Electrochemistry is a branch of chemistry that deals with the interrelation of electrical and chemical phenomena. It focuses on the study of chemical processes that cause electrons to move, which in turn generates an electric current. This field encompasses a variety of processes, including: 1. **Electrochemical Reactions**: These are chemical reactions that involve the transfer of electrons, such as oxidation-reduction (redox) reactions.
Electroanalytical chemistry is a branch of analytical chemistry that focuses on the study of chemical processes and phenomena at the interface between an electrode and an electrolytic solution. It encompasses a wide range of techniques that measure the electrical properties of chemical systems, primarily to analyze the concentration of chemical substances. Key components and principles of electroanalytical chemistry include: 1. **Electrodes**: These are conductive materials that facilitate the transfer of electrons in electrochemical reactions.
Electrochemical cells are devices that convert chemical energy into electrical energy or vice versa, based on the principles of electrochemistry. These cells consist of two electrodes (an anode and a cathode) immersed in an electrolyte solution, which facilitates the movement of ions. There are two main types of electrochemical cells: 1. **Galvanic (Voltaic) Cells**: - These cells convert chemical energy into electrical energy through spontaneous redox reactions.
Electrochemical concepts encompass the principles and theories that govern the interactions between electrical energy and chemical reactions. These concepts are fundamental to understanding various phenomena in chemistry, biology, and materials science. Here are some key components of electrochemistry: 1. **Redox Reactions**: Electrochemistry is primarily concerned with oxidation-reduction (redox) reactions, where electrons are transferred between species. Oxidation is the loss of electrons, while reduction is the gain of electrons.
Electrochemical equations are mathematical representations of the chemical reactions that occur during electrochemical processes, such as electrolysis or galvanic (voltaic) cell reactions. They depict the transfer of electrons at an electrode and describe how chemical species are transformed during these processes. ### Key Components of Electrochemical Equations: 1. **Half-Reactions**: Electrochemical processes can be split into two half-reactions—one for oxidation and one for reduction.
Electrochemical potentials refer to the ability of an electrochemical system, which involves chemical reactions and electric charges, to perform work or drive reactions due to differences in energy. Understanding electrochemical potentials is fundamental to fields like electrochemistry, battery technology, corrosion science, and fuel cells. ### Key Concepts: 1. **Gibbs Free Energy**: The electrochemical potential is often related to changes in Gibbs free energy (ΔG) for a reaction.
Electrochemistry is a branch of chemistry that deals with the interaction between electrical energy and chemical reactions. Electrochemists are scientists who study this field, focusing on the processes where electrons are transferred between molecules, as well as the relationship between electricity and chemical change. Electrochemists may work on various applications, including: 1. **Batteries**: Developing better energy storage systems, such as lithium-ion batteries, fuel cells, and other types of rechargeable batteries.
Electrodes are conductive materials that facilitate the transfer of electrons between an external circuit and a substance (such as an electrolyte or a semiconductor) in electrochemical cells, batteries, capacitors, and other electronic devices. The primary function of electrodes is to provide an interface for chemical reactions to occur in processes such as oxidation-reduction (redox) reactions. There are two main types of electrodes: 1. **Anode**: This is the electrode where oxidation occurs.
Electrolytes are substances that dissociate into ions when dissolved in a solvent, typically water. They are essential for a range of physiological processes in the body and play a critical role in maintaining fluid balance, nerve function, muscle contraction, and acid-base balance. Common electrolytes include: 1. **Sodium (Na⁺)**: Important for fluid balance and nerve signaling.
Photoelectrochemistry is a branch of chemistry that studies the interaction between light and electrochemical processes. It involves the use of light to drive electrochemical reactions, typically for applications such as solar energy conversion, photocatalysis, and the production of chemical fuels. In a typical photoelectrochemical system, a semiconductor material is used as a photoelectrode.
Redox, short for reduction-oxidation, refers to a class of chemical reactions in which the oxidation states of atoms are changed. These reactions involve the transfer of electrons between species, leading to the oxidation of one substance and the reduction of another. - **Oxidation** is the process where an atom or molecule loses electrons, resulting in an increase in oxidation state. - **Reduction** is the process where an atom or molecule gains electrons, resulting in a decrease in oxidation state.
