硫酸溶液中Ag+离子对Mn2+离子阳极氧化的催化作用

Anodic oxidation of Mn2+ and Ag+ ions and anodic oxidation of Mn2+ ion on platinum electrode in H2SO4 solution catalyzed by Ag+ ion are studied by using RRDE and triangle voltammetry techniques. Mn2+ ion is oxidized on the anode surface with adsorped OH group to form a certain compound containing Mn3+, which causes Mn2+difficult to be oxidized directly on anode. Near the potential of oxygen evolution from H2O decomposition, Ag+ ion is oxidized to form Ag2+ ion. This is the main reaction on anode because of its reversability. At higher potential silver oxide is formed on the anode. The oxide catalyzes the decomposition of H2O strongly. The anodic oxidation of Mn2+ion catalyzed by Ag+ takes place and Ag2+ ion and silver oxide are no longer the product of Ag+ anodic oxidation when Mn2+ exists in solution at the potential for Ag+ anodic oxidation. It is confirmed that the catalysis reaction is homogeneous and very fast.     

Selection of Anodic Material Used in Electrolytic Process for Producing Hypophosphorous Acid

Black lead, Ti-Ru and Ti-PbO2 were used as anode and stainless steel was used as cathode The electrolytic process of producing hypophosphorous acid with four-compartment electrodialytic cell was studied. The comparison of some factors, such as anodic voltage, product concentration and current efficiency, of black lead, Ti-Ru, and Ti-PbO2 electrodes was conducted. As a result, theTi-PbO2 electrode is the optimal anode material used, it can be in electrolytic process for producing hypophosphorous acid.     

Ti基IrO2＋Ta2O5阳极在H2SO4溶液中的电解时效行为

研究了450 ℃制备所得Ti/70％IrO2 30％Ta2O5（摩尔分数）高寿命阳极在H2SO4溶液电解过程中电极的物理、化学及电化学性能的时效行为.结果发现，整个电解过程可分为“活化”、“稳定”及“失效”三个阶段.在“活化”及“稳定”区内主要发生电极表面活性氧化物的溶解，涂层中IrO2金红石相的（110）、（101）晶面择优取向随电解时间延长而减弱，而（002）晶面择优增强.但是在“失效区”内，各晶面的择优程度却不随电解时间的变化而变化，这表明在“失效区”内氧化物的损失机制发生了变化.电化学阻抗谱测试表明，电极的析氧电化学反应电阻随电解时间的延长发生缓慢而连续的上升，而整个电极的物理阻抗在“失效区”内却发生突升现象.X射线衍射分析（XRD）表明，随电解时间的延长TiO2金红石相的衍射强度增大，达“失效区”时衍射强度发生突升.根据实验现象特别是“失效区”内阳极的时效行为提出高寿命Ti基氧化物涂层阳极的失效机制.     

采用循环伏安与Tafel曲线比较不同阳极的电催化性能

采用循环伏安和Tafel曲线两种方法评价了Pt电极、钛基二氧化钌电极(Ti/RuO2)及钛基二氧化锡电极(Ti/SnO2)的电催化氧化性能.结果表明,在500 mg/L的苯酚溶液中,Pt,Ti/RuO2和Ti/SnO2电极氧化苯酚的峰电位依次为0.93,0.95和1.40 V(vsAg/AgCl).Tafel曲线表明,三种电极析氧过电位的顺序依次是Ti/RuO2相似文献   

纳米金标记电化学检测DNA特异性结合蛋白

将单分子发夹寡核苷酸固相延伸形成双链寡核苷酸, 以纳米金颗粒标记NF-κB并银染放大, 采用阳极溶出电位法对NF-κB进行检测. 结果表明, 本法检测序列特异性蛋白质具有高度特异性、高灵敏度和快速等特点, 为转录因子调控机制、开放阅读框识别和功能基因检测等的研究提供了有利工具.     

铈、锂盐对铝阳极氧化膜的协同封闭作用

研究了铈、锂盐在铝阳极氧化膜封闭处理中的协同作用.场发射扫描电镜和X射线衍射谱对铈、锂盐协同封闭前后铝阳极氧化膜形貌和结构的研究结果表明，封闭后膜表面的孔洞消失，封闭产物分布均匀，封闭后膜仍然以非晶态形式存在.根据X射线光电子能谱的结果，封闭后的膜主要由含结晶水的Al2O3及铈、锂的混合氢氧化物组成，同时膜中还含有及封闭溶液组分中的一些阴离子.电化学阻抗谱的研究结果表明铈、锂盐协同封闭能够显著提高膜的耐蚀性能.在实验结果基础上，初步认为铈、锂盐封闭是通过生成结构紧密的封闭产物填充、覆盖膜孔，从而显著提高铝阳极氧化膜的耐蚀性能.     

DNA在纳米金标上的组装、杂交、检测与银增强

利用电化学方法进行DNA的杂交检测.将目标ss-DNA固定在玻碳电极表面, 使其与纳米金标记的互补DNA发生杂化反应, 通过银增强试剂（该种试剂可以使银在纳米金表面沉积, 达到信号增强的效果）在纳米金上沉积银, 形成银包金的核壳结构.在酸性介质中沉积的银被氧化释放, 以离子状态存在于溶液中.用阳极溶出伏安法(ASV)检测银离子从而达到间接检测目标DNA的目的.测定结果表明，ss-DNA的浓度在100～1 000 pmol•L－1 范围内有非常好的线性关系, 检测限为10 pmol•L－1.     

取向碳纳米管/硅纳米线复合阵列的制备

在阳极氧化铝模板(AAO)的取向微孔内, 利用化学气相沉积(CVD) 技术首先制备了两端开口高度取向的碳纳米管阵列, 再在碳纳米管中间的孔洞内沉积硅纳米线, 成功制备了碳纳米管/硅纳米线(CNTs/SiNWs)核鞘复合阵列结构. 用SEM, TEM, XRD等仪器分析了CNTs/SiNWs核鞘复合阵列和沉积在碳纳米管孔洞内的硅纳米线的生长特性和晶体结构, 利用I-V关系和Fowler-Nordheim方程研究了其场发射(FE)特性, 用荧光光谱分析仪分析了复合阵列的荧光(PL)特性. 证明了模板法制备的CNTs/SiNWs核鞘复合阵列结构可用来制作具有金属/半导体(M/S)特性的纳米PN结, 该复合阵列结构也使SiNWs包覆在CNTs惰性鞘内, 可防止SiNWs在空气中的进一步氧化. 制备出的CNTs/SiNWs核鞘复合阵列结构生长方向高度有序, 直径和长度易于控制, 极少产生其他制备方法中出现的纳米结构弯曲和相互缠绕现象.     

Improved device reliability in organic light emitting devices by controlling the etching of indium zinc oxide anode

A controllable etching process for indium zinc oxide （IZO） films was developed by using a weak etchant of oxalic acid with a slow etching ratio. With controllable etching time and temperature, a patterned IZO electrode with smoothed surface morphology and slope edge was achieved. For the practical application in organic light emitting devices （OLEDs）, a sup- pression of the leak current in the current-voltage characteristics of OLEDs was observed. It resulted in a 1.6 times longer half lifetime in the IZO-based OLEDs compared to that using an indium tin oxide （ITO） anode etched by a conventional strong etchant of aqua regia.