Electrochemical workstation.pptx

Electrochemical

1. Electrochemical workstation Potentiostats / galvanostats

2. Potentiostats (sometimes referred to as electrochemical workstations or potentiostats / galvanostats ) are vital measurement and control tools used primarily in electrochemical research, as well as in other industrial fields. In electrochemistry, potentiostats are used both in fundamental and applied research to gain an increased understanding of electrode processes, analytical chemistry, battery research, and corrosion research . Secondary applications include chemical synthesis and biology. You will see a full list of these applications in this article.

3. A potentiostat   / galvanostat is an instrument that manages the application of voltage or current to an electrochemical cell electrode (detailed description below). The potentiostat / galvanostat is the main tool used in electrochemical and electroanalytical experiments.

4. function modes Potentiostatic vs Galvanostatic modes Potentiostats / galvanostats have two main function modes depending on the electric quantity being controlled – the potential or the current. These are called the potentiostatic and galvanostatic modes (see Figures 1 & 2 below). When the potentiostat / galvanostat is used in potentiostatic mode, it can be referred to as a potentiostat . In potentiostatic mode, the potentiostat applies and controls the potential, and measures the current flowing through the electrochemical system 

5. At a glance: What is Potentiostatic mode?  The potentiostatic mode measures and controls the voltage difference between a working electrode and a reference electrode, which has a constant potential. This, perhaps the most commonly used mode of an electrochemical workstation, measures the current flow between the working electrode and counter electrode (that completes the cell circuit).

6. galvanostatic mode In galvanostatic mode, the electrochemical instrument performs the measurements for potential variations while the current is applied and controlled

7. What is Galvanostatic mode?   Galvanostatic mode is based on the control of current flowing through the system. When the device is used for these measurements it is called a galvanostat . The most common application for galvanostatic mode is research into batteries.

8. Other function modes Potentiostats also have specific control modes: the Open Circuit Voltage (OCV), the Zero Resistance Ammeter (ZRA) and by the Electrochemical Impedance Spectroscopy (EIS). Each of these control modes has a specific purpose.  

9. How do potentiostats / galvanostats work? Controlling the potential: the three-electrode setup The potentiostat is an instrument dedicated to the study of electrochemical processes. The control of the interfacial working electrode potential is crucial to guarantee that current is measured at a constant potential. A three-electrode setup makes this possible.   These three electrodes are known as the working electrode, the reference electrode, and the counter-electrode (also called the auxiliary electrode).

10. The working electrode (WE) : The reaction of interest occurs at the interface of the working electrode. The reference electrode (RE) : The potential of the reference electrode is well-known and stable. It is the point of reference of the system for potential control and measurement. The current flow through this electrode is kept close to zero. The counter-electrode (CE) : The current flows between the working electrode and the counter-electrode. The counter-electrode has no role in electrochemical reactions except for specific situations: battery cell, galvanic corrosion, electrochemical noise measurements.

11. Key potentiostat components: reference electrode and control amplifier To guarantee that currents flows as a result of potential variations at the working electrode interface, the potential of the reference electrode must remain stable and correspond to its theoretical value. It must be properly maintained.

12. The control amplifier (CA) is a key electronic component in the potentiostat . It is used to keep the voltage between the reference electrode and the working electrode as close as possible to the voltage of the input source  EiEi .

13. Electrochemical workstation provides several techniques (cyclic voltammetry , linear sweep voltammetry , differential pulse voltammetry , square wave voltammetry , chronoamperometry , impedance spectroscopy, etc.)windows-based software, integrated digital CV simulator, impedance simulation and fitting program. These features provide powerful tools for the understanding of reaction kinetics, trace level analysis, fundamental research, corrosion, energy conversion and storage studies.

14. Working Principles The electrochemical work station is a digital potentiostat / galvanostat instrument generally utilized in advanced electrochemical studies . The Electrochemical Workstation is utilized for amperometric (measurement of current), potentiometric (measurement of potential/charge accumulation) and conductometric (change in conductivity of medium) studies of any electrochemical reaction. The workstation is also capable of carrying out Electrochemical Impedence Spectroscopy (EIS)and Electrostatic deposition (ESD).

15. Applications Biosensing Electrodeposition Potentiometery Votametery Amperommetery