Search results for "electroquímica"
showing 10 items of 75 documents
Galvanic Corrosion Following Local Breakdown of a Scale Formed on X-65 in CO2 Saturated Solutions
2015
Under some conditions in sweet environments, the precipitation of corrosion products (primarily FeCO3) on the surface of X-65 pipeline steel can decrease the corrosion rate of the metal, this precipitated film acting like a protective scale. However, when these scales are damaged due to effects such as solidparticle erosion or mechanical stress, a galvanic pair can form between the bare steel (anode) and the surrounding undamaged scale (cathode). The aim of this work is to evaluate the magnitude of galvanic coupling that arises when the protective scale is broken and a corrosion cell is established between the defect and the surrounding scale. This study has been conducted in two stages: fi…
The shiny side of copper: bringing copper(i) light-emitting electrochemical cells closer to application
2020
Heteroleptic [Cu(P^P)(N^N)][PF6] complexes, where N^N is 5,50-dimethyl-2,20-bipyridine (5,50-Me2bpy), 4,5,6-trimethyl-2,20-bipyridine (4,5,6-Me3bpy), 6-(tert-butyl)-2,20-bipyridine (6-tBubpy) and 2-ethyl-1,10- phenanthroline (2-Etphen) and P^P is either bis(2-(diphenylphosphino)phenyl)ether (POP, PIN [oxydi(2,1- phenylene)]bis(diphenylphosphane)) or 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (xantphos, PIN (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphane)) have been synthesized and their NMR spectroscopic, mass spectrometric, structural, electrochemical and photophysical properties were investigated. The single-crystal structures of [Cu(POP)(5,50-Me2bpy)][PF6], [Cu(xantphos)(5,…
Dimensionality Controls Anion Intermixing in Electroluminescent Perovskite Heterojunctions.
2022
Metal halide perovskites have emerged as a promising group of materials for optoelectronic applications such as photovoltaics, light emission, and photodetectors. So-far, in particular, the stability of light-emitting devices is limited, which is in part attributed to the intrinsic ionic conductivity of these materials. High-performance devices inevitably contain heterojunctions similar to other optoelectronic devices based on oxide perovskites, II-VI, or III-V group semiconductors. To enable efficient heterojunctions, ion exchange at the interface between different layers should be controlled. Herein, we report a method that enables to control and monitor the extent of anion intermixing be…
Influence of Fe-clustering on the water oxidation performance of two-dimensional layered double hydroxides
2022
Among the two-dimensional (2D) materials family, layered double hydroxides (LDHs) represent a key member due to their unparalleled chemical versatility. In particular, Fe-based LDHs are distinguished candidates due to their high efficiency as oxygen evolution reaction (OER) electrocatalysts. Herein, we have selected MgFe-based LDH phases as model systems in order to decipher whether Fe-clustering exerts an effect on the OER performance. For that, we have optimized hydrothermal synthesis by using triethanolamine (TEA) as the chelating agent. The magnetic characterisation allows us to identify the Fe-clustering degree by following both magnetic susceptibility as well as magnetization values a…
Remote modification of bidentate phosphane ligands controlling the photonic properties in their complexes: Enhanced performance of [Cu(RN-xantphos)(N…
2020
A series of copper(I) complexes of the type [Cu(HN-xantphos)(N^N)][PF6] and [Cu(BnN-xantphos)(N^N)][PF6], in which N^N = bpy, Mebpy, and Me2bpy, HN-xantphos = 4,6-bis(diphenylphosphanyl)-10H-phenoxazine and BnNxantphos = 10-benzyl-4,6-bis(diphenylphosphanyl)-10H-phenoxazine is described. The single crystal structures of [Cu(HN-xantphos)(Mebpy)][PF6] and [Cu(BnN-xantphos)(Me2bpy)][PF6] confirm the presence of N^N and P^P chelating ligands with the copper(I) atoms in distorted coordination environments. Solution electrochemical and photophysical properties of the BnNxantphos- containing compounds (for which the highest-occupied molecular orbital is located on the phenoxazine moiety) are repor…
Green light-emitting electrochemical cells based on platinum(ii) complexes with a carbazole-appended carbene ligand
2022
This article is part of the themed collections: Paul R. Raithby at 70: in celebration of a life in chemistry, Recent Open Access Articles and 2022 Journal of Materials Chemistry C Most Popular Articles.
Transparent Light‐Emitting Electrochemical Cells
2022
Single layer light-emitting electrochemical cells (LECs) are amongst the simplest electroluminescent devices and operate with air-stable electrodes. Transparent light-emitting devices are of great interest as they can enable new applications in consumer electronics. In this work, a transparent ionic transition metal complex based LEC is fabricated by developing a transparent top contact based on tin (IV) oxide (SnO2) and indium-tin oxide, processed by low-temperature atomic layer deposition and pulsed laser deposition, respectively. The resulting devices present transparency in excess of 75% over the full visible spectrum (380-750 nm), with 82% transmission at the emission peak (563 nm). Th…
Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells
2022
Funding: M. K. would like to thank 2214-A International Research Fellowship Programme for Ph.D. students (1059B141900585). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska Curie grant agreement No 838885 (NarrowbandSSL). S.M.S. acknowledges support from the Marie Skłodowska-Curie Individual Fellowship (grant agreement No 838885 NarrowbandSSL). A. K. G. is grateful to the Royal Society for Newton International Fellowship NF171163. L.M acknowledges that the project who gave rise to these results received support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and inno…
Effect of Temperature on Thermogalvanic Coupling of Alloy 31 in Libr Solutions Studied by Means of Imposed Potential Measurements
2011
[EN] Corrosion resistance of Alloy 31, a highly alloyed stainless steel (UNS N08031) were studied in heavy brine LiBr solutions (400, 700 and 992 g/l) at different temperatures using electrochemical techniques. The mixed potential theory was used to evaluate thermogalvanic corrosion of Alloy 31 in the studied LiBr solutions. Potentiodynamic curves indicate that high temperatures favoured both cathodic and anodic processes, increasing passive current densities and decreasing the pitting potential. Generally, the cold electrode of the pair was the anode of the thermogalvanic cell.
Formation of Hematite Nanotubes by Two-Step Electrochemical Anodization for Efficient Degradation of Organic Pollutants
2016
[EN] Nowadays, hematite (alpha-Fe2O3) has emerged as a promising photocatalyst for efficient degradation of organic pollutants due to its properties such as suitable band-gap (similar to 2.1 eV), stability against photocorrosion, abundance and low cost. However, some drawbacks such as low carrier mobility and short hole diffusion length limit its efficiency. In order to overcome these issues, self-ordered nanotubes can be synthetized. Anodization is one of the simplest and most economic techniques to produce nanostructures with high control. In the present study, self-ordered hematite nanotubes were synthetized by two-step electrochemical anodization. In two-step anodization, a first-step w…