首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
A Pr-doped TiO2-NTs/SnO2-Sb electrode was prepared by a simple method, cyclic voltammetry(CV). The methyl orange(MO)aqueous solution was selected as a simulated wastewater. The ordered microstructural TiO2-NTs substrate was synthesized by an electrochemical method to obtain large specific surface area and high space utilization. The phase structure, electrode surface morphology and electrochemical properties of electrodes were characterized by XRD, SEM and electrochemical technology, respectively. The results showed that praseodymium oxide was successfully doped into the SnO2-Sb film by CV method. Due to the doped Pr, the oxygen evolution potential increased from 2.25 V to 2.40 V. The degradation of MO was investigated by UV-vis. The C t /C 0 (φ) was studied as a function to obtain the optimal parameters, such as the amount of doped Pr, current density and initial dye concentration. In addition, the degradation process followed pseudo-first-order reaction kinetics and the rate constant was 0.099 3 min-1. The result indicated that the introduction of Pr reduced the formation of oxygen vacancies or enhanced the formation of adsorbed hydroxyl radical groups on the surface, thus leading to better activity and stability.  相似文献   

2.
In this study, a bulk composite material symbolized as NiCo LDH-rGO/Ni F was developed by a solvothermal process for the first time. This material was fabricated through simultaneous growth of nickel-cobalt layered double hydroxide(NiCo LDH) and reduced graphene oxide(rGO) on nickel foam. This bulk composite can be used directly as a binder-free electrode for supercapacitors(SCs). The physicochemical properties of this composite were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The electrochemical properties of the composite were measured by the cyclic voltammetry and galvanostatic charge-discharge. The results show that this composite had a hierarchical structure and exhibited a significantly enhanced specific capacitance of up to 3383 F/g at 1 A/g. The asymmetric SC using this composite as a positive electrode had a high energy density of 40.54 Wh/kg at the power density of 206.5 W/kg and good cycling stability. Owing to the synergies between the metal oxides and the rGO, the preparation method of in situ growth and its hierarchical structure, this bulk composite displayed excellent electrochemical performance and had a promising application as an efficient electrode for high-performance SCs.  相似文献   

3.
以邻苯二胺(o-PD)为功能单体,采用电化学聚合的方法,在金电极表面电聚合成分子印迹聚合物膜。洗脱模板分子,优化制备过程的条件,获得了L-酪氨酸(L-Tyrosine)分子印迹传感器敏感膜。并通过循环伏安法(CV)、示差脉冲伏安法(DPV)和电化学阻抗谱法(EIS)三种方法考察了电极的性能;在循环伏安法(CV)方法测试结果表明,模板分子L-酪氨酸在磷酸缓冲溶液(PH=8.0)中与功能单体邻苯二胺能聚合并吸附在金电极表面,并且在聚合前后及洗脱模板分子前后峰电流有明显差异;由示差脉冲法(DPV)测试结果表明,在(1×10-22.0)mg/m L范围内,峰电流与L-酪氨酸的浓度成线性关系,检出为2.0 mg/m L。选择识别性实验结果表明,该分子印迹修饰电极对与L-酪氨酸相似的L-苯丙氨酸、L-丙氨酸、L-色氨酸、L-天冬氨酸的电流响应很小,说明分子印迹传感膜对L-酪氨酸有特异性识别功能;EIS方法测试表明,印迹电极对L-酪氨酸分子具有识别作用。  相似文献   

4.
以电合成前驱体Ti(OEt)4直接水解法和电沉积法制备Ti基纳米TiO2-碳纳米管复合膜载P(tPt/nanoTiO2-CNT)复合电极。透射电镜(TEM)和X射线衍射(XRD)测试表明,锐钛矿型纳米TiO2粒子和Pt纳米粒子(粒径约8nm)均匀地分散在碳纳米管表面。通过循环伏安法研究Pt/nanoTiO2-CNT电极对Ce3+的电催化性能,Ce3+氧化峰电位约为1.27V(vs.SCE),比Pt/nanoTiO2电极负移30mV,峰电流约高45mA·cm-2。  相似文献   