Redox indicators are chemical compounds that undergo a color change when they are oxidized or reduced, allowing them to serve as visual signals in redox (reduction-oxidation) reactions. These indicators are useful in various applications, particularly in titrations, electrochemical experiments, and as sensors for determining the redox state of a solution.
Absolute electrode potential refers to the potential difference between an electrode and a reference point in a solution, often associated with the ability of an electrode to gain or lose electrons in electrochemical reactions. It is expressed in volts (V) and is used to quantify the driving force behind electrochemical processes.
Afterhyperpolarization (AHP) is a phase that occurs in the action potential of a neuron following the depolarization phase and repolarization. During AHP, the membrane potential becomes more negative than the resting membrane potential, making the neuron less excitable for a brief period. This phenomenon is primarily due to the slow closure of potassium (K⁺) channels that open in response to the cell’s depolarization.
Alkaline water electrolysis is a method of producing hydrogen gas (H₂) and oxygen gas (O₂) through the electrolysis of water in an alkaline solution. This process involves the use of an electrolyzer, which typically consists of two electrodes (an anode and a cathode) submerged in an electrolyte solution, usually containing sodium hydroxide (NaOH) or potassium hydroxide (KOH).
The Asian Conference on Electrochemical Power Sources (ACEPS) is a scientific and technical conference focused on the field of electrochemical power sources, which includes batteries, fuel cells, supercapacitors, and other related technologies. The conference typically brings together researchers, engineers, and industry professionals from various countries in Asia and beyond to share their latest research findings, technological advancements, and best practices in the field of electrochemistry and energy storage.
Bipolar electrochemistry is a technique in electrochemistry that involves the use of bipolar electrodes to facilitate electrochemical reactions. A bipolar electrode (BPE) is unique in that it has two distinct regions: one that is positively polarized (anodic) and another that is negatively polarized (cathodic).
CO stripping, or carbon monoxide stripping, is a technique commonly used in electrochemistry and analytical chemistry to investigate and analyze various electrochemical processes. It primarily involves the application of a potential to a working electrode in a controlled environment where carbon monoxide is adsorbed on the electrode surface.
A calcium battery is a type of electrochemical battery that uses calcium ions as the primary charge carriers. These batteries are an alternative to lithium-ion batteries and are being researched and developed for various applications, including energy storage and electric vehicles. The key components of a calcium battery include: 1. **Anode (Negative Electrode)**: Typically made from calcium or a calcium-containing compound.
Camille Alphonse Faure (also known as Camille Faure) was a French inventor, most famously known for his development of a process to produce silver-colored, high-energy nickel-cadmium batteries in the early 20th century. He was granted patents for his work in battery technology, which contributed to advancements in rechargeable battery systems. His innovations were significant in the context of energy storage and were influential in various applications, including early electric vehicles and portable electronics.
The charge transfer coefficient, often denoted by the symbol \( \alpha \) (alpha), is a parameter used in electrochemistry to describe the efficiency of the electron transfer process during an electrochemical reaction. It plays a crucial role in determining the kinetics of electrode reactions, particularly in the context of the Butler-Volmer equation, which describes the current density (current per unit area) at an electrode as a function of overpotential.
A Chemical Field-Effect Transistor (ChemFET) is a type of field-effect transistor (FET) that is sensitive to the presence of specific chemicals or biochemical analytes. It operates based on the principle of modulating the conductivity of a channel between source and drain terminals by an electric field, where the gate of the transistor interacts with chemical species. **Key Features of ChemFETs:** 1.
Concentration polarization is a phenomenon that occurs in electrochemical systems where there is a difference in concentration of reactants or products in a solution, typically near the interface of an electrode. This effect can impede the rate of electrochemical reactions and is predominantly observed in systems like batteries, fuel cells, and electrolyzers. In more detail, concentration polarization arises when the rate of mass transfer of reactants to the electrode surface cannot keep up with the rate of the electrochemical reaction that consumes these reactants.
