1-4丁炔二醇和乙二胺对离子液体电沉积Cu的影响(英文)

研究了1-4丁炔二醇和乙二胺作为添加剂对在离子液体1-甲基-3-甲基咪唑三氟甲磺酸盐中电沉积Cu的影响。紫外可见光吸收光谱结果表明,当采用1-4丁炔二醇作为添加剂时,1-4丁炔二醇吸附在工作电极表面且未与溶液中的Cu2+形成配合物。扫描电镜测试结果表明由于1-4丁炔二醇与离子液体的正离子的竞争吸附使得Cu的沉积电势发生正移并使镀层表面更加均匀平整。当采用乙二胺作为添加剂时,紫外可见光吸收光谱和循环伏安测试结果表明乙二胺与溶液中的Cu2+离子形成带有正电荷的络合离子使得Cu的沉积电势发生正移,扫描电镜和原子力显微镜测试结果表明得到了更加均匀的镀层。当同时加入1-4丁炔二醇和乙二胺时,Cu的沉积电势仍然发生正移并得到具有纳米粒径的镀层。     

添加剂对离子液体中电沉积金属钴的影响

在含有氯化钴的室温离子液体氯化1-甲基-3-乙基咪唑(EMIC)和乙二醇(EG)体系中,采用扫描电子显微镜(FE-SEM）、阴极极化曲线、循环伏安及X射线衍射等方法研究了添加剂对电沉积金属钴的影响。结果表明,在EMIC-EG-CoCl₂熔盐中加入丁炔二醇能够有效地改善钴镀层的外观质量,丁炔二醇的加入量在0.3～0.7 g·L^-1范围内,能够得到银灰色、具有金属光泽的良好镀层。从FE-SEM照片可以看出,在EMIC-EG-CoCl₂熔盐中加入丁炔二醇后,使金属钴的结晶变得更加细致;阴极极化曲线表明,丁炔二醇的加入不仅增大了阴极极化,而且还消除了钴的欠电势沉积;循环伏安测试证明,添加剂的加入对阴极沉积过程有阻化作用;XRD分析证实,丁炔二醇的加入使金属钴的衍射峰变宽,晶粒尺寸为纳米级。     

2,2′-联吡啶在化学镀铜中的作用研究

研究了以次磷酸钠作还原剂的化学镀铜体系,添加剂2,2′-联吡啶对化学镀铜沉积速率、次磷酸钠阳极氧化和铜离子阴极还原、以及镀层形貌、结构和组分存在状态的影响.结果表明,2,2′-联吡啶对化学沉积起阻化作用.电化学线性伏安扫描实验显示,镀液中加入2,2′-联吡啶,次磷酸钠的氧化峰电势有所负移,但峰电流减小;铜离子的还原峰电势负移,但峰电流逐渐增大.扫描电子显微镜(SEM)、能量色散谱(EDS)、X射线衍射(XRD)及X射线光电子能谱(XPS)等实验分别表明,添加剂使镀层致密和光亮、镍含量降低;镀层为Cu-Ni合金,呈面心立方结构,无明显晶面择优取向现象;镀层中铜和镍以金属态存在,磷的质量含量小于0.05%.     

离子液体电沉积CuInxGa1-xSe2薄膜

采用循环伏安法(CV)对离子液体Reline中三元CuCl₂+InCl₃+SeCl₄体系和四元CuCl₂+InCl₃+GaCl₃+SeCl₄体系的电化学行为进行了研究。研究表明,In³⁺并入三元CIS(Cu-In-Se)薄膜体系和Ga³⁺并入四元CIGS(Cu-In-Ga-Se)薄膜体系均有两种途径：一是发生共沉积,二是直接还原。利用电感耦合等离子体发射光谱(ICP)和扫描电镜(SEM)对沉积电势、镀液温度和主盐浓度对CIGS薄膜组成、镀层表面形貌的影响进行了测试,结果表明通过工艺参数的选择可以控制Ga/(Ga+In)和CIGS薄膜组成并得到化学计量比为Cu_1.00In_0.78Ga_0.27Se_2.13的薄膜。     

