二乙烯三胺改性多壁碳纳米管对溶液中Au(Ⅲ)和Pd(Ⅱ)的吸附

以二乙烯三胺(DETA)为改性剂, 对多壁碳纳米管(MWCNTs) 进行共价键修饰,合成了一种对Au(Ⅲ)和Pd(Ⅱ)有选择性的吸附剂MWCNTs-DETA, 并对Au(Ⅲ)和Pd(Ⅱ)的吸附参数进行了研究和优化. 结果表明, 最佳洗脱剂浓度为1.0 mol/L 硫脲-1.0 mol/L 盐酸, Au(Ⅲ)和Pd(Ⅱ)的洗脱率分别为94.48%和89.06%, 最佳条件下Au(Ⅲ)和Pd(Ⅱ)的饱和吸附容量分别为50.45和25.68 mg/g. 在对吸附等温线的考察中, Au(Ⅲ)拟合Langmuir等温线较好, 而Pd(Ⅱ)则拟合Freundlich等温线较好. 吸附动力学均拟合二级模型较好.     

Electrochemical Reduction of Oxygen on Multi-walled Carbon Nanotubes Electrode in Alkaline Solution

The multi-walled carbon nanotubes (MWNTs) electrode was constructed using polytetrafluoroethylene as binder, and the electrochemical reductive behavior of oxygen in alkaline solution was first examined on this electrode. Compared with other carbon materials, MWNTs show higher electrocatalytic activity, and the reversibility of O2 reduction reaction is greatly improved. The experiments reveal that the electrochemical reduction of O2 to HO2 is controlled by adsorption. The preliminary results illustrate the potential application of MWNTs in fuel cells.     

Noncovalent Functionalization of Multiwalled Carbon Nanotubes by Anionic Polymer Poly(Sodium 4‐Styrenesulfonate) in Water

We have found that polymer poly (sodium 4‐styrenesulfonate) (PSS) is a facile and effective polymer to assist in the dispersion of MWCNTs in aqueous solutions. With the increase of the concentration of PSS solutions, the dispersibility of MWCNTs in PSS solution increases. Cast films of MWCNTs/PSS (2 wt.%) on GC electrode show a typical redox couple at scan rate of 1 V/s in phosphate buffer solution, indicating good electrical conductivity.     

Use of 2-(tert-butoxy)-N-(3-carbamothioylphenyl)acetamide and graphene oxide for separation and preconcentration of Fe(Ⅲ),Ni(Ⅱ),Cu(Ⅱ) and Zn(Ⅱ) ions in different samples

A simple and selective method using a column packed with graphene oxide(GO) as a solid phase extractant has been developed for the multi-element preconcentration of Fe(Ⅲ),Ni(Ⅱ),Cu(Ⅱ) and Zn(Ⅱ)ions prior to flame atomic absorption spectrometric determinations.The method is based on the sorption of mentioned ions on synthesized GO using 2-(tert-butoxy)-N-(3-carbamothioylphenyl)acetamide as a chelating agent.Several parameters on the extraction and complex formation were optimized.Under the optimized conditions(pH 6,flow rate 9 mL/min),metal ions were retained on the column,then quantitatively eluted by HNO3solution(5 mL,3.0 mol/L).The preconcentration factor was calculated as250.The detection limits for the analyte ions of interest were found in the range of 0.11 ng/mL(Ni2+) to0.63 ng/mL(Cu2+).The column packed with GO was adequate for metal ions separation in matrixes containing alkali,alkaline earth,transition and heavy metal ions.     

Pd/MWCNTs(多壁碳纳米管)催化剂的制备及其Heck反应催化活性

以浓硝酸处理后的多壁碳纳米管(MWCNTs)为载体,通过微波辅助法简单而快速地制备了高度分散、粒径均一的Pd/MWCNTs催化剂。利用XRD、HRTEM、XPS等手段对催化剂进行了表征。考察了Pd/MWCNTs催化剂对Heck反应的催化活性,并优化了反应温度、碱的种类和用量等反应条件。结果表明,Pd/MWCNTs在Heck反应中具有良好的催化活性。     

meso-四(4-酰肼基苯基)卟啉及其金属配合物共价和非共价修饰多壁碳纳米管

采用新方法合成了meso-四(4-酰肼基苯基)卟啉及其金属配合物, 通过化学键将酰肼卟啉上的酰肼基与活化的多壁碳纳米管(MWNTs)发生酰胺化反应, 从而得到卟啉共价化学修饰的多壁碳纳米管复合物; 利用卟啉环上的π电子与多壁碳纳米管管壁上的π电子通过π-π堆积效应, 得到卟啉非共价化学修饰的碳纳米管复合物. 通过红外光谱、紫外和荧光光谱对比分析, 发现在卟啉与碳纳米管间存在强烈的电子效应, 且非共价修饰的卟啉-碳纳米管复合物的荧光猝灭率更高.     