A Conductive Anodic Filament (CAF) refers to conductive pathways that can form within multilayer printed circuit boards (PCBs) during the manufacturing or operational lifecycle. These filaments typically arise due to the electrochemical migration of ions, especially under certain conditions like moisture, heat, and voltage. CAF formation can lead to short circuits and reliability failures in electronic devices.
Continuous adsorption-regeneration is a process used primarily in industrial applications for the removal or recovery of specific substances (such as pollutants, contaminants, or valuable materials) from a liquid or gas stream through an adsorption mechanism, followed by a regeneration phase that restores the adsorbent's capacity for further use. This two-step process is designed to operate continuously, maximizing efficiency and minimizing downtime.
Debye length is a measure of a charge carrier's influence in a plasma or an electrolyte, specifically related to how far electric potential from a charged particle can be felt in its surrounding medium. It characterizes the distance over which significant screening of electric fields occurs due to the presence of free charges.
Depolarization is a term primarily used in the context of cell biology and neuroscience. It refers to a change in the membrane potential of a cell, making it less negative (or more positive) compared to its resting state. This change in voltage is crucial for various physiological processes, particularly in neurons and muscle cells. In neurons, depolarization typically occurs when a stimulus causes sodium channels in the cell membrane to open, allowing sodium ions (Na⁺) to flow into the cell.
A depolarizer is a chemical substance used in electrochemistry, particularly in batteries and fuel cells, to counteract the buildup of polarization that occurs during electrochemical reactions. In these systems, polarization can hinder the efficiency of the reaction by increasing the resistance at the electrode surface, leading to reduced performance.
A dry cell is a type of electrochemical cell that converts chemical energy into electrical energy. It is called "dry" because it uses a paste or solid mixture of electrolyte, rather than a liquid electrolyte, making it portable and less likely to leak. Dry cells are commonly used in batteries for various devices, such as flashlights, remote controls, clocks, and many small electronic devices.
An electrical conductivity meter is an instrument used to measure the electrical conductivity of a solution, which quantifies its ability to conduct electricity. This property is primarily determined by the presence of ions in the solution; more ions result in higher conductivity. ### Key Features and Functions: 1. **Measurement Range**: Conductivity meters are capable of measuring a wide range of conductivity values, from very low (pure water) to very high (saline solutions or industrial waste).
Electro-osmosis is a phenomenon that occurs when an electric field is applied to a fluid that contains charged particles or ions, causing the fluid to move through a porous medium or a gel. This movement is driven by the interaction between the electric field and the charged species in the fluid, leading to the bulk flow of the liquid.
An electrocatalyst is a material that facilitates electrochemical reactions by lowering the activation energy required for the reactions to occur. These reactions typically take place at the interface of an electrode and an electrolyte in electrochemical cells, such as fuel cells, batteries, and electrolyzers. Electrocatalysts play a critical role in processes like hydrogen production (through water splitting), oxygen reduction, and carbon dioxide reduction.
The Electrochemical Society (ECS) is a professional organization focused on advancing the interdisciplinary field of electrochemistry and solid-state science and technology. Established in 1902, it serves as a platform for researchers, engineers, and educators involved in these fields to share knowledge, collaborate on research, and promote advancements in electrochemical science and technology.
Electrochemical aptamer-based biosensors (EABBs) are a type of biosensor that combine the specificity of aptamers with electrochemical detection methods to identify and quantify various biomolecules, pathogens, or small molecules.
Electrochemical dualism is a theoretical framework that addresses the nature of electrical and chemical processes within a system, particularly focusing on how these processes intertwine and influence one another. While the term itself may not have a widely recognized or standardized definition in scientific literature, it generally relates to the interplay between electrical phenomena—such as electron movement—and chemical reactions, particularly in the context of electrochemistry.
Electrochemical engineering is a specialized field of engineering that focuses on the principles and applications of electrochemistry in chemical processes and systems. It combines aspects of chemistry, physics, materials science, and chemical engineering to understand and exploit the interactions between electrical energy and chemical transformations. Key areas of focus in electrochemical engineering include: 1. **Electrochemical Reactions**: Understanding how electrons are transferred during chemical reactions, which is fundamental to processes like corrosion, batteries, fuel cells, and electrolysis.
