Copper In Neutral Solutions Research Articles

Simultaneous detection of copper and mercury in water samples using in-situ pH control with electrochemical stripping techniques

The performance of electrochemical sensors using an in situ pH control technique for detection of mercury and copper in neutral solutions is described herein. Sensors are comprised of two distinct parallel gold interdigitated microband electrodes each of which may be polarised separately. Biasing one interdigitated “protonator” electrode sufficiently positive to begin water electrolysis, resulted in the production of H+ ions, which, consequently droped the interfacial pH at the other second interdigitated “sensing” electrode. This decrease in pH permitted the electrodeposition (and consequent stripping) of metals at a sensing electrode without the need to acidify the whole test solution. In this work, the local pH could be adjusted in the acidic pH range in a stable and reproducible way just by tailoring the polarization of the protonator electrode. Using this approach, a linear range for copper 5 to 100 ppb and for mercury 1 to 75 ppb were obtained. The sensors also have an extremely high sensitivity for the metals. The in-situ pH control, coupled with electrochemical stripping, allowed metal detection in a complex water matrix, e.g., river water without the need for sample pre-treatment. The electrochemical results were confirmed by comparison to those obtained using inductively coupled plasma – optical emission spectroscopy. A very good agreement was observed between both sets of results. The electrode reproducibility was high (RSD < 10%) and the metals could be co-detected simultaneously. Thus, this work shows a fast and easy approach for in-situ pH control for multi metal detection using solid state sensors.

Adsorption and anticorrosion mechanism of glucose-based functionalized carbon dots for copper in neutral solution

BackgroundThis work aims at developing some environmental-friendly corrosion inhibitors for copper in neutral solution. MethodsA glucose-based functionalized carbon dots (FCDs) was synthesized through a facile one-pot hydrothermal method. The inhibition performance of FCDs was firstly researched systematically on copper in neutral 3.5 wt% NaCl solution by potentiodynamic polarization curves, electrochemical impedance spectroscopy and scanning vibrating electrode technique. The above electrochemical results show that FCDs is an effective corrosion inhibitor for copper in neutral solution, and its optimal corrosion inhibition efficiency exceeds to 88% at 70 ppm. The protective performance of FCDs depends on the coverage of adsorption film on copper surface. Its adsorption isotherm is in accordance with Langmuir adsorption model, involving both physisorption and chemisorption. Atomic force-distance curve directly quantifies the adhesion force between the adsorption film and copper surface. Significant findsThe adsorption and anticorrosion mechanism of FCDs in neutral solution is proposed, which could provide theoretical guidance for design and synthesis of nanomaterial corrosion inhibitor.

A Study of Adsorption of 5-Mercaptopentyl-3-amino-1,2,4-triazole on Copper in Neutral Solutions

The inhibiting action by 5-mercaptopetyl-3-amino-1,2,4-triazole and its adsorption on copper in neutral borate buffer solutions were studied. The potentiodynamic curves were used to detect the influence of the inhibitor concentration on the anodic dissolution current and activation potential of passive state. X-ray photoelectron spectroscopy was applied to determine both the composition and thickness of surface films as a function of the exposure time of the sample in a solution containing the inhibitor. Quantum-chemical calculations made it possible to identify the most probable structure of a copper–inhibitor complex.

Guanidine derivative as a new corrosion inhibitor for copper in 3% NaCl solution

The effect of a new corrosion inhibitor namely, N-(5,6-diphenyl-4,5-dihydro-[1,2,4]triazin-3-yl)-guanidine (NTG) has been synthesized and its inhibitive performance towards the corrosion of copper in neutral solution of 3% NaCl has been investigated. Corrosion inhibition was studied by chemical method (weight loss) and electrochemical techniques including potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM). These studies have shown that NTG was a very good inhibitor and the inhibition efficiency up to 99% in 3% NaCl is obtained. Data obtained from EIS were analyzed to model the corrosion inhibition process through equivalent circuit. Comparable results were obtained by different chemical and electrochemical methods used. The adsorption of the inhibitor on the copper surface in the acid solution was found to obey Langmuir's adsorption isotherm.

Film Formation Process of Corrosion Inhibitors on Copper in Neutral Solutions

Film Formation Process of Corrosion Inhibitors on Copper in Neutral Solutions

Film Formation Process of Corrosion Inhibitors on Copper in Neutral Solutions

Film Formation Process of Corrosion Inhibitors on Copper in Neutral Solutions

Reduction of Nitrate Ions by Iron Powder Coated with Copper in Neutral Solutions

Reduction of Nitrate Ions by Iron Powder Coated with Copper in Neutral Solutions

ChemInform Abstract: The Influence of Halide Ions at Submonolayer Levels on the Formation of Oxide Layer and Electrodissolution of Copper in Neutral Solutions

Abstractis studied by voltammetry, SEM, and EDAX.

The influence of halide ions at submonolayer levels on the formation of oxide layer and electrodissolution of copper in neutral solutions

The formation of submonolayers of copper (I) halide preceding anodic oxide layer growth and copper electrodissolution has a remarkable influence on these two processes. Chloride electroadsorption on copper at the submonolayer level takes place as two successive stages at potentials 0.7 V lower than the reversible potential of the Cu/CuCl redox couple. Similar results are obtained for iodide, bromide and fluoride ions although the driving force for electroadsorption decreases in the order I − > Br − > Cl − > F −. The relative contributions of OH − and halide ion electroadsorption can be modified through the solution composition, applied potential and electroadsorption time. The increase surface coverage by the electroadsorbate diminishes the amount of the passive oxide layer and strongly increases the metal electrodissolution rate, particularly when the amount of passive oxide layer becomes smaller than that required to form a compact monolayer.