2，2＇-联吡啶在化学镀铜中的作用研究

研究了以次磷酸钠作还原剂的化学镀铜体系，添加剂2，2＇-联吡啶对化学镀铜沉积速率、次磷酸钠阳极氧化和铜离子阴极还原、以及镀层形貌、结构和组分存在状态的影响．结果表明，2，2＇-联吡啶对化学沉积起阻化作用．电化学线性伏安扫描实验显示，镀液中加入2，2＇-联吡啶，次磷酸钠的氧化峰电势有所负移，但峰电流减小；铜离子的还原峰电势负移，但峰电流逐渐增大．扫描电子显微镜（SEM）、能量色散谱（EDS）、X射线衍射（XRD）及X射线光电子能谱（XPS）等实验分别表明，添加剂使镀层致密和光亮、镍含量降低；镀层为Cu-Ni合金，呈面心立方结构，无明显晶面择优取向现象；镀层中铜和镍以金属态存在，磷的质量含量小于0．05％．     

偏压控制Cu2O和Cu在TiO2表面的生长及其光电化学性质

基于TiO₂/Ti 电极在含Cu²⁺溶液中的循环伏安图,调节电沉积的沉积电压,我们在TiO₂平整表面制备出Cu₂O和/或Cu颗粒. 通过扫描电镜（SEM）、X射线衍射（XRD）和X射线光电子能谱（XPS）表征,发现Cu₂O和Cu有不同的生长机制：Cu₂O颗粒在TiO₂表面分散结晶,而Cu颗粒是在已生长的颗粒上成核,从而形成堆积颗粒结构. 这是由于在Cu₂O/TiO₂界面和Cu/TiO₂界面形成不同的能带结构,使得电子的转移方式不同. 与纯TiO₂光阳极比较,可以观察到Cu₂O/TiO₂和Cu/TiO₂异质结构的光电流均有显著增强. 特别地,存在一个电压区间使得Cu₂O和Cu同时生长在TiO₂表面,此时对应的光电流比较稳定并且能达到最大. 紫外-可见（UV-Vis）漫反射光谱、电化学阻抗谱（EIS）和光电流-电压特性曲线均显示,Cu₂O和Cu明显有助于光的可见光吸收,同时Cu/TiO₂在光电转换过程中显示更宽波段的可见光利用率. 此外,开路电压的增加、有效的电荷分离和电极/电解质界面上载流子的快速迁移也增强了材料的光电化学性质.     

咪唑基离子液体非共价修饰的石墨烯结构与分散性

在离子液体氯化-1-烯丙基-3-甲基咪唑（AmimCl）存在的条件下,利用水合肼对氧化石墨烯进行同步还原,制备了一种可稳定分散在N,N-二甲基甲酰胺（DMF）和乙酸丁酯等有机溶剂中的离子液体改性石墨烯（IL-G）。运用红外光谱（FTIR）、紫外-可见吸收光谱（UV-Vis）、热失重分析（TGA）、原子力显微镜（AFM）、拉曼光谱（Raman）、X射线电子衍射（XRD）和X射线光电子能谱（XPS）对制备的改性石墨烯进行结构性能测试,结果表明离子液体AmimCl与石墨烯之间存在π-π和阳离子-π的相互作用,能较好的吸附在石墨烯表面。TGA测试表明IL-G中离子液体的比例约为7.20wt%。同时,AFM结果显示改性石墨烯剥离在DMF中的平均厚度是0.962nm。由于非共价改性石墨烯可再分散于DMF和乙酸丁酯中,通过紫外可见吸收光谱测得其最大分散浓度分别是1.69mg·mL^-1和1.12mg·mL^-1。     

在离子液体[BMIm][BF4]中电沉积光亮金镀层

在离子液体1-丁基-3-甲基咪唑四氟硼酸盐（[BMIm][BF₄]）中以HAuCl₄·3H₂O为主盐、通过添加5,5-二甲基乙内酰脲（DMH）和胞嘧啶可得到色泽光亮、厚度达1.5 μm的金镀层,沉积过程中阴极电流效率可达到100%。SEM和XRD测试结果表明,DMH和胞嘧啶具有细化晶粒、平整镀层的作用。电化学测试结果表明,DMH可分别与Au³⁺、Au⁺形成配合物Au（DMH）₄^-、Au（DMH）₂^-,抑制了还原过程的表面转化步骤,从而增加了阴极极化,起到光亮镀层、细化晶粒的作用;胞嘧啶可在金核表面吸附,从而可以进一步光亮镀层、细化晶粒,与DMH有协同作用。循环伏安测试研究了镀液的电化学行为,研究表明在此体系中Au³⁺的还原为两步还原过程,分别为Au³⁺→ Au⁺和Au⁺→ Au。此外DMH和胞嘧啶的添加不会带来副反应。     

