PANI-SnP复合膜电极在镍镉废水中的电控离子交换性能

采用滴涂法在铂基底制备了电活性聚苯胺-磷酸锡(PANI-SnP)复合膜电极,考察了该电极在Ni2+、Cd2+溶液的电控离子交换性能.用傅立叶变换红外光谱和扫描电镜分析观察复合膜的组成及表面形貌;在0.1 mol.L-1Ni(NO3)2、Cd(NO3)2溶液中,通过循环伏安法比较了PANI膜、SnP膜及PANI-SnP复合膜电极的电化学性能,并结合电化学石英晶体微天平技术重点考察了PANI-SnP复合膜的离子交换机制;同时,通过循环伏安法调控复合膜电极的氧化还原电位,结合X射线能谱和X射线光电子能谱分别测定了其氧化和还原状态的元素组成.结果表明,PANI-SnP复合膜电极在Ni2+、Cd2+溶液均有良好的氧化还原电活性和可逆离子交换性能,其Cd2+离子选择性优于Ni2+离子,通过电控离子交换可使Cd2+离子从镍镉废水高效分离.     

铂-氧化铈/聚苯胺/聚砜复合膜电极的制备及对甲醇的电催化氧化

采用电化学聚合法制备了掺杂CeO2纳米粒子的聚苯胺(PAN)/聚砜(PSF)复合膜电极,在其上电沉积铂粒子,制得了铂-氧化铈/聚苯胺/聚砜的复合膜修饰电极。 复合膜的形貌和化学组分通过冷场发射扫描电子显微镜（Cold FE-SEM）和能量散射X射线谱（EDS）进行了表征,用循环伏安法和电化学交流阻抗法考察了复合膜电极对甲醇的电催化氧化性能。 结果表明,复合膜的双层多孔结构使铂粒子与CeO2粒子在复合膜内层的多孔聚苯胺上均匀沉积,粒子平均尺寸约为80 nm;CeO2为铂质量的7%时,铂-氧化铈/聚苯胺/聚砜复合膜修饰电极对甲醇有很好的电催化氧化性能和高的稳定性。     

PANI-SnP复合膜电极在镍镉废水中电控离子交换性能

采用滴涂法在铂基底制备了电活性聚苯胺-磷酸锡(PANI-SnP)复合膜电极,考察了该电极在Ni²⁺、Cd²⁺溶液的电控离子交换性能. 用傅立叶变换红外光谱和扫描电镜分析观察复合膜的组成及表面形貌;在0.1 mol·L^-1 Ni(NO₃)₂、Cd(NO₃)₂溶液,通过循环伏安法比较了PANI膜、SnP膜及PANI-SnP复合膜电极的电化学性能,并结合电化学石英晶体微天平技术重点考察了PANI-SnP复合膜的离子交换机制;同时,通过循环伏安法调控复合膜电极的氧化还原电位,结合X射线能谱和X射线光电子能谱分别测定了其氧化和还原状态的元素组成. 结果表明,PANI-SnP复合膜电极在Ni²⁺、Cd²⁺溶液均有良好的氧化还原电活性和可逆离子交换性能,其Cd²⁺离子选择性优于Ni²⁺离子,通过电控离子交换可使Cd²⁺离子从镍镉废水高效分离.     

载钯聚苯胺/聚砜复合膜修饰电极对甲酸的电催化氧化

采用电化学聚合法在铂电极表面制备了三维网状结构的聚苯胺(PAN)/聚砜(PSF)复合膜,并以此为载体制备了Pd/PAN/PSF复合膜电极,并用扫描电子显微镜对复合膜的微观形貌进行了表征。结果显示,此复合膜具有双层多孔结构,Pd纳米粒子在复合膜上平均粒径小、分散性好,有效地改善了Pd粒子的分散度和电极结构。电化学测试结果表明,Pd/PAN/PSF复合膜修饰电极对甲酸的电催化性能明显优于直接电沉积Pd的聚苯胺电极,并且表现出较高的稳定性。     

大面积铂-硅纳米线阵列的制备及其在增强甲醇电催化氧化中的应用

提出了一种室温条件下构筑铂覆盖硅纳米线阵列的有效方法.通过将种子生长法和化学沉积技术的有机结合,高质量的铂纳米结构被成功地构筑在硅纳米线阵列表面.采用扫描电镜、X-射线衍射和电化学方法对制备材料的形貌和性质进行了表征.结果表明:所沉积的铂膜具有多孔三维结构,展现了一个放大的电化学活性面积,是相同几何面积硅片电极的6.1...     

