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Phosphorus-doped nanomesh graphene (PG) with huge specific surface area and lamellar hexagonal structure has been synthesized by a thermal annealing method using MgO as a template and triphenylphosphine (TPP) as both phosphorus and carbon source. The synthesized PG with a high phosphorous content of 1.61 at% is found to exhibit efficient metal-free heterogeneous catalytic activity for aerobic oxidative...
Quantum chemical molecular dynamics simulations based on the density-functional tight-binding (DFTB) method were performed to investigate the role of oxygen in single-walled carbon nanotube (SWCNT) growth process. We found that a suitable content of oxygen in an iron nano-catalyst particle can reduce the internal thermal mobility of Fe atoms in catalyst due to the formation of strong FeO bonds. These...
High-strength carbon nanotube (CNT) fibers are strongly desired as they offer both excellent mechanical and electrical properties compared to traditional fiber materials. Here, we adopt twisting and compression as two complementary steps to tailor the fiber structure and obtain extraordinary mechanical properties. We have fabricated twist-compressed ribbon-like CNT fibers with predefined, uniform,...
The H2O molecule dissociation on the alkali-earth (Ba and Mg) or transition-metal (Ti)-embedded nitrogen-doped graphene was studied systematically using first-principles calculation. The metal-embedded nitrogen-doped graphene (MN4-graphene) (M = Ba, Mg and Ti) membranes are good candidates for single-atom catalysts (SACs), because the single metal atom can be strongly trapped in the divacancy of the...
Designing the low cost, long durability and high efficient substitutes for platinum (Pt) electrocatalyst to facilitate ORR is significant for the large-scale commercial application of fuel cells. In this work, single Pd atoms supported on graphitic carbon nitride (i.e., Pd/g-C3N4) with different Pd coverages acting as electrocatalyst for ORR is investigated by using the density functional theory calculations...
After the discovery of the highly symmetric Buckminsterfullerene (BF), a major goal of the fullerene community has been to understand its formation mechanism. In the various mechanisms proposed in literature, BF forms by either a bottom-up only or a top-down only process. Here we present a comprehensive quantum mechanical molecular dynamics simulation study, that reports for the first time the observations...
By taking advantage of the structural tunability of ionic liquids (ILs), a series of imidazolium ILs were employed as precursors to prepare carbon dots (IL-CDs) and as regulators to control their properties. The simultaneous formation of hydrophilic CDs (IL-HCDs) and organophilic CDs (IL-OCDs) is achieved in hydrothermal reaction system by undergoing sulfuric acid carbonization. The quantum yields...
The heteroatom-doped fullerene is systematically studied as an electrocatalyst for oxygen reduction reaction (ORR) on the cathode of fuel cells under the alkaline and acid conditions. Nitrogen-doped C60, i.e. C59N, can facilitate the ORR process and it is a promising candidate for efficient ORR electrocatalysts. The intrinsic C60 also possesses a high catalytic activity, which is different from graphene...
Rational design on the microstructure of electromagnetic composites offers immense potential for overcoming the challenges related to the microwave absorption performance. In this study, uniform core-shell Co@C microspheres are innovatively fabricated through an in situ transformation from Co3O4@phenolic resin precursor. Carbon shells restrain the agglomeration of Co particles during high-temperature...
As one of the potential candidates of electrocatalysts, non-precious transition metal and nitrogen embedded graphene has attracted extensive attention in recent years. Deep understanding of the oxygen reduction reaction (ORR) mechanism including the specific active sites and reaction pathways will contribute to the further enhancement of their catalytic activity. In this work, density functional study...
The reaction mechanisms for oxygen reduction reaction (ORR) on phosphorus doped divacancy graphene (P-GDV) are investigated by using the density functional theory method. Our results showed that all of the possible ORR elementary reactions could take place within a small region around the P atom and its adjacent four carbon atoms. The hydrogenation of O2 molecule which forms OOH and hydrogenation...
Carbon materials, as a typical dielectric loss medium, are always the most attractive candidates for microwave absorption due to their characteristic advantages; however, much less attention has been paid to upgrading their performance by rational design on the microstructure. According to the transmission behavior and loss mechanism of electromagnetic waves, uniform yolk-shell C@C microspheres are...
Organic phototransistor (OPT) is a promising organic device with substantial attention due to its photodetection combined with lightweight, flexibility, large-scale yields, and low cost of organic materials. In addition, spectral tunability and long photocarrier lifetime for organic materials make them highly attractive for advanced optoelectronic device applications. Here, we report high-performance...
A columnar bamboo/lignite material was prepared by briquetting a mixture of bamboo carbon and lignite. Activated carbons were obtained by carbonizing the material at 500°C for 30min, followed by activation at 850°C for 2h using either steam or a gaseous mixture of ammonia in water with an ammonia concentration of 2.42mass%. The ammonia-activated carbon was soaked in 21.91% ammonia water for 5h and...
Nonequilibrium quantum chemical molecular dynamics (QM/MDs) simulation of early stages in the nucleation process of carbon nanotubes from acetylene feedstock on an Fe38 cluster was performed based on the density-functional tight-binding (DFTB) potential. Representative chemical reactions were studied by complimentary static DFTB and density functional theory (DFT) calculations. Oligomerization and...
Nonequilibrium high-temperature quantum chemical molecular dynamics simulations based on the self-consistent-charge density-functional tight-binding (DFTB) method for the conversion of C60 to SiC fullerene by way of periodic Si atom supply are presented. Random supply of Si atoms on the surface of a perfect Ih-C60 buckminsterfullerene without simultaneous carbon atom removal merely leads to formation...
Double-walled carbon nanotubes (DWCNTs) have been effectively synthesized by direct current (DC) arc discharge in low pressure air using a mixture of Fe catalyst and FeS promoter. Compared with conventional arc methods, this method is easier to implement without using expensive high purity gas sources. A tip structural DWCNT film has been successfully fabricated by a mixing process of electrophoresis,...
Highly efficient and large-scale synthesis of graphene from graphite was produced by electrolytic exfoliation using poly(sodium-4-styrenesulfonate) as an effective electrolyte. Scanning and transmission electron microscopy, and atomic force microscopy confirmed the existence of monolayer graphene sheets and stacks containing a few graphene sheets. Raman spectroscopy demonstrated that the as-prepared...
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