改性PTFE纤维金属配合物的制备及其光催化降解性能

使用聚丙烯酸接枝改性聚四氟乙烯(PAA-g-PTFE)纤维分别与Fe³⁺及其与Cu²⁺的混合物反应制备改性PTFE纤维铁和铁铜双金属配合物, 并分别使用傅里变换叶红外(FTIR)光谱和紫外-可见(UV-Vis)漫反射光谱(DRS)对两种配合物的化学结构和光吸收性能进行表征. 然后将两种配合物分别作为非均相光Fenton 反应催化剂应用于典型偶氮染料活性蓝222氧化降解反应中, 考察和比较了二者在不同pH介质中对降解反应的催化作用. 结果表明, 在有或无Cu²⁺的存在条件下, 一个Fe³⁺能够与三个PAA-g-PTFE表面的6个羧基发生反应形成配合物, 并且它们在紫外和可见光区表现出好的光吸收特性. 当两种金属离子共存时Cu²⁺比Fe³⁺更容易与PAA-g-PTFE发生配位反应形成铁铜双金属配合物. 在可见光辐射下PAA-g-PTFE铁配合物对不同pH水溶液中染料降解反应均表现出显著的催化作用, 但是溶液pH的升高不利于配合物催化活性的发挥. 而配合物中铁离子含量提高特别是引入Cu²⁺作为助金属离子能够较大幅度地改善其在高pH范围内的催化活性和重复利用性.     

激光刻蚀模板中电沉积特殊结构CIGS薄膜

本文利用激光刻蚀模板,在水溶液中电沉积制备金属铜薄膜,讨论了温度、电流、硫酸铜浓度对薄膜形貌的影响. 采用SEM对制备的铜薄膜进行表征,结果表明在沉积温度为30 ℃,沉积电流为4 A·dm^-2(表观工作电流密度),硫酸铜浓度在20 ~ 50 g·L^-1的水溶液中电沉积可以得到中空馒头状和开口碗状结构的铜薄膜. 利用激光刻蚀模板,在离子液体1-丁基-3-甲基咪唑三氟甲磺酸盐([BMI][TfO]) - 30 Vol%丙醇混合电解质中电沉积CIGS薄膜,研究了沉积电势、沉积时间对薄膜形貌的影响. SEM观察发现,在沉积电势为-1.8 V,沉积时间为1.5 h条件下电沉积可以得到近似柱状的簇状花束样的CIGS薄膜, 电沉积铜后再进一步电沉积CIGS,得到了均匀有序的鼓包柱状结构的Cu/CIGS复合薄膜. 用恒电势方波法对制备的薄膜真实表面积进行测试,计算结果表明,与无模板电沉积制备的CIGS薄膜相比,激光刻蚀模板法制备的Cu/CIGS复合薄膜的表面积提高了约8倍.     

反气相色谱法测定离子液体1-己基-3-甲基咪唑三氟甲磺酸盐的热力学参数

采用反气相色谱法研究了343.15~373.15 K温度范围内离子液体1-己基-3-甲基咪唑三氟甲磺酸盐([HMIM]OTF)的热力学参数。根据18种探针溶剂的保留时间计算出探针溶剂与[HMIM]OTF之间的摩尔吸附焓、无限稀释的摩尔混合焓、摩尔蒸发焓、质量部分活度系数、Flory-Huggins相互作用参数及[HMIM]OTF的溶解度参数。结果表明,所选溶剂中正构烷烃、四氢呋喃、乙醚、环己烷和苯为[HMIM]OTF的不良溶剂;二氯甲烷、丙酮、氯仿、乙酸乙酯、四氯化碳、乙酸甲酯、甲苯和甲醇为[HMIM]OTF的良溶剂;运用外推法得到了室温(298.15 K)时[HMIM]OTF的溶解度参数为20.74 (J/cm³)^0.5。本研究为离子液体的应用及相关工作提供了参考。     

