7440-44-0 Usage
Chemical Properties
Carbon, C, is a nonmetallic element, grey solid. It is found in nature as graphite (specific gravity2.25), diamond(specific gravity 3.51), and coal (specific gravity 1.88). Carbon is found in all living things, is insoluble in common solvents,and forms an almost infinite numberof organic compounds. Anaturally occurring radioactive isotope,14C, has a half-life of 5780 years and is used in archaeo logical investigations to date artifacts and ancient documents. Other uses of carbon depend on its form. For example, diamonds for jewels and abrasives,graphite for lubricants, activated carbon to absorb color and gases, and wood carbon for fuel are some common examples.
Physical properties
All the elements in group 14 have four electrons in their outer valence shell. Carbon exhibitsmore nonmetallic properties than do the others in group 14 and is unique in several ways.It has four forms, called allotropes:1. Carbon black is the amorphous allotrope (noncrystal form) of carbon. It is produced byheating coal at high temperatures (producing coke); burning natural gas (producing jetblack); or burning vegetable or animal matter (such as wood and bone), at high temperatureswith insufficient oxygen, which prevents complete combustion of the material, thusproducing charcoal.2. Graphite is a unique crystal structure of carbon wherein layers of carbon atoms are stackedparallel to each other and can extend indefinitely in two dimensions as in the shafts ofcarbon fiber golf clubs. Graphite is also one of the softest elements, making it an excellentdry lubricant.3. Diamonds are another allotrope whose crystal structure is similar to graphite. Naturaldiamonds were formed under higher pressure and extreme temperatures. Synthetic diamondshave been artificially produced since 1955.4. Fullerenes are another amorphous (no crystal structure) form of carbon that have the basicformula of C60H60 and are shaped like a soccer ball. (See the “Atomic Structure” sectionof the book for more on fullerenes.)The different allotropes of carbon were formed under varying conditions in the Earth,starting with different minerals, temperature, pressure, and periods of time. Once the distinctcrystal structures are formed, they are nearly impossible to change.Carbon-12 is the basis for the average atomic mass units (amu) that is used to determinethe atomic weights of the elements. Carbon is one of the few elements that can form covalentbonds with itself as well as with many metals and nonmetals.
Isotopes
There are 15 isotopes of carbon, two of which are stable. Stable carbon-12makes up 98.89% of the element’s natural abundance in the Earth’s crust, and carbon-13 makes up just 1.11% of carbon’s abundance in the Earth’s crust. All the otherisotopes of carbon are radioactive with half-lives varying from 30 nanoseconds (C-21) to5,730 years (C-14).
Origin of Name
Carbon’s name is derived from the Latin word carbo, which means,
“charcoal.”
Occurrence
Carbon is the 14th most abundant element, making up about 0.048% of the Earth’s crust.It is the sixth most abundant element in the universe, which contains 3.5 atoms of carbonfor every atom of silicon. Carbon is a product of the cosmic nuclear process called fusion,through which helium nuclei are “burned” and fused together to form carbon atoms withthe atomic number 12. Only five elements are more abundant in the universe than carbon:hydrogen, helium, oxygen, neon, and nitrogen.
Characteristics
Carbon is, without a doubt, one of the most important elements on Earth. It is the majorelement found in over one million organic compounds and is the minor component in mineralssuch as carbonates of magnesium and calcium (e.g., limestone, marble, and dolomite),coral, and shells of oysters and clams.The carbon cycle, one of the most essential of all biological processes, involves the chemicalconversion of carbon dioxide to carbohydrates in green plants by photosynthesis. Animalsconsume the carbohydrates and, through the metabolic process, reconvert the carbohydratesback into carbon dioxide, which is returned to the atmosphere to continue the cycle.
History
Carbon, an element of prehistoric discovery,
is very widely distributed in nature. It is found in abundance
in the sun, stars, comets, and atmospheres of most planets.
