Cu_2O/聚苯胺/不锈钢电极光电催化还原CO_2

利用电化学氧化还原法在不锈钢基底上制备聚苯胺纳米管(PANI-NTs),将Cu2O沉积到PANI-NTs上,得到Cu2O/PANI/不锈钢电极,通过循环伏安法(CV)考察了Cu2O/PANI/不锈钢电极的电化学行为。采用XRD、TEM对Cu2O/PANI/不锈钢电极的结构进行了表征,借助乙酰丙酮分光光度法和气相色谱法对CO_2还原产物进行了检测。结果表明:PANI在不锈钢基底上以直立的中空纳米管形式横向生长,内径约为100 nm,外径约为200 nm;Cu2O/PANI/不锈钢电极对HCO3-/CO_2具有优良的光电催化还原性能;Cu2O/PANI/不锈钢电极光电催化还原CO_215 h后,溶液中甲醛的浓度为29.5μmol/L。     

Cu2O/PANI/不锈钢电极光电催化还原CO2

利用电化学氧化还原法在不锈钢基底上制备聚苯胺纳米管(PANI NTs),将Cu2O沉积到PANI NTs,得到Cu2O/PANI/不锈钢电极,通过循环伏安法（CV）研究Cu2O/PANI/不锈钢电极的电化学行为。采用X-射线衍射（XRD）、透射电子显微镜（TEM）对Cu2O/PANI NTs进行结构表征,借助乙酰丙酮分光光度法和气相色谱法对CO2还原产物进行检测。结果表明：PANI在不锈钢基底上以直立的中空纳米管的形式横向生长,内经约为100nm,外径约为200nm;Cu2O/PANI NTs具有优良的光电催化还原性能,对 /CO2具有催化活性;Cu2O/PANI/不锈钢电极光电催化还原CO215h 后溶液中甲醛的浓度为29.5μmol/L。     

甲醛的电化学检测方法研究

甲醛是一种电活性不活泼的有机物质,其很难在电极表面直接电催化氧化,所以利用复合纳米材料对甲醛的催化作用,将复合纳米材料修饰在玻碳电极表面制成修饰电极,进而利用修饰电极对甲醛的电催化活性,从而建立甲醛的电化学检测分析方法。以玻碳电极为基础电极,将氧化石墨烯用滴涂法滴涂于基础电极表面,再在饱和的氯化钾溶液中还原,随后采用电沉积法将纳米铂粒子沉积于还原的氧化石墨烯表面,制备出纳米铂/石墨烯复合电极,依据甲醛在电极表面反应时,产生了电流的改变,甲醛的浓度与产生的氧化电流成线性关系,从而建立了甲醛的电化学分析方法,并对其条件优化进行了探究。     

一步电沉积制备高活性高稳定镍铁合金析氧电催化剂

以镍网为基底,通过一步电沉积方法成功制备出用于碱性水电解的多孔镍铁合金析氧反应(Oxygen Evolution Reaction,OER)电极.镍铁的沉积伴随强烈的析氢,此条件下构筑出的多级孔结构成为电极用于OER反应时液相中传质与气泡释放的适宜传递通道.在析氧反应中,电流密度为10 mA·cm-2时的过电位仅为21...     

几种多孔电极材料镓电沉积性能的研究

在工业上,稀散金属镓通常是从碱性溶液中电解提取得到的。在镓电解过程中,由于析氢副反应和传质速率低的原因导致镓电沉积的电流效率很低。本工作采用三维多孔电极电沉积镓,利用三维多孔电极发达的表面积促进镓电沉积过程,研究了不同电极材料(泡沫金属和多孔碳)的析氢特性,结合不同电解温度和电流密度下各材料的镓电沉积行为,揭示三维多孔电极上镓电沉积的特性规律。结果表明,泡沫铜和石墨毡(GF)具有较低的析氢活性,但两种电极的镓电沉积性能差别很大。其中泡沫铜表现出最佳的镓电沉积性能,在温度为40℃、电流密度为0.1 A/cm²条件下镓电沉积的电流效率(QE)达到22.5%,远高于铜片电极(10.7%);而相同条件下,GF电极的QE值仅为9.6%,低于铜片,这与电极表面的疏水性有关。具有较高析氢活性的泡沫铁、泡沫镍和网状玻璃碳(RVC)电极的镓电沉积过程受电解温度和电流密度的影响较大。在高电流密度下,泡沫铁电极表现出仅次于泡沫铜的QE值,在低电流密度下难以发生镓的电沉积;泡沫镍和RVC电极仅在低于镓熔点(20℃)的条件下发生镓的电沉积,在高于镓熔点(40℃)的条件下,由于电沉积的液态镓...     

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。     

电沉积制备多孔铅电极及其对CO2的电还原性能

采用铜片为基底,利用其自身析出的氢气泡为模板,通过电沉积的方法合成了具有三维多孔结构的铅沉积层,并将其作为电极材料应用到CO2的电还原反应中.考察了不同沉积时间及不同沉积电流密度对电极形貌及电催化还原CO2性能的影响,得出在5℃下,沉积电流密度为-6 A/cm2,沉积时间为20 s时,电极催化效果最好,在施加电位为-1.7V时生成甲酸的最高电流效率可达96.8％.     

