活性层制备方法对二氧化铅电极性能的影响

分别采用电沉积法和热分解法制备了含SnO_2-Sb_2O_3中间层的钛基二氧化铅活性层。分别采用扫描电镜、X射线衍射、电化学测量、加速寿命试验等方法,对比研究了不同方法制备的二氧化铅活性层的晶体结构、表面形貌、电化学特性、降解有机污染物的能力和使用寿命。结果表明,热分解法制备的电极的析氧过电位低于电沉积电极,但具有较大的比表面积,所以在电催化氧化苯胺过程中显示出较高的降解能力;热分解制备的电极表面疏松多孔,而电沉积制备的电极表面致密,所以电沉积电极的使用寿命远远高于热分解电极。     

电沉积法制备二氧化铅电极的研究进展

电沉积法近几年来成为制备二氧化铅电极的有效方法之一。本文主要阐述了电沉积法制备二氧化铅电极的改进方法和最新研究进展,包括基体改性、元素掺杂、纳米颗粒复合以及新的电沉积制备技术,这些改性方法能够大大提升二氧化铅电极的电催化性能。     

脉冲电镀制备钛基二氧化铅电极

应用脉冲电镀技术制备钛基二氧化铅电极，考察了制备电极在1mol／L的硫酸溶液中的电化学特性．对制备电极进行SEM研究，测定了电极的电化学动力学参数，并与直流电镀制备的电极进行了比较．结果表明，脉冲电镀电沉积可以降低晶粒大小，改善镀层的物理性能，增高电极的析氧电位．     

氟硼酸铅镀液中电沉积钛基二氧化铅

以电沉积法从氟硼酸铅镀液中制备Ti基PbO2阳极(FB/PbO2)及其掺杂氟离子的FB/F - PbO2阳极.应用计时电位法研究了所制备阳极的电沉积成核速率,发现氟硼酸铅镀液在钛基表面电沉积二氧化铅的结晶速度比硝酸铅镀液更快.采用XRD和SEM技术对这两种电极进行了表征,并与传统的硝酸镀液制备的钛基二氧化铅对比,发现电...     

钛基锡锑中间层上二氧化铅电沉积过程的研究

运用电化学手段研究了钛基锡锑中间层上二氧化铅的阳极电沉积过程.循环伏安曲线表明,二氧化铅的电沉积经历了晶核形成过程,通过恒电位阶跃暂态曲线可知,二氧化铅在Ti/SnO2-Sb2O5电极上的电沉积初始过程遵循扩散控制的瞬时成核和三维长大方式,且随着过电位的增加,电极表面上晶核数增多.     

镍网基NiHCF膜电极电控离子分离性能

在镍网基体上通过阳极氧化、循环伏安电沉积、化学沉积与脉冲电沉积分别制备出具有电化学控制离子分离(ECIS)性能的铁氰化镍(Nickel hexacyanoferrate,NiHCF)薄膜电极.在1mol·L<'-1>KNO<,3>溶液中采用电势循环可逆地置入与释放碱金属离子,考察不同制备方法膜电极的离子交换容量、循环寿命与再生能力,并通过SEM、IR、IC分析了膜电极表面形貌、组成与ECIS过程性能.研究结果表明,镍网基NiHCF膜电极制备工艺简单,具有较大的离子分离能力、良好的循环稳定性与再生能力,其中脉冲电沉积膜电极的离子交换容量和循环稳定性优于其它方法制得的膜电极.     

α-PbO2-CeO2-TiO2复合电极材料的耐蚀性研究

将TiO2和CeO2颗粒添加到由PbO和NaOH组成的镀液中,通过阳极电沉积的方法在铝基体上制备了α-PbO2-TiO2-CeO2复合镀层,用作铝基二氧化铅电极的中间层。研究了CeO2及TiO2纳米微粒质量浓度及工艺条件对制备的复合电极耐蚀性能的影响。确定了最佳电解液组成为:将PbO加入到140g/LNaOH溶液中至饱和,15 g/LTiO2,10 g/LCeO2。温度40℃,电流密度0.5 A/dm2,电沉积时间3 h。在此条件下所得的复合镀层综合性能较好,复合镀层中w(TiO2)为3.74%,w(CeO2)为2.15%。     

新型钛基PbO2阳极电氧化降解 有机污染物的特性研究

用电沉积法制备了PbO2/SnO2+Sb2O3/Ti、Bi-PbO2/SnO2+Sb2O3/Ti、PbO2（超声）/SnO2+Sb2O3/Ti、Bi-PbO2（超声）/SnO2+Sb2O3/Ti等4种二氧化铅电极,用稳态极化曲线表征了它们的电催化性和选择性,分析了电解苯酚废水的处理效果,用加速寿命实验测定了电极寿命,用电子扫描电镜表征了沉积层晶相和形貌。结果表明：掺Bi可以提高电极的电催化性和电氧化苯酚的选择性,超声电沉积可以增大电极比表面积,提高电极的表观催化活性,显著增长电极加速寿命。     