Carbon in the form of microscopic diamonds is found in
some meteorites. Natural diamonds are found in kimberlite
or lamporite of ancient formations called “pipes,” such as
found in South Africa, Arkansas, and elsewhere. Diamonds
are now also being recovered from the ocean floor off the
Cape of Good Hope. About 30% of all industrial diamonds
used in the U.S. are now made synthetically. The energy of
the sun and stars can be attributed at least in part to the wellknown
carbon-nitrogen cycle. Carbon is found free in nature
in three allotropic forms: amorphous, graphite, and diamond.
Graphite is one of the softest known materials while diamond
is one of the hardest. Graphite exists in two forms: alpha and
beta. These have identical physical properties, except for their
crystal structure. Naturally occurring graphites are reported
to contain as much as 30% of the rhombohedral (beta) form,
whereas synthetic materials contain only the alpha form. The
hexagonal alpha type can be converted to the beta by mechanical
treatment, and the beta form reverts to the alpha on
heating it above 1000°C. Of recent interest is the discovery
of all-carbon molecules, known as “buckyballs” or fullerenes,
which have a number of unusual properties. These interesting
molecules, consisting of 60 or 70 carbon atoms linked together,
seem capable of withstanding great pressure and trapping
foreign atoms inside their network of carbon. They are said to
be capable of magnetism and superconductivity and have potential
as a nonlinear optical material. Buckyball films are reported
to remain superconductive at temperatures as high as
45 K. In combination, carbon is found as carbon dioxide in the
atmosphere of the Earth and dissolved in all natural waters. It
is a component of great rock masses in the form of carbonates
of calcium (limestone), magnesium, and iron. Coal, petroleum,
and natural gas are chiefly hydrocarbons. Carbon is
unique among the elements in the vast number and variety of
compounds it can form. With hydrogen, oxygen, nitrogen, and
other elements, it forms a very large number of compounds,
carbon atom often being linked to carbon atom. There are
close to ten million known carbon compounds, many thousands
of which are vital to organic and life processes. Without
carbon, the basis for life would be impossible. While it has
been thought that silicon might take the place of carbon in
forming a host of similar compounds, it is now not possible
to form stable compounds with very long chains of silicon atoms.
The atmosphere of Mars contains 96.2% CO2. Some of
the most important compounds of carbon are carbon dioxide
(CO2), carbon monoxide (CO), carbon disulfide (CS2), chloroform
(CHCl3), carbon tetrachloride (CCl4), methane (CH4),
ethylene (C2H4), acetylene (C2H2), benzene (C6H6), ethyl alcohol
(C2H5OH), acetic acid (CH3COOH), and their derivatives.
Carbon has fifteen isotopes. Natural carbon consists of 98.89%
12C and 1.11% 13C. In 1961 the International Union of Pure and
Applied Chemistry adopted the isotope carbon-12 as the basis
for atomic weights. Carbon-14, an isotope with a half-life
of 5715 years, has been widely used to date such materials as
wood, archeological specimens, etc. A new brittle form of car-
4-8 The Elements
bon, known as “glassy carbon,” has been developed. It can be
obtained with high purity. It has a high resistance to corrosion,
has good thermal stability, and is structurally impermeable to
both gases and liquids. It has a randomized structure, making
it useful in ultra-high technology applications, such as crystal
growing, crucibles for high-temperature use, etc. Glassy carbon
is available at a cost of about $35/10g. Fullerene powder
is available at a cost of about $55/10mg (99%C10). Diamond
powder (99.9%) costs about $40/g.
Uses
Different sources of media describe the Uses of 7440-44-0 differently. You can refer to the following data:
1. Crucibles, retorts, foundry facings, molds,
lubricants, paints and coatings, boiler compounds,
powder glazing, electrotyping, monochromator in
X-ray diffraction analysis, fluorinated graphite
polymers with fluorine-to-carbon ratios of 0.1–1.25,
electrodes, bricks, chemical equipment, motor and
generator brushes, seal rings, rocket nozzles, moderator
in nuclear reactors, cathodes in electrolytic
cells, pencils, fibers, self-lubricating bearings, intercalation
compounds.