不锈钢基二氧化铅-碳化钨-氧化铈复合电极的制备

研究了不锈钢基体上PbO2-WC-CeO2复合电极材料的电沉积工艺,通过分析其在由65g/LZn2+和150g/LH2SO4组成的电解锌液中的析氧动力学参数、Tafel曲线以及扫描电镜观察,考察了温度、电流密度和WC、CeO2固体颗粒质量浓度对该电极催化活性和耐蚀性的影响,确定了复合电沉积的较佳工艺:CeO240g/L和WC20g/L,电流密度25mA/cm2,温度60°C。在此工艺条件下可以获得致密、均匀的不锈钢基PbO2-WC-CeO2复合电极材料,其交换电流密度为0.732A/cm2,腐蚀电流密度为3.924×105A/cm2。     

不锈钢基催化电极的制备及应用

以不锈钢基为基体,制备了PbO2/PbO2-CeO2电催化电极,研究了沉积温度、电流密度、稀土等因素对电沉积PbO2电极的影响,通过实验确定了制备电极的沉积温度为60℃,电流密度为5～15mA/cm2,且加入稀土能够细化PbO2颗粒.将电极应用到罗丹明B溶液脱色处理中,结果表明在20min催化时间内溶液脱色率可以达到100%,电压对溶液脱色率的影响不大,随电流密度的增加,脱色率显著升高.     

改性PbO_2电极的制备参数优化及对苯酚去除性能的研究

采用电沉积的方法制备改性的钛基PbO2电极。通过在降解苯酚过程中改变制备电极的涂刷次数、电沉积温度、制备电极电流密度、电沉积液的性质和表面掺杂其他金属影响因素,来优化制备改性钛基PbO2电极的工艺参数。实验结果表明:底层涂刷2次,电沉积液温度85℃,制备中间层电流密度为8mA/cm2,电沉积2h,制备表层电流密度为6mA/cm2,电沉积2h,电沉积液中加入0.5g/L的NaF,电极表面层掺杂5mmol铋对Ti/β-PbO2电极降解苯酚电催化性能有明显改善,掺杂1.5mmol的钴电极降解苯酚较好,而铁掺杂的Ti/β-PbO2电极没能取得良好的电极稳定性。铋掺杂的Ti/β-PbO2电极对苯酚的去除率达到98.8%。     

Kinetics of hydrogen evolution reaction on a stainless steel electrode

The kinetic parameters for the hydrogen evolution reaction on a stainless steel substrate have been obtained from a study of the steady-state polarization curves as well as the galvanostatic transients. The high Tafel slope obtained in the steady-state polarization measurements was ascribed to the presence of an oxide film present on the surface of the stainless steel electrode.     

不锈钢基PbO2电极电催化氧化降解甲基橙性能的研究

本研究以自制的不锈钢基PbO2电极对25mg·L^-1的甲基橙溶液进行电催化氧化降解。考察了电流密度、支持电解质浓度、溶液pH值、温度等因素对甲基橙脱色率的影响,确定了电催化氧化甲基橙的最佳反应条件,即电流密度为50mA/cm^2,支持电解质Na2SO4的浓度为0．04mol·L^-1,降解20min后,甲基橙脱色率可达到90％以上。本研究还对几种不同印染废水进行了电催化氧化降解,结果表明,不锈钢基PbO2电极对不同的印染废水均有较好的脱色效果。     

Stainless steel electrode characterizations by electrochemical impedance spectroscopy for dye-sensitized solar cells

Electrochemical impedance spectroscopy (EIS) was used to understand the electrochemical mechanisms which appear in dye-sensitized solar cells (DSSCs). This qualitative and quantitative technique permits identification of the phenomena proceeding within the different elements composing the cell and at their interfaces.In this study, the classical conducting glass substrate was replaced by a protected stainless steel (304 type) substrate as the counter-electrode (cathode) in dye-sensitized solar cells. Platinum was deposited at the substrate surface to optimize the charge transfer resistance of the electrode.After a few days of immersion in the electrolytic solution, stainless steel substrates coated with low thickness of Pt show pitting corrosion due to iodine. Defects in the Pt layer such as discontinuity of the film and micro-cracks may explain the corrosion of the stainless steel substrate. However the Pt layer degradation is retarded for thicker films. On the other hand, polished substrates show a better behaviour probably due to the elimination of the defects on the stainless steel surface.Electrolytic solution was optimized. For this, components such as 1-butyl-3-methylimidazolium iodide (BMII), guanidine thiocyanate (GT) and 4-tert-butylpyridine (TBP) were added. No corrosion phenomena on stainless steel 304 appeared within 3 days when TBP was added. This means that TBP acts as a corrosion inhibitor.A schematic equivalent circuit is also proposed.     