用稀土(镱)杂多酸盐/多壁碳纳米管修饰的玻碳电极测定亚硝酸根

将多壁碳纳米管分散在镱(Ⅲ)杂多酸盐溶液中,将上述获得的悬浊液滴涂在玻碳电极表面,制备了镱(Ⅲ)杂多酸盐/多壁碳纳米管修饰的玻碳电极(YbHS-MWCNT′s/GCE)。采用交流阻抗法对电极表面的性能进行了表征,采用循环伏安法对其电化学性能进行研究。研究发现,亚硝酸根在该修饰电极上出现一个氧化峰,氧化峰电位在-0.45V处,提出了用循环伏安法测定亚硝酸根的方法。亚硝酸根的浓度在5.0×10-6～1.0×10-4mol.L-1范围内,氧化峰电流与其浓度呈线性关系。修饰电极用于环境水样中亚硝酸根离子的测定,回收率在97.2%～98.0%之间。     

Synthesis,Crystal Structure and Bioactivity of a Pd(Ⅱ) Complex with Demethylcantharate and 2,2′-Bipyridine

A novel crystal with the molecular formula [Pd(DCA)(bipy)]2 [Pd(bipy)Cl2 ]·6.75H2O was formed by PdCl2 with disodium demethylcantharate (Na2 (DCA),DCA2= 7-oxa-bicyclo[2.2.1]heptane-2,3-bicarboxylate) and 2,2-bipyidine (bipy) through the hydrothermal method.The complex was characterized by elemental analysis and infrared spectroscopy.The structure of the complex was determined by single-crystal X-ray diffraction,which is of triclinic system,space group P1 with a=13.6818(7),b=14.8426(8),c=15.0043(8),α=97.319(3),β=92.521(3),γ=105.776(2)°,V=2898.4(3) 3,Dc=1.545 g·cm-3,Z=1,F(000)=1420,S=0.852,the final R=0.0525 and wR=0.1777 for 13634 observer reflections (I>2σ(I)).The binding reaction of the complex with ct-DNA and bovine serum albumin (BSA) was studied by fluorescence spectroscopy.The results indicated that the complex binds to ct-DNA via the partial intercalation.The binding constant K A of the complex interaction with BSA was 3.98×10 5 L·mol-1 and one binding site would be formed.The antiproliferative activity of the complex against human hepatoma cells (SMMC7721) in vitro is much higher than that of Na 2 (DCA).     

Comparison of the Activities of Pd(0) and Pd(I) in Low-Temperature Oxidation of Carbon Monoxide on the Pd/γ-Al2O3 Catalyst

Kinetics and Catalysis - Low-temperature oxidation of carbon monoxide on the Pd/γ-Al2O3 catalyst has been studied at room temperature and atmospheric pressure of air containing 100 mg/m3 CO....     

Stability Constants and Fluorescence of Terbium(Ⅲ) Complexes with Polyaminopolycarboxylates in Aqueous Solution

ＩｎｔｒｏｄｕｃｔｉｏｎＡｖａｒｉｅｔｙｏｆｎｅｗｐｏｌｙａｍｉｎｏｐｏｌｙｃａｒｂｏｘｙｌａｔｅｌｉｇａｎｄｓａｎｄｔｈｅｉｒｌａｎｔｈａｎｉｄｅｃｏｍｐｌｅｘｅｓｈａｖｅｂｅｅｎｓｙｎｔｈｅｓｉｚｅｄｉｎｒｅｃｅｎｔｙｅａｒｓｂｅｃａｕｓｅｏｆｔ...     