2. There are many uses for the very versatile element carbon. It, no doubt, forms morecompounds than any other element, particularly in the world of modern carbon chemistry.Carbon’s nature allows the formation-rings and straight- and branched-chains types of compoundsthat are capable of adding hydrogen as well as many different types of elemental atomsto these structures. (See figure 5 in the book’s section titled “Atomic Structure” for a depictionof a snake eating its tail as an analogy for the carbon ring of benzene.) In addition, theseringed, straight, and branched carbon molecules can be repeated over and over to form verylarge molecules such as the polymers, proteins, and carbohydrates that are required for life.Carbon is an excellent reducing agent because it readily combines with oxygen to form COand CO2. Thus, in the form of coke in blast furnaces, it purifies metals by removing the oxidesand other impurities from iron.Carbon, as graphite, has strong electrical conductivity properties. It is an importantcomponent in electrodes used in a variety of devices, including flashlight cells (batteries).Amorphous carbon has some superconduction capabilities.Graphite is used for the “lead” in pencils, as a dry lubricant, and as electrodes in arc lamps.Of course, carbon is a popular jewelry item (e.g., diamonds).Future uses of carbon in the forms of fullerenes (C60 up to C240) and applications of nanotechnologywill provide many new and improved products with unusual properties.
3. Glassy carbon rod is used as an electrode material in electrochemistry. It is also used as high temperature crucibles. Used as a component of some prosthetic devices. Used electrical conductor ion-selective membrane.
Definition
Different sources of media describe the Definition of 7440-44-0 differently. You can refer to the following data:
1. The crystalline allotropic form of carbon.
2. A porous form of carbonproduced by the destructive distillationof organic material. Charcoalfrom wood is used as a fuel. All formsof charcoal are porous and are usedfor adsorbing gases and purifyingand clarifying liquids. There are severaltypes depending on the source.Charcoal from coconut shells is a particularlygood gas adsorbent. Animalcharcoal (or bone black) is made byheating bones and dissolving out thecalcium phosphates and other mineralsalts with acid. It is used in sugarrefining. Activated charcoal is charcoalthat has been activated for adsorptionby steaming or by heatingin a vacuum.
3. carbon: Symbol C. A nonmetallic element belonging to group 14 (formerly IVB) of the periodic table; a.n. 6; r.a.m. 12.011; m.p. ～3550°C; b.p. ～4827°C. Carbon has three main allotropic forms. Diamond (r.d. 3.52) occurs naturally and can be produced synthetically. It is extremely hard and has highly refractive crystals. The hardness of diamond results from the covalent crystal structure, in which each carbon atom is linked by covalent bonds to four others situated at the corners of a tetrahedron. The C–C bond length is 0.154 nm and the bond angle is 109.5°.Graphite (r.d. 2.25) is a soft black slippery substance (sometimes called black lead or plumbago). It occurs naturally and can also be made by the Acheson process. In graphite the carbon atoms are arranged in layers, in which each carbon atom is surrounded by three others to which it is bound by single or double bonds. The layers are held together by much weaker van der Waals’ forces. The carbon–carbon bond length in the layers is 0.142 nm and the layers are 0.34 nm apart. Graphite is a good conductor of heat and electricity. It has a variety of uses including electrical contacts, high-temperature equipment, and as a solid lubricant.Graphite mixed with clay is the ‘lead’ in pencils (hence its alternative name). The third crystalline allotrope is fullerite. There are also several amorphous forms of carbon, such as carbon black and charcoal. There are two stable isotopes of carbon (proton numbers 12 and 13) and four radioactive ones (10, 11, 14, 15). Carbon–14 is used in carbon dating.Carbon forms a large number of compounds because of its unique ability to form stable covalent bonds with other carbon atoms and also with hydrogen, oxygen, nitrogen, and sulphur atoms, resulting in the formation of a variety of compounds containing chains and rings of carbon atoms.
