易产生"铜粉"Cu2O而影响镀层质量;冷轧紫铜作为阳极最适宜.     

Cr_2O_3在KOH溶液中电场强化溶出机理及溶出影响因素

通过矿物修饰电极结合紫外光谱法研究了电场作用下Cr_2O_3在KOH介质中的电化学溶出机理及其温度、KOH浓度、外加电场电压对Cr_2O_3电化学溶出的影响,推导得出其溶出过程发生的反应,包括-0.05 V处Cr_2O_3直接电化学氧化溶出反应Cr_2O_3+10OH~-→2CrO_4~(2-)+5H_2O+3e~-和1.05 V处Cr_2O_3发生间接电化学氧化溶出反应3OH-→HO_2~-+H_2O+2e~-和Cr_2O_3+3HO_2~-+OH~-→2CrO_4~(2-)+2H_2O.本研究为实际铬盐生产工艺提供理论支撑,为优化和提升铬矿电化学清洁生产工艺提供参考.     

铜的光谱电化学定量测定

<正> 光谱电化学是将光谱技术和电化学方法相结合而产生出的一门交叉学科。它产生于六十年代初,而将这种方法用于定量分析只有十年的历史,并且报道较少。本文进行了铜的光谱电化学定量测定,其工作曲线线性良好,结果令人满意。原理:首先将铜离子还原沉积在工作电极(阴极)的表面,加入显色剂PAR试剂。加正向电压使沉积的铜又以离子形式溶出。溶     

电化学杀菌技术在水处理中的研究进展

电化学杀菌是一种对环境友好的杀菌技术,现对该技术近30 a在杀菌机理和电极材料方面的研究进展进行了总结.电化学杀菌的机理包括活性氯、H2O2、O3、活性中间体、铜或银离子的化学作用以及电场的物理作用;采用的电极材料分别为钛阳极、炭阴极、PbO2阳极等;根据应用对象和目标选择适宜的电极材料,是提高杀菌效果的有效途径;目前电化学杀菌技术存在的主要问题是电流效率较低,阴极结垢以及杀菌剂浓度难以控制等.     

电化学介导胺再生CO2捕集系统电化学性能研究

二氧化碳(CO2)捕集是实现我国碳中和目标的重要手段.电化学介导胺再生(EMAR)CO2捕集系统是一种极具应用前景的碳捕集技术.为了进一步研究EMAR的电化学性能,利用H型电解池,对以乙醇胺(MEA)溶液为吸收剂,铜离子为金属配体的体系开展电化学行为研究.结果表明:阴极和阳极反应均是分步进行的,且均由扩散和电荷传递共同...     

问题解答

问:1、请问光亮酸性镀铜液中亚铜的影响与处理方法。2、请问光亮镍1.4丁炔二醇—糖精体系中十二烷基硫酸钠的使用量及注意事项。 (福建省长河县一号信箱郭承宗)答:1.在酸性光亮镀铜溶液中,铜阳极主要是溶解成二价铜离子,在阴极上放电还原成金属铜。但在电镀过程中,当铜阳极和镀液中二价铜接触时,可能产生下列反应:     

阴极材料对MEC-AD体系产甲烷性能的影响评估

为了研究阴极材料对微生物电解池(MEC)耦合厌氧消化(AD)体系产甲烷性能的影响，分别将不锈钢、钛、泡沫铜、泡沫镍作为阴极，分析不同阴极材料所处体系在不同电压条件下的产气性能、阴极材料的电化学特性以及阳极微生物群落结构。结果表明：在4种阴极材料中，泡沫铜和泡沫镍所处的体系产甲烷、析氢性能最强，电子传递效率及电化学活性较不锈钢和钛强，所处体系中阳极产甲烷功能菌含量明显高于不锈钢和钛，故直接电子传递效率较强。由于泡沫铜易被氧化，故泡沫镍作为阴极材料具有一定的优越性。     

光催化-电氧化联合作用对氨氮去除效果的研究

探索光电联合反应的可行性,通过对阴极(Ti)涂覆光催化剂薄膜前后进行对比试验,发现涂膜后阴极在电化学反应中表现出相对较强的氨氮去除效果,以此为基础开展基于阳极直接氧化及阴极吸附光催化氧化模式的光电联合反应装置设计。在相同通电功率和光照条件下,与单纯光催化氧化和单纯电化学氧化法相比,光电联合反应表现出相对更高的氨氮去除效率。     

液体的电化学处理设备Akahori,Massaii 等 （Ebara Comoration. Japan） .