Electrochemical fluorination (ECF) is a chemical process that utilizes electrochemistry to introduce fluorine atoms into organic compounds. This method is often employed to produce fluorinated organic compounds, which have various applications, particularly in the pharmaceutical, agrochemical, and materials science industries.
Electrochemical promotion of catalysis (EPOC) is a phenomenon where the catalytic activity of a solid catalyst can be significantly enhanced through the application of an external electric potential or current. This approach leverages the interplay between electrochemistry and catalysis, exploring how electric fields can influence the rates of chemical reactions occurring on catalytic surfaces.
The Electrochemical Quartz Crystal Microbalance (EQCM) is a sensitive analytical technique that combines electrochemical and quartz crystal microbalance (QCM) methods to study mass changes and interfacial phenomena at the nanoscale. It is based on the principles of piezoelectricity, where a quartz crystal oscillates at a specific frequency. When mass is deposited or removed from the crystal surface, it alters the frequency of oscillation, which can be measured very precisely.
Electrochemical regeneration refers to a process where an electrochemical cell is used to restore or regenerate a substance, often a catalyst, reactant, or solution, thereby allowing it to be reused in a chemical process. This technique is commonly applied in various fields, including waste treatment, energy storage, and environmental remediation.
Electrochlorination is a process that involves the generation of chlorine through the electrolysis of brine (a concentrated solution of sodium chloride or similar salts) in water. This method utilizes electrical energy to drive the reaction, enabling the production of chlorine gas (Cl₂) or sodium hypochlorite (NaOCl) directly in situ, which can be used for various applications, primarily in water treatment, disinfection, and other industrial processes.
Electrode potential is a measure of the tendency of an electrode to either gain or lose electrons in an electrochemical reaction. It reflects the energetic favorability of the reduction or oxidation process occurring at that electrode. Electrode potential is typically measured in volts (V) and can be defined in relation to a standard reference electrode, most commonly the Standard Hydrogen Electrode (SHE), which is assigned a potential of 0.
Electrolysis is a chemical process that uses electrical energy to drive a non-spontaneous chemical reaction. It involves the breaking down of a compound into its individual elements or simpler compounds through the application of an electric current. Electrolysis typically occurs in an electrolytic cell, which consists of two electrodes (an anode and a cathode) immersed in an electrolyte solution. Key components of electrolysis include: 1. **Electrodes**: These are conductive materials that allow the flow of electricity.
Electrosynthesis is a chemical process that uses electrical energy to drive chemical reactions, often to produce complex organic compounds or materials. This technique typically involves the application of an electric current to induce chemical transformations, facilitating processes such as synthesis, reduction, oxidation, or polymerization. In electrosynthesis, electrodes are immersed in an electrolyte solution, where the reaction occurs at the surface of the electrodes.
Exchange current density, often denoted as \( j_0 \), is a crucial parameter in electrochemical kinetics and interfaces, particularly in the context of electrochemical reactions. It represents the current density at which the rate of the forward reaction (e.g., oxidation) is equal to the rate of the reverse reaction (e.g., reduction) in a system at equilibrium.
The FFC Cambridge process, named after researchers at the University of Cambridge, specifically Professor Sir Harry Bhadeshia and his colleagues, refers to a method for the extraction of metals, particularly titanium, from their ores in a more efficient and environmentally friendly manner than traditional methods.
FLiNaK is a type of salt mixture that is primarily composed of three components: lithium fluoride (LiF), sodium fluoride (NaF), and potassium fluoride (KF). These components are typically combined in a specific molar ratio, often around 46.5% LiF, 11.5% NaF, and 42% KF, although variations exist.
Faradaic current refers to the electric current that is produced during an electrochemical reaction, particularly in processes where charge transfer occurs due to oxidation and reduction reactions at the electrode-electrolyte interface. This current is directly related to the movement of electrons as a result of these redox processes and is driven by the transfer of charged species (ions or electrons) during the reaction.
Faraday's laws of electrolysis are fundamental principles that describe the quantitative relationship between the amount of substance transformed at an electrode during electrolysis and the electrical charge passed through the electrolyte. There are two main laws: 1. **First Law of Electrolysis**: This law states that the amount of chemical change (or mass of the substance) that occurs at an electrode during electrolysis is directly proportional to the quantity of electric charge (Q) passed through the electrolyte.