General Description
Black grains that have been treated to improve absorptive ability. May heat spontaneously if not properly cooled after manufacture.
Air & Water Reactions
Highly flammable. Dust is explosive when exposed to heat or flame. Freshly prepared material can heat and spontaneously ignite in air. The presence of water assists ignition, as do contaminants such as oils. Insoluble in water.
Reactivity Profile
Carbon is incompatible with very strong oxidizing agents such as fluorine, ammonium perchlorate, bromine pentafluoride, bromine trifluoride, chlorine trifluoride, dichlorine oxide, chlorine trifluoride, potassium peroxide, etc. . Also incompatible with air, metals, unsaturated oils. [Lewis].
Hazard
Different sources of media describe the Hazard of 7440-44-0 differently. You can refer to the following data:
1. (Powder, natural) Fire risk.
2. Many compounds of carbon, particularly the hydrocarbons, are not only toxic but alsocarcinogenic (cancer-causing), but the elemental forms of carbon, such as diamonds andgraphite, are not considered toxic.Carbon dioxide (CO2) in its pure form will suffocate you by preventing oxygen from enteringyour lungs. Carbon monoxide (CO) is deadly, even in small amounts; once breathed intothe lungs, it replaces the oxygen in the bloodstream.Carbon dioxide is the fourth most abundant gas in the atmosphere at sea level. Excess CO2produced by industrialized nations is blamed for a slight increase in current temperaturesaround the globe. CO2 makes up only 0.03+ percent by volume of the gases in the atmosphere.However, even a small amount in the upper atmosphere seems to be responsible forsome global warming. Since pre-industrial times, the concentration of CO2 in the Earth’satmosphere has risen by approximately one-third, from 280 ppm (parts per million) to about378 ppm. At the same time methane (CH4) doubled its concentration over the years to about2 ppm in the atmosphere. Methane is many times more effective as a “greenhouse” gas than iscarbon dioxide, even though it breaks down in a shorter period of time. Some Scandinaviancountries have experimented with pumping excess CO2 produced by their industries deeponto the ocean floor where it will reenter the carbon cycle just as it does through trees andvegetation on the surface of the Earth. There are a number of super-computer programsattempting to predict the extent of global warming. The problem is the number of variablesaffecting climate change. The process is akin to trying to determine the shape of a cloud overthe next hour. Unfortunately, neither well-meaning politicians nor scientists can agree onthe extent of potential damage that excess carbon dioxide may do to the Earth in the future.Global warming and cooling are cyclic, which means that these processes have been alternatingover eons of time.
Health Hazard
Fire may produce irritating and/or toxic gases. Contact may cause burns to skin and eyes. Contact with molten substance may cause severe burns to skin and eyes. Runoff from fire control may cause pollution.
Fire Hazard
Flammable/combustible material. May be ignited by friction, heat, sparks or flames. Some may burn rapidly with flare burning effect. Powders, dusts, shavings, borings, turnings or cuttings may explode or burn with explosive violence. Substance may be transported in a molten form at a temperature that may be above its flash point. May re-ignite after fire is extinguished.
Agricultural Uses
Carbon (C) is found in every living being as it forms the
major constituent of living cells. As an essential element
for plants and animals, carbon is derived from
atmospheric carbon dioxide assimilated by plants and
photoautotrophic microbes during photosynthesis.
Carbon occurs in nature both in an elemental form and as
compounds. For example, coal contains elemental
carbon which, upon heating in the absence of air, loses
the volatile substances, and gives coke. Both coal and
coke are amorphous (non-crystalline) forms of carbon.
The two crystalline forms of carbon are diamond and
graphite. These are called the two allotropes of carbon.
Allotropes are two or more forms of an element that exist
in different physical forms, and differ in the bonding or
molecular structure of their fundamental units. Carbon is
found in a combined state in all living organisms, as well
as in fossil fuels such as methane and petroleum. It also
occurs in large amounts in carbonates such as limestone.
