槲皮素在多壁碳纳米管修饰电极上的电化学行为研究

实验制备了多壁碳纳米管修饰玻碳电极(MWNTs/GCE),在pH=3.0的磷酸盐缓冲溶液(PBS)中,用循环伏安法(CV)和微分脉冲伏安法(DPV)探讨了槲皮素在修饰电极上的电化学行为。结果表明:MWNTs/GCE对槲皮素的氧化还原反应有更明显的电催化作用。微分脉冲伏安法检测表明:在2.0×10-6~1.0×10-4mol·L-1浓度范围内,槲皮素的主氧化峰峰电流与浓度存在良好的线性关系,表明该电极可用于槲皮素的检测。     

多壁碳纳米管修饰电极测定诺氟沙星

运用循环伏安法、线性扫描伏安法及示差脉冲伏安法等测试技术研究了诺氟沙星在多壁碳纳米管修饰玻碳电极上的电化学行为,建立了一种直接测定诺氟沙星的电化学分析方法.结果表明,与裸玻碳电极相比,多壁碳纳米管修饰电极能显著提高诺氟沙星的氧化峰电流.在优化的实验条件下,氧化峰电流与诺氟沙星浓度在1.0×10-7～1.0×10-6mol/L和1.0×10-6～2.5×10-5 moL/L范围呈现良好的线性关系,检出限为3.0×10-8mol/L对1.0×10-5mol/L诺氟沙星溶液平行测定10次的RSD为4.1%.测定了诺氟沙星胶囊中诺氟沙星的含量,结果满意.     

色氨酸在多壁碳纳米管-Nafion修饰玻碳电极上的电化学行为及测定

采用滴涂法制备了多壁碳纳米管-Nafion修饰玻碳电极(MWCNTs-Nafion/GCE),基于此修饰电极,建立了发酵液中色氨酸的电化学检测方法。结果表明:在pH 4.0的磷酸盐缓冲溶液中,色氨酸在MWCNTs-Nafion/GCE电极上有良好的响应,氧化峰电势为1.01 V,在5×10-7-2×10-4mol/L范围内,色氨酸氧化峰电流与其浓度呈良好的线性关系,线性方程为:Ip(10-6 A)=2.432×104 C(mol/L)+3.1452,R2为0.9973,检测限为2.7×10-8mol/L(S/N=3),回收率在98.3%~104.3%之间,相对标准偏差≤3.0%。该方法操作简单、结果稳定、选择性和灵敏度良好。     

5-羟色胺在碳纳米管修饰电极上的电化学行为及检测

研究了5-羟色胺在碳纳米管修饰电极上的电化学行为。结果表明,在0.1 mol·L-1磷酸盐(pH=8.0)缓冲溶液中,5-羟色胺在碳纳米管修饰电极上的氧化峰峰电位为0.23 V;5-羟色胺吸附在电极表面,电化学反应由表面控制;根据5-羟色胺氧化过程中失去4个电子和4个质子,讨论了反应机理。5-羟色胺浓度在1.36～16...     

多壁碳纳米管修饰电极测定水样中痕量镉

通过多壁碳纳米管修饰玻碳电极,建立了水样中痕量镉的线性扫描阳极溶出伏安分析法。优化了支持电解质及pH、修饰剂用量、富集电位及时间等测定条件,在pH 4.0的NaAc-HAc缓冲液中,-1.10 V富集5 min后,溶出峰电流与Cd2 浓度在2.0×10-8~5.0×10-5mol/L的范围内呈良好的线性关系,检测限为8.0×10-9mol/L。该法用于实际水样中痕量镉的测定,平均回收率在98.7%~105.0%之间,结果满意。     

