溶液电阻对稳态极化曲线测量的影响及一种消除此影响的数据处理方法

如果电极反应过程遵循Ｔａｆｅｌ规律，则在进行稳态极化测量情况下，可以用本文提出的数据处理方法对用等间距恒电位测量或等间距恒电流测量的极化数据进行处理，求得参考电极至工作电极之间的溶液电阻和Ｔａｆｅｌ斜率的数值，从而得到消除了溶液电阻欧姆电位降的真实极化曲线．计算机模拟结果和实验结果都证明，即使在溶液电阻并不大的介质中，如果腐蚀电流密度比较大，溶液电阻对于极化测量的影响也不可忽视．     

电流密度对Al/导电涂层/α-PbO2-CeO2-TiO2/β-PbO2-MnO2-WC-ZrO2复合电极材料制备和性能的影响

通过电化学氧化共沉积技术在A1/导电涂层/α-Pb O2-Ce O2-Ti O2基体上,制备了A1/导电涂层/α-PbO 2-Ce O2-Ti O2/β-Pb O2-MnO 2-WC-Zr O2复合阳极材料。通过能量色散X射线光谱（EDXS）、阳极极化曲线、暂稳态极化曲线（Tafel）、交流阻抗谱（EIS）、扫描电子显微镜（SEM）以及X射线衍射（XRD）等方法研究电流密度对复合阳极材料的化学组分、电化学活性和稳定性的影响。研究结果表明：在电流密度为1 A/dm2条件下制备的A1/导电涂层/α-PbO 2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2复合材料具有最低的析氧过电位（0.610 V,条件：500 A/m2）,最好的电化学活性,最长的使用寿命（360 h,条件：150 g/L H2SO4,2 A/cm2,40°C）以及最低的槽电压（2.75 V,条件：500 A/m2）。而且,随着电流密度的增加,涂层晶粒逐渐增大,MnO 2含量也逐渐降低,晶体结构几乎没有变化。     

ELECTROCATALYTIC BEHAVIORS OF CER ON SOME METAL OXIDES IN CHLORIDE MELT AT 700℃

１ＩＮＴＲＯＤＵＣＴＩＯＮＥｌｅｃｔｒｏｃｈｅｍｉｃａｌｉｎｄｕｓｔｒｙｉｓｉｎｇｅｎｅｒａｌａｈｕｇｅｅｎｅｒｇｙｃｏｎｓｕｍｅｒ．Ｅｌｅｃｔｒｏｃａｔａｌｙｓｉｓ,ａｓａｐｏｗｅｒｆｕｌｗｅａｐｏｎｉｎｌｏｗｅｒｉｎｇｏｖｅｒｐｏｔｅｎｔｉａｌ,...     

离子液体[Emim]BF4改性二氧化铅电极的制备与表征

采用电沉积法制备了离子液体[Emim]BF₄改性PbO₂电极. 通过电化学氧化降解苯酚实验对电极催化性能进行了考察, 发现苯酚模拟废水的COD去除率符合一级反应动力学, [Emim]BF₄改性PbO₂电极的速率常数为0.00739 min_-1, 明显高于未改性PbO₂电极的速率常数0.00383 min_-1. 通过扫描电镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)对电极表面结构进行表征. 结果显示, 在加有离子液体[Emim]BF₄的电积溶液中沉积得到的钛基PbO₂涂层表面致密规整、结晶度高、晶格氧含量高. 通过莫特-肖特基(Mott-Schottky)曲线、稳态极化和线性扫描伏安法(LSV)考察了电极的电化学性质. 稳态极化实验表明改性电极的析氧过电位相比未改性电极有明显提高, 对莫特-肖特基曲线的分析表明, 改性电极表面氧空位含量相比未改性电极有很大降低. 通过与未改性电极结构和电化学性质的对比研究, 得出改性电极催化活性的提高主要是由于其氧空位含量较低, 从而降低了氧化物电极表面发生羟基自由基(?OH)向晶格氧(O_lat)转移的发生率.     

