bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased Corrosion Resistance of Zinc Magnesium Aluminum Galvanised Coating through Germanium Additions
Authors: Mehraban Shahin
Published: February 2020

Improvements in the corrosion resistance of hot dipped galvanised steel coatings have been brought about over the last 20 years through binary alloy additions such as Al and more recently ternary Mg additions [1], [2], to further improve corrosion resistance quaternary additions were made to a commercially produced Zn-Mg-Al (ZMA) alloy.

Corrosion performance of the ZMA alloy coating was shown to improve through the addition of a quaternary element, Germanium. This was added in the molten state and the alloy mixture was rapidly cooled to mimic the cooling rate of a galvanised steel production line.

The increased corrosion resistance can be attributed to microstructural changes in the alloy composition due to Ge addition while in the molten state. The proportion of the most active MgZn2 phase which has been shown to initiate the corrosion reaction in a ZMA alloy [3] was reduced thorough the formation of Mg2Ge crystals. The formation of crystal structures within the experimental alloy also increased the heterogeneous nucleation of the primary zinc phase.

The Scanning Vibrating Electrode Technique (SVET) was used to measure the rate of corrosion, anode life and zinc loss of the alloy samples. Phases present in experimental alloy were identified using SEM in conjunction with EDX analysis and a relationship was determined between the observed microstructural phases and the corrosion rates for varying Ge addition.

[1] D. A. Worsley, H. N. McMurray, J. H. Sullivan, and I. P. Williams, “Quantitative Assessment of Localized Corrosion Occurring on Galvanized Steel Samples Using the Scanning Vibrating Electrode Technique,” Corrosion, vol. 60, no. 5, pp. 437–447, May 2004.

[2] A. R. Marder, “The metallurgy of zinc-coated steel,” Prog. Mater. Sci., vol. 45, no. 3, pp. 191–271, Jun. 2000.

[3] J. Sullivan, S. Mehraban, and J. Elvins, “In situ monitoring of the microstructural corrosion mechanisms of zinc–magnesium–aluminium alloys using time lapse microscopy,” Corrosion Science, vol. 53, no. 6, pp. 2208- 2215, Jun. 2011.
New Superhydrophobic Coatings for Protection Against Corrosion
Authors: Abdullah Aboubakr Moustafa , Mohamed Adel M. A. , Bahgat Ahmed , Almaadeed Mariam
Published: February 2020

Mitigation of metals and alloys’ corrosion is of a great importance because of the negative effect that corrosion causes for the environment and economy. In this study, a superhydrophobic polyvinylidene fluoride (PVDF) coating with oxide nanoparticles (< 100 nm) was synthesized using the electrospinning technique on pretreated Al and C-steel surfaces. The pretreatment of the metallic surfaces was done by immersing them in different inorganic corrosion inhibitors at different temperatures for different periods of time. A synergism effect, when using the superhydrophobic coating and the corrosion inhibitors, was found where the corrosion resistance increased significantly. The contact angle of the prepared superhydrophobic coating was found to increase to 155±2 through using the oxide nanoparticles, in addition to, the the PVDF and the adsorbed corrosion inhibitor. Contact angle measurements, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) were used to characterize the coating and the target metallic surfaces. The corrosion resistance performance of the superhydrophobic surface formed on carbon steel and aluminum sheet was estimated by electrochemical impedance spectroscopy (EIS) measurements through creating appropriate equivalent circuit models.
Electrical Characterization of a Cement Paste with Carbon Fiber by Electrochemical Impedance Spectroscopy
Authors: Barrios Carlos P. , Nuñez Rosa Elba , Pellegrini Manuel Jesus , Castorena Jose H , Garcia Jorge P.
Published: February 2020

In this work is presented a methodology to determine the electrical conductivity percolation threshold for a cement paste added with graphite powder (with size maximum particle 1mm) and carbon fiber (10mm length by 7.2 mm in diameter). For graphite cement ratio of 1:1 and different volumetric fraction of carbon fiber (0-1.2%). the electrical conductivity of the cement paste is obtained by two techniques: four point method (4P, DC) and Electrochemical Impedance Spectroscopy (EIS AC). The electrical conductivity of cement paste specimens with different percentage of carbon fibers shows a percolation threshold of 0.27% of carbon fiber weight.
(Morris Cohen Graduate Student Award of the Corrosion Division) Stainless Steel in Biological Environments – Relation Between Material, Surface Chemistry and Toxicity
Authors: Hedberg Yolanda
Published: February 2020

Stainless steels are commonly used in a variety of essential applications in our daily-life, for instance as biomaterials and in food contact applications. Even though the corrosion resistance of such grades is high, or very high, alloy components will be released to different extent in contact with biological media of varying composition, acidity and metal complexation capacity, a process that may induce adverse toxicological effects. Research activities have focused to quantitatively determine, and kinetically and mechanistically assess the metal release process in relation to material and surface properties of stainless steels of different grade as massive sheet and as powders in contact with biological systems of relevance for human exposure. Surface-protein interactions have been addressed from a combined surface chemistry, corrosion and material science and toxicological approach. Generated findings clearly show that both bulk and surface oxide properties such as phase, structure, morphology, chemical and electrochemical stability, largely influence the metal release process, biointerfacial interactions, bioavailability of released metals, and subsequent toxicity. For example, the cooling-rate dependent surface oxide speciation (surface oxide thickness, composition, phase and phase distribution, crystallinity etc.) of stainless steel particles strongly determines whether the dominant mechanism of metal release in complexing biological environments is corrosion-controlled or ligand-induced chemical dissolution. Research findings are of vital importance for risk assessments of stainless steel and alloys, to understand adsorption phenomena on stainless steel, metal release and corrosion processes, and the influence of surface oxide speciation on metal release, corrosion, and toxicity.
Influence of Environment and Applied Stresses on the Susceptibility to Corrosion and Anodic Dissolution of α,β’-Brass in NaNO3 Solutions
Authors: Berne Clément , Andrieu Eric , Reby Jean , Sobrino Jean-Michel , Blanc Christine
Published: February 2020