本发明提供液体电化学处理设备的电极室结构，它可稳定地运行，用纯水作为电极室液体，不要求浓度调节，没有反向电极反应。该电化学处理设备在阳极和阴极之间有离子交换膜，由阳极和阳离子交换膜形成阳极室，由阴极和阴离子交换膜形成阴极室，每个阳极室和阴极室中都填充离子交换纤维。     

氨氮在两种电解质体系下的电化学氧化

以钛基氧化物涂层材料(IrO2,RuO2,TiO2/Ti)为阳极,石墨为阴极,考察了氨氮的直接电化学氧化与其在两种液相电解质体系下(存在氯离子与否)的氧化效果。检测了氨氮氧化过程中亚硝态氮和硝态氮的生成量。结果表明,当不存在氯离子时NH4+-N的电化学氧化可被忽略,但游离态氨氮(NH3-N)在约1.25V阳极电位下可发生直接氧化。当电解质中存在氯离子时,有效氯的生成使氨氮的氧化效率显著提高,在碱性体系下氨氮的去除作用包括间接电化学氧化和直接电化学氧化,但以前者为主。在两种电解质体系下均有少量硝态氮生成,而亚硝态氮仅在无氯离子体系下有少量生成。硝态氮和亚硝态氮的存在说明部分氨氮可能发生了非有效氯的间接氧化。本研究表明氨氮的电化学氧化机理与介质条件、阳极电位密切相关。     

Dissolution processes of titanium—copper alloys. ESCA studies of surface layers in active and passive states

The use of photoelectron spectroscopy has shown that the surface of titanium—copper alloys is enriched with metallic copper as their dissolution progresses. In the active state, the cathodic dissolution of copper through an intermediate reaction product, Cu hydride, seems to occur simultaneously with the anodic dissolution of titanium; the dissolution of copper from the alloys is immediately followed by copper redeposition. In the passive state the active anodic dissolution of copper, which is mass transfer controlled, occurs through the TiO₂ passive film.     

The kinetics of copper dissolution in acetonitrile-water copper(II) solutions

The rate of dissolution of rotating copper discs in acidified copper(II) solutions prepared in an acetonitrile-water solvent (mole fraction ACETONITRILE = 0.·25) was measured in the temperature range 270–360 K. The rate of dissolution was found to be proportional to the square root of the rotation speed and to have an activation energy of 18 ± 2kJ mol⁻¹. The reaction is therefore considered to be diffusion controlled.

The reduction of copper(II) to copper(I) on a rotating platinum electrode, and the oxidation of copper(O) to copper(I) on a rotating copper electrode, were investigated. These two reactions together make up the dissolution reaction. From the intersection of the polarization curves, it was confirmed that the dissolution reaction was diffusion controlled. Dissolution rates calculated from the electrochemical measurements agreed with the kinetic measurements. Estimates of some electrochemical parameters in the acetonitrile mixed solvent were made.

The surface characteristics of annealed and unannealed copper discs which had been etched in the copper(II) solution are discussed briefly.     