Carbon, a non-metallic element, is found at the head
of Group 14 (formerly IV) in the Periodic Table. It is unique in the variety and complexity of
compounds it forms, which is due to the ability of carbon
atoms to bond to one another in long chains, rings and
combinations of rings and chains. Carbon in combination
with H, O, N, S and other elements produces such a
variety of compounds, that a separate branch of
chemistry called organic chemistry, came into being
around carbon compounds.
Elemental carbon is a fairly inert substance. It is
insoluble in water, dilute acids and bases, and organic
solvents.
Each carbon atom has four valence electrons and
these tend to share with other atoms in the formation of
four covalent bonds. Carbon forms two oxides - carbon
monoxide (CO) and carbon dioxide (CO2)-which are
formed when carbon or carbon-containing compounds
are burned in insufficient or inexcess air, respectively.
The free element has many uses, ranging from
ornamental applications as diamond in jewelry to the
black-colored pigment of carbon black in automobile
tires and printing inks. Graphite, another form of carbon,
is used for high temperature crucibles, arc lights, dry-cell
electrodes, lead pencils and as a lubricant.
Charcoal, an amorphous form of carbon, is used as
an absorbent for gases and as a decolorizing agent in its
activated form.
Safety Profile
Moderately toxic by
intravenous route. Experimental
reproductive effects. It can cause a dust
irritation, particularly to the eyes and
mucous membranes. See also CARBON
BLACK, SOOT. Combustible when
exposed to heat. Dust is explosive when
exposed to heat or flame or oxides,
peroxides, oxosalts, halogens, interhalogens,
02, (NH4NO3 + heat), (NH4ClO4 @ 240°),
bromates, Ca(OCl)2, chlorates, (Cla +
Cr(OCl)2), Cl0, iodates, 105, Pb(NO3)~,
HgNO3, HNO3, (oils + air), (K + air), NaaS,
Zn(NO3)a. Incompatible with air, metals,
oxidants, unsaturated oils.
Purification Methods
Charcoal (50g) is added to 1L of 6M HCl and boiled for 45minutes. The supernatant is discarded, and the charcoal is boiled with two more lots of HCl, then with distilled water until the supernatant no longer gives a test for chloride ion. The charcoal (now phosphate-free) is filtered onto a sintered-glass funnel and air dried at 120o for 24hours. [Lippin et al. J Am Chem Soc 76 2871 1954.] The purification can be carried out using a Soxhlet extractor (without cartridge), allowing longer extraction times. Treatment with conc H2SO4 instead of HCl has been used to remove reducing substances.
Check Digit Verification of cas no
The CAS Registry Mumber 7440-44-0 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,4,4 and 0 respectively; the second part has 2 digits, 4 and 4 respectively.
Calculate Digit Verification of CAS Registry Number 7440-44:
(6*7)+(5*4)+(4*4)+(3*0)+(2*4)+(1*4)=90
90 % 10 = 0
So 7440-44-0 is a valid CAS Registry Number.
InChI:InChI=1/C
7440-44-0Relevant articles and documents
Aluminium powder as a reactive template for preparation of carbon flakes from CCl4
?imon, Erik,Billik, Peter,Orov?ík, ?ubomír,Nagy, ?tefan,Sasinková, Vlasta,Palou, Martin T.,?krátek, Martin,Trembo?ová, Veronika,Plesch, Gustav
, p. 4599 - 4607 (2020)
Abstract: This work presents a simple procedure for the preparation of 2D carbon flakes by a catalyst-free redox reaction in the range of 400–600?°C at atmospheric pressure. Tetrachloromethane (CCl4) was reduced by aluminium flakes (Al), which also serve as a?template for carbon flakes, for either 60?min or 120?min. Gaseous aluminium chloride (AlCl3) was released from the?synthesis. According to BET analysis, the prepared carbon flakes exhibit a mesoporous structure with surface area in?the?range of 300–500?m2?g?1. The 2D morphology and amorphous character was confirmed by XRD, Raman spectra and TEM analyses. In addition, SEM and TEM images revealed the carbon flakes are composed from carbon layers which can be also folded. A?mechanism of their formation was also proposed. At?higher reaction temperature, e.g., 700?°C, 1D carbon nanostructures with worm-like morphology was obtained. Graphic Abstract: [Figure not available: see fulltext.].