α,β’-brasses, used for components in gas distribution network, are believed to be susceptible to simultaneous dissolution (Cu, Zn) and/or selective dissolution (dezincification) processes in corrosive environments. These phenomena are suspected to play a major role during the first stages (incubation and initiation) of SCC damage development observed on in service network components. In this framework, it is of interest to improve knowledge on kinetics and mechanisms of brass dissolution. The present study aimed at contributing to a better understanding of the dissolution processes of α,β’-brass, this topic being little studied to date.

The specimens, corresponding to α,β’-brass CuZn40Pb2 (CW617N), were machined from stamping rods used to manufacture gas transfer valves. The corrosion tests were performed in NaNO3 solution selected with reference to research on α-brass (1). Two types of objectives were defined; the first corresponded to test the influence of environment (pH, nitrate ions concentration) and mechanical loading on the corrosion behaviour through electrochemical methods, and the second, to determine the dissolution and dezincification kinetics from immersion tests at constant potential, in selected environments and under specific loadings.

In order to reach the first objective, results obtained over a wide range of testing conditions (pH, nitrate ions concentration, loadings…) were analysed by comparing open circuit potential measurements, anodic polarisation curves, and surface characterizations (Optical Microscope, Scanning Electron Microscope and X-Ray photoelectron spectrometry). For the second objective, measurements of both the dissolution depths and the weight loss, chemical analyses of the corroded materials and the corrosion products (Inductively Coupled Plasma, Energy-dispersive X-ray spectroscopy) were used to quantify the dissolution kinetics. Finally, discussion focuses on understanding the dissolution mechanism, in comparison with α-brass dissolution process proposed in the literature (2). The influence of load on the basic mechanisms (opening of damages, stability of oxides layers....) will be discussed to better understand the SCC incubation and initiation stages.

1. S.A. Fernandez and M.G. Alvarez, Corros. Sci., 53, 82 (2011).

2. A.P. Pchelnikov, A.D. Sitnikov, I.K. Marshakov and V.V. Losev, Electrochim. Acta., 26, 591 (1981).

“This work was performed in the framework of a joint laboratory, called CETIMAT, where CIRIMAT and CETIM collaborate for some aspects of their research."
Salvia Hispanica as Eco-Friendly Inhibitor for Mild Steel in Sulfuric Acid
Authors: Hermoso Díaz Irma Alondra , Gonzalez Rodriguez Jose Gonzalo , Ramírez Arteaga América María
Published: February 2020

Salvia hispánica seeds extract has been investigated as a carbon Steel corrosion inhibitor in 0.5 M sulfuric acid by using polarization curves, electrochemical impedance spectroscopy, electrochemical noise and weight-loss, tests at different concentrations (0, 100, 200, 400, 600, 800 and 1000 ppm) and temperatures, namely 25, 40 and 60 °C. Results show that inhibition efficiency increases as the inhibitor concentration increases, decreases with temperature. The extract inhibit corrosion mainly by an adsorption mechanism. Potentiodynamic polarization studies show that extract is mixed-type inhibitors.
High-Temperature Corrosion of AISI 316L in Chlorosilane Environments at 550°C
Authors: Aller Joshua L , Gannon Paul E. , White Preston
Published: February 2020

Chlorosilanes (Cl-Si-H compounds) are ubiquitous in modern silicon refining and semiconductor device manufacturing technologies, which are often operated at temperatures above 500°C. Corrosion of metals-based process hardware (e.g., reactors, tanks, and piping) in these environments can compromise manufacturing productivity and hardware durability. In this study, AISI 316L was subjected to various high-temperature (550°C) chlorosilane environments for up to 100 hours. Hydrogen gas ((H2) saturated with silicon tetrachloride (SiCl4) (STC)) was combined with clean hydrogen (H2) and anhydrous hydrogen chloride (HCl) in ratios relevant to manufacturing process streams. The presence of both STC and HCl during these exposures leads to the formation of metal chlorides and silicides on the surfaces of AISI 316L. While the metal silicides were stable and formed a protective surface layer, the metal chlorides were volatile and formed non-protective surface layers. Surface and mass analyses before and after 100 hour exposures showed predominately surface chlorination (and sample mass loss) with HCl/STC mole ratios (feed stream) >~0.18. With no HCl in the feed stream, surface silicidation was predominate, and the samples gained mass. Experimental methods, data (316L) and interpretations will be presented and discussed in the context of advancing understanding of high-temperature corrosion (and protection) of metals in chlorosilane environments.
On the Galvanic Coupling of Bulk-AlCu Intermetallic Phases (Al2Cu, Al7Cu2Fe) and Pure Aluminium in NaCl Solution
Authors: Rocca Emmanuel , Tardelli Joffrey , Mathieu Stephane
Published: February 2020

Aluminium alloys with high mechanical properties, from the 2xxx and 7xxx series, are very sensitive to corrosion because of the presence of numerous intermetallic phases in these materials. It is well known that these phases are responsible of the formation of pits that can spread in bulk alloys via the grain boundaries or lead to generalised corrosion of alloys.