稀土Nd掺杂Ti/RuO2-Co3O4电极电催化性能研究

采用热分解法在400℃下制备了稀土Nd改性Ti/RuO2-Co3O4氧化物阳极,对稀土Nd掺杂量进行优化。利用SEM、EDX及XRD等分析方法对电极表面形貌、组成及结构进行了表征,通过开路电压、循环伏安、极化曲线及强化电解寿命等电化学方法研究了电极的析氧催化活性及稳定性。结果表明:稀土Nd掺杂使表面层晶粒细化,晶型饱满,且促进活性组分RuO2向电极表面富集,增加电极催化活性中心;掺杂量为20:1时,电极析氧性能最佳,伏安电荷容量高达686mC/cm2,反应活化能低至16.76kJ/mol,掺入稀土Nd后电极基体与涂层的结合力增强,电极强化电解寿命高达158h。     

Ni-Cr-Mo-Cu多孔磷化物电极的制备及电催化析氢性能研究

为了解决电解水析氢过程中所用电极材料的低效率、高成本问题,采用粉末冶金法—低温磷化法制备了一种Ni-Cr-Mo-Cu多孔磷化物电极。采用X射线衍射分析(XRD)、场发射电镜(SEM)、X射线能谱分析(EDS)等对电极的物相、形貌结构以及元素分布等进行表征;通过开路电位、线性极化、交流阻抗等方法测试了磷化物电极材料的电催化析氢性能。结果表明Ni-Cr-Mo-,Cu多孔磷化物电极具有优异的析氢性能,调节磷化时间可在较大程度上提高其析氢催化活性。在室温条件下,磷化时间为2小时的Ni-Cr-Mo-Cu多孔磷化物电极在6mol/L KOH的溶液中析氢性能较好,其析氢过电位仅有-0.19V (vs RHE),交换电流密度为10mA/cm2时对应的极化电位为-0.20V (vs RHE);经开路电位测试18000s后,电极材料的开路电位 (η) 从+0.80变化为0.78V (vs RHE),仅降低0.02 V,表明其具有良好的电催化稳定性。     

Properties of electrodeposited Ni-S（La） coatings

Ni-S(La) coatings were obtained by electrodeposition in a typical Watt bath by adding CS(NH2)2 and LaCl3. The minimum HER overpotential is 75 mV. The corresponding electrochemical parameters (Tafel slope b, exchanging current density J0 ) were obtained by measuring the steady-state polarization curves. The content of S, La in the coating and its structure were measured by EPMA and XRD. The results show that there is no lanthanum in such coating and its structure is amorphous. From the anodic polarization curves, it is shown that the corrosion resistance of coating is^* very good. Based on the cathodic polarization curves during electrodeposition, it is found that LaC13 is benefit for amorphous coating structure to form.     

Influence of process parameters on electrochemical and physical properties of sputtered iron-doped nickel oxide thin films

1Introduction A principal focus of modern research in electrocatalysis is to discover electrode materials that exhibit excellent electrochemical stability and show interesting activity towards typical electrochemical reaction[1?10].It is desirable that th…     

CALCULATION OF ELECTROCHEMICAL OVERPOTENTIAL AND CONCENTRATION OVERPOTENTIAL BASED ON CURVE OF ANODIC POLARIZATION IN HYDROGEN STORAGE ALLOY ELECTRODE

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Mo电极上磁控反应溅射AlN薄膜

采用射频反应磁控溅射法在Mo电极上沉积了AlN薄膜.研究了溅射气压、靶基距、溅射功率、衬底温度及N_2含量等不同工艺条件对AlN薄膜择优取向生长的影响.用XRD分析了薄膜的择优取向,用原子力显微镜、高分辨场发射扫描电镜表征了薄膜的形貌.实验结果表明,靶基距和溅射气压的减小,衬底温度及溅射功率的升高有利于AlN(002)晶面的择优取向生长.氮氩比对AlN薄膜择优取向生长影响较小,N_2≥50%(体积分数)时均可制得高c轴择优取向的AlN薄膜.经优化工艺参数制备的AlN柱状晶薄膜适用于体声波谐振滤波器的制备.     

Anodic dissolution of iron in acidic chloride solutions

The dissolution of iron in acidic chloride solutions was studied by both rotating disc and impedance techniques. Two regions of different slope were observed in the Tafel graphs after the effects of diffusion were eliminated. The Tafel slope was seen to change from ca. 44 to ca. 85 mV/decade at more positive potentials. The lower slope was confirmed by impedance measurements. An electrode reaction sequence is proposed for the dissolution reaction in the region where the Tafel slope is ca. 44 mV/decade.The addition of decylamine reduced the rate of the dissolution reaction, but the form of the polarization curves and the mechanism of dissolution remained unchanged. It was also established that decylamine is not involved in the electrode reaction of the dissolving polycrystalline iron.     

