石墨烯电化学传感器检测4-氯苯氧乙酸的研究

将利用电化学法制备的石墨烯溶于N,N-二甲基甲酰胺溶液中超声分散1 h,并滴涂在玻碳电极表面,构建了一种基于石墨烯修饰电极的电化学传感器。利用循环伏安法和线性扫描伏安法探究了4-氯苯氧乙酸在该修饰电极上的电化学行为,差分脉冲伏安法检测了4-氯苯氧乙酸的浓度。结果表明,该传感器在浓度为0.5～100μmol/L的范围内呈良好的线性关系,最低检出限为0.13μmol/L(S/N=3)。具有良好的稳定性和抗干扰能力,将其应用于黄豆芽中的4-氯苯氧乙酸的检测,回收率为93.36%～101.40%。     

甲醛在nano-Pt/GC电极上的电催化氧化研究

应用循环伏安法制备了nano-Pt/GC电极,并用SEM和电极在H2SO4中的循环伏安曲线对其进行了表征。结果表明,该方法制备的电极表面铂粒子分布较为均匀,粒径大小约为140nm,电极具有较大比表面积。电化学实验表明,该电极对甲醛电氧化的催化活性明显好于铂片电极。修饰电极的催化活性与铂粒子的沉积条件有关,铂微粒在电极表面的最佳沉积条件为循环次数100次和沉积速度5mV/s。     

甲醇在聚苯胺修饰铂钼共沉积电极上的催化氧化

用恒电位法和循环伏安法在铂电极上分别制备了聚苯胺修饰的分散氢钼青铜电极和分散铂电极,以及聚苯胺修饰的不同铂钼比例的铂与氢钼青铜共沉积电极。用循环伏安法研究了制备电极在c(H2SO4)=0.5mol/L水溶液中的电化学行为,以及对c(CH3OH)=0.1 mol/L的催化氧化行为。其中,分散氢钼青铜电极对甲醇无催化氧化的作用,铂与氢钼青铜共沉积电极对甲醇的催化氧化效果优于分散铂电极。铂-氢钼青铜共沉积电极对甲醇氧化的催化能力与共沉积铂钼的比例有关,当制备电极所用的溶液中n(氯铂酸)∶n(钼酸钠)=2∶1时,共沉积电极对甲醇的催化氧化活性最高,此时甲醇在共沉积电极上的氧化峰电流是单纯铂电极的2.632倍。     

电化学方法研究KOH溶液中高铁酸根的性质

在铂微盘电极上利用电位阶跃和循环伏安技术,求出了高铁酸根离子在不同温度、不同浓度的KOH溶液中的扩散系数.探讨了高铁酸根离子在KOH溶液中扩散传质过程的特点对超铁电池放电性能所造成的影响.另外,循环伏安试验发现高铁酸根离子在KOH溶液中的电化学还原是一个多步过程.     

非水体系中铂微盘电极上甲酸的电催化氧化行为

采用循环伏安法,以铂微盘为工作电极,铂片为辅助电极,饱和甘汞电极为参比电极,研究了甲酸在含有四丁基高氯酸铵(TBAP)电解质的乙腈有机溶液中的电氧化行为,并探讨了扫描速度、底物浓度和温度等因素对甲酸电化学氧化行为的影响.结果表明该反应是受扩散控制的不可逆反应.     

甲醇在碳载纳米Pt电极上的电化学研究

应用循环伏安法制备了nano-Pt/GC修饰电极,优化了铂微粒在电极表面的沉积条件,并用扫描电子显微镜(SEM)和在硫酸中的循环伏安曲线对其进行了表征。结果表明铂微粒较为均匀地分散在玻碳电极表面,粒径约为140nm,电极具有很大的比表面积。循环伏安实验结果表明nano-Pt/GC电极对甲醇电氧化的催化活性明显高于铂片电极,在该修饰电极上甲醇正向扫描和反向扫描时的氧化峰电位分别是0.67V和0.49V,峰电流为61.00mA/cm2和50.50mA/cm2,分别是铂片电极上的3.13倍和3.10倍,有效地提高了金属铂的利用率,铂微粒在电极表面的最佳沉积条件是循环次数为100次和沉积速度为5mV/s。     

金微粒修饰的电极对细胞色素C的直接电化学响应

采用循环伏安法制备了金微粒修饰的金刚石膜电极。用循环伏安法、电化学交流阻抗法对得到的修饰电极进行了表征。同时考查了细胞色素C在修饰电极上的电化学行为,发现细胞色素C在修饰电极上有显著的直接电化学响应,其氧化还原峰电流与扫描速度呈良好的线性关系,表明细胞色素C在修饰电极上呈现吸附控制的电极反应过程。     