In many studies on corrosion of aluminium alloys, the galvanic coupling between the AlCu intermetallic phases and the aluminium matrix is the main phenomenon, supposed to explain the formation of pits. On the other hand, some authors have clearly highlighted the copper enrichment of some intermetallic phases as Al7Cu2Fe (1) and Al2CuMg (2, 3).

The objective of this work is to study the electrochemical behaviour of Al2Cu andAl7Cu2Fe intermetallic phases in NaCl solution, to characterize the corrosion rate by stationary electrochemical techniques and electrochemical impedance spectroscopy.

FEG-SEM observations, X-ray diffraction and X-ray photoelectron spectroscopy show that the two phases undergo a more or less complex dealloying phenomenon leading to the formation of a nanometric sponge of pure copper, covered with amorphous aluminium hydroxide. This dealloying phenomenon depends on both the copper content in the phase and on its crystallographic structure.

Then, the galvanic current density between the bulk AlCu phases and pure aluminium was monitored in function of immersion time. The comparison between the corrosion current density of the AlCu phases and the galvanic current density show that the galvanic coupling is often negligible compared to the intrinsic corrosion phenomenon of the phase.

So, the formation of pits on AlCu alloys seems to be mainly linked to the particular corrosion mechanism of AlCu intermetallic phases, inducing the formation of holes and pure copper.

References:

N. Birbilis, M.K Cavanaugh, R.G Buchheit, Corrosion Science 48 (2006) 4202-4215

R.G Buchheit, M.A Martinez, L.P Montes, Journal of the Electrochemical Society 147 (2000) 119-124

R.G Buchheit, L.P Montes, M.A Martinez, J. Michael, P.F Hlava, Journal of the Electrochemical Society 146 (12) (1999) 4424-4428
Electrochmical Corrosion Behavior of Alloy 600 and SA508Cl.3 in Solutions with Various Sodium-to-Chloride Ratios
Authors: Im Kyung Soo , Hur Do Haeng
Published: February 2020

The laboratory and field experience data indicate that both IGA and SCC of Alloy 600 nuclear steam generator tube material are minimized at a near neutral pH of the range between 6~8. The neutral pH can be achieved by controlling the molar ratio of the cation to anion impurities dissolved in the crevice to be near one. Tubesheet and tubes are galvanically contacted in the tube to tubesheet crevice region of a steam generator. Therefore, the corrosion behavior of tubesheet material should be considered in the application of the molar ratio control. In addition, since the molar ratio is a simple ratio of the cations to anions, the total concentration of the soluble impurities is not considered.

In this paper, the corrosion behaviors of tube and tubesheet material are examined by a electrochemical polarization method in solutions with various sodium-to-chloride ratios at room temperature. The effect of the impurity concentration at a constant sodium-to-chloride ratio is also evaluated. Both the corrosion potentials and corrosion rates of Alloy 600 and SA508Cl.3 were significantly decreased as the sodium-to-chloride ratio increased from 0.1 to 10. The corrosion potential and corrosion rate were not affected by a change of the impurity concentration from 0.011 M to 0.11 M at a constant sodium-to-chloride ratio. The corrosion rate of SA508Cl.3, acting as an anode, was increased by about 2~6 times by a galvanic coupling with Alloy 600.
Benzodimidazole and Imidazole as Corrosion Inhibitors of AISI 316L Stainless Steel in Sulphuric Acid Medium
Authors: Cardona Clara , Narváez Lilia , Miranda Juana María , Acosta Andres
Published: February 2020

The corrosion behaviour of AISI 316L stainless steel in 0.5 M H2SO4 solution containing various concentrations of dimethyl benzodimidazole (BZD) as corrosion inhibitor was investigated. Inhibition efficiency was evaluated using potentiodynamic polarization and electrochemical impedance techniques. 40 ppm of BZD showed the best behaviour at 25 °C, above this concentration the efficiency was decrease. All results were compared with imidazole as inhibitor as same conditions, founded a similar performance at 40 ppm. Both inhibitors showed absorptions on the stainless steel surface which obeyed the Frumklin isotherm adsorption equation.
Electrochemical Studies on Zero VOC Coated Steel through Atmospheric Exposure and REAP Test in the Laboratory
Authors: Ramirez-Reryes Jose Luis , Galicia-Aguilar Gonzalo , Malo-Tamayo Jose Maria , Uruchurtu-Chavarin Jorge
Published: February 2020

The application of coatings for control the degradation of materials has been historically used since ancient civilizations, but usually the coating systems take a long time to show the physical evidence of corrosion on coated metals, so the evaluation of coatings in aggressive atmospheres and with a rapid way has been the dream of the experts and users through the time. Cabinete standard tests have been developed as a quality control for coatings, including salt fog, climate chamber or artificially damage conditions.