Electrodeposition of nanocrystalline Ni–Cu alloy from environmentally friendly lactate bath

A new environmentally friendly electroplating bath for Ni–Cu alloy deposition was developed. Lactic acid was used as a complexing agent. The influence of bath composition, current density, pH and temperature on cathodic polarization, cathodic current efficiency and alloy composition was studied. Different proportions of the two metals were obtained by using different deposition parameters, but at all [Ni²⁺] / [Cu²⁺] ratios studied, preferential deposition of Cu occurred and regular co‐deposition took place. The Ni content of the deposit increased with Ni²⁺ content and current density and decreased with temperature. The surface morphology of the deposited Ni–Cu alloy was investigated using scanning electron microscopy. The crystal structure was examined using the X‐ray diffraction technique. The results showed that the deposits consisted of a single solid solution phase with a face‐centered cubic structure. The crystallite size lies in the range of 12 to 25 nm for as‐plated alloys. Copyright © 2014 John Wiley & Sons, Ltd.     

Pyrrolidone ligand improved Cu‐based catalysts with high performance for acetylene hydrochlorination

A series of Cu‐pyrrolidone/spherical activated carbon (SAC) catalysts were prepared via a simple incipient wetness impregnation method and then assessed in acetylene hydrochlorination, and the catalytic evaluation result indicated that the 1‐methyl‐2‐pyrrolidinone (NMP) ligand was found to be the most effective one to significantly improve the activity and stability of Cu catalyst. The catalyst with the optimal molar ratio of NMP/Cu = 0.25 showed 94.2% acetylene conversion at 180°C and an acetylene gas hourly space velocity of 180 h^?1. Moreover, the acetylene conversion of Cu‐0.25NMP/SAC remained stable over 99.1% for about 220 h under the industrial condition. Transmission electron microscopy (TEM) analyses proved that NMP ligand improved the dispersion of Cu species. In addition, hydrogen temperature‐programmed reduction (H₂‐TPR), X‐ray photoelectron spectra (XPS), thermogravimetric analysis (TGA), and Brunner–Emmet–Teller (BET) indicated that the additive of NMP was preferential to stabilize the catalytic active Cu⁺ and Cu²⁺ species and inhibit the reduction of Cu^α+ to Cu⁰ during the preparation process and reaction, hence restraining the coke deposition. Furthermore, the steady coordination structure between Cu and NMP was confirmed by Fourier‐transform infrared spectra (FT‐IR) and Raman combining with density functional theory (DFT) calculation, which could effectively lower the adsorption energy of catalyst for C₂H₂ and inhibit the serious carbon deposition caused by excessive acetylene self‐accumulation. Our findings suggest that the efficient, well‐stabilized cost‐effective, and environmentally friendly Cu catalyst has great potential in acetylene hydrochlorination.     

Chelation of Theranostic Copper Radioisotopes with S-Rich Macrocycles: From Radiolabelling of Copper-64 to In Vivo Investigation

Copper radioisotopes are generally employed for cancer imaging and therapy when firmly coordinated via a chelating agent coupled to a tumor-seeking vector. However, the biologically triggered Cu²⁺-Cu⁺ redox switching may constrain the in vivo integrity of the resulting complex, leading to demetallation processes. This unsought pathway is expected to be hindered by chelators bearing N, O, and S donors which appropriately complements the borderline-hard and soft nature of Cu²⁺ and Cu⁺. In this work, the labelling performances of a series of S-rich polyazamacrocyclic chelators with [⁶⁴Cu]Cu²⁺ and the stability of the [⁶⁴Cu]Cu-complexes thereof were evaluated. Among the chelators considered, the best results were obtained with 1,7-bis [2-(methylsulfanyl)ethyl]-4,10,diacetic acid-1,4,7,10-tetraazacyclododecane (DO2A2S). DO2A2S was labelled at high molar activities in mild reaction conditions, and its [⁶⁴Cu]Cu²⁺ complex showed excellent integrity in human serum over 24 h. Biodistribution studies in BALB/c nude mice performed with [⁶⁴Cu][Cu(DO2A2S)] revealed a behavior similar to other [⁶⁴Cu]Cu-labelled cyclen derivatives characterized by high liver and kidney uptake, which could either be ascribed to transchelation phenomena or metabolic processing of the intact complex.     