具有微通道的微型饱和银-氯化银电极的研制及其应用

介绍了一种自制的参比电极。银丝为工作电极,在盐酸溶液中用循环伏安法制得了银-氯化银电极,它的形貌是由棒状的氯化银和银颗粒构成。其策略是根据铂丝与硬质玻璃的线性热膨胀系数的差异,将铂丝熔融封入硬质毛细管玻璃底部构成饱和银-氯化银电极。该电极具有可靠而准确的电位值,特别适用于现场光谱-电化学实验,也可用于有机电解质体系中的电化学研究。     

苯甲醇在铂和钯电极上的电化学反应活性研究

为研究电极性能对苯甲醇（BA）反应活性的影响,用差示电化学质谱分析（DEMS）和循环优安法对0．1mol/L HCIO4中的2mmol/L苯甲醇在铂和钯电极上的电化学反应进行了研究。挥发性产物的在线质谱分析显示,苯甲醇和这些金属相互作用,部分离解成苯。CO2是检测出来的唯一一种氧化产物。相应的质谱信号显示出3种不同的组成。用伏安扫描时发现,每种组成的范围强烈依赖于电极性质,但以钯为电极时,每种组成的范围也随着伏安扫描时的电极电势范围的变化而变化。在电解还原过程中,铂和钯表现出不同的催化活性,在铂电极上发生分子的氢解和芳环的氢化作用,而在钯电极上芳环的氢化作用很少发生。     

联苯菊酯的快速测定及电化学性质

[目的]为探索联苯菊酯的快速测定方法,实验研究了联苯菊酯的电化学性质,对实验条件进行了优化选择.[方法]在pH值11.0的PBS缓冲溶液中,采用循环扫描伏安法,结合差分脉冲伏安法等手段,研究体系的电化学行为.[结果]在铂电极上得到一个还原峰,峰电位为-0.211 V(vs,Ag/AgCl),联苯菊酯电极反应过程具有不可逆性,对联苯菊酯的线性检测范围为0.05~0.5 mg/L,线性相关系数为0.9932.[结论]利用联苯菊酯在PBS缓冲溶液中的还原性,根据铂电极上的电化学信号,可快速、方便、灵敏的检测出该农药的残留量.     

酸性氧化电位水制备条件的优化研究

用由不同电极材料制成的两种电解槽分别进行正交实验,考察了电解电压、电解质浓度、酸碱出水量比三因素对酸性氧化电位水各项指标的影响。结果表明:Ⅰ号槽(钛镀铂、铱电极),三种工艺对pH、ORP及有效氯影响的显著性顺序均为电解质浓度>电解电压>酸碱出水量比,最优工艺为,电解电压8.5 V,电解质浓度0.67 g/L,酸碱出水量比0.8∶1;水质指标为pH 2.26、ORP1185.7 mV、有效氯50.42 mg/L。Ⅱ号槽(钛镀铂电极),三种工艺对pH、ORP影响的显著性顺序为电解电压>电解质浓度>酸碱出水量比,而对有效氯影响最为显著的因素是电解质浓度,最优工艺为,电解电压8.5 V,电解质浓度1.11 g/L,酸碱出水量比0.8∶1;水质指标为pH 2.23、ORP1180.2 mV、有效氯41.66 mg/L。说明由于电解槽电极材料的不同,使得各因素对水质指标的影响有所差别。     

硝基苯在离子液体BPyBF4/H2O中的电化学行为

在离子液体1-丁基吡啶四氟硼酸盐(BPyBF₄)的水溶液中,采用循环伏安法(CV)、计时电流法(CA)、恒电位电解及原位红外光谱法(in-situ FTIRS)等研究了硝基苯在铂电极上的电化学还原行为。研究结果表明:硝基苯在离子液体BPyBF₄/H₂O体系中的还原过程是受扩散控制的,其还原产物主要是偶氮苯,经估算得到硝基苯在该体系中的扩散系数为3.1×10^-7 cm²·s^-1,提高温度和加入一定浓度的水均有利于硝基苯在该体系中的电化学还原。     

Electrochemical study of benzene on Pt of various surface structures in alkaline and acidic solutions

The electrochemical behaviour of benzene on platinum electrodes (polycrystalline and single-crystal electrodes) has been studied in acidic and alkaline solutions. In acid solutions the reduction of benzene to cyclohexane takes place in all the platinum surface structure employed, however it does not occur in alkaline media (0.1 M NaOH). In this case, the hydrogen adsorption-desorption processes displace the adsorbed benzene from the electrode surface. The oxidation of benzene is also affected by the pH of the electrolyte and also by the surface structure of the platinum electrode used. In acid solutions, this oxidation at higher potentials (1.4 V vs. RHE) yields CO₂, benzoquinone and α,β-unsaturated esters or lactones, however in alkaline media carbonate anions coming from CO₂ and salts of carboxylic acids have been detected by in situ FTIR spectroscopy using a platinum polycrystalline electrode. Bulk electrolysis of benzene solutions using a platinum electrode in acid and alkaline media was performed in order to confirm the results obtained by spectroscopic measurements.     