The paint systems utilized for the study were zero volatile organic or water base paints with Zinc phosphate content. The electrochemical measurements were made before and after the potentiostatic test using the electrochemical techniques of Corrosion Potential (Ecorr), Linear Polarization Resistance (LPR), Electrochemical Impedance Spectroscopy (EIS) and the Polarization Curves. For the evaluation of the atmospheric exposed coatings they were retired at different times and applied the electrochemical tests in the laboratory and returned to the exposure rack. For the application of the Rapid Electrochemical Assessment of Paints (REAP), the galvanic current was registered during the potentiostatic conditions providing an excellent parameter for the qualification of paint systems, while a degradability parameter for the paint systems can be calculated from the LPR results that can be compared with results from atmospheric exposure.
Epoxy Polyaniline–SBA15/Fluconazole Hybrid Nanocomposite Coatings: As a Self-Healing Corrosion Protection of Mild Steel
Authors: Terrones Victoria Bustos , Uruchurtu Jorge , Romo Mario Alberto Romero , Menchaca Carmina , Esparsa Marco J
Published: February 2020

The objective of this research is the production of an epoxy coating blended with organic–inorganic hybrid nanocomposite applied over mild steel, as a self-healing corrosion protection of defects.

A series of conducting polyaniline (PANI)–SBA15/Fluconazole nanocomposites materials are being prepared by an in situ chemical oxidative method of aniline monomers in the presence of SBA15/fluconazole complex nanorods which were synthesized previously with camphor-sulfonic acid (CSA) and ammonium peroxydisulfate (APS) as surfactant and initiator, respectively. A commercial epoxy coating was applied over samples afterwards.

The synthesized materials were characterized by X-ray diffraction pattern (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM).

To determine the best inhibitor concentration, the anti-corrosion behavior of the Fluconazole was studied in a ammonium sulfide-sodium chloride pH 7 solution, at a temperature of 25 ͦ C using electro-chemical techniques including electrochemical impedance spectroscopy (EIS) and polarization potentiodynamic. The electrochemical results show that this inhibitor has an effect on anodic region forming a passivation layer, and the best result was achieved with 150 ppm of Fluconazole.

The next step was to prepare the SBA15/Fluconazole nanorods, and finally the PANI-SBA15/Fluconazole composite, and evaluate the self-healing effect over mild steel.

It was found that the presence of SBA15/Fluconazole nanorods dispersed in the PANI matrix can significantly improve the corrosion protection and barrier effect performance of the epoxy coating due to the flaky shaped structure of the PANI–SBA15/Fluconazole nanocomposites, evaluated electrochemically.
Development of a Thin and Flexible Sensor for Assessing Corrosion Damage of Hard-to-Access Painted Surfaces
Authors: Kuentzler Matthew , Cook Daniel , Sikora Elizabeth , Shaw Barbara A
Published: February 2020

Thin, flexible sensors to measure corrosion in hard-to-access areas are very attractive tools in corrosion monitoring. These sensors can be used to monitor the degradation of painted steel in areas where visual monitoring would be difficult and time consuming. Having a network of thin, flexible (conforming) sensors which would detect coating degradation and actual steel corrosion rates (through measuring the electrochemical impedance ), placed in strategic locations, would allow collection of vital corrosion data. Such an approach would allow a transition from time-based to condition-based assessment of corrosion in many areas.

The three electrode sensor used for these measurements consist of Ag/AgCl ink screen printed on thin flexible polymer substrate material. This ink and substrate combination has allowed the sensor to function for 600+ hours without failure. To make the electrical connection, wires were bonded to the sensor through a silver conductive epoxy. To keep this bonded area from corroding and giving false readings it was sealed with a waterproof, self-fusing silicon wrap. The preliminary results of EIS measurements (Figure 1) of painted steel panel with sensor (blue) and conventional paint cell (red) show an excellent agreement between these spectra.
Development of New Multifunctional Coatings for Protection Against Erosion and Corrosion in Qatar Oil and Gas Production
Authors: Wang Dailin , Dizvay Isin , Sikora Elizabeth , Shaw Barbara A , Al-Jassem Nasser
Published: February 2020

Due to expanding marine oil and gas production, protection of steel in marine environments is particularly important. Combined corrosion and erosion seriously compromises the integrity of tools, pumps and transport pipes. To improve the corrosion resistance of the pipelines, coatings are used widely on oil and gas production equipment.

Coatings can provide low-cost protection against corrosion and erosion in pipelines and vessels. Points where fluids impinge on surfaces, such as pipe bends and separator walls, are particularly vulnerable. Application of coatings in such instances is particularly promising because the protective vehicle can be applied over low-cost alloys, proving economical solutions to materials problems.

Recently multiphase coatings have been examined for a wide variety of applications. Such coatings consist of a polymer matrix containing hard, abrasion-resistant ceramic particles. Several ceramics are used to impart erosion resistance. Typically, aluminum oxide or titanium dioxide are used because they have desired physical properties, and the cost of these materials is relatively low.

The present investigation focuses on electrochemical evaluation of protective properties of a set of multiphase coatings in the environment encountered inside of off-shore natural gas pipelines. The coatings ranged in thickness and amount of abrasion-resistant ceramic filler (listed in Table 1).

Coating
Powder-phenolic novolac

Filler Amount

Thickness

1.3 X
4.5-12 mils

X
4.5-14 mils

0.125X
4.5-14 mils

The coated panels were immersed in a solution of 2000 ppm Cl-, pH 3.5,saturated with CO2, at temperature 60C . The electrochemical impedance spectra were collected as a function of immersion time. In addition, the effect of erosion on corrosion performance of the coatings is being tested according to ASTM D968 standard. For these erosion corrosion tests the coatings are periodically removed from the testing solution, subjected to abrasive action of falling SiC particles and then immediately immersed back in the solution.