Effect of hydrogen peroxide on oxidation of copper in CMP slurries containing glycine and Cu ions

This study compares the oxidative dissolution, passivation, and polishing behavior of copper chemical-mechanical polishing in the presence of hydrogen peroxide, glycine, and copper sulfate. High purity discs were used to study the dissolution and oxidation kinetics under static and dynamic conditions at pH 4 with varying H₂O₂ concentrations. Changes in surface chemistry of the statically etched copper disc were investigated using X-ray photoelectron spectroscopy (XPS). In the presence of H₂O₂, the copper removal rate reached a maximum at 1% H₂O₂ concentration, and decreased with further increase in H₂O₂ concentration. Electrochemical studies indicate a strong passivation process at higher H₂O₂ concentrations due to the rapid formation of oxide on the surface. With the further addition of glycine and copper sulfate to the slurry, the copper removal rates increased significantly and the maximum removal rate shifted to a H₂O₂ concentration of 3%. Electrochemical investigation indicates an enhanced dissolution of copper, which might be due to the strong catalytic activity of Cu(II)-glycine complexes in decomposing H₂O₂ to yield hydroxyl radicals. XPS results suggest that the passivation at higher H₂O₂ concentrations in the presence of glycine and copper sulfate is provided by the OH radicals adsorbed on Cu surface.     

Determination of the Optimum Conditions for Copper Leaching from Chalcopyrite Concentrate Ore Using Taguchi Method

The optimum conditions for the extraction of copper from chalcopyrite concentrate into SO₂-saturated water were evaluated using the Taguchi optimization method. High level copper recovery was obtained in an environmentally friendly process that avoids sulfur dioxide emission into the atmosphere because SO₂ forming in the roasting is used in the dissolution. Experimental parameters and their ranges were chosen as follows: reaction temperature, 293–333 K; solid-to-liquid ratio, 0.025–0.15 g/mL; roasting time, 30–90 min; roasting temperature, 773–973 K; stirring speed, 400–800 rpm; and reaction time, 10–60 min. The particle size and gas flow rate were 63 µm and 10 cm³/min, respectively. The optimum conditions of the dissolution process were determined to be reaction temperature of 318 K, a solid-to-liquid ratio of 0.025 g mL^?1, a roasting time of 75 min, a roasting temperature of 773 K, a stirring speed of 400 rpm, and a reaction time of 30 min. Under optimum conditions, dissolution yield of copper was 91%.     

The anodic dissolution of 90% copper-10% nickel alloy in hydrochloric acid solutions

The anodic dissolution of the 90% copper-10% nickel alloy in hydrochloric acid solutions at the rotating disk was found to be controlled by both mass transfer and reaction in the apparent Tafel region. The kinetics of dissolution are similar to those of pure copper for the partial currents due to the dissolution of both the copper and nickel components from the alloy. A mechanism for the dissolution of the alloy is proposed. This mechanism describes the dissolution as being controlled by the dissolution of the copper from the alloy. In the limiting-current region a film of CuCl precipitates on the surface of the electrode. The reaction in the limiting-current region is controlled by mass transfer. A mechanism which describes the precipitation and dissolution of this film, and which describes the diffusion of the chloride to the surface of the electrode is proposed.     

过氧化氢氧化苯酚铜锰复合氧化物催化剂的制备

采用固相法制备了新型催化剂铜锰复合氧化物催化剂。利用高效液相色谱法对苯酚过氧化氢氧化反应产物进行分析,以苯酚转化率和苯二酚收率为评价指标,对催化剂进行了评价。结果表明,催化剂性能随铜与锰物质的量比、焙烧温度、焙烧时间和研磨时间等因素的增大呈先升高再降低的趋势,并与络合剂的还原性有关。确定最佳工艺条件为:室温下,按锰与铜物质的量比1:2将Cu_2(OH)_2CO_3、MnCO_3和适量H_2C_2O_4·2H_2O混匀,置于研钵匀速研磨10 min,马弗炉400℃焙烧2 h。最佳条件下,苯酚转化率为63.7%,苯二酚收率为59.1%。     

The dissolution of cupric hydroxide films from copper surfaces

The dissolution of cupric hydroxide films grown under well defined potentiostatic conditions has been studied in lithium hydroxide as a function of hydroxide ion concentration, electrode rotation speed (at a rde, and formation potential. The dissolution reaction was followed by monitoring the amount of cupric hydroxide on the copper surface electrochemically at any given time. The open-circuit potential was used as an indication of when the dissolution of when the dissolution reaction was complete.

