Surface enhanced Raman spectra of benzotriazole adsorbed on a copper electrode

The surface enhanced Raman spectrum of benzotriazole (BTAH) adsorbed on a copper electrode has been studied as a function of the potential applied to the electrode. The effect of pH and of the type of halide in the electrolyte solution has also been investigated. The presence of some complexes involving Cu(I), benzotriazole or benzotriazolate (BTA^-) and the halide has been characterized. The protective film formed on copper surface, in the presence of benzotriazole, has been identified as cuprous benzotriazolate [Cu(I)BTA].     

非水体系中苯并三唑在铜电极上吸附的电化学表面增强拉曼光谱研究

采用电化学现场表面增强拉曼光谱(SERS)研究了非水体系中苯并三唑(BTAH)在铜电极上的吸附及成膜行为, 结果表明非水体系中BTAH的吸附行为随电位变化而不同. 较负电位区间主要以中性分子形式吸附; 中间电位区间主要以BTA^－吸附并不可逆成膜; 而在氧化电位区间主要表现为铜的氧化. 随中性配体三苯基膦(pph₃)的加入, 在中间电位区间, 由于易溶的Cu(pph₃)_n⁺的生成而使铜的溶解速度加快, 最终该阳离子在溶液中和BTA^-作用而生成了多核铜的配合物. 采用直接电化学方法模拟电极表面过程合成了相应的吸附产物, 并对其组成进行了相关表征.     

复方钨酸盐对铜缓蚀协同作用的光电化学和SERS 研究

主要采用光电化学方法和表面增强拉曼光谱技术对具有环境友好性的钨酸盐与BTA复配使用对铜的缓蚀协同效应和作用机理进行了研究。实验表明Na2WO4对铜的缓蚀作用机理与BTA不同,在电位正向扫描过程中,光电流并不发生转型,其大小变化也不大;但在电位负向扫描过程中产生的阴极光电流峰值明显增大,缓蚀剂浓度越大,光电流越大,缓蚀效果越好,而Na2WO4与BTA复配使用时具有较好的协同效应,光电化学和SERS结果都说明其协同机理为两者都能对铜的缓蚀产生作用,前暑能促使电极表面产生的铜的氧化物增多;后者能与铜(Ⅰ)生成聚合物膜。     

Spectroelectrochemical study of the corrosion of a copper electrode in deaerated 1.0 M HCl solutions containing Fe(III): Effect of the corrosion inhibitor benzotriazole

The corrosion rate of a copper electrode in deaerated 1.0 M HCl by Fe(III) ions, in the absence and presence of benzotriazole (BTAH), has been evaluated through weight-loss experiments using a rotating disk electrode (RDE). The corrosion process is controlled by transport of the Fe(III) ions to the electrode surface both in the absence and presence of BTAH. The inhibiting action is initiated at BTAH concentrations around 10 mM and the Langmuir adsorption isotherm is obeyed in the BTAH concentration range from 10 to 45 mM with an apparent equilibrium adsorption constant of 10 M⁻¹. Above this concentration, the Langmuir plot is not obeyed due to the formation of a multilayer. The surface films formed during the corrosion process have been investigated by “in situ” and “ex situ” fluorescence and Raman spectroscopy and characterized as being composed of the polymeric [Cu(I)BTA] complex and [Cu(I)CIBTAH]₄, the former as an inner layer response for the corrosion inhibition process.     

苯并三氮唑及其衍生物在NaCl溶液中对铜缓蚀作用的表面增强拉曼光谱

铜电极;苯并三氮唑及其衍生物在NaCl溶液中对铜缓蚀作用的表面增强拉曼光谱     

A study of FTIR and XPS analysis of alkaline-based cleaning agent for removing Cu-BTA residue on Cu wafer

This study is to focus on the benzotriazole (BTA) residue problem in the postchemical mechanical planarization (post-CMP) cleaning process. The adsorption of BTA on copper surface was studied by analyzing the FTIR spectra; it indicates that the oxidation of the copper surface could affect the adsorption of BTA on the wafer surface. It used an alkaline-based chelating agent, ethylenediamine tetra acetic acid with four equivalents of 3,4-diaminobutane-1,1,2,2-tetraol, to deal with Cu-BTA film, compared with the tetraethyl ammonium hydroxide at the same pH of 10.3, and used X-ray photoelectron spectroscopy (XPS) analysis to characterize the BTA residue on Cu wafer. The results show that the alkaline-based chelating agent is very effective in removing the Cu-BTA from the Cu surface and leaving the cuprous species to passivate the Cu surface.     