5.
在磷酸盐缓冲溶液(pH 7.4)中,利用循环伏安法研究了丝裂霉素的电化学行为.结果显示,丝裂霉素在玻碳电极上出现一对氧化还原峰,其中Epa=-0.520 V,Epc=-0.556 V.方波伏安峰电流与丝裂霉素的浓度在5×10-6~1.0×10-4mol/L之间呈良好的线性关系,检出限为1.5×10-6mol/L,可用于样品的测定.  相似文献   

6.
在壳聚糖-氮掺杂石墨烯-十二烷基苯磺酸钠复合膜电极上实现了多巴胺(DA)和对乙酰氨基酚(PT)的同时测定.用循环伏安法(CV)和差分脉冲法(DPV)研究了DA和PT在该修饰电极的电化学行为.结果表明,在pH=5.0的磷酸缓冲溶液(PBS)中,修饰电极对于DA和PT的电化学氧化具有良好的催化性能.DA的氧化峰电流在2~10、10~90μmol/L浓度范围内呈良好的分段线性关系,检出限为0.178 μmol/L,PT的氧化峰电流在4~150μmol/L浓度范围内呈良好的线性关系,检出限为1.06μmol/L.实验结果表明,十二烷基苯磺酸钠能显著提高检测的灵敏度,选择性和重现性.  相似文献   

7.
芦丁在玻碳电极上的电化学行为研究   总被引:3,自引:0,他引:3  
在0.lmol/L B-R缓冲溶液(pH=3.10)中,用循环伏安法可得到芦丁的一对氧化还原峰。峰电位Epc=0.405V,Epa=0.467V(vs.SCE)。实验表明,Rt在玻碳电极上的电极过程为一受吸附和扩散同时控制的准可逆过程。测得还原峰的电子转移系数为0.39,标准速率常数为kn=0.48s^-1。用该法测定了芦丁片中Rt的含量。  相似文献   

8.
基于羧基化多壁碳纳米管的催化作用,建立了一种测定体液中尿酸含量的新方法.通过扫描电子显微镜和电化学手段对传感器的表面形貌和性能进行了表征,并且优化了检测条件,研究了传感器对尿酸的响应.结果表明,多壁碳纳米管对尿酸的氧化有明显的催化作用.在最优实验条件下,尿酸在修饰电极表面的峰电流与其浓度在8.0×10^-7-8.0×10^-4 mol·L^-1内呈良好线性关系,检测限为5×10^-8 mol·L^-1,该传感器已经应用于实际样品中的测定,测定的回收率在94%-105%.  相似文献   

9.
利用自组装的方法制备了一种新型六氮杂铜配合物修饰的金电极。采用循环伏安法和电化学隧道扫描显微镜对该电极进行了表征。计算了该电极电子转移系数为0.42,标准速率常数为38S^-1。该电极可以有效地催化氧化多巴胺,当抗坏血酸浓度为1-5mmol/L时,可用于多巴胺的分析测定,检测限低至1.8×10^-8mol/L。  相似文献   

10.
利用扫描电镜和交流阻抗法对以滴涂法制备的掺铝的硫化镉、壳聚糖修饰的玻碳电极进行纳米膜特性表征,并采用循环伏安法研究核黄素在其上的电化学行为.结果显示,在多种缓冲溶液中测试,发现在0.05 mol/L的邻苯二甲酸氢钾作为缓冲溶液时,电化学氧化还原峰形最好,峰电流较大.结果还表明,在修饰电极上的扩散系数D为5.08×10-4 cm2/s,反应速率常数k为5.36×10-7 mol/(L·s).在实验优化选定的测试条件下,氧化峰电流与核黄素的浓度在5.00×10-6 ~4.50×10-5 mol/L范围内呈良好线性关系,检出限达2.55×10-6 mol/L,相对标准偏差(n=10)为4.25%,可用于核黄素含量的测定.  相似文献   