A facile electrochemical synthesis of covellite nanomaterials at room temperature

A novel method for the electrochemical synthesis of covellite (CuS) nanoparticles (NPs) in aqueous phase was developed. In this experiment, thioglycerol (TG) is used as the catalyst for the hydrolysis of sodium thiosulfate, the sulfur source for the synthesis of CuS. Cu foil, which acts as the sacrificing anode, is oxidized to Cu²⁺ by applying a potential of 0.5 V while OH^- was produced on the cathode surface at the same time. The production of OH^- facilitates the reaction between Cu²⁺ and thiosulfate under the catalysis of TG. The evolution of hydrogen bubbles effectively prevents the deposition of copper sulfide on the cathode. Copper sulfide sols of “golden-brown”, and “dark-green” forms can be obtained by varying the concentration of TG. The “golden-brown” copper sulfide sols are also observed to convert to the green form with time, and the rate of this conversion process is faster at higher temperatures. X-ray diffraction (XRD) and chemical analysis indicate that the “dark-green” form of product is pure hexagonal phase CuS. The obtained CuS NPs were covered by a layer of TG as suggested by Fourier transform infrared (FTIR) data. The size and morphology of the particles are studied by transmission electron microscope (TEM).     

Amino acid influence on copper binding to peptides: Cysteine versus arginine

Matrix assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) and theoretical calculations [density functional theory (DFT)] were utilized to investigate the influence of cysteine side chain on Cu⁺ binding to peptides and how Cu⁺ ions competitively interact with cysteine (−SH/SO₃H) versus arginine. Results from theoretical and experimental (fragmentation reactions) studies on [M+Cu]⁺ and [M+2Cu−H]⁺ ions suggest that cysteine side chains (−SH) and cysteic acid (−SO₃H) are important Cu⁺ ligands. For example, we show that Cu⁺ ions are competitively coordinated to the −SH or SO₃H groups; however, we also present evidence that the proton of the SH/SO₃H group is mobile and can be transferred to the arginine guanidine group. For [M+2Cu−H]⁺ ions, deprotonation of the −SH/SO₃H group is energetically more favorable than that of the carboxyl group, and the resulting thiolate/sulfonate group plays an important role in the coordination structure of [M+2Cu−H]⁺ ions, as well as the fragmentation patterns.     

Ring‐to‐Cage Structural Conversion via Template Effect in a Gold(I) Metallosupramolecular System

A unique example of a ring‐to‐cage structural conversion in a multinuclear gold(I) coordination system with d ‐penicillamine (d ‐H₂pen) is reported. The reaction of [Au₂Cl₂(dppe)] (dppe=1,2‐bis(diphenylphosphino)ethane) with d ‐H₂pen in a 1:1 ratio gave [Au₄(dppe)₂(d ‐pen)₂] ([ 1 ]), in which two [Au₂(dppe)]²⁺ units are linked by two d ‐pen S atoms in a cyclic form so as to have two bidentate‐N,O coordination arms. The subsequent reaction of [ 1 ] with Cu(OTf)₂ afforded [Au₄Cu(dppe)₂(d ‐pen)₂]²⁺ ([ 2 ]²⁺), in which a Cu^II ion is chelated by the two coordination arms in [ 1 ] to form an Au^I₄Cu^II bicyclic metallocage. A similar reaction using Cu(NO₃)₂ was accompanied by the ring expansion of [ 1 ] to [Au₈(dppe)₄(d ‐pen)₄], leading to the production of [Au₈Cu₂(dppe)₄(d ‐pen)₄]⁴⁺ ([ 3 ]⁴⁺). In [ 3 ]⁴⁺, two Cu^II ions are each chelated by the two coordination arms to form an Au^I₈Cu^II₂ tricyclic metallocage, accommodating a nitrate ion. The use of Ni(NO₃)₂ or Ni(OAc)₂ instead of Cu(NO₃)₂ commonly gave a tricyclic metallocage of [Au₈Ni₂(dppe)₄(d ‐pen)₄]⁴⁺ ([ 4 ]⁴⁺), but a water molecule was accommodated inside the Au^I₈Ni^II₂ metallocage.     