The EIS data of coatings prior to any erosion indicates that the corrosion performance is independent on amount of filler used; however, the thicker coatings showed the best corrosion resistance. EIS of specimens exposed to periodic erosion is still underway and these results will be presented.
Characterization of Coatings of New Technology for Corrosion Prevention
Authors: Espino Aracely , Vega Victor , Antaño Rene
Published: February 2020

Nowadays, there are various types of new technology coatings used in the corrosion protection. These include from organic solvent-based formulations to water solvent-based and solvent free (high content of solids). Regardless of their nature, these protection systems must present properties to ensure good performance against various environmental conditions.

In this work, factors such as degradation, corrosion resistance and the effect of type of coatings formulation are investigated, by implementing contact angle tests and accelerated weathering. Thus, qualitative information about the systems is obtained. For this purpose the samples are exposed to different solutions which simulate the corrosive environments, according to ASTM B117 -11 and ASTM D 5894-10 standards. Also, electrochemical techniques as electrochemical impedance spectroscopy (EIS) and electrochemical frequency module (EFM), were employed to provide quantitative information about the process of degradation and corrosion.

The visual defects usually appear when the resistance of the coatings tends to a value ≤ 1x106 Ohm/cm2. The obtained information allows to enquire the process of degradation of the systems and their level of protection, and the relationship between the electrochemical parameters and visual assessment.
Pulsed Potential based E-ALD of PV Materials
Authors: Stickney John Lewellen , Czerniawski Justing , Perdue Brian
Published: February 2020

A family of absorber materials of interest for high volume production of photovoltaics is referred to as CZTS, or Cu2ZnSn(S,Se)4. The primary advantages of these materials are that they are made from nontoxic earth abundant elements. This group has been working on E-ALD as a method for the formation of materials an atomic layer at a time for many years. E-ALD provides atomic level control during the growth process and has been shown to form high quality deposits. E-ALD is based on alternating precursor solutions of the desired elements and the use of UPD to limit growth to an atomic layer at a time. The E-ALD method has important advantages for the formation of nanofilms of materials. There are a broad range of new PV designs involving nanostructured electrodes and plasmonic layers where the thickness of an absorber layer can be much thinner than the µm needed for a typical thin film PV. On such substrates, E-ALD should show important advantages for the formation of conformal nanofilms without annealing. The main disadvantage to the use of E-ALD for the growth of PV, is the time it takes to grow a µm thick absorber layer. The rate of growth is presently limited by the time it takes to change solutions. Efforts by this group are being directed to the development of a variant of E-ALD based on potential changes, pulses, rather than solution exchanges. This greatly increases the rate of deposition. Presently, the Authors referred to it as potential pulse ALD (PP-ALD). Preliminary results on the formation of Cu2Se and other components of a CZTS buffer layer will be discussed.
Effect of Au Content in Aupd Electro-Synthesized Mixtures Toward Formic Acid/Formate Electro-Oxidation
Authors: Arjona Noé , Guerra-Balcázar Minerva , Álvarez-Contreras Lorena , Ledesma-García Janet , Arriaga Luis Gerardo
Published: February 2020

AuPd mixtures were electrochemically synthesized using pulse potential techniques such as differential pulse amperometry, square wave voltammetry and second harmonic AC voltammetry in order to modify the metal content of the mixtures. Pure Au and Pd were electrochemical synthesized for comparison purposes. The metal proportions of 90:10, 60:40, 50:50, 35:65 and 15:85 Au-Pd were obtained according to EDS and XRF analyses. Formic acid/formate was worked in 0.3 M KOH (as electrolyte) in order to preserve the presence of formate. At low Formic acid/formate concentration (0.01 and 0.1 M) pure-Pd material exhibited good electrocatalytic activity in terms of current density. Pure-Au material showed no response for formic acid/formate electrooxidation at low concentrations. On the other hand, AuPd mixtures exhibited different behavior as function of the bimetallic content. At low concentrations (0.01 and 0.1 M) mixtures enriched with Au exhibited a poor electrocatalytic activity. Meanwhile, Pd-enriched mixtures content showed low current density than pure-Pd. However, when the formic acid concentration was increase to 0.3 and 0.5 M, pure-Pd showed higher CO-poisoning effect than Pd-enriched AuPd mixtures.
Aupd/Polyaniline Composites Toward Ethylene Glycol Electro-Oxidation
Authors: Palacios Alexander , Arjona Noé , Ledesma-García Janet , Guerra-Balcázar Minerva , Arriaga Luis Gerardo
Published: February 2020