铝合金阳极氧化膜上交流电沉积制备含铈复合膜

通过交流电解沉积的方法在铝合金阳极氧化膜上制备了稀土铈复合膜, 并考察了氧化膜的厚度对形成复合膜的影响. 电解成膜溶液为含1 g · L-1 CeCl3 · 7H2O和10 mL · L-1 H2O2的水溶液, 正弦交流电的平均电压为10 V, 交流沉积的时间为5 min. 结果表明, 阳极氧化膜的厚度是影响成膜的主要因素, 在实验中, 氧化膜的厚度大于6.8 μm时才能形成连续均匀的复合膜. 测试分析结果表明, 复合膜表面的铈元素分布均匀, 平均含量为1.70%(质量分数);Ce元素主要分布在氧化膜多孔层的表层, 分布深度约1.5 μm.     

DMFC寿命测试过程中膜电极的表面和结构研究(英文)

设计并组装单电池寿命测试系统,测试直接甲醇燃料电池(DMFC)的运行寿命,获得不同运行时间下单电池的极化和功率曲线.测试结束后,分别对运行过的膜电极(MEA)催化剂(铂黑和铂钌黑)和Nafion117(膜作XRD,HRTEM,FTIR及Raman等表征.考察在长期运行条件下电池寿命性能与膜电极中催化剂的颗粒大小、分布、形态、表面物种以及膜的结构之间的关系.寿命测试结果表明,单电池在不同运行阶段其性能变化也不同.运行前200 h,电池性能衰减较显著;运行200~704 h性能较稳定,运行1 002 h后电池性能恶化.波谱实验发现,单电池长期运行后,其膜电极的阴、阳极催化剂颗粒变大.电池寿命性能的衰退伴随膜电极微结构、表面组成、催化剂/膜界面结构的变化以及Nafion 117(膜的老化.     

电极材料对含水花岗岩阻抗谱的影响

本文研究了不同电极材料对含水花岗岩阻抗谱的影响。在相同实验条件下,分别用铜、含氧化膜的钛片及钛/二氧化钛纳米管作为电极材料进行交流阻抗实验,结果表明,电极材料主要对阻抗谱的低频有影响,其中钛/二氧化钛纳米管电极的微观结构增大了其与岩石的接触面积,使有效导电通路增加,从而减小了测试阻抗,在同样的测试频率范围内得到更丰富的阻抗信息。     

碳纳米管添加剂对质子交换膜燃料电池低铂载量膜电极性能的影响研究

以碳纳米管（CNT）作为低铂载量膜电极（CCM）催化层（0.1 mg_Pt·cm^-2）添加剂，研究了CNT的添加方式对催化层微观结构以及膜电极性能的影响.结果表明，与常规低铂载量催化层相比，在其表面喷涂一层CNT或将CNT均匀分散到Pt/C催化层中均有利于提升低铂载量膜电极的输出性能，在70℃和100%相对湿度条件下最高输出功率比常规低铂载量膜电极的0.522 W·cm^-2分别提升了22.4%和60.0%，并且均匀分散添加方式优于分层添加方式.其原因在于分层添加CNT后改善了低铂催化层和气体扩散层之间的接触界面，降低了催化层与扩散层间的接触电阻，而均匀分散添加方式除了可降低界面接触电阻外，还显著改善了低铂催化层中的气体传输，大幅提升了Pt催化剂的利用效率，使得膜电极电化学反应电阻明显降低.进一步对均匀分散添加方式中CNT的载量进行优化，表明CNT添加量为37.5 μg·cm^-2时电池输出性能最佳，70℃和100%相对湿度条件下的最大输出功率达到0.91 W·cm^-2.本研究工作表明，将CNT均匀分散添加到催化层中是一种有效提升低铂载量膜电极性能的方法.     

过量铈对铸造高镍铬不锈钢耐蚀性的影响

通过腐蚀失重和电化学试验,研究了不同铈含量的铸造高镍铬不锈钢在还原性酸中的耐蚀性能。测定了钝化膜的自活化时间,分析了钝化膜表层的结构、元素含量和分布及其氧化物的组态。结果表明,当钢中铈含量超过0.1%时,在钝化膜表层由于铈的富集,使耐蚀元素铬、钼含量减少,降低其稳定性,削弱钼对钝化膜的修补作用,增加膜表层活性点,从而破坏了钢的钝化,降低其耐蚀性能。     

纳米多孔型碳基铂铜合金薄膜催化剂的结构及析氢性能表征

采用离子束溅射(Ion Beam Sputtering,IBS)与Pt、Cu移动双靶技术,结合真空退火及酸蚀处理等后处理工艺,制备出PtCu/C薄膜催化剂。采用高分辨透射电镜(HRTEMSTEM)、原子力显微镜测试(AFM)、X射线衍射(XRD)测试薄膜催化剂的表面形貌及组织结构。通过循环伏安法(CV)和线性扫描伏安法(LSV)测试薄膜催化剂的电化学析氢性能。结果表明,经过真空退火(400℃保温1 h)及酸蚀处理(1 mol/L HNO3,50℃,120 h)后的薄膜催化剂出现类蜂窝状纳米多孔结构,其电化学析氢交换电流密度达到0.004 27 A/cm2,相较于未后处理样品的铂载量降低8.77%,催化性能提升20.62%。     

