Search results for " electrode"
showing 10 items of 301 documents
Influence of Iron Sulfide Nanoparticle Sizes in Solid‐State Batteries**
2021
Abstract Given the inherent performance limitations of intercalation‐based lithium‐ion batteries, solid‐state conversion batteries are promising systems for future energy storage. A high specific capacity and natural abundancy make iron disulfide (FeS2) a promising cathode‐active material. In this work, FeS2 nanoparticles were prepared solvothermally. By adjusting the synthesis conditions, samples with average particle diameters between 10 nm and 35 nm were synthesized. The electrochemical performance was evaluated in solid‐state cells with a Li‐argyrodite solid electrolyte. While the reduction of FeS2 was found to be irreversible in the initial discharge, a stable cycling of the reduced sp…
High-performance of PbO2 nanowire electrodes for lead-acid battery
2014
Abstract PbO2 nanowires were obtained by template electrodeposition in polycarbonate membranes and tested as positive electrode for lead-acid battery. Nanowires were grown on the same material acting as current collector that was electrodeposited too. The nanostructured electrodes were assembled in a zero-gap configuration using commercial negative plate and separator. Cell performance was tested by galvanostatic charge/discharge cycles in a 5 M H2SO4 aqueous electrolyte. PbO2 nanostructured electrodes were able to deliver at 1C rate an almost constant capacity of about 190 mAh g−1 (85% of active material utilization), close to the theoretical value (224 mAh g−1). The nanowire array provide…
Highly activated screen-printed carbon electrodes by electrochemical treatment with hydrogen peroxide
2018
An easy effective method for the activation of commercial screen-printed carbon electrodes (SPCEs) using H2O2 is presented to enhance sensing performances of carbon ink. Electrochemical activation consists of 25 repetitive voltammetric cycles at 10 mV s−1 using 10 mM H2O2 in phosphate buffer (pH 7). This treatment allowed us to reach a sensitivity of 0.24 ± 0.01 μA μM−1 cm−2 for the electroanalysis of H2O2, which is 140-fold higher than that of untreated SPCEs and 6-fold more than screen-printed platinum electrodes (SPPtEs). Electrode surface properties were characterized by SEM, EIS and XPS. The results revealed atomic level changes at the electrode surface, with the introduction of new ca…
Ni alloy nanowires as high efficiency electrode materials for alkaline electrolysers
2021
Abstract The fabrication and characterization of nickel-alloy electrodes for alkaline electrolysers is reported. Three different alloys (Ni–Co, Ni–Zn and Ni–W) at different composition were studied in order to determine the optimum condition. Nanostructured electrodes were obtained by template electrodeposition into a nanoporous membrane, starting from aqueous solution containing the two elements of the alloy at different concentrations. Composition of alloys can be tuned by electrolyte composition and also depends on the difference of the redox potential of elements and on the presence of complexing agents in deposition bath. Electrochemical and electrocatalytic tests, aimed at establishin…
Fabrication and Characterisation of Perovskite Thin Films for Photovoltaic Application
2018
This paper presents an alternative way to obtain perovskite thin films for photovoltaic application. This technique results more competitive, scalable, low-cost, reproducible and is different from other most common methods of fabrication.
Discrimination of papers used in conservation and restoration by the means of the voltammetry of immobilized microparticles technique
2019
Herein, voltammetry of immobilized microparticles (VIMP) is employed for the discrimination of papers used in the conservation and restoration field. The electrochemical parameters are used for the discrimination of different samples coming from China, Japan and Korea. The method is based on the recording of the voltammetric response of microparticulate deposits from acetone extracts of paper samples deposited on a glassy carbon electrode in contact with 1.0 M H2SO4. The voltammetric responses attributed to the lignin and the oxidation products of the cellulose were collected and are discussed. The grouping of samples was obtained upon the application of the chemometric methods, as well as …
Nanostructured Ni–Co alloy electrodes for both hydrogen and oxygen evolution reaction in alkaline electrolyzer
2021
Abstract Ni–Co alloy nanostructured electrodes with high surface area were investigated both as a cathode and anode for an alkaline electrolyzer. Electrodes were obtained by template electrosynthesis at room temperature. The electrolyte composition was tuned in order to obtain different NiCo alloys. The chemical and morphological features of nanostructured electrodes were evaluated by EDS, XRD and SEM analyses. Results show that electrodes with different composition of Ni and Co, made of nanowires well anchored to the substrate, were obtained. For both hydrogen and oxygen evolution reactions, electrochemical and electrocatalytic tests, performed in 30% w/w KOH aqueous solution, were carried…
Dual Ni/Ni-Co electrodeposited coatings for improved erosion-corrosion behaviour
2019
Abstract Industrial applications of hydrophobic metallic coatings are limited to durability of their surface structures against detrimental effects of the surrounding environments. In the present research, the life-long of the hierarchical structure of hydrophobic nickel coating in an erosive-corrosive solution was investigated. The effect of alloying with cobalt on strengthening the hierarchical structures was also investigated. In this regard, highly hydrophobic Ni/Ni, Ni-Co/Ni-Co, dual Ni/Ni-Co and dual Ni-Co/Ni coatings with rough hierarchical structures were electrodeposited. In situ electrochemical measurements were performed to investigate changes in corrosion resistance and hydropho…
Reagent free electrochemical-based detection of silver ions at interdigitated microelectrodes using in-situ pH control
2021
Abstract Herein we report on the development of an electrochemical sensor for silver ions detection in tap water using anodic sweep voltammetry with in-situ pH control; enabled by closely spaced interdigitated electrode arrays. The in-situ pH control approach allowed the pH of a test solution to be tailored to pH 3 (experimentally determined as the optimal pH) by applying 1.65 V to a protonator electrode with the subsequent production of protons, arising from water electrolysis, dropping the local pH value. Using this approach, an initial proof-of-concept study for silver detection in sodium acetate was undertaken where 1.25 V was applied during deposition (to compensate for oxygen producti…
Influence of magnesium content on the corrosion resistance of the cut-edges of Zn–Mg-coated steel
2015
Abstract The ability of Zn–Mg coatings (with magnesium content between 5.8 and 15.5 wt.%) to protect steel sheets has been evaluated with local electrochemical techniques (scanning vibrating electrode technique, microcapillary electrochemical cell) and rotating disk electrode, and compared with the corrosion protection afforded by a pure zinc coating. From immersion tests of coated steel cut-edges, it is observed that alloying zinc with magnesium leads to a decrease of the galvanic current between the coating and the steel surface, and to an improvement of the steel corrosion resistance after a drying period, due to the presence of magnesium in the corrosion products.