AuPd/polyaniline composites were synthesized using and electrochemical/chemical method. The materials were physicochemical characterized by SEM, XRD and XRF and electrochemical techniques. Ethylene glycol electro-oxidation was performed in 0.3 M KOH (as electrolyte) at different ethylene glycol concentrations 0.5, 1 and 2 M. The SEM characterization showed semispherical homogenous microparticles around 0.7 μm composed by nanoparticles of 30 nm. Electrochemical results showed that all AuPd/polyaniline materials exhibited good electrocatalytic activity toward ethylene glycol oxidation at room temperature with a low poisoning effect of the catalysis. The electrocatalytic activity was in function of the mass ratio between Au and Pd in the AuPd mixture.AuPd/polyaniline composites were synthesized using and electrochemical/chemical method. The materials were physicochemical characterized by SEM, XRD and XRF and electrochemical techniques. Ethylene glycol electro-oxidation was performed in 0.3 M KOH (as electrolyte) at different ethylene glycol concentrations 0.5, 1 and 2 M. The SEM characterization showed semispherical homogenous microparticles around 0.7 μm composed by nanoparticles of 30 nm. Electrochemical results showed that all AuPd/polyaniline materials exhibited good electrocatalytic activity toward ethylene glycol oxidation at room temperature with a low poisoning effect of the catalysis. The electrocatalytic activity was in function of the mass ratio between Au and Pd in the AuPd mixture.
Electrochemical Deposition of Highly Efficient Cztsse Thin Film Solar Cells
Authors: Kim Jin Young
Published: February 2020

Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) thin films are attracting a lot of interest as an alternative system to Cu(In,Ga)Se2 (CIGS) thin films, owing to their majority carrier type (p-type), proper band gap energy (1.0-1.5 eV), and high optical absorption coefficient (> 104 cm-1). More promisingly, the CZTSSe is composed of earth-abundant (cf. In in CIGS), environmentally-friendly (cf. Cd in CdTe), and relatively cheap elements. We have recently reported that a highly efficient CZTSSe thin film solar cell can be fabricated via an electrochemical method involving the electrochemical deposition of metallic Cu-Zn-Sn (CZT) precursor thin films and the subsequent sulfurization/selenization process. In this study, we investigated the effect of the electrochemical deposition conditions on the physical and chemical properties of the metallic precursor films and the final CZTSSe thin films. In particular, the oxygen content in the precursor and CZTSSe thin films was found to influence the film morphology and the device performance. By carefully controlling the deposition condition, such as the bath temperature, solution composition, and the cell configuration, the oxygen content in the thin films could be successfully reduced. After some additional optimization processes including the annealing condition, an efficiency exceeding 8% was obtained, which is one of the highest efficiencies reported on the electrochemically deposited CZTSSe thin film solar cells.
Electrodeposition of CZTS Thin Films for Solar Cells
Authors: Khalil Md Ibrahim , Bernasconi Roberto , Ieffa Simona , Magagnin Luca
Published: February 2020

In the present work, Cu2ZnSnS4 (CZTS) thin films were successfully prepared using a coelectrodeposition–annealing route, in which Cu-Zn-Sn metal precursors were deposited by a novel electrolyte formula, followed by annealing in elemental sulfur environment in quartz tube furnace with N2 atmosphere on Mo substrate. The morphological, compositional, structural analyses of the films were investigated using scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction in both cases before and after sulfurization. Raman spectroscopy was also performed on the films after sulfurization to fully characterize the film. Glow discharge optical emission spectroscopy (GDOES) has also been carried out to see how composition changes along the film thickness. Results demonstrated the formation of the CZTS kesterite structure after sulfurization of the film. The result showed that CZTS crystalline properties depend on annealing times and ramping rate during sulfurization. Electrodeposition is a potentially suitable preparation method to obtain low-cost precursors films because it is inexpensive, uses an environment-friendly process, produces large deposition areas and low temperature deposition. Actually it is easier to control different process parameter during coelecrodeposition of Cu-Zn-Sn rather than sequential electrodepositon of Cu/Zn/Sn. In case of coelctrodeposited precursors, most of the researcher used an acidic electrolyte where tri sodium citrate used as complexing agent. In our studies a novel basic electrolyte formula was used where the salt of Cu2+, Zn2+ and Sn4+ were complexed in a better way with respect to the acidic electrolyte. The co-electrodeposited metallic precursor’s films were subsequently sulfurized in a quarts tube furnace in an elemental sulfur environment with N2 atmosphere. Raman spectroscopy confirmed the presence of kesterite CZTS in the films. Results on other characteristics have also shown how the annealing times and ramping rates during sulfurization influence the grain size and impurities (other binary/ ternary phases).
Mechanism for the Growth of Thin Films of WO3 and Bronzes from Suspensions of WO3 Nanoparticles
Authors: Martín Antonio José , Maffiotte César , Chaparro Antonio M.
Published: February 2020

WO3 is an oxide with semiconducting and electrocatalytic properties, of high interest in a number of applications. It may exist in different hydrates, like WO3.2H2O and WO3.H2O. In aqueous solution, it may be reduced reversibly to bronzes (WO3Hx) and lower valence oxides (WO3-x), exhibiting different physical and chemical properties, like colour, hydrophobicity, and conductivity (protonic and electronic). In combination with platinum, it forms a mixed compound, Pt-WO3, with interesting possibilities as catalyst for fuel cell electrodes.

Thin films of WO3 can be grown electrochemically from aqueous solutions containing dissolved W precursors. Another possibility is the growth from WO3 suspensions formed from insoluble tungsten compounds. The electrochemical growth from WO3 suspensions is a process that requires the diffusion and sticking of the suspended (nano-) particles on the electrode surface.

In this communication, the growth of WO3 films and derived compounds, from aqueous suspensions of WO3 is studied with the help of the quartz crystal microbalance (EQCM). WO3 suspensions are prepared from acidic WO4
2- solutions, and deposited on gold and Pt substrates. Film growth rates by stepping and cycling the electrode potential are analysed with EQCM.