2,4,6-三氯苯酚封闭PAPI的研究

以2,4,6-三氯苯酚作为多亚甲基多苯基多异氰酸酯(PAPI)的封闭剂制备可低温解封的封闭异氰酸酯。讨论了nOH/nNCO、反应温度和反应时间对PAPI封闭反应的影响,并对封闭产物进行了FT-IR、1H-NMR、13C-NMR和DSC分析。结果表明,当nOH/nNCO为1.1、温度为80℃、时间为3 h时,封闭效果较好;加入催化剂可缩短封闭反应时间;封闭产物的初始解封温度约为80℃。     

纳米金／碳纳米管修饰电极测定硝基苯酚

实验制备了纳米金/碳纳米管/Nafion膜修饰电极。研究了在修饰电极上硝基苯酚的电化学特性。实验采用循环伏安法研究硝基苯酚的电化学行为,研究发现在醋酸盐缓冲溶液pH值为4.80（0.2 mol/L HAc-0.2 mol/L NaAc ）底液中,硝基苯酚的浓度与峰电流值在2.5×10-7～1.8×10-5 mol/L范围呈现良好的线性关系,最低检测限5×10-8 mol/L。用此电极对实际样品中硝基苯酚的含量进行了测定。     

2,6-二甲基苯酚在玻碳电极上的电化学行为研究

研究了2,6-二甲基苯酚在玻碳电极上的电化学行为。通过线性扫描伏安法研究了支持电解质、溶液pH和扫描速度对2,6-二甲基苯酚测定的影响。并采用示差脉冲伏安法研究了氧化峰电流与2,6-二甲基苯酚浓度之间的关系,结果显示峰电流与2,6-二甲基苯酚的浓度在7.0×10^-5～2.0×10^-2 mol/L之间有良好的线性关系。同时玻碳电极对2,6-二甲基苯酚的测定具有较好的重现性和稳定性。     

基于多壁碳纳米管修饰电极的磺胺的电化学检测

运用线性扫描伏安法(LSV)研究了磺胺(SA)在多壁碳纳米管修饰电极(MWNTs/GCE)上的电化学行为,探讨并确定了修饰体积和浓度、支持基质种类、最佳pH值、富集电位和时间等磺胺的最佳检测条件。结果表明,在pH=8.0的Na2HPO4-NaH2PO4缓冲体系中,磺胺在多壁碳纳米管修饰电极上检测到一个不可逆的氧化峰,且在1.0×10-5~2.0×10-4mol/L浓度范围内,磺胺氧化峰电流与其浓度呈现良好的线性关系,线性回归方程为Ip(μA)=0.493 6×C(μmol/L)+9.984 1,相关系数为R=0.996 3,检测下限为8.0×10-6mol/L,平行测定的相对误差(RSD)小于1.463%(n=8),样品平均加标回收率为99.21%~100.93%。     

基于多壁碳纳米管修饰电极的磺胺的电化学检测

运用线性扫描伏安法(LSV)研究了磺胺(SA)在多壁碳纳米管修饰电极(MWNTs/GCE)上的电化学行为,探讨并确定了修饰体积和浓度、支持基质种类、最佳pH值、富集电位和时间等磺胺的最佳检测条件。结果表明,在pH=8.0的Na2HPO4-NaH2PO4缓冲体系中,磺胺在多壁碳纳米管修饰电极上检测到一个不可逆的氧化峰,且在1.0×10-5².0×10-4mol/L浓度范围内,磺胺氧化峰电流与其浓度呈现良好的线性关系,线性回归方程为Ip(μA)=0.493 6×C(μmol/L)+9.984 1,相关系数为R=0.996 3,检测下限为8.0×10-6mol/L,平行测定的相对误差(RSD)小于1.463%(n=8),样品平均加标回收率为99.21%2.0×10-4mol/L浓度范围内,磺胺氧化峰电流与其浓度呈现良好的线性关系,线性回归方程为Ip(μA)=0.493 6×C(μmol/L)+9.984 1,相关系数为R=0.996 3,检测下限为8.0×10-6mol/L,平行测定的相对误差(RSD)小于1.463%(n=8),样品平均加标回收率为99.21%¹00.93%。     