Electrochemical response of natural and induced passivation of high strength duplex stainless steels in alkaline media

The passivation of two high strength duplex stainless steels (HSSS) was investigated in alkaline solutions simulating the pore solution of concrete by the growth of natural and induced passive films. Induced passive films were generated both by cyclic voltammetry and by chronoamperometry. Natural passive films were spontaneously grown by the immersion of the steel in the alkaline electrolyte. These passive layers were characterised by electrochemical impedance spectroscopy, corrosion current density (i _corr) and corrosion potential (E _corr) monitoring. The effect of significant parameters, such as the pH in the HSSS/alkaline solution interface, the composition of the duplex stainless steels and the ageing of the passive layer, on the electrochemical performance of both induced and spontaneously grown passive films has been analysed. The increase of alkalinity highly influences the electrochemical performance of the passive film by promoting the formation of a passive layer with a less resistant electrochemical response. The electrochemical behaviour of the passive layer is also affected by the alloying elements like Mo or Ni. Both natural and induced passive films show similar electrochemical trend with respect to significant parameters such as the pH and the composition of the steel. The ageing of the spontaneously grown passive layer promotes a higher resistive electrochemical response which might be related to the enrichment of the passive layer in non-conducting (or semi-conducting) oxides.     

纳米氧化锰负载钛基电催化膜制备及处理含酚废水性能研究

以多孔钛膜为基膜,醋酸锰为锰源,采用溶胶凝胶法制备出负载纳米氧化锰的钛基电催化膜（nano-MnO_x/Ti膜）. 运用X射线衍射(XRD)、 X射线光电子能谱(XPS)、场发射扫描电子显微镜(FESEM)、循环伏安法(CV)、交流阻抗法（EIS）和计时电流法(CA)等测试手段,对MnO_x/Ti膜电极的微观形貌、晶型、电化学性能等进行表征. 结果表明：所得催化剂是由直径为50 nm的γ-MnO₂和Mn₂O₃纳米棒所组成,且均匀分布于Ti膜上,负载催化剂后钛膜电极电化学性能和催化性能明显提高,催化剂与基体之间键合的形成提高其稳定性. 以棒状nano-MnO_x/Ti膜电极为阳极构建电催化膜反应器(ECMR)处理含酚废水,当苯酚溶液浓度为10mmol·L^-1,电流密度为0.25mA·cm^-2、停留时间为15 min时,COD去除率可达95.1%.     

Solvent effects on Pt-Ru/C catalyst for methanol electro-oxidation

Alloying degree, particle size and the level of dispersion are the key structural parameters of Pt-Ru/C catalyst in fuel cells. Solvent(s) used in the preparation process can affect the particle size and alloying degree of the object substance, which lead to a great positive impact on its properties. In this work, three types of solvents and their mixtures were used in preparation of the Pt-Ru/C catalysts by chemical reduction of metal precursors with sodium borohydride at room temperature. The structure of the catalysts was characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). The catalytic activity and stability for methanol electro-oxidation were studied by Cyclic Voltammetry (CV) and Chronoamperometry (CA). Pt-Ru/C catalyst prepared in H₂O or binary solvents of H₂O and isopropanol had large particle size and low alloying degree leading to low catalytic activity and less stability in methanol electro-oxidation. When tetrahydrofuran was added to the above solvent systems, Pt-Ru/C catalyst prepared had smaller particle size and higher alloying degree which resulted in better catalytic activity, lower onset and peak potentials, compared with the above catalysts. Moreover, the catalyst prepared in ternary solvents of isopropanol, water and tetrahydrofuran had the smallest particle size, and the high alloying degree and the dispersion kept unchanged. Therefore, this kind of catalyst showed the highest catalytic activity and good stability for methanol electro-oxidation.     

锂离子电池SiAg复合材料研究

应用机械合金化法制备了两种不同组分的Si-Ag复合材料.扫描电镜(SEM)、X射线衍射(XRD)、充放电测试和循环伏安法对该材料的微观形貌、相组成及电化学性能.研究表明,组成原子比为1∶1的复合材料具有很好的循环稳定性和可逆性,在0.2mA·cm-2的电流密度下,经50周循环后可逆容量仍保持300mAh·g-1.实验发现,借助充放电控制,即可有效提高合金材料的循环性能.     