Poly(2,2′-(1,4-phenylenedivinylene) Bis-8-hydroxyquinaldine) Modified Glassy Carbon Electrode for the Simultaneous Determination of Paracetamol and p-Aminophenol

A novel assay is reported for the simultaneous determination of paracetamol and p-aminophenol using a poly(2,2′-(1,4-phenylenedivinylene)bis-8-hydroxyquinaldine) modified glassy carbon electrode. Poly(2,2′-(1,4-phenylenedivinylene)bis-8-hydroxyquinoline) modified electrodes were prepared by electrochemical polymerization. The electrode surface was characterized by scanning electron microscopy. The electrochemical behavior of the modified electrode was investigated by cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy. The anodic peak potentials for paracetamol and p-aminophenol were at 580 and 337 millivolts, respectively, with a separation of 243 millivolts, adequate for their simultaneous determination. The results showed that the linear dynamic ranges for paracetamol and p-aminophenol were 0.5–200 micromolar and 3–150 micromolars, whereas the limits of detection were 0.075 and 0.45 micromolar, respectively. The novel poly(2,2′-(1,4-phenylenedivinylene)bis-8-hydroxyquinaldine) modified electrode provided excellent selectivity, sensitivity, and stability and was employed for the determination of paracetamol and p-aminophenol in pharmaceutical products and urine.     

Determination of Reduced Nicotinamide Adenine Dinucleotide Based on Immobilization of Tris(2,2′‐bipyridyl) Ruthenium(II) in Multiwall Carbon Nanotubes/Nafion Composite Membrane

Abstract

An electrochemiluminescence (ECL) method for reduced nicotinamide adenine dinucleotide (NADH) was proposed by immobilizing tris(2,2′‐bipyridyl) ruthenium(II) (Ru(bpy)₃ ²⁺) in multiwall carbon nanotubes (MWCNTs)/Nafion composite membrane that was formed on glassy carbon electrode surface. The electrochemical and ECL behaviors of the immobilized Ru(bpy)₃ ²⁺ were investigated. The cyclic votammogram of the modified electrode in pH 7.0 phosphate buffer solution showed a couple of redox peaks at +1190 and +1060 mV at 100 mV/s. The composite film had a more open structure and a large surface area allowing faster diffusion of Ru(bpy)₃ ²⁺. The presence of MWCNTs resulted in the improved ECL sensitivity and longer‐term stability of the modified electrode. The modified electrode showed a linear response to NADH in the concentration range of 1.0×10^?6 to 1.6×10^?5 M with a detection limit of 8.2×10^?7 M.     

Adsorption behavior of Me_2-CA-BTP/SiO_2-P adsorbent toward MA(Ⅲ) and Ln(Ⅲ) in nitrate solution

A porous Me_2-CA-BTP/SiO_2-P adsorbent was prepared to separate MA(Ⅲ) from Ln(Ⅲ) in high level liquid waste(HLLW).The adsorption behavior of Me_2-CA-BTP/SiO_2-P toward ~(241)Am(Ⅲ) and Ln(Ⅲ) in 0.01 M HNO_3-NaNO_3 solution was studied.Me_2-CA-BTP/SiO_2-P showed high adsorption and selectivity toward ~(241)Am(Ⅲ) over Ln(Ⅲ) fission products with the separation factor(SF) reaching to 557,2355,1952,1082,214,105,86,14 for Y,La,Ce,Nd,Sm,Eu,Gd and Dy respectively in 0.01 M HNO_3-0.99 M NaNO_3 solution.The adsorption kinetics of both Dy(Ⅲ) and Eu(Ⅲ) on Me_2-CA-BTP/SiO_2-P was studied and followed pseudo-second-order rate equation indicating chemical sorption as the rate-limiting step of the adsorption,and the adsorption isotherm of Dy(Ⅲ) and Eu(Ⅲ) matched better with the Langmuir isotherm than the Freundlich isotherm with the adsorption amount around 0.22 and 0.20 mmol/g respectively.Thermodynamic study revealed that the adsorption of both Dy(Ⅲ)and Eu(Ⅲ) on Me_2-CA-BTP/SiO_2-P was spontaneous and endothermic processes with a positive entropy at 298,308,313 K.     

Kinetics and Thermodynamics of the Adsorption of Copper(Ⅱ) onto a New Fe-Si Adsorbent

A new kind of Fe-Si adsorbent was synthesized by iron oxide and diatomite after calcining and hydrothermal process. The influences of the initial Cu2+ concentration, p H and adsorption time on the Cu2+ removal efficiency were discussed. Three adsorption empirical kinetics equations and two thermodynamics equations were used to simulate the adsorption process. The microstructures of newly developed copper removal materials and properties of copper removal are characterized in details by SEM and EDS. Adsorption mechanism of the adsorbent was discussed. The suitable p H value for Cu2+ removal is 5.0 to 6.0 and the adsorption capacity increases with increasing the initial Cu2+ concentration. The adsorption kinetics of the adsorbent could be better described by pseudo second order kinetic model, whereas the adsorption isotherms highly conform to the Freundlich equation. The main crystalline phase of the adsorbent is Fe(Si O3) which can build porous structures conducive to the Cu2+ adsorption.     