Electrochemical behavior of glassy carbon electrodes modified by multi-walled carbon nanotube/surfactant films in a buffer solution and an ionic liquid

The electrochemical behavior of glassy carbon (GC) electrodes coated with multi-walled carbon nanotube (MWCNT)/surfactant films was studied in an ionic liquid and a phosphate buffer solution (pH = 6.86), using cyclic voltammetry. The dispersion of MWCNTs in different media was investigated by scanning and transmission electron microscopy. Cast films of MWCNT/zwitterionic dodecyldimethylamine oxide on a GC electrode show a typical redox couple in phosphate buffer solution, which is better than that of MWCNT/anionic sodium dodecyl sulfate and cationic alkyltrimethylammonium bromide. However in the ionic liquid, 1-n-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF₆]), the GC electrode modified by MWCNT/cationic surfactant films shows a well-defined irreversible reduction of MWCNTs. The cyclic voltammograms clearly show that the surfactant hydrophilic group plays an important role in the electrochemical behavior of the MWCNTs. The electrolytes also have an important effect. In an ionic liquid, the strong binding of the ionic liquid cations with the MWCNTs may change the structure of the modified films and lead to changes of electrochemical behavior.     

Electrochemical behavior of sodium cholate and deoxycholate on an electrode modified with multi-walled carbon nanotubes (MWNTs) linked up with cyclodextrin

The electrochemical behavior of sodium cholate (CA) and deoxycholate (DCA) was investigated on ITO electrodes coated with β-cyclodextrin (β-CD) modified multi-walled carbon nanotubes (MWNTs) in aqueous solution. β-CD modified MWNTs (MWNT–CDs) showed electrocatalytic effect on the reduction of CA, while electrochemical response of DCA was not observed. To further understand the mechanism of the electrochemical process, the electrochemical behavior of CA and DCA on bare ITO electrode and the electrode modified with MWNTs possessing carboxyl groups (MWNT–COOHs) was also discussed. The results indicate that the electrochemical response of CA can be improved through the use of carbon nanotubes. The introduction of cyclodextrin moieties enhances the selectivity of the electrodes to CA and DCA.     

The pH-dependence of oxygen reduction on multi-walled carbon nanotube modified glassy carbon electrodes

The pH-dependence of oxygen electroreduction has been investigated on multi-walled carbon nanotube (MWCNT) modified glassy carbon (GC) electrodes. Various surfactants were used in the electrode modification: dihexadecyl hydrogen phosphate, cetyltrimethylammonium bromide, sodium dodecyl sulfate and Triton X-100. Electrochemical experiments were carried out in 0.5 M H₂SO₄ solution, acetate buffer (pH 5), phosphate buffers (pH 6, 7 and 8), borate buffer (pH 10), 0.01 M KOH, 0.1 M KOH and in 1 M KOH solution, using the rotating disk electrode (RDE) method. The oxygen reduction behaviour of MWCNT-modified GC electrodes at different pHs was compared. The RDE results revealed that the half-wave potential (E_1/2) of oxygen reduction was higher in solutions of high pH. At lower pHs (pH < 10) the value of E_1/2 did not essentially depend on the solution pH. A comparison with previous studies on bare GC showed that the pH-dependence of the half-wave potential of oxygen reduction on MWCNT-modified GC electrodes follows a similar trend to that observed for bare GC.     

多壁碳纳米管改性水泥基复合材料的性能研究

通过试验研究了多壁碳纳米管(MWCNTs)掺量对水泥净浆的力学性能、水化特性、凝结时间、孔隙分布等性能的影响,并采用SEM(扫描电镜)观察与分析了MWCNTs改性水泥净浆的微观形貌。结果表明,MWCNTs的掺入会降低水化过程中矿物的溶解速率,因而延缓了水泥的水化进程;在适宜的掺量范围内,MWCNTs能够有效提升水泥净浆的力学强度,但当其掺量过高时,反而会对力学强度造成不利影响;MWCNTs在水泥净浆中能够分散均匀并降低水泥净浆的孔隙率,使其变得更加密实。     