Harnessing the Flexibility of Peptidic Scaffolds to Control their Copper(II)‐Coordination Properties: A Potentiometric and Spectroscopic Study

Designing small peptides that are capable of binding Cu²⁺ ions mainly through the side‐chain functionalities is a hard task because the amide nitrogen atoms strongly compete for Cu²⁺ ion coordination. However, the design of such peptides is important for obtaining biomimetic small systems of metalloenyzmes as well as for the development of artificial systems. With this in mind, a cyclic decapeptide, C‐Asp, which contained three His residues and one Asp residue, and its linear derivative, O‐Asp, were synthesized. The C‐Asp peptide has two Pro? Gly β‐turn‐inducer units and, as a result of cyclization, and as shown by CD spectroscopy, its backbone is constrained into a more defined conformation than O‐Asp, which is linear and contains a single Pro? Gly unit. A detailed potentiometric, mass spectrometric, and spectroscopic study (UV/Vis, CD, and EPR spectroscopy) showed that at a 1:1 Cu²⁺/peptide ratio, both peptides formed a major [CuHL]²⁺ species in the pH range 5.0–7.5 (C‐Asp) and 5.5–7.0 (O‐Asp). The corrected stability constants of the protonated species (log K*_CuH(O?Asp)=9.28 and log K*_CuH(C?Asp)=10.79) indicate that the cyclic peptide binds Cu²⁺ ions with higher affinity. In addition, the calculated value of K_eff shows that this higher affinity for Cu²⁺ ions prevails at all pH values, not only for a 1:1 ratio but even for a 2:1 ratio. The spectroscopic data of both [CuHL]²⁺ species are consistent with the exclusive coordination of Cu²⁺ ions by the side‐chain functionalities of the three His residues and the Asp residue in a square‐planar or square‐pyramidal geometry. Nonetheless, although these data show that, upon metal coordination, both peptides adopt a similar fold, the larger conformational constraints that are present in the cyclic scaffold results in different behaviour for both [CuHL]²⁺ species. CD and NMR analysis revealed the formation of a more rigid structure and a slower Cu²⁺‐exchange rate for [CuH(C‐Asp)]²⁺ compared to [CuH(O‐Asp]²⁺. This detailed comparative study shows that cyclization has a remarkable effect on the Cu²⁺‐coordination properties of the C‐Asp peptide, which binds Cu²⁺ ions with higher affinity at all pH values, stabilizes the [CuHL]²⁺ species in a wider pH range, and has a slower Cu²⁺‐exchange rate compared to O‐Asp.     

Molecular Simulations of Human and Mouse Aβ1–16 at Different pH Values: Structural Characteristics toward Understanding Cu2+‐Coordinated Amyloid Beta Spheres

As the main sequence responsible for metal ion coordination in the amyloid beta (Aβ) peptide, Aβ_1–16 plays a key role in the understanding of the aggregation of Aβ induced by Cu²⁺ ions. There is no consensus on the nature of the coordination sphere of the Cu²⁺–Aβ complex so far due to the amorphous conformation of the Aβ_1–16 peptide itself and the pH dependence of Cu²⁺–Aβ coordination. The simulation reported here reveals that human Aβ_1–16 monomer has a U‐shape morphology, which is preserved at any pH. This morphology accommodates Cu²⁺ ions with several binding sites and is also the basis for establishing a center‐distance statistical method (CDSM). Based on this CDSM, specific histidine residues for a Cu²⁺‐coordinated sphere are identified and the corresponding accurate pH range is established, indicating that the CDSM can be used as a reference to predict the potential coordination sites of metal ions in other amorphous peptides. By contrast, mouse Aβ_1–16 monomer has a more open and random morphology than human Aβ_1–16 due to the differences of three sequence positions. These mutations not only reduce the number of binding sites required by a stable Cu²⁺‐binding sphere but also diminish the capacity to generate salt bridges compared to the human peptide. These observations offer insights into the roles of three residues that differ in the mouse Aβ_1–16 and perhaps into the reasons mice seldom develop Alzheimer's disease.