The Faradaic efficiency (often referred to as Faraday efficiency) is a measure of the efficiency of an electrochemical reaction in converting electrical charge into a desired chemical product. It quantifies how effectively the charge passed through an electrochemical cell contributes to the formation of the target product, rather than being wasted in side reactions or other processes.
The Faraday Medal is a prestigious award presented by the Electrochemistry Group of the Royal Society of Chemistry (RSC) in the United Kingdom. It is named in honor of Michael Faraday, a pioneering scientist known for his contributions to electromagnetism and electrochemistry. The medal is awarded annually to recognize outstanding achievements in the field of electrochemistry.
Faraday efficiency, often referred to as Faradaic efficiency, is a measure of how effectively an electrochemical reaction converts electric charge into chemical products. It quantifies the fraction of charge that results in the desired electrochemical reaction compared to the total charge passed through the system.
A flow battery is a type of electrochemical energy storage system that separates the storage of energy from its conversion to electrical power. Unlike conventional batteries, which store energy directly within the electrodes, flow batteries use two electrolyte solutions that are stored in separate tanks and are pumped through a cell stack where the electrochemical reactions take place. ### Key Features of Flow Batteries: 1. **Electrolyte Solutions**: Flow batteries typically use two different liquid electrolyte solutions, which are housed in external tanks.
A Frost diagram, also known as a Frost circle or Frost plot, is a graphical representation used in inorganic chemistry to show the stability of different oxidation states of elements, particularly transition metals. The diagram is named after the chemist A. A. Frost, who developed this method. In a Frost diagram, the oxidation states of an element are plotted on the vertical axis, while the standard electrode potential (often in volts) is plotted on the horizontal axis.
A galvanic anode is a type of anode used in cathodic protection systems to prevent corrosion of metal structures, such as pipelines, tanks, and ships. It works on the principle of electrochemistry, specifically the concept of galvanic corrosion. In a galvanic cell, two different metals are immersed in an electrolyte.
Galvanism refers to a physiological phenomenon related to the effects of electricity on living organisms, particularly how electrical currents can stimulate muscles and nerves. The term is named after the Italian scientist Luigi Galvani, who, in the 18th century, discovered that electrical currents could cause frog legs to twitch, leading to the idea that electrical impulses are involved in the functioning of living tissues.
Gas-diffusion electrocrystallization is a technique used in materials science and electrochemistry to grow crystalline materials, particularly metal or semiconductor crystals, by exploiting the diffusion of gases in an electrochemical environment. This method allows for the precise control of crystal growth conditions, which can lead to the formation of high-quality crystals with desirable properties. ### Key Principles: 1. **Electrochemical Reaction**: The process involves the electrochemical reduction of gaseous precursors at an electrode surface.
A half-reaction is a way of representing either the oxidation or reduction part of a redox (reduction-oxidation) reaction. In a redox reaction, one species is oxidized (loses electrons) and another is reduced (gains electrons). Half-reactions help to clearly illustrate these processes by separating the two components. Each half-reaction shows the transfer of electrons and can be balanced for mass and charge.
Halorespiration is a type of anaerobic respiration in which certain microorganisms utilize halogenated organic compounds as terminal electron acceptors instead of oxygen. This process is significant in bioremediation, particularly in the breakdown of environmental pollutants such as chlorinated solvents, which are commonly found in industrial waste. During halorespiration, microbes metabolize compounds like trichloroethylene (TCE) or tetrachloroethylene (PCE) by reducing them to less harmful substances.
The history of electrochemistry is a fascinating journey that spans several centuries, marked by key discoveries and advancements in the understanding of chemical and electrical phenomena. Here’s an overview of its evolution: ### Ancient Beginnings - **Early Experiments (circa 600 BCE)**: The earliest observations related to electrochemistry can be traced back to ancient civilizations such as the Greeks, who discovered that amber could attract lightweight objects when rubbed (the phenomenon of static electricity).