11.
在0.1mol/LHAc—NaAc缓冲溶液(pH=4.54)中,用循环伏安法可得到维生素B12的两个还原峰。峰电位EP1=-0.458V,EP2=-0.831V(vs.SCE)。实验表明,维生素B12在玻碳电极上的电极过程为一受吸附控制的不可逆过程。测得还原峰的电子转移系数为0.3,标准速率常数为ks=2.40s^-1。用该法测定了维生素B12针剂中维生素B12的含量,结果与标示含量相吻合。  相似文献   

12.
We previously reported the direct electrochemical detection of insulin at bare carbon electrodes. Here a novel modified acetylene carbon black paste electrode(SiC/CB-CPE), based on the outstanding characteristics of silicon carbide nanostructure,was developed for the electrooxidation of insulin in alkaline solution and it was characterized by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) in 5 mmol/L Fe(CN)63-/4- solution. It is found that silicon carbide nanostructure doped into the CB-CPE greatly facilitates the redox electrochemistry of Fe(CN)63-/4- probe and the electrochemical oxidation of insulin. The electrooxidation of insulin is a one-electron and one-proton reaction and an irreversible adsorption-controlled electrode process. The anodic oxidation current increases linearly with the concentration of insulin from 1×10-7mol/L to1.2×10-6mol/L in 0.1 mol/L Na2CO3-NaHCO3 buffer solution(pH 10.0) and the detection limit was 50 nmol/L. In addition, the SiC/CB-CPE shows good sensitivity, reproducibility, renewability and capacity of resisting disturbance.  相似文献   

13.
A novel fluidized electrochemical reactor that integrated advanced electrochemical oxidation with activated carbon (AC) fluidization in a single cell was developed to model pollutant p-nitrophenol (PNP) abatement. AC fluidization could enhance COD removal by 22%–30%. In such a combined process, synergetic effects on PNP and COD removal was found, with their removal rate being enhanced by 137.8% and 97.8%, respectively. AC could be electrochemically regenerated and reused, indicating the combined process would be promising for treatment of biorefractory organic pollutants. Project (No. 20306027) supported by the National Natural Science Foundation of China  相似文献   

14.
提出用丁二酮肟修饰碳糊电极的制备及对Cu(Ⅱ)的测定.以铂丝电极为对电极,Ag/AgCl电极为参比电极,在pH=3.2的邻苯二甲酸氢钾—盐酸缓冲溶液中通过在-1.0V电位下富集后,在-1.0V~+0.6V电位范围内作线性扫描溶出伏安法测定,峰电流与Cu(Ⅱ)浓度在4.0×10^-6~5.0×10^-5mol/L范围内呈良好线性关系,当富集300s时检测限为1.0×10^-9mol/L,且大多数阳离子不干扰测试结果.  相似文献   

15.
Starting with an elementary problem that appeared in the Putnam mathematics competition, we proceed to discuss some techniques of transcendental number theory and prove the following result. If p, q, r are distinct primes and if c is a real number with the property that pc, qc, rc are integers, then c must be a non-negative integer. The tools used are some linear algebra and complex analysis. The zero-density estimate method discussed here was used by Alan Baker to prove his celebrated theorem on linear forms in logarithms. The question as to whether we can replace three primes by two primes is an open question.  相似文献   

16.
An electrochemical DNA sensor based on ferrocene-labelled peptide nucleic acid (PNA-Fc) was prepared. The hybridization between PNA-Fc and DNA immobilized on a gold electrode was examined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). PNA-Fc shows a good electrochemically activity and has a redox potential of 170 mV verus Ag/AgCl electrode after hybridization, representing the characteristic of ferrocene/ferrocenium (Fc/Fc+) transformation. The results illustrate that PNA-Fe can be used as an effective electrochemical DNA probe sensor.  相似文献   

17.