Raman spectroscopic studies on surface coordination mechanism of benzotriazole and triphenylphosphine with metals

The complexes of benzotriazole (BTAH) with Ag, Cu, Fe, Zn and Ni were prepared respectively in the non-aqueous solution by the direct electrochemical synthesis and characterized by microanalysis and normal Raman spectroscopy. The influence of the neutral ligand of triphenylphosphine (pph₃) on the coordination process was deduced by the normal Raman spectroscopy and electrochemistry. The metals were classified into two categories. For the first type, such as Cu and Ag, CuBTA and AgBTA were obtained in the solution without pph₃. The introduction of pph₃ led to its participation in the coordination processes of BTAH with Cu or Ag and appeared in the final complex. Fe, Zn and Ni belonged to the second type, there was no influence on the coordination of BTAH with Zn, Ni and Fe, i.e., the final complexes were Fe(BTA)₂, Zn(BTA)₂ and Ni(BTA)₂, respectively, in the solution with/without pph₃. The electrochemical results revealed that the BTAH can inhibit the corrosion of all the above metals, and the introduction of pph₃ resulted in the decrease of inhibition efficiency to Cu surface, while no influence was observed on the Ni surface. The different role of pph₃ was explained in terms of hard/soft acids and bases rule and coordination mechanism was proposed.     

Raman spectroscopic studies on surface coordination mechanism of benzotriazole and triphenylphosphine with metals

The complexes of benzotriazole (BTAH) with Ag, Cu, Fe, Zn and Ni were prepared respectively in the non-aqueous solution by the direct electrochemical synthesis and characterized by microanalysis and normal Raman spectroscopy. The influence of the neutral ligand of triphenylphosphine (pph₃) on the coordination process was deduced by the normal Raman spectroscopy and electrochemistry. The metals were classified into two categories. For the first type, such as Cu and Ag, CuBTA and AgBTA were obtained in the solution without pph₃. The introduction of pph₃ led to its participation in the coordination processes of BTAH with Cu or Ag and appeared in the final complex. Fe, Zn and Ni belonged to the second type, there was no influence on the coordination of BTAH with Zn, Ni and Fe, i.e., the final complexes were Fe(BTA)₂, Zn(BTA)₂ and Ni(BTA)₂, respectively, in the solution with/without pph₃. The electrochemical results revealed that the BTAH can inhibit the corrosion of all the above metals, and the introduction of pph₃ resulted in the decrease of inhibition efficiency to Cu surface, while no influence was observed on the Ni surface. The different role of pph₃ was explained in terms of hard/soft acids and bases rule and coordination mechanism was proposed.     

铜电极在含苯并三唑的硼砂-硼酸缓冲溶液中的光电化学行为研究

用光电化学方法研究了铜电极在含苯并三唑(BTA)的硼砂-硼酸缓冲溶液中的光电化学行为。BTA能使铜电极的光响应由p-型转变为n-型。产生光响应的原因是铜电极表面的Cu2O膜。当BTA存在时由于BTA的作用致使电极表面Cu2O膜中共存着p-型和n-型区域, 电位正移和频率增加导致电极显示n-型光响应。     

Application of AC-SECM in corrosion science: local visualisation of inhibitor films on active metals for corrosion protection

The suitability of frequency-dependent alternating-current scanning electrochemical microscopy (4D AC-SECM) for investigation of thin passivating layers covering the surface of corrosion-inhibited metals has been demonstrated. Inhibition of copper corrosion by benzotriazole (BTAH) and methylbenzotriazole (MBTAH), which are effective inhibitors for this metal under many environmental conditions, was investigated. Strong dependencies were found for the AC z-approach curves with both the duration of the inhibitor treatment and the frequency of the AC excitation signal applied in AC-SECM. Both negative and positive feedback behaviours were observed in the AC approach curves for untreated copper and for Cu/BTAH and Cu/MBTAH samples. Negative feedback behaviour occurred in the low-frequency range, whereas a positive feedback effect was observed at higher frequencies. A threshold frequency related to the passage from negative to positive regimes could be determined in each case. The threshold frequency for inhibitor-modified samples was found always to be significantly higher than for the untreated metal, because the inhibitor film provides electrical insulation for the surface. Moreover, the threshold frequency increased with increasing surface coverage by the inhibitor. 4D AC-SECM was successfully applied to visualizing spatially resolved differences in local electrochemical activity between inhibitor-free and inhibitor-covered areas of the sample.     

