The Creation Wiki is made available by the NW Creation Network
Watch monthly live webcast - Like us on Facebook - Subscribe on YouTube

Nanoelectrochemistry

From CreationWiki, the encyclopedia of creation science
Jump to: navigation, search
electrochemistry picture

Nanoelectrochemistry is a branch of electrochemistry that investigates the electrical and electrochemical properties of materials at the nanometer size. Nanoelectrochemistry plays significant role in the fabrication of various sensors, and devices for detecting molecules at very low concentrations. [1] Electrochemistry is a branch of physical chemistry that studies the relationship between electricity, as a measurable and quantitative phenomenon, and identifiable chemical change, with either electricity considered an outcome of a particular chemical change or vice versa. Nanoelectrochemistry is really close to electrochmeistry. "Nano" means "small" so Nanoelectrochemistry means just a small electrochemistry. Therefore, electrochemistry and nanoelectrochemistry have the same meanings. [2]

Electrochemistry

nanoelectrochemistry piccture

Electrochemistry is a branch of chemistry that deals with the flow of electricity by chemical reaction. The electrons in a balanced half-reaction show the direct relationship between electricity and the specific redox reaction. Electrical reactions must be spontaneous or nonspontaneous. A nonspontaneous redox reaction occurs when an external voltage is applied. The reactions that occur in an electric battery are electrochemical reactions.These are Three components of an electrochemical reaction: A solution where redox reactions may occur, A conductor for electrons to be transferred, and A conductor for ions to be transferred. [3]

In all things about the nanoelectrochemistry or electrochemistry, nanoelectrodes or electrodes are needed. An electrode is strip of metal on which the reaction takes place. In a galvanic cell, the oxidation and reduction of metals occurs at the electrodes. There are two kinds of electrodes, which are anodes and cathodes. The cathode is where reduction takes place and oxidation takes place at anode. The reactions in nanoelectrochemistry or electrochemistry are reacting upon metal surfaces, or electrodes. Electrodes are called half - cells when they are immersed in a solution containing ions of the same metal. Electrolytes are ions in solution, usually fluid, that conducts electricity through ionic conduction. These are two possible reactions that can occur between the metal atoms on the electrode and the ion solutions. First, Metal ion Mn+ from the solution may collide with the electrode, gaining "n" electrons from it, and convert to metal atoms. Secondly, Metal atom on the surface may lose "n" electrons to the electrode and enter the solution as the ion Mn+ [4]

Electrolysis

Electrolysis is the chemical process of using an electrical current to stimulate non-spontaneous reactions. A non-spontaneous reaction is one that needs energy to work while it proceeds.Electrolysis can be used to separate a substance into its original components/elements and it was through this process that a number of elements have been discovered and are still produced in today's industry. [5]

The site where electrolysis occurs is in an electrolytic cell, which is a type of electrochemical cell that drives an electrical current using a non-spontaneous reaction. So, not like a cell in your body, but a container. Thus, these cells must have an energy source to drive the reaction in the reverse or opposite direction. [6]

he key process of electrolysis is the interchange of atoms and ions by the removal or addition of electrons from the external circuit. The desired products of electrolysis are often in a different physical state from the electrolyte and can be removed by some physical processes. For example, in the electrolysis of brine to produce hydrogen and chlorine, the products are gaseous. These gaseous products bubble from the electrolyte and are collected.[7]

The redox reaction in an electrolytic cell is nonspontaneous. Electrical energy is involved in inducing the electrolysis reaction. For example of an electrical cell, molten NaCl is electrolyzed to form liquid sodium and chlorine gas. The sodium ions migrate toward the cathode (where the reduction reaction takes place), where they are reduced to sodium metal. Similarly, chloride ions migrate to the anode (where oxidation reaction takes place) and are oxidized to form chlorine gas. This type of cell is used to produce sodium and chlorine. The chlorine gas can be collected surrounding the cell. The sodium metal is less dense than the molten salt and is removed as it floats to the top of the reaction container. [8]

Galvanic Cells

nanoelectrochemistry picture

Galvanic Cells, also known as voltaic cells, were discovered by Luiji Galvani. Reactions are put into two different containers and a wire is used to drive the electrons from one side to the other. Galvanic cells are created in this process. They are used to capture the energy of a spontaneous redox reaction. They are electrochemical cells that obtain the electrical energy from the spontaneous reaction. [9] They consist of two separate half - cells. A half - cell is composed of electrodes (solid metal) that is submerged in a solution; the solution contains cations of the electrode metal and anions to balance the charge of the cations. Mainly, a half-cell contains a metal in two oxidation states. There are two electrodes which are cathode(Where reduction takes place) and anode(oxidation takes place). [10]

The key to gathering the electron flow is separating the oxidation and reduction half - reactions connecting them by a wire, so that the electrons must flow through that wire. This electron flow is called current and can be can be sent through a circuit which could be part of any number of electrical devices. The salt bridge or porous disk is required in maintaining the charge neutrally for half - cells by allowing the flow of ions with minimal mixing of the half-cell solutions. As electrons are transferred from the oxidation half-cell to the reduction half-cell, a negative charge builds in the reduction half-cell and a positive charge in the oxidation half-cell. That charge buildup would serve to oppose the current from anode to cathode [11]

Nanogap electrochemical cell

a nanogap electrochemical cell is created by separating two working electrodes by 10-100 mm wide layer of electroyte. The potential of each electrode is controlled independently with respect to a reference electrode in the bulk solution and the current at each electrode measured separately. Nanogap electrochemical cells are operated in a generation/collection configuration, where one electrode is held at an oxidizing potential and the second electrode at a reducing potential, allowing a redox species to be oxidized at one electrode, transported across the nanoscale gap between the electrodes and then be reduced at the second electrode. The nanogap electrochemical cell traps the redox species and allows the redox species to repeatedly cycle between the two electrodes that lead to a greatly enhanced electrochemical signal. This process is called redox cycling. [12]

Video

nanoelectrochemistry video.

References

  1. Wikipedia "Nanoelectrochemistry". Web. February 3, 2013. Unknown Author.
  2. Khanacademy "electrochemistry" Web. January 4, 2018 Unknown Author.
  3. Unknown Author Wikipedia "General Chemistry/Redox Reactions/Electrochemistry' Web. November,16 2017
  4. The Editors of Encyclopædia Britannica Britannica Web. Unknown date.
  5. Kimberly SongChemistry LibreTexts "Electrolysis" Web. 9, Feb. 2014
  6. Reid, Danielle Wikibooks "What is Electrolysis? - Definition, Process & Facts" Web. Unknown date
  7. Richard J. D. Tilley Wikipedia "Understanding Solids: The Science of Materials" Web. September,3 2004
  8. Anne Marie Helmenstine, Ph.D. Chemistry LibreTexts "Galvanic or Voltaic Cells" Web. 7, March. 17
  9. Wikipedia "Galvanic Cell" Web. January 4, 2018 Unknown Author
  10. Shamsher Singh, Deborah Gho Thought Co "Voltaic Cells" Web. 21 Mar‎‎, ‎2017
  11. sparknotes "Galvanic Cells" Web. January 4, 2018 Unknown Author
  12. Henry S.White, Kim McKelvey ScienceDirect "Redox cycling in nanogap electrochemical cells" Web. 21, October. 2017