Ni Foam-Supported Tin Oxide Nanowall Array: An Integrated Supercapacitor Anode

A novel product consisting of a homogeneous tin oxide nanowall array with abundant oxygen deficiencies and partial Ni-Sn alloying onto a Ni foam substrate was successfully prepared using a facile solvothermal synthesis process with subsequent thermal treatment in a reductive atmosphere. Such a product could be directly used as integrated anodes for supercapacitors, which showed outstanding electrochemical properties with a maximum specific capacitance of 31.50 mAh·g⁻¹ at 0.1 A·g⁻¹, as well as good cycling performance, with a 1.35-fold increase in capacitance after 10,000 cycles. An asymmetric supercapacitor composed of the obtained product as the anode and activated carbon as the cathode was shown to achieve a high potential window of 1.4 V. The excellent electrochemical performance of the obtained product is mainly ascribed to the hierarchical structure provided by the integrated, vertically grown nanowall array on 3D Ni foam, the existence of oxygen deficiency and the formation of Ni-Sn alloys in the nanostructures. This work provides a general strategy for preparing other high-performance metal oxide electrodes for electrochemical applications.     

Pd-Fe/C催化剂中Fe的状态对氧还原电催化活性的影响

直接甲醇燃料电池;Pd-Fe/C催化剂;氧还原;合金化     

Synthesis and characterization of benzimidazolium‐functionalized polysulfones as anion‐exchange membranes

Anion‐exchange membranes containing pendant benzimidazolium groups were synthesized from polysulfone by chrolomethylation followed by nucleophilic substitution reaction with 1‐methylbenzimidazole. The structures of the polymers were characterized by ¹H‐NMR and FTIR analysis. The resulting membranes showed high thermal stability below 200 °C. The values of water uptake and swelling degree increased with the ion‐exchange capacity of the polymeric membrane. The ionic conductivity was measured by means of impedance spectroscopy in aqueous solution of potassium hydroxide (10^?4?10^?1 M). The results show not only a clear correlation between the membrane's electrochemical behavior with the electrolyte solution embedded in the membrane, but also with the degree of the polysulfone's chloromethylation.Thus, the ionic conductivity increased more than two orders of magnitude when the degree of chloromethylation increased from 40 to 140%. Benzimidazolium‐functionalized polysulfones exhibited better thermal, mechanical, and electrochemical properties than the widely used polymeric membranes containing quaternary ammonium groups. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2363–2373     

纳米颗粒对Ni基复合镀渗层耐冲蚀性能的影响

采用复合镀渗工艺在316L不锈钢表面分别制备了两种纳米颗粒(非晶nano-SiO2颗粒和nano-SiC颗粒)增强的Ni基复合镀渗合金层. 利用扫描电子显微镜(SEM)和透射电子显微镜(TEM)观察了两种复合镀渗合金层的微观组织特征. 通过外加电位(+0.2 V)条件下的电流密度、冲蚀条件下的极化曲线和冲蚀后的交流阻抗谱表征了这两种复合镀渗层在单相流(3.5%(w, 质量分数)NaCl溶液)与料浆流(3.5%NaCl+10%(w)石英砂)中的电化学腐蚀特征, 并采用SEM观察两种复合镀渗层冲蚀后的截面形貌, 探讨这两种纳米颗粒增强的Ni基复合镀渗层在料浆流中的冲蚀机理. 电化学测试结果表明: 静态条件下, 电刷镀含纳米SiO2颗粒的复合镀渗层的耐蚀性能低于单一合金层, 而动态冲蚀条件下, 结果与之相反; 电刷镀含SiC颗粒的复合镀渗层的耐蚀性能在静态和动态冲蚀条件下均低于单一合金层. 对两种复合镀渗层的冲蚀截面形貌观察表明: 弥散分布的纳米SiO2颗粒能明显改善Ni基合金层的耐冲蚀性能; 而添加纳米SiC颗粒在渗金属过程中已完全分解, 导致三元硅化物(Cr6.5Ni2.5Si)和碳化物(Cr23C6)的析出, 而析出相在冲蚀过程易于脱落, 加速了Ni基合金层的质量流失.     

Synthesis of anion conducting polymer electrolyte membranes by Pd-Catalyzed Buchwald-Hartwig Amination coupling reaction

A novel aryl bromine bearing polymer was synthesized by Friedel-Crafts polycondensation. This precursor polymer substrate was used for C–N coupling via Buchwald-Hartwig amination to incorporate 9 examples of aryl amines into the polymer chains with high conversions (80–100%). Two aminated polymers were subsequently quaternized to give anion conducting polymers. These quaternary ammonium polymers show promising electrochemical membrane property because of their ability to transport mobile anions through the material while being electrically insulating. Membrane characteristics crucial to high electrochemical performance including ion exchange capacity, anion conductivity, water uptake, swelling ratio, and alkaline stability were evaluated.