电沉积制备铁基β-PbO2电极

采用电沉积法制备PbO2/Fe电极,研究了电镀液配方、电沉积温度、电流密度、添加剂以及底层(SnO2 Sb2O3)对电极外观、导电性能和使用寿命的影响。正交试验得出了制备电极的最佳工艺为:先在低温40℃大电流密度55mA/cm2条件下电沉积1h制备α-PbO2底层,而后在高温70℃小电流密度35mA/cm2条件下电沉积2h制备β-PbO2。     

Ni-Cu合金电极上苯甲醇的选择性电氧化

通过恒电流电沉积法在不同条件下制备了一系列Ni-Cu合金电极,采用扫描电镜(SEM)表征了其表面形态,用循环伏安法(CV)研究了在碱性溶液中苯甲醇在不同工艺条件下制备的Ni-Cu合金电极上的电氧化行为.并进一步用电化学原位红外光谱(in situ FTIP)从分子水平研究了苯甲醇在Ni-Cu合金电极上的电氧化过程.结果...     

膜电极产生臭氧的工作时间特性

采用Nafion膜作为电解质、b-PbO2颗粒作为阳极、碳载铂作为阴极,制备了固体聚合物电解质复合膜电极. 利用SEM和XRD研究发现,膜电极运行220 h后,阳极PbO2中约有6%左右的α-PbO2,阳极催化层颗粒之间变得疏松,PbO2颗粒的表面也出现了大量重结晶的纳米尺寸的PbO2颗粒,膜电极出现电流效率下降和槽压上升的趋势. 阳极PbO2重结晶导致的催化层结构和形貌改变是这种趋势出现的主要原因;晶体中的Pb2+被氧化为Pb4+所致的晶体原有结构的破坏可能是膜电极性能下降的原因之一. 膜电极在运行到180 h后,槽压和电流效率趋于稳定,这可能是由于阳极催化层的结构已趋于稳定.     

钛基二氧化铅电极的制备及其应用

本文综合介绍了国内外近年来钛基PbO2电极技术的发展,包括电极的制备方法,电极的改性研究及钛基PbO2电极在工业领域中的应用。     

电解法去除PAM生产废水中氨氮的研究

分别研究了铁板、铝板、钛板、镀钌钛板、镀二氧化铅钛板作为电极时PAM生产废水中氨氮的去除效果.结果表明,采用镀钌钛板电极比采用镀二氧化铅钛板电极具有更高的氨氮去除率;极板间距为0.5 cm时的氨氮去除率略优于极板间距为1 cm时的氨氮去除率;当放电时间超过6 min时,氨氮去除率随时间的变化曲线趋于平缓;采用镀钌钛板电...     

Discharge behaviour of tubular lead dioxide electrodes Part III: Two-dimensional current density distribution

The initial current density distribution in lead acid batteries with tubular lead dioxide electrodes and flat lead electrodes has been studied by means of a two-dimensional model and experimental verification by polarization curves and potential transients during galvanostatic discharge. The cell geometry was modelled with and without separators and a tubular electrode envelope. The governing equations were solved with a finite element method. It was found that the tube envelope has a large impact on the current density distribution and had to be incorporated into the model to fit the experimental results. Although the envelope increases the ohmic losses, it has the positive effect of giving a more uniform current distribution around the electrode tube. A lead acid cell with tubular positive electrodes and flat negative electrodes can therefore be approximated by a one-dimensional model consisting of a positive electrode tube placed concentrically in a cylindrical lead electrode. The two-dimensional model was further used to study the effects of different design factors, for example, cell width and kinetic parameters of the lead dioxide electrode.     

Investigation on electrochemical properties of cerium doped lead dioxide anode and application for elimination of nitrophenol

The present work focused on the investigation of electrochemical properties of cerium doped lead dioxide anode, i.e. Ti/Ce–PbO₂. SEM, AFM, XRD and XPS were used to characterize the morphology, crystal structure and elemental states of the modified anode. Electrochemical impedance spectroscopy (EIS) was also utilized to study the electrochemical property of Ti/Ce–PbO₂. The electrochemical activity of the Ti/Ce–PbO₂ anode was investigated by means of bulk electrolysis and compared with that of a PbO₂ anode. The accelerated life test and oxidants determination were also conducted. The results indicated that the incorporation of cerium improved the electrocatalytic activity and stability of PbO₂ anode. The service life of Ti/Ce–PbO₂ electrode was much longer than that of traditional lead dioxide electrode. The electrochemical activity obtained from degradation of o-nitrophenol (o-NP) outperformed the traditional lead dioxide electrode as well. The Ti/Ce–PbO₂ electrode is considered a promising anode for the treatment of organic pollutants.     