Effect of process parameters on the efficiency of dye sensitized solar cells

The impact of process parameters on the efficiency of dye-sensitized solar cell (DSSC) was studied in order to improve its performance. TiO₂ working electrodes were prepared on FTO glass for various TiO₂ mixing time. Also these electrodes were sintered at four different temperatures (400, 450, 500, and 550°C) for one hour in ambient atmosphere. Platinum-sputtered counter electrodes were prepared at different light transmittance (70, 50, 30, and 0%). Microstructural charecterization of these electrodes were studied by X-ray diffraction method (XRD) and Scanning electron microscope (SEM). I–V characteristics of DSSCs made up of different working and counter electrodes were studied using solar simulator. Maximum efficiency (open circuit voltage (V_oc)∼0.68 V and short-circuit current density (J_sc) ∼ 12.3 mA/cm²) was observed for DSSC consisting of TiO₂ working electrode (12h mixing time, 500°C sintering temperature) and 0% transmittance Pt counter electrode. These results indicate that enhancement possibility of overall performance in DSSC was obtained by controlling process parameters, especially TiO₂ mixing time, sintering temperature and counter electrode transmittance.     

手工电弧堆焊接头组织及微动磨损性能研究

用手工电弧堆焊技术,在基体材料45钢表面上,分别选用CHR237和CHR207两种堆焊焊条在相同的工艺参数下进行堆焊。用光学显微镜和显微硬度计对堆焊金属的显微组织和显微硬度进行了分析,用PLINT型微动磨损试验机考察了基体材料及堆焊层金属在室温条件下的微动磨损行为。结果表明,堆焊金属的显微组织和显微硬度跟焊条的种类,硬质相的类型、数量及其分布有关;其抗微动磨损能力均优于基材45钢,且CHR237堆焊金属的抗微动磨损性能最好。     

Engineered Three-Dimensional Electrodes by HVOF Process for Hydrogen Production

High velocity oxy-fuel process was used to prepare nickel electrode coatings for hydrogen production by alkaline water electrolysis. To further increase the active surface area of the electrodes, pyramidal fin arrays with two different sizes were deposited on the top surface of the electrodes using mesh screen masks. The surface microstructure, topology and roughness of the coatings were studied using scanning electron microscope, optical microscopy and confocal laser scanning microscopy. Steady-state polarization curves were used to evaluate the electrocatalytic activity of the electrodes. The performance of the electrodes coated using mesh outperformed the electrode deposited without using mesh. In addition, the electrode that was coated using the coarse mesh was characterized with the highest activity with the exchange current density and overpotential values of 9.3 × 10^?3 A/cm² and ?306 mV, respectively. Formation of different roughness levels due to the combination of normal and off-normal impact of the coating particles on the surface of the fins was identified as the main factor for the increased activity of this electrode toward the hydrogen evolution reaction.     

PREPARATION AND ANALYSIS OF Ni-P-Zn ELECTROLESS DEPOSITION FROM ALKALT BATH

Electroless Ni-P-Zn alloys deposited from alkali bath were investigated in this paper. The deposition bath contained nickel sulfate, zinc chloride and hypophosphate. The process parameters, such as temperature, pH and zinc salt concentration were presented and discussed.The microstructure of the coatings was studied by XRD and SEM. The cathode glowing discharge characters of Ni-P-Zn depositions were studied with luminous Neon lamps. Electrodes deposited by electroless Ni-P alloys were apt to sputter during luminous working hours. Electroless Ni-P-Zn depositions improved the discharge characters of the electrodes.With the concentration of zinc in the deposition rising to 4wt%, electrode sputter was largely restrained. The thickness of the deposition also influenced the discharge characters of the electrode. To avoid electrode sputter, the concentration of zinc has to rise with the thickness of the depositions.     