Preparation of a platelike carbon nanomaterial using MgO as a template
Davydov,Kryukov,Gerya,Izvol'skii,Rakov
, p. 244 - 248 (2012)
A carbon nanomaterial in the form of hollow hexagonal platelets with shells of disordered graphene layers has been synthesized through CH4 pyrolysis on pseudomorphic hexagonal MgO platelets 1-2 μm in average size, followed by dissolution of the magnesium oxide. The material has a specific surface area above 1300 m2/g, specific pore volume of 3.23 cm 3/g, and resistivity of 0.08 Ω cm. Pleiades Publishing, Ltd., 2012.
Chemical vapor deposition of methane for single-walled carbon nanotubes
Kong, Jing,Cassell, Alan M.,Dai, Hongjie
, p. 567 - 574 (1998)
We report the synthesis of high-quality single-walled carbon nanotubes (SWNT) by chemical vapor deposition (CVD) of methane at 1000°C on supported Fe2O3 catalysts. The type of catalyst support is found to control the formation of ind
A novel emulsion-based replica method for the synthesis of mesoporous carbon
Kang, Jin Kyeong,Xiong, Wei,Kang, Ji Hoon,Kang, Jukyoung,Kim, Seok,Jung, Yongju
, p. 7259 - 7262 (2018)
We present a novel approach for the synthesis of large-pore mesoporous carbon with a highly porous structure, based on an oil/water (O/W) emulsion templating method. For the formation of oil-in-water emulsions with nanoscale oil droplets, polyvinylpyrrolidone was used as an emulsifier. Mesoporous carbon materials with large mesopores were successfully synthesized via a three-step process: (1) polymerization in the oil-in-water emulsion, (2) filtration, and (3) carbonization. We confirmed that the pore size of the carbon can be significantly reduced through a modified O/W emulsion method. The mesoporous carbon materials prepared without an activation step exhibited an appreciable surface area (705 m2/g) and a noticeable capacitive performance of ～100 F/g at 2.0 A/g. We believe that the approach presented here can be widely applied to the synthesis of mesoporous carbon using various carbon sources, and the structural properties of the mesoporous carbon can be improved through proper optimization.
STRUCTURE OF THE RESIDUAL CARBON MADE BY FLUOROCARBON PYROLYSIS
Fialkov, A. S.,Dobryakov, S. N.,Khorkhorin, A. V.,Tyan, L. S.,Polyakova, N. V.,et al.
, p. 413 - 416 (1990)
Fluorocarbon defluorination products show an anusual temperature dependence for the paramagnetic susceptibility in the range 77-300 K after pyrolysis at 650-1000 deg C, which is explained from dynamic equilibrium between the formation and dissociation of free radicals involving a bond eergy of 11.22 kJ/mole.The ESR line width initially increases with temperature but then decreases.The width of the inhomogeneously broadened line has been calculated as a function of the frequencies of the static and dynamic spin exchange, which shows that at low temperatures there is alocal increase in the radical concentration, but at higher temperatures, the dynamic exchange averages out this dipole spin-spin interaction.A suggestion confirmed by x-ray structures analysis is that the products contain a linear form of carbon.