Electrochemical deposition of lead dioxide in the presence of polyvinylpyrrolidone: A morphological study

In this work, we investigate the effect of polyvinylpyrrolidone (PVP) on the morphology and the interfacial properties of lead dioxide (PbO₂). The electrodeposition of lead dioxide was achieved in the presence of PVP on Pt and Ti substrates under constant current density from solutions containing Pb(NO₃)₂ and NaF in HClO₄. Scanning electron microscopy (SEM) showed that the morphology and particle size of PbO₂ are strongly affected by the concentrations of Pb(NO₃)₂, PVP and HClO₄. It seemed that PVP can control both the morphology and particle size of lead dioxide and increases the overpotential for oxygen evolution during the electrodeposition of lead dioxide. The resulting lead dioxide was composed of nano-metric globular particles aligned in rice shaped structure with diameter in the range of 30-50 nm. It was suggested that the growth of PbO₂ crystals is affected by the aqueous network of self-assembled surfactant formed on the electrode surface during the electrodeposition process. The electrochemical impedance spectroscopy (EIS) was used to investigate the interfacial behavior of deposited lead dioxide in 0.5 M H₂SO₄ solution. The EIS results revealed a typically porous electrode behavior consisted of a straight line, at high frequency region, turning to a potential dependent semicircle, at low frequency region, the diameter of which being decreased with increasing potential increments. The X-ray diffraction (XRD) patterns show that samples were composed of β-PbO₂.     

The lead dioxide electrode

The recent literature dealing with the redox mechanism of the lead-acid cell positive electrode is reviewed. The basis electrochemistry of lead dioxide in its various polymorphic modifications and states of subdivision is considered in relation to the important aspects of electrode technology of which the major industrial application of the material is the conventional lead-acid cell. The proposed mechanism of the reduction (discharge) of lead dioxide in various acidic solutions are considered in relation to the present state of electrode kinetic theory. The reverse reaction by which lead dioxide is formed and the parasitic intrusion of the self discharge are dealt with as a precursor to the total cyclic process. It is concluded that in a number of respects the mechanisms proposed do not adequately represent the totality of the experimental observations. Such shortcomings are emphasized and extensions to present research are proposed.     

A mathematical model for the porous lead dioxide electrode

A theoretical model for the porous lead dioxide electrode is proposed on the basis of the macrohomogeneous model for porous electrodes.The structural changes during discharge, due to precipitation of lead sulphate, are considered.The two main structural effects, plugging of the pores and gradual insulation of the active electrode surface by the reaction product, lead sulphate, are both considered by relating them to the local degree of discharge.The numerical results show that, at high current densities, the discharge capacity is limited by both structural and transport restrictions.At the end of discharge a layer of lead sulphate crystals blocks the electrode surface in the outer layers of the electrode. The current can then neither be transferred across this insulated surface nor reach remaining active material in the inner parts of the electrode because of acid depletion, which is furthermore accelerated by the decreasing porosity.     

掺杂铁的二氧化铅电极的制备及性能研究

主要研究了不锈钢/PbO₂电极和掺杂的不锈钢/Fe-PbO₂电极的制备,用其对有机废水的处理效果及影响因素来评价该电极的性能。实验结果表明:采用恒流阳极电沉积技术制备的PbO₂电极,掺杂和不掺杂铁的电极主要成分都是β-PbO₂;两电极外观都没有明显的裂纹等缺陷,掺杂铁的二氧化铅镀层颗粒大小镶嵌,很好地清除了内应力,保证了基材与镀层不易脱落,未掺杂铁的二氧化铅镀层颗粒细小、均匀,内应力有些大;将Fe（NO₃）₂添加至电沉积溶液中,致使PbO₂电沉积层的析氧电位向正方向移动,改善了PbO₂电极的电催化活性,以至于更有利于氧化降解有机物。用改性的Fe-PbO₂电极和常规的PbO₂电极分别降解初始浓度相同的邻苯二酚和苯酚有机物废水,改性的Fe-PbO₂电极对苯酚和邻苯二酚的去除率均高于常规的PbO₂电极。掺杂铁的二氧化铅电极较未掺杂电极有更好的电催化活性,更高的析氧电位,更适宜于用作电催化阳极。