多壁碳纳米管改性水泥基复合材料的性能研究

通过试验研究了多壁碳纳米管(MWCNTs)掺量对水泥净浆的力学性能、水化特性、凝结时间、孔隙分布等性能的影响,并采用SEM(扫描电镜)观察与分析了MWCNTs改性水泥净浆的微观形貌。结果表明,MWCNTs的掺入会降低水化过程中矿物的溶解速率,因而延缓了水泥的水化进程;在适宜的掺量范围内,MWCNTs能够有效提升水泥净浆的力学强度,但当其掺量过高时,反而会对力学强度造成不利影响;MWCNTs在水泥净浆中能够分散均匀并降低水泥净浆的孔隙率,使其变得更加密实。     

Direct electrochemistry of guanosine on multi-walled carbon nanotubes modified carbon ionic liquid electrode

A multi-walled carbon nanotubes (MWCNTs) modified carbon ionic liquid electrode (CILE) was fabricated and used to investigate the electrochemical behavior of guanosine. CILE was prepared by mixing hydrophilic ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF₄), graphite powder and liquid paraffin together. The fabricated MWCNTs/CILE showed great electrocatalytic ability to the oxidation of guanosine and an irreversible oxidation peak appeared at 1.067 V (vs. SCE) with improved peak current. The electrochemical behavior of guanosine on the MWCNTs/CILE was carefully studied by cyclic voltammetry and the electrochemical parameters such as the charge transfer coefficient (α) and the electrode reaction standard rate constant (k_s) were calculated with the result as 0.66 and 2.94 × 10⁻⁴ s⁻¹, respectively. By using differential pulse voltammetry (DPV) as the detection method, a linear relationship was obtained between the oxidation peak current and the guanosine concentration in the range from 1.0 × 10⁻⁷ to 4.0 × 10⁻⁵ mol/L with the detection limit as 7.8 × 10⁻⁸ mol/L (3σ). The common coexisting substances showed no interferences to the guanosine detection and the modified electrode showed good ability to distinguish the electrochemical response of guanosine and adenosine.     

碳纳米管修饰电极的研究进展

化学修饰电极如今在电化学和电分析化学中应用极为广泛。综述了碳纳米管的结构和性能,介绍了碳纳米管修饰电极的制备及应用。     

H酸废水处理技术研究进展

概述了国内外H酸废水处理的方法,包括吸附法、混凝法、萃取法、光催化氧化法、催化湿式氧化法、Fenton及类Fenton氧化法、电化学法以及各种综合处理工艺,分析了各种处理方法的优点、缺点。     

改性玉米芯对水中2,4,6-三氯酚的吸附研究

通过化学改性的玉米芯(MC),用于去除水中的2,4,6-三氯酚(TCP)。研究了吸附的影响因素,确定了最优的实验条件。研究表明,298 K下,MC对初始浓度为225 mg/L的TCP溶液中TCP的平衡吸附量达到215.4 mg/g。吸附动力学符合准二级动力学模型,吸附等温式符合Temkin模型。改性玉米芯可有效去除水中的TCP,是一种有应用潜力的吸附材料。     

Electrochemical detection of catechol at integrated carbon nanotubes electrodes

The mechanical stability of the electrode plays a very important role in the long-term stability of electrochemical behavior. In this paper, multi-wall carbon nanotubes (MWCNTs) electrodes were prepared in the holes of glass directly by microwave plasma chemical vapor deposition and the electrochemical behavior of catechol at the integrated MWCNT electrodes was investigated. The oxygen plasma treated CNTs had excellent electrochemical behavior for the analysis of catechol. The catechol was detected in the linear concentration range of 1.0 × 10^− 6 mol L^− 1–1.0 × 10^− 3 mol L^− 1. And because CNTs were integrated directly on the substrate, the stable response to catechol solution showed that the carbon nanotubes electrodes had long-term stability.