In biology, hyperpolarization refers to a change in a cell's membrane potential that makes it more negative compared to the resting membrane potential. This occurs primarily in neurons and muscle cells and is an essential aspect of how these cells function in response to stimuli. ### Mechanism: - **Resting Membrane Potential:** Normally, a cell maintains a resting membrane potential, typically around -70 mV in neurons.
ISFET stands for Ion-Sensitive Field-Effect Transistor. It is a type of field-effect transistor that is used primarily for sensing ion concentrations in fluids, making it particularly useful in applications such as pH measurement, ion concentration detection, and biochemical sensing.
Induced-charge electrokinetics refers to the phenomena associated with the movement of fluid and particles caused by electric fields acting on induced charges at interfaces. This concept is often explored in the context of colloidal science, microfluidics, and electrochemistry. When an external electric field is applied to a system containing charged particles, such as colloids in a liquid, the electric field can induce charge separation on those particles or at the interfaces between different materials (like electrodes and electrolytes).
John Newman is a prominent American engineer and scientist known for his contributions to the fields of electrochemical engineering and battery technology. He is particularly well-known for his work on lithium-ion batteries and his research into the modeling and simulation of electrochemical systems. Newman has been influential in advancing the understanding of battery performance and efficiency, and his work has had significant implications for the development of energy storage technologies. He has published extensively on topics related to electrochemical processes, fuel cells, and battery design.
José Zagal Moya is a noted figure in the field of computer science, particularly known for his contributions to the areas of artificial intelligence, multi-agent systems, and game design. He is affiliated with the Pontificia Universidad Católica de Chile, where he has worked on various research projects and has been involved in educational initiatives.
LISICON, or lithium silicate conductors, refers to a class of solid-state ionic conductors made primarily from lithium, silicon, and oxygen. These materials are of significant interest in battery technology and other electrochemical applications due to their high ionic conductivity, which can facilitate the movement of lithium ions. LISICON is commonly studied for use in solid-state batteries, where it can serve as a solid electrolyte, potentially improving safety and energy density when compared to traditional liquid electrolytes.
Lithium aluminium germanium phosphate (LAGP) is a type of solid-state electrolyte that has gained attention in the field of battery technology, particularly for lithium-ion batteries and solid-state batteries. It is represented by the chemical formula Li1.3Al0.3Ge1.7(PO4)3. **Key Characteristics:** 1. **Structure:** LAGP has a crystal structure that allows for the conduction of lithium ions, which is crucial for its function as an electrolyte.
The "Marchywka effect" does not appear to be a widely recognized term in scientific literature, psychology, or other established fields as of my last knowledge update in October 2023. It is possible that it could refer to a specific phenomenon, theory, or effect that has been introduced after that time, or it might be a lesser-known concept that hasn’t gained widespread attention.
The term "Mercury's beating heart" refers to the planet's unique and active geological processes found at its core. Recent studies, especially from data obtained by NASA's MESSENGER spacecraft, suggest that Mercury has a partially molten outer core, which contributes to its magnetic field. This dynamic activity creates a phenomenon that can be likened to a "beating heart" due to the constant motion and interaction within the planet's core.
A Microbial Desalination Cell (MDC) is a type of bioelectrochemical system that uses microorganisms to facilitate the desalination of saline water, such as seawater or brackish water, while simultaneously generating electrical energy. MDCs represent a novel approach that combines water treatment and energy generation. ### Key Features and Components: 1. **Microbial Fuel Cell Principles**: MDCs are based on the principles of microbial fuel cells, where microbes oxidize organic substrates to produce electrons.
Nanoelectrochemistry is a field of study that focuses on the electrochemical processes that occur at the nanoscale. It involves the investigation of electrochemical reactions and phenomena involving materials, structures, and devices that are at the nanometer scale (typically less than 100 nanometers). Key aspects of nanoelectrochemistry include: 1. **Nanoscale Electrode Materials**: Researchers investigate how electrochemical properties change when materials are made into nanoscale forms.
Norman Hackerman is primarily known as an American chemist and educator, especially recognized for his contributions to the field of electrochemistry. He served as the president of the University of Texas at Austin and had a significant impact on academic leadership and research in chemistry during his career. In addition to his academic work, Hackerman is noted for his involvement in various scientific organizations and has received numerous awards and honors for his contributions to science.
