Nanoflower
Encyclopedia
A nanoflower, in chemistry, refers to a compound of certain elements that results in formations which in microscopic view resemble flowers or, in some cases, trees that are called nanobouquets or nanotrees. These formations are nanometers long and thick so they can only be observed using electron microscopy.
s, energy is stored because the electrodes are coated with a porous material that soaks up ions like a sponge, usually activated carbon
. Nanomeadow supercapacitors store ions in manganese oxide
(MnO), a material with a much greater capacity for ions than activated carbon.
Scientists at Research Institute of Chemical Defence (Beijing, China) and Peking University
created a nanomeadow of microscopic structures, fuzzy flowers of MnO each about 100 nanometres across on a field of messy carbon nanotube grass grown on a tantalum
metal foil
. Nanomeadows perform 10 times better than MnO alone and can store twice as much charge as the carbon-based electrodes in existing ultracapacitors.
Production
Several ways to produce nanoflowers are known:- A process similar to the making of a carbon nanotubeCarbon nanotubeCarbon nanotubes are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1, significantly larger than for any other material...
using a hydrocarbonHydrocarbonIn organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
gas. - Heating galliumGalliumGallium is a chemical element that has the symbol Ga and atomic number 31. Elemental gallium does not occur in nature, but as the gallium salt in trace amounts in bauxite and zinc ores. A soft silvery metallic poor metal, elemental gallium is a brittle solid at low temperatures. As it liquefies...
(Ga) and then flowing methaneMethaneMethane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
(CH4) over, under specific pressure and heat. This forms flower-shaped silicon carbideSilicon carbideSilicon carbide , also known as carborundum, is a compound of silicon and carbon with chemical formula SiC. It occurs in nature as the extremely rare mineral moissanite. Silicon carbide powder has been mass-produced since 1893 for use as an abrasive...
(SiC) structures. - Heating a molybdenum dioxideMolybdenum dioxideMolybdenum dioxide is the chemical compound with the formula MoO2. It is a violet-colored solid and is a metallic conductor. It crystallizes in a monoclinic cell, and has a distorted rutile, crystal structure. In TiO2 the oxide anions are close packed and titanium atoms occupy half of the...
(MoO2) thin filmThin filmA thin film is a layer of material ranging from fractions of a nanometer to several micrometers in thickness. Electronic semiconductor devices and optical coatings are the main applications benefiting from thin film construction....
on a piece of molybdenumMolybdenumMolybdenum , is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores...
foil surrounded by sulfurSulfurSulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
vapour.
Nanomeadow
In supercapacitorSupercapacitor
An electric double-layer capacitor , also known as supercapacitor, supercondenser, electrochemical double layer capacitor, or ultracapacitor, is an electrochemical capacitor with relatively high energy density. Their energy density is typically hundreds of times greater than conventional...
s, energy is stored because the electrodes are coated with a porous material that soaks up ions like a sponge, usually activated carbon
Activated carbon
Activated carbon, also called activated charcoal, activated coal or carbo activatus, is a form of carbon that has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions.The word activated in the name is sometimes replaced...
. Nanomeadow supercapacitors store ions in manganese oxide
Manganese(II) oxide
Manganese oxide is the inorganic compound with formula MnO. MnO is a basic oxide that is insoluble in water but dissolves in acids, forming manganese salts.-Preparation and occurrence:...
(MnO), a material with a much greater capacity for ions than activated carbon.
Scientists at Research Institute of Chemical Defence (Beijing, China) and Peking University
Peking University
Peking University , colloquially known in Chinese as Beida , is a major research university located in Beijing, China, and a member of the C9 League. It is the first established modern national university of China. It was founded as Imperial University of Peking in 1898 as a replacement of the...
created a nanomeadow of microscopic structures, fuzzy flowers of MnO each about 100 nanometres across on a field of messy carbon nanotube grass grown on a tantalum
Tantalum
Tantalum is a chemical element with the symbol Ta and atomic number 73. Previously known as tantalium, the name comes from Tantalus, a character in Greek mythology. Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion resistant. It is part of the refractory...
metal foil
Metal leaf
Metal leaf, also called composition leaf or schlagmetal, is a thin foil used for decoration. Metal leaf can come in many different shades. Some metal leaf may look like gold leaf but not contain any real gold...
. Nanomeadows perform 10 times better than MnO alone and can store twice as much charge as the carbon-based electrodes in existing ultracapacitors.
See also
- Carbon nanotubes in photovoltaicsCarbon nanotubes in photovoltaicsOrganic photovoltaic devices are fabricated from thin films of organic semiconductors, such as polymers and small-molecule compounds, and are typically on the order of 100 nm thick...
- Carbon nanotubeCarbon nanotubeCarbon nanotubes are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1, significantly larger than for any other material...
- Selective chemistry of single-walled nanotubes
- Resonance Raman spectroscopyResonance Raman spectroscopyResonance Raman spectroscopy is a specialized implementation of the more general Raman spectroscopy.- Overview :As in Raman spectroscopy, RR spectroscopy provides information about the vibrations of molecules, and can also be used for identifying unknown substances. RR spectroscopy has found wide...
- Allotropes of carbonAllotropes of carbonThis is a list of the allotropes of carbon.-Diamond:Diamond is one of the most well known allotropes of carbon. The hardness and high dispersion of light of diamond make it useful for both industrial applications and jewellery. Diamond is the hardest known natural mineral. This makes it an...
- grapheneGrapheneGraphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. The term graphene was coined as a combination of graphite and the suffix -ene by Hanns-Peter Boehm, who described single-layer...
- buckypaperBuckypaperBuckypaper is a thin sheet made from an aggregate of carbon nanotubes. The nanotubes are approximately 50,000 times thinner than a human hair. Originally, it was fabricated as a way to handle carbon nanotubes, but it is also being studied and developed into applications by several research groups,...
- Electric double-layer capacitor
- Hiromichi KatauraHiromichi Kataurais a Japanese scientist known for his work on synthesis and characterization of single-wall and double-wall carbon nanotubes and on encapsulation of water, fullerene and other organic molecules into carbon nanotubes....