Fig. 1 contains steady state deposition rate and electrode current on a Pt substrate. For potentials above 0.15 V exists just an attachment of WO3 particles leading to a constant, low, growth rate. Film grown in this regime tends to come off the electrode surface after some minutes. Below 0.15 V, growth rates increases linearly up to -0.2 V. The same figure shows that the film growth rate has close resemblance with the logarithm of stationary reductive current density due to reduction of water (H+ + e- --> 0.5H2). The acceleration of film growth rate in parallel with water reduction appears to indicate that hydrogen reduced species on the Pt surface participate in the electrochemical reduction of WO3 suspensions. Such possibility is probable in the light of the well known H-spillover mechanism from Pt to WO3 phase. Reactions for film growth can be proposed in this way:

Pt + H+ + e- --> Pt-Hsp

[WO3]sus
+ xPt-Hsp --> WO3Hx + Pt

The growth mechanism is analysed on the light of EQCM results, thin films are characterized (SEM, XPS), and the stability of the films in aqueous solutions is also analysed in view of their possible application as an electrocatalyst component for fuel cell electrodes.

Acknowledgements

This work is financed by the project ELECTROFILM, MAT2011-27151 from Ministry of Science and Innovation of Spain.
Electrochemical Studies of the Lithium Deposition on Au(111) from a Piperidinium-Based Ionic Liquid
Authors: Berger Claudia , Jacob Timo
Published: February 2020

For large-scale applications of modern lithium ion batteries, e.g.in electric car applications, thermal stability has to be absolutely ensured. Further, the required increasing power density of modern batteries demands for a larger electric potential of the cell. Room-temperature ionic liquids (RTILs) satisfy these requirements, as they provide low vapour pressure and high thermal stability combined with large electrochemical windows and good ionic conductivities [1,2]. However, internal short circuits due to the formation of lithium dendrites is one of the major issues of modern batteries, but the knowledge of this dendrite formation from RTILs is rather poor. Since an in-depth understanding of these processes is highly desirable we carried out extensive studies regarding the initial stages of lithium deposition from RTILs on single crystal electrodes.

Lithium was electrodeposited on a Au(111) substrate from the solution of lithium bis(trifluoromethylsulfonyl)imide in the commercially available RTIL 1-methyl-1-propylpiperidinium bis(trifluoromethylsulfonyl)imide. Electrochemical investigations were carried out by means of cyclic voltammetry (CV) and the initial stages of metal deposition were followed by in-situscanning tunnelling microscopy (STM). As additional and independent characterization method, Electrochemical Quartz Crystal Microbalance (EQCM) measurements were performed to determine the actual adsorbate species with high accuracy.

We found, that three cathodic peaks appear in the potential range of −0.5 to −2.5 V vs. a Pt pseudo-reference electrode. Each one seems to be related to the deposition of lithium according to the EQCM measurement. This is also in accordance with the in-situ STM investigations, which confirm Li-deposition in various morphologies within this potential range. Further, a strand-like growth of a lithium species on the gold terraces can be recognized in the potential regime of the first cathodic peak. After applying a potential in the order of the second cathodic peak the growth of islands of one monolayer height takes place on the electrode surface. The third peak at very negative potential coincides with a three dimensional growth of lithium.

[1] M. C. Buzzeo, R. G. Evans, R. G. Compton, ChemPhysChem 5 (2004) 1106.

[2] R. Hagiwara, T. Hirashige, T. Tsuda, Y. Ito, J. Electrochem. Soc. 149 (2002) D1.
Keynote: Corrosion-Electrochemistry Based Undergraduate Curricula: Finding a Balance Between Chemistry, Materials and Engineering
Authors: Lillard Scott , Haritos George , Payer Joe , Evans Edward , Castaneda Homero , Cong Hongbo
Published: February 2020

The baccalaureate program in Corrosion Engineering at The University of Akron is the first of its kind in the nation. It was formed in response to Federal Government interest and industry need in the area. The idea was first presented in 2006 and the University welcomed its first freshman class in 2010. The degree is a traditional engineering degree based on a math, science and general education courses that support engineering science and engineering design courses; students take courses from five different engineering programs. At its core are classes and laboratories in corrosion electrochemistry, high temperature oxidation, and corrosion engineering management. In addition, the students are exposed to hands-on experience as a corrosion engineer through the co-op program. This curriculum was developed using input from a number of stakeholders in government, industry and academia that wanted students with knowledge in corrosion basics, materials characterization and corrosion prevention and the ability to diagnose failures, guide maintenance and repair as well as perform risk based assessment. In this presentation we will review the method that lead to the current program as well as feedback from co-op experiences including both student and employer perspectives.
NSF Industry University Cooperative Research Center for Electrochemical Processes and Technology a Model for Open Innovation
Authors: Botte Gerardine G.
Published: February 2020

Introduction

In the path from invention to product it becomes important to consider multiple options for generation of ideas that could lead to out of the box solutions to technological problems. In the search for new ideas and solutions the concept of Open Innovation has become a new paradigm for companies [1]. Within this paradigm cooperation among industry, universities, customers, and rivals is needed for success. One model that has been successful in such approach is the National Science Foundation's (NSF's) Industry/University Cooperative Research Centers (I/UCRC) program.