TARNISH AND PROTECTION OF SILVER DEPOSIT——MECHANISM AND METHOD

The mechanism of tarnish caused by exposure to light and Na_2S solution treatment on silver-electroplated deposit and the antitarnish effects of various antitarnish agents have been investigated in this paper. The results showed that 1-phenyl-5-mercaptotetrazole (PMTA) has excellent antitarnish effect for UV light and H_2S tests.The studies of XPS and AES and UV absorption spectra showed that PMTA can absorb effectively UV light and form a dense surface film which can prevent effectively the reactions between silver deposit with corrosive media.Antitarnish surface film could be composed of a polynuclear coordination polymeric compound with structure unit approximate to [Ag_3(PMTA)]. according to the depth dependence of percent component (C%) and sputtering time.     

Inhibition of copper corrosion in acidic sulphate media by eco-friendly amino acid compound

This investigation aimed to study a “green” non-toxic biodegradable copper corrosion inhibitor in an acidic sodium sulphate solution. The methods used in the investigation of cysteine as a copper corrosion inhibitor in an acidic sodium sulphate solution were: potentiodynamic measurements, open circuit potential measurements, and chronoamperometric measurements. Optical microscopy was used in addition to electrochemical methods. Potentiodynamic measurements show that cysteine has good inhibitory properties in an acidic medium. Polarisation curves indicate that the presence of cysteine in a sulphate solution decreases the current density and that using various cysteine concentrations results in the formation of a protective film on the surface of the electrode due to the formation of the Cu(I)-cys complex. These results are confirmed by chronoamperometric measurements. Furthermore, it is clear from microphotographs that a protective film does form on copper electrode in the presence of cysteine. The Langmuir adsorption isotherm indicates that cysteine is chemisorbed on the surface of the electrode.     

Copper oxides: kinetics of formation and semiconducting properties. Part I. Polycrystalline copper and copper-gold alloys

The anodic formation of Cu(I) and Cu(II) oxides on polycrystalline copper and copper-gold alloys (4 and 15 at% Au) in deoxygenated 0.1 M KOH was examined by voltammetry, chronoamperometry, and chronopotentiometry with a synchronous registration of photocurrent and photopotential, in situ spectroscopy of photocurrent as well as XPS and SEM measurements. The band gap of p-Cu₂O is 2.2 eV for indirect optical transitions independent of the concentration of gold in Cu-Au alloy. It grows on CuOH or n-Cu₂O underlayer. The increase of anodic potential results in a thickening of oxide film which is a mixture of Cu(I) and Cu(II) oxides. The latter is a p-type semiconductor with a low photosensitivity. The rate of oxide formation on the alloys is lower than on copper. The structure-dependent properties of the oxide phase on the alloys and copper are different. Copper is prone to corrosive oxidation even in deoxygenated alkaline solution by the traces of molecular oxygen. The corrosive growth of Cu(I) oxide film occurs according to the parabolic law. After the cathodic polarization, the surface of copper remains free of corrosive oxide no longer than 15–20 min. The preliminary anodic formation even of a thin Cu₂O film as well as the alloying of copper with gold suppresses the corrosive oxidation of copper.     

Poly(vinylpyrrolidone)‐based films grown on copper surfaces

The influence of molecular weight and the amount of the poly(vinylpyrrolidone) (PVP) on the growth of poly(vinylpyrrolidone)–based films on copper surfaces was studied by electrochemical, infrared and electronic spectroscopy, and thermogravimetric methods. Complex polymer/metal ions were deposited onto a copper surface, as the result of the electrochemically generated reaction of copper cations with PVP and SCN^?, in sulfuric acid media. Spontaneous film growth on copper surfaces was generated and characterized as a Cu(II)/PVP/SCN^? complex. Infrared spectra and thermal gravimetric curves of the films generated at + 0.7 V were compared with the chemically synthesized complex, and show the same patterns. The oxidation process can be described as: Cu(0)→Cu(I) and Cu(I)→Cu(II), and the copper complex formed at more positive potentials was characterized as Cu(II)/PVP/SCN^?, with copper bonded to the oxygen atom of PVP and thiocyanate ligand N‐linked. This study focuses on the complex formation on a copper surface in acid media and its characterization through electrochemical and spontaneously generated reactions. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2206–2214, 2009     

苯并三唑和8-羟基喹啉对铜的缓蚀协同作用

通过电化学极化曲线和电化学阻抗谱研究了苯并三唑（BTA）和8 羟基喹啉（HQ）对铜的缓蚀协同作用， BTA和HQ复配使用后提高了电极的膜电阻，降低了电极的膜电容，增强了对铜腐蚀的抑制作用.通过MM2分子力学程序和PPP SCF量子化学方法优化计算了BTA和HQ的分子结构参数，分析讨论了它们之间的缓蚀协同效应.     