An oxidizing agent, or oxidant, is a substance that gains electrons in a chemical reaction and thereby causes another substance to be oxidized. In the process, the oxidizing agent itself is reduced. Oxidizing agents are crucial in redox (reduction-oxidation) reactions, where the transfer of electrons occurs. Common examples of oxidizing agents include: 1. **Oxygen (O₂)** - Often involved in combustion and respiration.
The oxygen reduction reaction (ORR) is a key electrochemical reaction that involves the reduction of molecular oxygen (O₂) to water (H₂O) or hydroxide ions (OH⁻) in an electrochemical cell. This reaction is crucial in various applications, particularly in fuel cells, batteries, and corrosion processes. In the context of fuel cells, the ORR occurs at the cathode, where oxygen from the air is reduced.
A pH meter is an electronic device used to measure the acidity or alkalinity of a solution. The pH scale ranges from 0 to 14, with 7 being neutral. Values below 7 indicate acidic solutions, while values above 7 indicate alkaline (basic) solutions. Key components of a pH meter include: 1. **Glass Electrode**: This is the primary sensing element that measures the hydrogen ion concentration in the solution.
A photocathode is a type of material that emits electrons when it absorbs light, a process known as the photoelectric effect. It typically consists of a semiconductor or a metal that is sensitive to particular wavelengths of light. When photons strike the surface of the photocathode, they can impart enough energy to the electrons within the material to overcome the work function (the minimum energy needed for an electron to escape from the surface).
Photovoltaics (PV) is a technology that converts light energy, primarily from the sun, directly into electricity using semiconductor materials. The most common application of photovoltaics is solar panels, which are widely used for residential, commercial, and utility-scale power generation. The basic principle of photovoltaics involves the photovoltaic effect, which occurs when photons (light particles) hit a semiconductor material, typically silicon, causing electrons to be knocked loose and generate an electric current.
A Pourbaix diagram, also known as a potential-pH diagram, is a graphical representation used in electrochemistry to illustrate the thermodynamic stability of chemical species in an aqueous environment as a function of pH (alkalinity or acidity) and electrode potential (voltage). In a Pourbaix diagram: - The x-axis typically represents the pH of the solution, ranging from very acidic (low pH) to very basic (high pH).
Proton-coupled electron transfer (PCET) is a fundamental process in chemistry that involves the concerted transfer of an electron and a proton, typically in an acid-base context. This process is important in various biochemical reactions, including those seen in the function of enzymes and in the processes of photosynthesis and respiration.
A proton-exchange membrane (PEM), also known as a polymer electrolyte membrane, is a type of membrane that conducts protons (hydrogen ions) while acting as an insulator for gases such as hydrogen and oxygen. PEMs are primarily used in fuel cells and electrolyzers, where they facilitate the electrochemical reactions by allowing protons to pass through while blocking electrons and gases.
Pulse electrolysis, also known as pulsed electrolysis, is a technique that involves the application of pulsed electric current to facilitate chemical reactions during electrolysis. This method is often employed in various fields, including electroplating, metal extraction, and wastewater treatment, among others. In traditional electrolysis, a constant direct current (DC) is applied, which can sometimes lead to issues such as overheating, hydrogen evolution, or inefficient ion transfer.
Pulvermacher's chain, also known as Pulvermacher's catholicon or Pulvermacher's electro-galvanic chain, is a type of medical device that was developed in the 19th century. It consists of a series of connected galvanic cells made from galvanic metals—typically zinc and copper—arranged in a chain. The purpose of this device was to deliver low-level electrical currents to the body for therapeutic purposes.
Quantum electrochemistry is an interdisciplinary field that combines elements of quantum mechanics, electrochemistry, and molecular science to study the electronic processes that occur during electrochemical reactions at the atomic and molecular levels. This area of research seeks to understand how quantum effects influence the behavior of electrons, ions, and molecules in electrochemical systems.
Quantum photoelectrochemistry is a specialized field that combines principles from quantum mechanics, electrochemistry, and photovoltaics to study and harness the interactions between light and matter, particularly for chemical transformations. It focuses on the processes that occur when photons (light particles) interact with materials, leading to excited states that can drive chemical reactions, typically at electrodes or semiconductor interfaces.