ZnO-MWCNTs/Nafion Inorganic-organic composite film： Preparation and application in bioelectrochemistry of hemoglobin

Multi-walled carbon nanotubes(MWCNTs) were coated with ZnO by a hydrothermal method.The resulting nanocomposites were mixed with the Nafion solution to form a composite matrix for the fabrication of hemoglobin(Hb) biosensor.To prevent the leak of Hb molecules of the biosensor,silica sol-gel film was coated on the surface of the Hb/ZnO-MWCNTs/Nafion electrode.The silica sol-gel/Hb/ZnO-MWCNTs/Nafion film exhibited a pair of well-defined,quasi-reversible redox peaks.This biosensor showed excellent electroca...     

Preparation and Spectroscopic Properties of Tris(2,2′-bipyridine)ruthenium(Ⅱ) Loaded in Siliceous Mesoporous MCM-41

[Ru(bpy)3]2+/MCM-41 composite material obtained by loading tris(2,2′-bipyridine)ruthenium(Ⅱ)([Ru(bpy)3]2+) in siliceous mesoporous MCM-41 was characterized by X-ray powder diffraction, UV-Vis absorption and emission spectroscopies. The absorption spectrum of [Ru(bpy)3]2+/MCM-41 is similar to that of [Ru(bpy)3]2+ aqueous solution, whereas its emission spectrum exhibits hypsochromic shift compared to the solution spectrum. On the other hand, the peak position of the emission spectrum of [Ru(bpy)3]2+/MCM-41 shifts towards longer wavelength when the loading amount increases.     

Copper(Ⅱ) and 2,2′-Biimidazolyl-promoted Ullmann Coupling Reaction of Phenols and Aryl Iodides

Ullmann-type diaryl ether synthesis can be performed at 100℃ in good to excellent yields by aryl iodides asthe substrates under the assistance of copper(Ⅱ)and 2,2'-biimidazolyl.     

Solution equilibria of zinc(II) and cadmium(II) complexes with 2,2′-bipyridine in N,N-dimethylacetamide at 25°C

Complexation of zinc(II) and cadmium(II) ions with 2,2-bipyridine (bpy) are studied in N,N-dimethylacetamide (DMA) by calorimetry. Formation constants, enthalpies, and entropies of five mononuclear complexes, [Zn(bpy)_n]²⁺ (n=1–3) and [Cd(bpy)_n]²⁺ (n=1,2), are determined, and compared with the corresponding values in an analogous but less bulky solvent, N,N-dimethylformamide (DMF). The zinc complexes are more stable and the formation is more exothermic in DMA than in DMF, whereas the solvent effect on the cadmium complexes are rather small. A largely positive value of the enthalpy of transfer of Zn²⁺ from DMF to DMA shows that the greater stability of the zinc complexes in DMA is due to the weaker solvation of the metal ion, which is caused by the steric hindrance of DMA molecules. The transfer enthalpies become smaller in the order Zn²⁺>[Zn(bpy)]²⁺>[Zn(bpy)₂]²⁺>[Zn(bpy)₃]²⁺ and dictate gradual relaxation of the steric effect in the complexes. On the other hand, the transfer enthalpies of Cd²⁺ and its complexes are all small, indicating that the hindrance is insignificant in the vicinity of this larger cation.     

沸石咪唑酯骨架材料-8/多壁碳纳米管电化学传感器灵敏检测镉离子(Ⅱ)和铅离子(Ⅱ)

将沸石咪唑酯骨架材料-8(ZIF-8)与多壁碳纳米管(MWCNT)结合,制备得到ZIF-8/MWCNT复合材料,并基于此构建了一种可用于Cd²⁺和Pb²⁺同时测定的电化学传感器。MWCNT的引入增强了复合材料的导电性;同时,ZIF-8与MWCNT之间的协同作用使ZIF-8/MWCNT复合材料表现出优异的电催化活性,将ZIF-8/MWCNT复合材料修饰玻碳电极(GCE),能够实现Cd²⁺和Pb²⁺的分别和同时检测。在最优实验条件下,基于ZIF-8/MWCNT/GCE的电化学传感器对Cd²⁺和Pb²⁺分别检测的线性范围分别为0.03～8.00μmol/L和0.03～6.00μmol/L,检出限分别为0.019和0.035μmol/L(S/N=3);对Cd²⁺和Pb²⁺同时检测的线性范围分别为0.03～5.00μmol/L和0.03～5.00μmol/L,检出限分别为0.022和0.048μmol/L(S/N=3)。此...