Protection of stainless steel by polyaniline films against corrosion in aqueous environments

Polyaniline (PANI) thin films were electrochemically deposited by cyclic voltammetry on stainless steel electrode previously covered by a thin film of polyvinyl acetate (PVAc). The corrosion resistance of PANI covered stainless steel substrates was estimated by using potentiodynamic polarization curves and its linear polarization resistance (LPR) was measured in 0.5 M H₂SO₄, 0.5 M NaCl and 0.5 M NaOH aqueous solutions at room temperature. The results indicate that the PANI-PVAc films did improve the corrosion resistance of the stainless steel in NaOH, behaving even worst, in the case of PANI film, than the uncoated substrate. In H₂SO₄ both PANI and PANI-PVAc coatings gave good protection for the stainless steel electrode, with a slightly better performance of PANI-PVAc than PANI. In NaCl solution both PANI and PANI-PVAc films provided a good protection against corrosion. The better performance of PANI-PVAc coatings for corrosion protection in basic media may be due to its major chemical stability compared to simple PANI films, which lose their conductivity in high pH solutions. The E _corr (free corrosion potential) value of the coated substrate was in the passive region of the uncoated substrate in acidic environment but in the active region in neutral or basic environment.     

Synthesis and characterization of poly(aniline) and poly(o-anisidine) films in sulphamic acid solution and their anticorrosion properties

Poly(o-anisidine) (POA) and polyaniline (PANI) coatings were synthesized on platinum (Pt) surface and stainless steel (SS) in monomer containing 0.50 M sulphamic acid (SA) solution by means of cyclic voltammetry (CV) technique. Meanwhile, poly(o-anisidine) film was also deposited with a different scan rate on SS electrode. The behaviour of PANI and POA films obtained on stainless steel examined by CV was different from the one obtained for PANI and POA on Pt electrode. The corrosion performances of PANI and POA coatings in 3.5% NaCl solution were investigated with anodic polarization technique and electrochemical impedance spectroscopy (EIS). EIS measurements verified the effect of monomers and that of scan rate on corrosion inhibition of coatings on SS electrode. The results showed that POA film synthesized at low scan rate exhibited an effective anticorrosive property on SS electrode. POA synthesized at low scan rate and PANI coatings provided a remarkable anodic protection to SS substrate for longer exposure time than the one observed for POA coating produced at high scan rate as well as that of bare SS electrode.     

电化学法对印染废水CODCr的处理效果研究

印染废水成分复杂,可生化降解性差。采用Fe-PbO2/不锈钢为阳极,不锈钢为阴极,活性炭为颗粒电极,电催化氧化处理上海某印染厂废水。当pH为3,电流密度为0.028 A/cm2,硫酸铝浓度为0.16 mol/L,极板距离为6 cm,电解时间为10 min时CODCr去除率达到71.1%,BOD5/CODCr由处理前的0.126上升为0.34,可生化降解性明显提高。Fe-PbO2/不锈钢阳极和不锈钢阳极在印染废水中的循环伏安曲线表明镀PbO2层的不锈钢电极具有较好的催化活性。     

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。     

流动腐蚀介质中双相不锈钢的电化学阻抗谱

测定了流动氯化物体系中双相不锈钢电极的电化学阻抗谱,发现在单相流中,当流速低于临界值时,阻抗谱为直径较大的容抗弧;一旦流速超过临界值,阻抗谱特征为2个容抗弧.流动介质中加入固体颗粒之后,阻抗谱在低流速下高频区为容抗弧,低频区为直线段,而高流速下低频区则出现实部收缩现象.根据腐蚀电化学理论,提出了流动体系中双相不锈钢电极反应过程动力学模型,较好地解释了流动体系中双相不锈钢电极的电化学阻抗谱,进一步揭示了电化学腐蚀在双相不锈钢流动腐蚀过程中的主导作用机理.     

A DC electrochemical method for studying the inhibition of metal corrosion by chromate-containing paint

A DC potentiodynamic curve method is used to observe the effect of a pigmented organic coating on the passivity of a metal substrate. In this method, a painted metal coupon, which is scribed to expose metal, functions as the working electrode (WE) of an electrochemical cell; the cell includes a graphite bar counter electrode (CE), a saturated calomel reference electrode (RE), and aqueous electrolyte. Increasingly oxidizing potentials are imposed on the WE by a potentiostat, and current between the WE and CE is measured at each applied potential. The resulting current–voltage (I–V) curve indicates effects of the coating on the metal's open circuit potential and passivity. The passivating effect of a chromate-containing primer paint on mild steel is demonstrated and compared to the passivity of 316 stainless steel.     

Effect of hydrodynamics on the deposition of CaSO4 scale on stainless steel

Laboratory experiments were conducted using a rotating cylinder electrode apparatus to study the effect of solution hydrodynamics on the deposition of calcium sulfate scale on stainless steel substrate. The results indicate that the solution hydrodynamics has a significant bearing on the deposition rate of calcium sulfate. The results are in agreement with the theoretical prediction of a diffusion controlled process. Furthermore, scanning electron microscopy revealed the secondary nucleation growth of prismatic needle- or rod-like crystals branching out randomly over the already existing primary crystals of CaSO₄ on the SS-316 substrate.