The dissolution reaction was found to be jointly controlled by surface kinetics and diffusion of the dissolution product away from the surface. The effect of incomplete dissociation of LiOH was also considered.     

Investigation of selective leaching and kinetics of copper from malachite ore in aqueous perchloric acid solutions

In this study, the leaching kinetics of malachite in perchloric acid solutions was investigated. The dissolution behaviors of copper, zinc, and iron in the ore matrix were determined at different acid concentrations and reaction temperatures. It was observed that the concentration of perchloric acid had a major effect on the dissolution of copper, zinc, and iron. It was determined that the effect of temperature on the dissolution of these species was not as significant as concentration impact. The results obtained shown that copper in the ore matrix was completely leached while zinc and iron were partially dissolved in perchloric acid solutions. In addition, the effects of the acid concentration, reaction temperature, stirring speed, particle size, and solid-to-liquid ratio on the leaching of malachite were researched. In these experiments, it was observed that the leaching rate of copper increased with increasing solution concentration, stirring speed, and reaction temperature, and with decreasing solid-to-liquid ratio and particle size. A kinetic analysis was performed, and it was found that the rate of leaching reaction obeyed the mixed kinetic control model in the unsteady state. The activation energy of the leaching process was calculated to be 34.69 kJ/mol.     

Determination of the Optimum Conditions for Leaching of Malachite Ore in H2SO4 Solutions

The Taguchi method has been used to determine the optimum conditions for the dissolution of malachite ore in H₂SO₄ solutions. The chosen experimental parameters and their range were (i) reaction temperature: 15 to 45 °C, (ii) solid‐to‐liquid ratio: 1/10 to 1/3 g cm^–3, (iii) acid concentration (in weight): 2 % to 10 %, (iv) particle size: –40 to –3.5 mesh, (v) stirring speed: 240 to 720 rpm, and (vi) reaction time: 5 to 45 minutes. The optimum conditions were found to be reaction temperature: 40 °C, solid‐to‐liquid ratio: 1/3 g cm^–3, acid concentration (in weight): 10 %, particle size: –30 mesh, stirring speed: 480 rpm, and reaction time: 45 minutes. Under these optimum working conditions, the dissolution of copper and iron in malachite ore was 100 % and 58 %, respectively. Besides, alternative working conditions reducing the total cost and dissolution of iron were found.     

Characterization and oxidation states of Cu and Pd in Pd–CuO/ZnO/ZrO2 catalysts for hydrogen production by methanol partial oxidation

Copper and zinc oxide based catalysts prepared by coprecipitation were promoted with palladium and ZrO₂, and their activity and selectivity for methanol oxidative reforming was measured and characterized by N₂O decomposition, X-ray absorption spectroscopy, BET, X-ray photoelectron spectroscopy, X-ray diffraction, and temperature programmed reduction. Addition of ZrO₂ increased copper dispersion and surface area, with little effect on activity, while palladium promotion significantly enhanced activity with little change of the catalytic structure. A catalyst promoted with both ZrO₂ and palladium yielded hydrogen below 150 °C. EXAFS results under reaction conditions showed that the oxidation state of copper was influenced by palladium in the catalyst bulk. A palladium promoted catalyst contained 90% Cu⁰, while the copper in an unpromoted catalyst was 100% Cu¹⁺ at the same temperature. Palladium preferentially forms an unstable alloy with copper instead of zinc during reduction, which persists during reaction regardless of copper oxidation state. A 100-h time on stream activity measurement showed growth in copper crystallites and change in copper oxidation state resulting in decreasing activity and selectivity. A kinetic model of the reaction pathway showed that palladium and ZrO₂ promoters lower the activation energy of methanol combustion and steam reforming reactions.