Over the past three decades, the I/UCRCs have led the way to a new era of partnership between universities and industry, featuring high-quality, industrially relevant fundamental research, strong industrial support of and collaboration in research and education, and direct transfer of university developed ideas, research results, and technology to U.S. industry to improve its competitive posture in world markets [2].

In this talk, the implementation of the NSF I/UCRC model will be described within the context of electrochemical processes and technology. A new NSF I/UCRC: Center for Electrochemical Processes and Technology (CEProTECH) had been established [3]. CEProTECH is dedicated to the improvement of chemical and biological processes utilizing novel, electrochemically-focused approaches. Ohio University (OHIO, lead Center site) and Washington University in St. Louis (WUSTL, Center site) are the founding universities. The Center facilitates fundamental, cross-cutting process analysis and research for a diverse range of industry applications. This includes both the classical electrochemical processes - chlor-alkali and aluminum processes, batteries, etc.- as well as processes that typically would not utilize electrochemical methods -remediation, advanced synthesis, and production of specialty gases, chemicals, and materials, etc.-.

This talk will discuss the process of engaging companies to partner with the center and learning about their advanced manufacturing needs that electrochemical solutions can address.

This presentation will focus on the path for the creation and operation of an industry focused research center, CEProTECH, the technology roadmap, the education opportunities for the participants, as well as discussing potential ways of collaboration.

References

[1] H. W. Chesbrough, MIT Sloan Management Review 44 (2003) 35-41.

[2] National Science Foundation, I/UCRC model partnerships, http://www.nsf.gov/eng/iip/iucrc/program.jsp (accessed 03/31/2014).

[3] NSF I/UCRC: Center for Electrochemical Processes and Technology, http://ceprotech.com, (accessed 03/31/2014).
Chemical Mechanical Planarization Processes in Cu Interconnects: Invention to Implementation
Authors: Krishnan Mahadevaiyer
Published: February 2020

Chemical mechanical planarization (CMP) is one of the most critical semiconductor process technologies that enabled the fabrication of Cu interconnects and helped to achieve the performance goals of modern microprocessor and memory chips. Cu interconnects were introduced at the 130 nm technology node with oxide ( k ≈ 4) as the dielectric material. Since then, It has been the industry standard and has been extended to 22 nm technology node with low-k /ultra low-k ( k < 3) materials as dielectrics. The relentless drive to improve processor performance accelerated the introduction of new materials along with simultaneous reduction in minimum wiring dimensions and increase in the number of interconnects levels. The aggressive interconnect scaling coupled with the necessity to introduce new materials resulted in several unique challenges for the CMP processes. This paper presents examples of the innovative approaches that were used in solving some of these problems.
Keynote: Integrating Discovery, Direct and Combinatorial Science for Solar Fuels Prototype Development
Authors: Lewerenz Hans Joachim
Published: February 2020

Photoelectrochemical water splitting has a more than four decade long history [1]. Research and development efforts, however, have been almost exclusively directed to the investigation of suited electrode materials and to the study of interfacial processes such as charge transfer and (photo)corrosion [2]. Half cell performance and characterization has predominantly been the focus [3, 4]. During this incubation period, some basic concepts have been developed [5] and thermodynamic aspects of stability and the basic processes in water oxidation and proton reduction were established [6].

The development of a technological device, comparable to that of the dye sensitized solar cell [7], was hitherto complicated by rather little coordinated research activities, pursued mostly in single investigator teams of limited size. Accordingly, some of the issues in light-induced water splitting, such as photoanode, -cathode and heterogeneous catalyst materials development, details of reaction mechanisms, successful implementation of stabilization strategies and tailored membrane design were delayed.

In this presentation, the strategy of the Joint Center for Artificial Photosynthesis in developing solar fuel prototypes in a field where a corresponding industry does not exist, where the work force has to be trained in photoelectrochemistry and the materials science for the envisaged prototype components and where design criteria for devices have to be developed, will be outlined. Examples for achievements in basic science, component integration and testbed/prototype assembly and characterization will be shown. They encompass (i) an efficient strategy to protect light absorbers against photocorrosion, which allows the use of technologically advanced semiconductors such as III-V compounds, (ii) the increased understanding of traditional and novel electrocatalysts by in operando synchrotron radiation experimentation, (iii) the use of advanced photonics for light management, (iv) combinatorial approaches for catalyst development, (v) modelling, design and realization of solar fuel reactors and (vi) feedback mechanisms for materials and system optimization.

The interaction and the training of the workforce demands advanced communication technologies and regular cross team and cross disciplinary meetings as well as educational means. An overview of the major communication and education instruments will be given.

1. A. Fujishima, K. Honda, Nature 238 (1972) 37

2. H. Gerischer, Pure and Appl. Chem. 52 (1980) 2649

3. A. Heller, R.G. Vadimsky, Phys. Rev. Lett. 46 (1981) 1153

4. H.J. Lewerenz, C. Heine, K. Skorupska, N. Szabo, T. Hannappel, T. Vo-Dinh, S. A. Campbell, H. W. Klemm and A. G. Muñoz, Energy and Environm. Sci. 3 (2010) 748

5. A. Nozik, Ann. Rev. Phys. Che. 29 (1978) 189

6. B.A. Parkinson, Acc. Chem. Res. 17 (1984) 431

7. M. Graetzel, J. Photochem. Photobiol. C: Photochemistry Reviews 4 (2003) 145