Background

Coronary heart disease (CHD) is characterized by arterial wall inflammation and matrix degradation. Matrix metalloproteinase (MMP)-22 and -29 and pro-inflammatory cytokine interleukin-18 (IL18) are present in human hearts. IL18 may regulate MMP-22 and -29 expression, which may correlate with CHD progression.

Methods and results

Immunoblot analysis showed that IL18 induced MMP-22 expression in human aortic smooth muscle cells. The Mann Whitney test from a prospective study of 194 CHD patients and 68 non-CHD controls demonstrated higher plasma levels of IL18, MMP-22 and -29 in CHD patients than in the controls. A logistic regression test suggested that plasma IL18 (odds ratio (OR)=1.131, P=0.007), MMP-22 (OR=1.213, P=0.040), and MMP-29 (OR=1.198, P=0.033) were independent risk factors of CHD. Pearson’s correlation test showed that IL18 (coefficient (r)=0.214, P=0.045; r=0.246, P=0.031) and MMP-22 (r=0.273, P=0.006; r=0.286, P=0.012) were associated with the Gensini score before and after adjusting for potential confounding factors. The multivariate Pearson’s correlation test showed that plasma MMP-22 levels correlated positively with high-sensitive-C-reactive protein (hs-CRP) (r=0.167, P=0.023), and MMP-29 levels correlated negatively with triglyceride (r=?0.169, P=0.018). Spearman’s correlation test indicated that plasma IL18 levels associated positively with plasma MMP-22 (r=0.845, P<0.001) and MMP-29 (r=0.548, P<0.001).

Conclusions

Our observations suggest that IL18, MMP-22 and -29 serve as biomarkers and independent risk factors of CHD. Increased systemic IL18 in CHD patients may contribute to elevated plasma MMP-22 and -29 levels in these patients.
  相似文献   

18.
采用N一丁基吡啶六氟磷酸盐EBuPy]PF6和壳聚糖(Chi)作为修饰剂,通过静电吸附作用在玻碳电极表面形成稳定性较强的自组装膜修饰电极[BuPy]PF4-Chi/GC.采用电化学阻抗谱技术和循环伏安法研究自组装膜在K3[Fe(CN)4]-K4EFe(CN)6]溶液中的电化学行为,结果表明:形成的自组装膜对溶液与基底间的界面电子转移有强烈的阻碍作用,氧化还原峰电流与扫速的1/2次方在20~100mV/s的范围内呈良好的线性关系,表明该电极过程受扩散控制.该修饰电极对铜离子有很好的选择性,响应灵敏度相比于未修饰的电极提高60倍,铜离子的溶出线性伏安峰电流与其浓度在1.56×10“~6.25×10-4mol·L-1范围内呈良好的线性关系(R=0.9966).  相似文献   

19.
通过胱胺将负电性的褐藻酸钠(AS)共价结合到纳米金表面形成聚合体,并以此来标记三碘甲状腺氨酸(T3).T3抗体固定在金电极上构成检测T3的电化学免疫传感器.通过免疫反应,标记T3和待检测的T3结合到金电极表面,使电极表面微环境发生显著改变,用Fe(CN)6^4 为电化学探针,用循环伏安法获取电极表面微环境改变的电化学信息来检测T3、其检测的线性范围为100—10000pg/mL,检测限为45pg/mL.  相似文献   

20.
在自制的碳纤维电极上,研究了碳纤维电极性能和对氯苯酚(p-CP)的电化学行为,考察了扫速、pH值以及浓度对p-CP在碳纤维电极上电化学行为的影响,实验结果表明p-CP在碳纤维电极上有灵敏的电化学响应,其电极氧化还原行为受吸附过程控制,p-CP在1 mol.L-1硫酸底液中,其氧化峰电流与对氯苯酚浓度在5×10-5~10-3mol.L-1范围内呈良好的线性关系(R2=9981),检出限为1×10-6mol.L-1,相对标准偏差为3.3%(n=10)。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号