New routes to high nuclearity clusters: fluoride-based octametallic and tridecametallic clusters of manganese

The reaction of MnF(3) with 5,6-dimethylbenzotriazole (Me(2)BTAH) gives the [Mn(III)(8)] complex [Mn(8)O(4)(OMe)(2)(Me(2)BTA)(6)F(8)(Me(2)BTAH)(MeOH)(8)] and the [Mn(IV)(3)Mn(III)(10)] complex [Mn(13)O(12)(Me(2)BTA)(12)F(6)(MeOH)(10)(H(2)O)(2)]. The octametallic species is an "intermediate" in the formation of the tridecametallic cluster.     

弱碱性介质中氯离子对铜电极腐蚀行为的影响

应用循环伏安法、X射线光电子能谱法、电化学阻抗谱法以及现场椭圆偏光法研究了在弱碱性介质中添加Cl－对铜电极腐蚀行为的影响.结果表明, Cl－的加入能加剧铜电极的腐蚀,使腐蚀电流以及现场椭圆偏振参数Δ的变化范围都增大1个数量级, Cl－对Cu2O的掺杂将使铜电极的表面膜变得疏松,膜的耐蚀性变差.椭圆偏光实验不仅与电化学和能谱实验的结果一致,而且还能定性地、清楚地分辨出铜电极腐蚀过程中Cu2O的生成、Cl－对Cu2O的掺杂、CuO的生成等不同阶段;同时,利用恰当的模型还能定量地确定各个阶段铜电极表面膜的组成、厚度的变化,从而为研究铜电极的腐蚀与防护机理提供更多有用信息.     

Copper in Acid Chloride Solutions: Electrochemical Behavior by Quartz Microgravimetry and Voltammetry

The cathodic deposition of copper on a gold electrode and its subsequent anodic dissolution in an acid chloride solution, where two successive stages of a one-electron transfer are distinguishable because of the stability of chloride complexes of Cu(I), is studied by voltammetry and quartz microgravimetry. The formation of a film of an intermediate compound of Cu(I) during the deposition and dissolution of copper is revealed experimentally. Techniques for identifying the intermediate solid species are suggested. During a cathodic polarization, a film of intermediate compound CuCl forms at a reduced concentration of chloride ions in the Cu(II)/Cu(I) process, while during the anodic dissolution of the copper deposit formed during the cathodic polarization the intermediates appear in the Cu(0)/Cu(I) process, the concentration of chloride ions notwithstanding. The change in the electrochemical behavior of the system caused by a decrease in the concentration of chloride ions is explained.     

Room temperature synthesis of curved ammonium copper molybdate nanoflake and its hierarchical architecture

A new strategy has been successfully designed to synthesize curved ammonium copper molybdate [(NH(4))(2)Cu(MoO(4))(2)] nanoflakes on a copper surface by employing a novel solution-phase approach at room temperature. This method consists of a liquid-solid reaction between Na(2)MoO(4) solution and the copper substrate itself in the assistance of formamide. The lamellar ammonium copper molybdate are approximately perpendicular to the copper substrate surface and are intermeshed with each other to form nanogroove structures. Formamide molecules cannot only promote the oxidation of copper substrate and the formation of copper complex, but also act as a NH(4)(+) source in the final products. Furthermore, the selective adsorption of formamide molecules on different crystallographic planes of ammonium copper molybdate plays the major role in determining the curved morphology. In addition, using glucose as additives to control the nucleation and growth process (through a stepwise nucleation mechanism) can lead to a hierarchical sphere-like architecture.     

Mechanism for the atomic layer deposition of copper using diethylzinc as the reducing agent: a density functional theory study using gas-phase molecules as a model

We present theoretical studies based on first-principles density functional theory calculations for the possible gas-phase mechanism of the atomic layer deposition (ALD) of copper by transmetalation from common precursors such as Cu(acac)(2), Cu(hfac)(2), Cu(PyrIm(R))(2) with R = (i)Pr and Et, Cu(dmap)(2), and CuCl(2) where diethylzinc acts as the reducing agent. An effect on the geometry and reactivity of the precursors due to differences in electronegativity, steric hindrance, and conjugation present in the ligands was observed. Three reaction types, namely, disproportionation, ligand exchange, and reductive elimination, were considered that together comprise the mechanism for the formation of copper in its metallic state starting from the precursors. A parallel pathway for the formation of zinc in its metallic form was also considered. The model Cu(I) molecule Cu(2)L(2) was studied, as Cu(I) intermediates at the surface play an important role in copper deposition. Through our study, we found that accumulation of an LZnEt intermediate results in zinc contamination by the formation of either Zn(2)L(2) or metallic zinc. Ligand exchange between Cu(II) and Zn(II) should proceed through a Cu(I) intermediate, as otherwise, it would lead to a stable copper molecule rather than copper metal. Volatile ZnL(2) favors the ALD reaction, as it carries the reaction forward.