钛基镍钴合金电极的制备及析氢性能

目的降低电极的析氢过电位,提高析氢性能,从而降低电解水制氢的成本,促进氢储能技术的发展。方法通过异相共沉积法,制备了镍钴合金电极。利用场发射扫描电镜(SEM)、电化学交流阻抗(EIS)对纯镍电极及镍钴合金电极进行表征,采用阴极极化曲线(LSV)探究了电沉积液中Ni/Co元素的比例、电沉积电位及电沉积时间对镍钴合金电极析氢性能的影响。结果 SEM结果揭示了纯镍电极及镍钴合金电极表面分别是粒径约为100 nm左右的镍颗粒和镍钴颗粒。EIS结果说明了镍钴合金电极的导电性能优于纯镍电极。此外,纯镍电极、镍钴合金电极的阴极极化曲线测试表明在电流密度为30 mA/cm~2时,镍钴合金电极的析氢过电位比纯镍电极降低55 mV,降低了近20%。结论通过异相共沉积法制备镍钴合金电极,制备方法简单、方便、快速,其析氢性能优于纯镍电极。镍钴合金电极的最优制备工艺条件为:NiSO_4·6H_2O 27 g/L,CoSO_4·7H_2O_3 g/L,H_3BO_3 10 g/L,Na_2SO_4 10 g/L,柠檬酸10 g/L,十二烷基硫酸钠0.1 g/L,pH值4.0,电沉积电位-1.3 V,电沉积时间10 s。     

电弧喷涂Ti6Al4V涂层的组织与耐蚀性能研究

采用电弧喷涂技术在Q235钢基体上喷涂Ti6Al4V涂层,并对涂层进行封孔处理.表征了涂层的物相组成和微观形貌,通过盐水浸泡实验和极化曲线测试对比分析了Q235钢基体、未封孔涂层和封孔涂层的耐腐蚀性能.结果表明:涂层呈典型的层状特征,物相组成为TiN,TiO和少量的Ti;未封孔涂层与封孔涂层均具有较宽的钝化电位区间,封...     

聚苯胺对锌电积用复合惰性阳极材料电化学性能的影响(英文)

为了寻找一种可以替代锌电积用 Pb-Ag 合金的阳极材料,通过 PANI(聚苯胺)、WC(碳化钨)颗粒与 Pb2+的双脉冲电沉积,在 Al 合金基体上制备了 Al/Pb-PANI-WC 复合惰性阳极材料。测试了镀液中不同 PANI 浓度下制备的惰性阳极材料的阳极极化曲线、循环伏安曲线和塔菲尔极化曲线,采用扫描电镜考察复合惰性阳极材料的微观组织特征。结果表明:当将制备镀液中 PANI 浓度控制在 20 g/L 时,Al/Pb-PANI-WC 复合惰性阳极材料的微观组织和成分分布均匀,在含 50 g/L Zn2+、150 g/L H2SO4的 35 °C锌电积液中具有较高的电催化活性、较好的电极反应可逆性和耐腐蚀性,在电流密度 500 A/m2和 1000 A/m2下的析氧过电位与 Pb-1%Ag 合金相比分别降低了 185 mV 和 166 mV。     

PREPARATION AND ANALYSIS OF Ni-P-Zn ELECTROLESS DEPOSITION FROM ALKALI BATH

Electroless Ni-P-Zn alloys deposited from alkali bath were investigated in this paper. The deposition bath contained nickel sulfate, zinc chloride and hypophosphate. The process parameters, such as temperature, pH and zinc salt concentration were presented and discussed. The microstructure of the coatings was studied by XRD and SEM. The cathode glowing discharge characters of Ni-P-Zn depositions were studied with luminous Neon lamps. Electrodes deposited by electroless Ni-P alloys were apt to sputter during luminous working hours. Electroless Ni-P-Zn depositions improved the discharge characters of the electrodes. With the concentration of zinc in the deposition rising to 4wt%, electrode sputter was largely restrained. The thickness of the deposition also influenced the discharge characters of the electrode. To avoid electrode sputter, the concentration of zinc has to rise with the thickness of the depositions.     

ELECTRODEPOSITED NiSCo ALLOY USED AS HYDROGEN EVOLUTION REACTION CATHODE IN WATER ELECTROLYSIS

NiSCo catalytic cathodes were obtained by electrodeposition in a typical Watt cell with addition of NH2CSNH2 and CoCl2 Using CoCl2 concentration, current density, temperature and pH value as main factors, an orthogonal experiment was designed to determine the optimum technological conditions according to HER overpotentials. The optimum technological conditions were obtained from the minimum HER overpoten-tial-70mV. The corresponding electrochemical parameters (Tafel slope b, exchange current density io) were determined by steady-state polarization curves. The content of S, Co and its microstructure were measured by EPMA and XRD.