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Magnetoelectrochemistry is a branch of electrochemistry dealing with magnetic effects in electrochemistry.
These effects have been supposed to exist since the time of Michael Faraday. There have also been observations on the existence of Hall effect in electrolytes. Until these observations, magnetoelectrochemistry was an esoteric curiosity, though this field has had a rapid development in the past years and is now an active area of research. Other scientific fields which contributed to the development of magnetoelectrochemistry are magnetohydrodynamics and convective diffusion theory. [ citation needed ]
There are three types of magnetic effects in electrochemistry:
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Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference and identifiable chemical change. These reactions involve electrons moving via an electronically-conducting phase between electrodes separated by an ionically conducting and electronically insulating electrolyte.
The voltaic pile was the first electrical battery that could continuously provide an electric current to a circuit. It was invented by Italian chemist Alessandro Volta, who published his experiments in 1799. Its invention can be traced back to an argument between Volta and Luigi Galvani, Volta's fellow Italian scientist who had conducted experiments on frogs' legs. Use of the voltaic pile enabled a rapid series of other discoveries, including the electrical decomposition (electrolysis) of water into oxygen and hydrogen by William Nicholson and Anthony Carlisle (1800), and the discovery or isolation of the chemical elements sodium (1807), potassium (1807), calcium (1808), boron (1808), barium (1808), strontium (1808), and magnesium (1808) by Humphry Davy.
Magnetohydrodynamics is a model of electrically conducting fluids that treats all interpenetrating particle species together as a single continuous medium. It is primarily concerned with the low-frequency, large-scale, magnetic behavior in plasmas and liquid metals and has applications in numerous fields including geophysics, astrophysics, and engineering.
In electrochemistry, cyclic voltammetry (CV) is a type of potentiodynamic measurement. In a cyclic voltammetry experiment, the working electrode potential is ramped linearly versus time. Unlike in linear sweep voltammetry, after the set potential is reached in a CV experiment, the working electrode's potential is ramped in the opposite direction to return to the initial potential. These cycles of ramps in potential may be repeated as many times as needed. The current at the working electrode is plotted versus the applied voltage to give the cyclic voltammogram trace. Cyclic voltammetry is generally used to study the electrochemical properties of an analyte in solution or of a molecule that is adsorbed onto the electrode. It is important to know where the CV was made. The difference of the CVs from different countries is shown in Elgrishi's paper.
In electrochemistry, a salt bridge or ion bridge is an essential laboratory device discovered over 100 years ago. It contains an electrolyte solution, typically an inert solution, used to connect the oxidation and reduction half-cells of a galvanic cell, a type of electrochemical cell. In short, it functions as a link connecting the anode and cathode half-cells within an electrochemical cell. It also maintains electrical neutrality within the internal circuit and stabilizes the junction potential between the solutions in the half-cells. Additionally, it serves to minimize cross-contamination between the two half cells and helps concentrate our focus on unfolding the funtion of working electrodes of the half-cells.
A magnetic flow meter is a transducer that measures fluid flow by the voltage induced across the liquid by its flow through a magnetic field. A magnetic field is applied to the metering tube, which results in a potential difference proportional to the flow velocity perpendicular to the flux lines. The physical principle at work is electromagnetic induction. The magnetic flow meter requires a conducting fluid, for example, water that contains ions, and an electrical insulating pipe surface, for example, a rubber-lined steel tube.
Nanoelectrochemistry is a branch of electrochemistry that investigates the electrical and electrochemical properties of materials at the nanometer size regime. Nanoelectrochemistry plays significant role in the fabrication of various sensors, and devices for detecting molecules at very low concentrations.
Electrochemistry, a branch of chemistry, went through several changes during its evolution from early principles related to magnets in the early 16th and 17th centuries, to complex theories involving conductivity, electric charge and mathematical methods. The term electrochemistry was used to describe electrical phenomena in the late 19th and 20th centuries. In recent decades, electrochemistry has become an area of current research, including research in batteries and fuel cells, preventing corrosion of metals, the use of electrochemical cells to remove refractory organics and similar contaminants in wastewater electrocoagulation and improving techniques in refining chemicals with electrolysis and electrophoresis.
The Electrochemical Society is a learned society based in the United States that supports scientific inquiry in the field of electrochemistry solid-state science and related technology. The Society membership comprises more than 8,000 scientists and engineers in over 85 countries at all degree levels and in all fields of electrochemistry, solid-state science and related technologies. Additional support is provided by institutional members including corporations and laboratories.
Solid-state ionics is the study of ionic-electronic mixed conductor and fully ionic conductors and their uses. Some materials that fall into this category include inorganic crystalline and polycrystalline solids, ceramics, glasses, polymers, and composites. Solid-state ionic devices, such as solid oxide fuel cells, can be much more reliable and long-lasting, especially under harsh conditions, than comparable devices with fluid electrolytes.
In electrochemistry, polarization is a collective term for certain mechanical side-effects by which isolating barriers develop at the interface between electrode and electrolyte. These side-effects influence the reaction mechanisms, as well as the chemical kinetics of corrosion and metal deposition. In a reaction, the attacking reagents can displace the bonding electrons. This electronic displacement in turn may be due to certain effects, some of which are permanent, and the others are temporary. Those effects which are permanently operating in the molecule are known as polarization effects, and those effects which are brought into play by attacking reagent are known as polarisability effects.
Electrochemical engineering is the branch of chemical engineering dealing with the technological applications of electrochemical phenomena, such as electrosynthesis of chemicals, electrowinning and refining of metals, flow batteries and fuel cells, surface modification by electrodeposition, electrochemical separations and corrosion.