Electrical and thermoelectric power measurements of GaInSe2 single crystals
Mobarak
, p. 1259 - 1263 (2009)
A single crystal of GaInSe2 was prepared from melt using a vertical Bridgman technique. The crystal was characterized by X-ray diffraction and Energy dispersive X-ray fluorescence spectrometer (EDXRF). Electrical conductivity, hall effect, and
Formation of carbon nanoparticles by the condensation of supersaturated atomic vapor obtained by the laser photolysis of C3O2
Gurentsov,Eremin,Schulz
, p. 194 - 203 (2007)
A new technique is suggested for obtaining nanoparticles from highly supersaturated vapor resulting from the laser photolysis of volatile compounds. The growth of carbon nanoparticles resulting from C3O2 photolysis has been studied in detail. Absorbing UV quanta (from an Ar-F excimer laser), C3O2 molecules decompose to yield atomic carbon vapor with precisely known and readily controllable parameters. This is followed by the condensation of supersaturated carbon vapor and the formation of carbon nanoparticles. These processes have been investigated by the laser extinction and laser-induced incandescence (LII) methods in wide ranges of experimental conditions (carbon vapor concentration, nature of the diluent gas, and gas pressure). The current and ultimate particle sizes and the kinetic parameters of particle growth have been determined. The characteristic time of particle growth ranges between 20 and 1000 μs, depending on photolysis conditions. The ultimate particle size determined by electron microscopy is 5-12 nm for all experimental conditions. It increases with increasing total gas pressure and carbon vapor partial pressure and depends on the diluent gas. The translational energy accommodation coefficients for the Ar, He, CO, and C3O 2 molecules interacting with the carbon particle surface have been determined by comparing the LII and electron microscopic particle sizes. A simple model has been constructed to describe the condensation of carbon nanoparticles from supersaturated atomic vapor. According to this model, the main process in nanoparticle formation is surface growth through the addition of separate atoms to the nucleation cluster. The nucleus concentrations for various condensation parameters have been determined by comparing experimental and calculated data.
Decomposition of methane over iron catalysts at the range of moderate temperatures: The influence of structure of the catalytic systems and the reaction conditions on the yield of carbon and morphology of carbon filaments
Ermakova,Ermakov,Chuvilin,Kuvshinov
, p. 183 - 197 (2001)
Decomposition of high-purity methane in the presence of α-Fe-based catalysts to produce filamentous carbon was studied at 650°-800°C. Filamentous carbon was formed at temperatures not lower than 680°C in the presence of both bare α-Fe and catalysts based
Synthesis of SiC nanorods using floating catalyst
Zhang, Yingjiu,Wang, NanLin,He, Rongrui,Chen, Xihua,Zhu, Jing
, p. 595 - 598 (2001)
The beta-silicon carbide (β-SiC) nanorods have been synthesized by a floating catalyst method. Iron particles, decomposed from ferrocene vapor while being carried into the reaction chamber by the flowing gases, are very tiny. These small Fe particles act as catalyst to promote the growth of SiC nanorods in the SiCl4-C6H6-H2-Ar system at 1100-1200°C. The diameters of the β-SiC in the products are less than 100 nm, and the SiC nanorods with uniform diameters are single crystals with the stacking faults on the {111} crystal planes.
The surface decoration and electrochemical hydrogen storage of carbon nanofibers
Yan, Xiaoqi,Gao, Xueping,Li, Ying,Liu, Zhanquan,Wu, Feng,Shen, Yutian,Song, Deying
, p. 336 - 341 (2003)
The tube-like carbon nanofibers (CNF) with cone-shaped structure were synthesized by catalytic pyrolysis of methane over Ni/MgO catalyst at 550°C for 30 min. The outer diameter of CNF with a rough surface increased to ～ 50-80 nm due to the deposition of Ni-P alloy particles in a ball shape. In the dark field under the selected electron diffraction, the Ni-P alloy particles with fine crystallites existed along the outer surface of CNF, like chain morphology. The heat treatment of CNF decorated with Ni-P alloy particles led to higher crystallization of surface alloy particles. The maximum discharge capacities of the composites with Ni-P content of 76.3 wt % before and after heat treatment were 101 and 149 mA h/g, respectively.
