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Mesoporous carbon (MC), prepared by the carbonization of phenol resin using ethylene glycol as a pore forming agent, was used as the catalyst of the counter electrode in dye-sensitized solar cells (DSCs) fabricated by a paste coating method at low temperature, where a non-ionic surfactant, Triton X100, was used as a modifier of the paste. Fractal dimensions (D F ) were used to evaluate the...
Ultrananocrystalline diamond (UNCD) films were prepared by microwave plasma chemical vapor deposition using argon-rich CH 4 /H 2 /Ar plasmas with different H 2 concentrations from 5% to 20%. The influence of the H 2 concentration on the microstructure, morphology and phase composition of the UNCD films was investigated by SEM, XRD, surface profilometry and Raman spectroscopy...
High efficient sulfur cathode materials were constructed by the incorporation of aligned sulfur-coated carbon nanotubes (CNTs) and a polyethylene glycol (PEG) barrier at one end. During the charge and discharge of lithium sulfur batteries, high Li ion storage performance can be achieved on the composite electrode, which was benefited from both the aligned CNT structure and the polymer barrier. Aligned...
In order to avoid the complicated purification process of carbon nanomaterials (CNMs) and obtain high-purity CNMs, NaNO 3 powder was used as catalyst for the synthesis of CNM. By controlling the decomposition temperature (400 and 450°C), liner carbon nanofibers and helical carbon nanofibers can be selectively synthesized. Because of the used catalyst is water-soluble, it can be removed easily...
Interconnected carbon micro-spheres (CMSs) with diameters in the range of 3–5μm were synthesized by acetylene pyrolysis at 750°C on a SiO 2 substrate. The CMSs have a graphitic structure with many intrinsic defects. Results indicate that the CMSs show both diamagnetic and paramagnetic behavior. Intrinsic defects have magnetic moments with spin 1/2. Approximately every 1000 carbon atoms contribute...
CoMgAl layered double hydroxides were prepared as catalysts for the in situ synchronous growth of graphene and single-walled carbon nanotubes (SWCNTs) from methane by chemical vapor deposition. The as-calcined CoMgAl layered double oxide (LDO) flakes served as the template for the deposition of graphene, and Co nanoparticles (NPs) embedded on the LDOs catalyzed the growth of SWCNTs. After the removal...
N-doped graphene (NG) was synthesized by annealing reduced graphene oxide (RGO) in an ammonia atmosphere. The dependence of the nitrogen content on the annealing temperature and the type of doping of NG were investigated. The photoluminescence (PL) properties of the RGO and NG samples were studied. The results show that RGO exhibits strong ultraviolet (UV) PL at 367nm. The PL of RGO can be quenched...
Through the pyrolysis of acetylene at 450°C, large quantities of carbon nanocoils or carbon nanofibers can be synthesized selectively by controlling the Na:K molar ratio of water-soluble Na x K y catalysts. We found that the temperature adopted for pyrolysis is an important factor for selectively obtaining the different kinds of products. Because the Na x K y catalysts...
Natural sepiolite mineral was used as a catalyst and catalyst support for the efficient growth of single-walled carbon nanotubes (SWCNTs). With the introduction of hydrogen, uniform active metal nanoparticles can be formed in the fibrous structure of sepiolite ore. High-quality SWCNTs with few defects and a large aspect ratio (over 10 4 ) were synthesized. The structure of the CNTs was modified...
By acetylene decomposition at 450°C over the Fe–Cu nanoparticles (Fe:Cu molar ratio=29:1, 5:1) derived from a combined sol–gel/reduction method, carbon nanobelts (CNBs) and carbon/Fe–Cu hybrid nanoparticles (CNPs) were synthesized simultaneously with high yield. The two carbon species could be easily separated according to color and were collected at different locations of the ceramic plates where...
Carbon nanotube (CNT) yarn was drawn directly from super aligned CNT arrays synthesized by an improved floating catalyst chemical vapor deposition method. The synthesis of aligned CNT was performed as a multi-step interim reactant supply reaction to produce a double-layered CNT array in a horizontal quartz tube reactor. During the growth period, most impurities were blocked on the top surface of the...
High purity (99.21wt.%) helical carbon nanotubes (HCNTs) were synthesized in large quantity over Fe nanoparticles (fabricated using a coprecipitation/hydrogen reduction method) by acetylene decomposition at 450°C. Field-emission and transmission electron microscope images reveal that the selectivity to HCNTs (with two or three coiled nanotubes connected to a catalyst nanoparticle) is up to ca. 93%...
Large amount of vertically aligned carbon nanotube (CNT) arrays were grown among the layers of vermiculite in a fluidized bed reactor. The vermiculite, which was 100–300μm in diameter and merely 50–100μm thick, served as catalyst carrier. The Fe/Mo active phase was randomly distributed among the layers of vermiculite. The catalyst shows good fluidization characteristics, and can easily be fluidized...
Fluffy carbon nanotubes (CNTs), which are cotton-like macroscopic structures, are obtained by simple high-speed shearing of vertically aligned CNT (VACNT) arrays. The fluffy CNTs are composed of CNT bundles with a diameter of several micrometers, and have an extremely low apparent density of 3–10g/L. A requisite for their formation is the alignment of CNTs in the initial array. The shear between the...
Double-walled carbon nanotubes (DWCNTs) were prepared from methane using a Fe/MgO porous catalyst. A series of catalyst powders with different pore size distributions were obtained by compression at pressures of 0–233MPa. These were used to decompose methane and synthesize DWCNTs which differed in activity, purity, yield and degree of perfection. Characterization by transmission electron microscopy,...
Vertically aligned carbon nanotube (VACNT) arrays grown on ceramic spheres are obtained from ethylene using a floating catalysis process. The exhaust gas mainly contains light gaseous hydrocarbons, which decreases the contamination at the outlet of the reactor. Linear synchronous growth of the VACNT arrays is demonstrated and the morphology evolution of VACNT array grown on spheres is shown. The VACNT...
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