Zinc–cerium batteries are a type of redox flow battery first developed by Plurion Inc. (UK) during the 2000s. In this rechargeable battery, both negative zinc and positive cerium electrolytes are circulated though an electrochemical flow reactor during the operation and stored in two separated reservoirs. Negative and positive electrolyte compartments in the electrochemical reactor are separated by a cation-exchange membrane, usually Nafion (DuPont). The Ce(III)/Ce(IV) and Zn(II)/Zn redox reactions take place at the positive and negative electrodes, respectively. Since zinc is electroplated during charge at the negative electrode this system is classified as a hybrid flow battery. Unlike in zinc–bromine and zinc–chlorine redox flow batteries, no condensation device is needed to dissolve halogen gases. The reagents used in the zinc-cerium system are considerably less expensive than those used in the vanadium flow battery.
In chemistry, ion transport number, also called the transference number, is the fraction of the total electric current carried in an electrolyte by a given ionic species i:
Bipolar electrochemistry is a phenomenon in electrochemistry based on the polarization of conducting objects in electric fields. Indeed, this polarization generates a potential difference between the two extremities of the substrate that is equal to the electric field value multiplied by the size of the object. If this potential difference is important enough, then redox reactions can be generated at the extremities of the object, oxidations will occur at one extremity coupled simultaneously to reductions at the other extremity. In a simple experimental setup consisting of a platinum wire in a weighing boat containing a pH indicator solution, a 30 V voltage across two electrodes will cause water reduction at one end of the wire and a pH increase and water oxidation at the anodic end and a pH decrease. The poles of the bipolar electrode also align themselves with the applied electric field.
Double-layer capacitance is the important characteristic of the electrical double layer which appears at the interface between a surface and a fluid. At this boundary two layers of electric charge with opposing polarity form, one at the surface of the electrode, and one in the electrolyte. These two layers, electrons on the electrode and ions in the electrolyte, are typically separated by a single layer of solvent molecules that adhere to the surface of the electrode and act like a dielectric in a conventional capacitor. The amount of charge stored in double-layer capacitor depends on the applied voltage.
In electrochemistry, a thermogalvanic cell is a kind of galvanic cell in which heat is employed to provide electrical power directly. These cells are electrochemical cells in which the two electrodes are deliberately maintained at different temperatures. This temperature difference generates a potential difference between the electrodes. The electrodes can be of identical composition and the electrolyte solution homogeneous. This is usually the case in these cells. This is in contrast to galvanic cells in which electrodes and/or solutions of different composition provide the electromotive potential. As long as there is a difference in temperature between the electrodes a current will flow through the circuit. A thermogalvanic cell can be seen as analogous to a concentration cell but instead of running on differences in the concentration/pressure of the reactants they make use of differences in the "concentrations" of thermal energy. The principal application of thermogalvanic cells is the production of electricity from low-temperature heat sources. Their energetic efficiency is low, in the range of 0.1% to 1% for conversion of heat into electricity.
Sonoelectrochemistry is the application of ultrasound in electrochemistry. Like sonochemistry, sonoelectrochemistry was discovered in the early 20th century. The effects of power ultrasound on electrochemical systems and important electrochemical parameters were originally demonstrated by Moriguchi and then by Schmid and Ehert when the researchers investigated the influence of ultrasound on concentration polarisation, metal passivation and the production of electrolytic gases in aqueous solutions. In the late 1950s, Kolb and Nyborg showed that the electrochemical solution hydrodynamics in an electrochemical cell was greatly increased in the presence of ultrasound and described this phenomenon as acoustic streaming. In 1959, Penn et al. demonstrated that sonication had a great effect on the electrode surface activity and electroanalyte species concentration profile throughout the solution. In the early 1960s, the electrochemist Allen J. Bard showed in controlled potential coulometry experiments that ultrasound significantly enhances mass transport of electrochemical species from the bulk solution to the electroactive surface. In the range of ultrasonic frequencies [20 kHz – 2 MHz], ultrasound has been applied to many electrochemical systems, processes and areas of electrochemistry both in academia and industry, as this technology offers several benefits over traditional technologies. The advantages are as follows: significant thinning of the diffusion layer thickness (δ) at the electrode surface; increase in electrodeposit/electroplating thickness; increase in electrochemical rates, yields and efficiencies; increase in electrodeposit porosity and hardness; increase in gas removal from electrochemical solutions; increase in electrode cleanliness and hence electrode surface activation; lowering in electrode overpotentials ; and suppression in electrode fouling.
The electrochemical promotion of catalysis (EPOC) effect in the realm of chemistry refers to the pronounced enhancement of catalytic reactions or significant changes in the catalytic properties of a conductive catalyst in the presence of electrical currents or interfacial potentials. Also known as Non-faradaic electrochemical modification of catalytic activity (the NEMCA effect), it can increase in catalytic activity (up to 90-fold) and selectivity of a gas exposed electrode on a solid electrolyte cell upon application of a potential. This phenomenon is well documented and has been observed on various surfaces (Ni, Au, Pt, Pd, IrO2, RuO2) supported by O2−, Na+ and proton conducting solid electrolytes.
Electrochemical quartz crystal microbalance (EQCM) is the combination of electrochemistry and quartz crystal microbalance, which was generated in the eighties. Typically, an EQCM device contains an electrochemical cells part and a QCM part. Two electrodes on both sides of the quartz crystal serve two purposes. Firstly, an alternating electric field is generated between the two electrodes for making up the oscillator. Secondly, the electrode contacting electrolyte is used as a working electrode (WE), together with a counter electrode (CE) and a reference electrode (RE), in the potentiostatic circuit constituting the electrochemistry cell. Thus, the working electrode of electrochemistry cell is the sensor of QCM.