Raman spectroelectrochemistry is a combined technique that integrates Raman spectroscopy and electrochemistry to study the chemical and electrochemical properties of materials at the molecular level. This method allows researchers to investigate the behavior of charged species, oxidation-reduction processes, and the structural characteristics of substances while they are undergoing electrochemical reactions.
A redox gradient refers to a variation in the oxidation-reduction potential (redox potential) across a particular environment, typically in soil, sediment, or aquatic systems. The term is derived from "reduction" (the gain of electrons) and "oxidation" (the loss of electrons), and it describes how different areas within a system can exhibit different levels of oxidizing or reducing conditions.
Repolarization is a physiological process that occurs in excitable cells, such as neurons and muscle cells, particularly during the action potential cycle. It refers to the return of the cell’s membrane potential to its resting state after it has been depolarized. During an action potential, a cell's membrane becomes depolarized when sodium ions (Na+) flow into the cell, causing the inside of the cell to become more positive.
A reversible solid oxide cell (RSOC) is a versatile electrochemical device that can function both as a fuel cell and as an electrolyzer. This dual functionality makes it capable of converting chemical energy into electrical energy and vice versa. The technology utilizes solid oxide materials that allow for high-temperature operations, typically between 500°C to 1000°C.
Single-entity electrochemistry refers to the study of electrochemical phenomena at the level of individual molecules or small entities, such as nanoparticles, rather than at the bulk or macroscopic scale. This field aims to probe the electrochemical behavior of single entities to gain insights into fundamental processes, mechanisms, and properties that can be masked in ensemble measurements.
Solar energy conversion refers to the process of transforming sunlight into other forms of energy that can be utilized for various applications. This process is essential for harnessing solar energy, which is a renewable and abundant energy source. There are several methods of solar energy conversion, the most common of which include: 1. **Photovoltaic (PV) Conversion**: This method uses solar panels made of semiconductor materials (such as silicon) to convert sunlight directly into electricity.
Sonoelectrochemistry is a specialized field that combines aspects of electrochemistry and sonochemistry. It involves the use of ultrasonic waves to enhance electrochemical reactions. In this approach, ultrasound waves generate intense local conditions (elevated temperature and pressure), leading to phenomena like cavitation—where rapid formation and collapse of bubbles occur in a liquid. The application of ultrasound can improve mass transport, increase reaction rates, and affect the mechanism of electrochemical processes.
Standard electrode potential (E°) refers to the measure of the individual potential of a reversible electrode at standard state conditions, which are typically 1 M concentration for solutions, 1 atm pressure for gases, and a temperature of 25°C (298 K). The standard electrode potential is measured against a standard hydrogen electrode (SHE), which is assigned a potential of 0.00 volts.
A thermogalvanic cell is a type of electrochemical cell that generates electrical energy from thermal energy differences. In essence, it converts heat into electrical energy through the thermoelectric effect. This can occur when there is a temperature gradient across two different conductive materials, typically involving an electrolyte and two electrodes made from different materials that create a potential difference when subjected to a temperature difference.
The virtual breakdown mechanism is a concept often discussed in the context of dielectric materials and electrical insulation. It refers to a phenomenon where, under certain high electric fields, a material that is normally considered an insulator begins to conduct electricity, but not in the traditional sense of breakdown where there is a catastrophic failure of the material. In a virtual breakdown scenario, the electric field is strong enough to create conditions where electrons can be temporarily excited to higher energy levels, allowing them to move through the material.
Yttria-stabilized zirconia (YSZ) is a crystalline compound formed by the addition of yttrium oxide (Y2O3) to zirconium dioxide (ZrO2). This stabilization process is essential because zirconia can exist in different crystalline forms (phases), and at high temperatures, it can transform from its stable monoclinic form to a tetragonal or cubic form. However, this phase transformation can make pure zirconia brittle.
Z-HIT, also known as Z-Health Information Technology, refers to a series of initiatives and frameworks designed to improve healthcare through the use of information technology. The specific context and details regarding Z-HIT can vary, as it may refer to various programs, technologies, or standards in the healthcare IT space.