Application of flow electrolysis on porous electrodes for the electroreduction of potassium p-Nitrobenzoate

The electrolysis of potassium p-nitrobenzoate in alkaline aqueous solution in a flow electrolytic cell employing a platinum grid porous electrode is described. The composition of the solution after the electrolysis was controlled by means of voltammetry on a platinum wire microelectrode. According to the electrochemical evidence the reduction of potassium p-nitrobenzoate requires 5 electrons per mole, and probably leads to the formation of the potassium salt of p, p′-dicarboxyhydrazobenzene.     

涂层电极的40年

钛阳极也称DSA,是以金属钛为基体在其表面涂覆以铂族元素氧化物的一种电极材料。总结了40年来DSA在电解工业中的应用概况。对各种型号的析氯电解用DSA涂层组分及其特点进行了说明,同时,对应用于硫酸电解、铜箔制造、印刷电路基板电镀、钢板镀锌和三价铬电镀等工业中的DSA进行了介绍。指出了今后的发展方向。     

Role of substituent in electrooxidation of poly(1-substituted pyrrole) films

Poly(1-substituted pyrrole)s were prepared on a platinum electrode with different electrolysis times, and their properties were studied by cyclic voltammetry. The oxidation potential for most of the poly(1-alkylpyrrole)s were almost 0.3 V versus the Ag/Ag⁺ reference electrode, except for poly(1-butylpyrrole). The electron transfer rate in polymer films depends on the electrolysis time and the size of the substituent. The difference of the redox peak potential of poly(1-phenylpyrrole) was smaller than that of poly(1-anisylpyrrole) films. The role of a substituent in the electrochemical behavior of the polymer main chain is discussed. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 471–475, 1998     

Electrochemical reforming of an acidic aqueous glycerol solution on Pt electrodes

The feasibility of the electrochemical conversion of glycerol to alternative, more valuable compounds was evaluated with platinum electrode under galvanostatic conditions. The results indicated a potentially good feasibility of reforming glycerol by electrolysis, particularly under strong acidic conditions (pH 1). Indeed, under controlled conditions at pH 1, various commercially valuable compounds, such as propanediol, glycidol, and 2-propenol, amongst others, were produced. The mechanism for the generation of the key compounds is proposed.     

Anodic oxidation of 2,6-xylenol in acetonitrile on platinum

Anodic oxidation of 2,6-xylenol at the platinum electrode in acetonitrile was investigated by the various electrochemical and chemical methods. Conductivity measurements indicated that the phenolic hydroxyl of 2,6-xylenol is undissociated in acetonitrile solution containing lithium perchlorate. By cyclic voltammetry and chronopotentiometry, it was shown that anodic oxidation of 2,6-xylenol at the platinum electrode proceeds in two steps. 2 electrons are involved in the first step, as determined by cyclic voltammetry using hydroquinone and DPPH as a reference compound. Polarographic study suggested that the first step is an electrophilic attack on the aromatic nucleus of the non-ionized phenol. The electrolysis products were analysed by thin-layer chromatography, ir and uv spectrophotometry and mass spectrometry. It is estimated that dimer, trimer and tetramer are produced by the anodic oxidation of 2,6-xylenol and that the dimer is 2,2′-dihydroxyl-3,3′-dimethylstilbene. The formation reactions of trimer and tetramer probably proceed by the same mechanism as dimer formation.     

钛基Pt-Ta电极在离子水生成器中的应用研究

电解离子水具有广泛的用途,可分为碱性水和酸性水。电极是离子水生成器中的核心部件,国外离子水生产器用的电极一般为Pt/Ti电极。为了降低成本,用热分解法制备了Pt-Ta/Ti电极,分析了离子水电极反应原理,用电子显微镜测试了Pt-Ta/Ti电极表面形貌及电极性能。结果表明,Pt-Ta/Ti电极强化寿命和铂含量呈正比,在间歇倒极操作条件下,电解特性满足离子水器使用要求。使用该电极可以生产出性能优异的离子水。     

库仑滴定法测定生物乙醇制备原料的还原糖含量

利用库仑滴定法测定生物乙醇原料蔗糖的还原糖含量.样品经5 mL 10％盐酸于65-70 ℃水解15 min后,以铂电极为电解电极和指示电极,1.0 mol/L硫酸亚铁(pH 2.0)为电解质溶液,恒电流电解生成Fe3+,与预处理样品后生成的氧化亚铜定量发生氧化还原反应,记录电解至滴定终点时间,通过法拉第电解定律,计算样...