Abstract In this paper, the adsorption mechanisms between different species (CH3, CH4, C2H2, C2H4, C2H6, and C6H6) and the carbon-based materials (pristine graphene, N-doped graphene, and vacancy graphene) during the chemical vapor infiltration process were systematically studied using the density functional theory. The optimized adsorption configurations were obtained by using Dmol3 code in Material Studio. The adsorption energies, Mulliken atomic charges, density of states, and charge density differences of the adsorption process were analyzed. It showed that the CH3 is chemisorbed, while the other species (CH4, C2H2, C2H4, C2H6, and C6H6) are weak physisorbed on pristine graphene, N-doped graphene and vacancy graphene. In addition, the introduction of nitrogen dopant and vacancy defect into the pristine graphene does not significantly affect the adsorption mechanisms between small hydrocarbons and graphene.
Abstract Soot particles are composed of planar and curved polycyclic aromatic hydrocarbons with different types of reactive sites, where their growth and oxidation reactions occur. This study presents the effect of curvatures in PAHs present in soot on their growth in the flame environment. For this, six planar and curved model PAH molecules having five to nine aromatic rings with armchair and zigzag sites are selected. Density functional theory (B3LYP functional and 6-311G (d,p) basis set) is u...
Last. Zhigang Zhao(NPU: Northwestern Polytechnical University)H-Index: 1
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Abstract To investigate the mechanism of the heterogenous reactions during the Chemical vapor infiltration (CVI) process of carbon/carbon composites, the dissociation of CH4 on graphene was calculated by density functional theory (DFT). Graphene was used as the adsorption surface in the course of the heterogenous reactions. Based on the energy analysis, the preferred adsorption sites of CHx(x = 0–4) and H on graphene were obtained. Then, the stable co-adsorption configurations of CHx/H(x = 0–3) ...
Carbon fiber-reinforced carbon matrix composites (C/C composites) have excellent properties such as specific strength and specific elastic modulus, along with excellent fatigue resistance, thermal shock resistance, ablation resistance, frictional properties, lightweight, heat/thermal conductivity, and dimensional stability. C/C composites are the materials that exhibit almost no decline in mechanical properties, even at 2000–3000 °C, when protected from oxidation. A method of directly coating th...
Abstract Density functional theory calculations have been carried out to study the adsorption of varous gas molecules (H 2 O, NH 3 , CO, NO 2 and NO) on pristine graphene and Ga-doped graphene in order to explore the feasibility of Ga-doped graphene based gas sensor. For each gas molecule, various adsorption positions and orientations were considered. The most stable configuration was determined and the adsorption energies with van der Waals interactions were calculated. Further, electronic prop...
#1Daoguo Yang(GUET: Guilin University of Electronic Technology)H-Index: 25
#2Ning Yang(GUET: Guilin University of Electronic Technology)H-Index: 8
Last. Xianping Chen(GUET: Guilin University of Electronic Technology)H-Index: 28
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Abstract In this work, graphene for use as methane (CH 4 ) sensors has been designed and evaluated via first-principles theory. Firstly, the effect of the number of layers of graphene on methane adsorption is investigated. The results show that the methane adsorption will be increased with the number of layers, the maximum energy is 0.267 eV. Furthermore, the adsorption of CH 4 leads to a small opening of the band structure of graphene. As for the doping (Al-doped) in graphene, we mainly focus o...
Last. Zongchang Yang(Henan Normal University)H-Index: 176
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As an efficient metal-free catalyst, graphene doped with heteroatoms is highly active in promoting electrochemical oxygen reduction reaction (ORR). The detailed kinetic and thermodynamic behaviors of the entire ORR process on sulfur doped monovacancy graphene (SGV), as well as the original mechanism are investigated by the dispersion-corrected density function theory (DFT-D) calculations. It is found that the SGV is rather stable and the sulfur dopant is probably the active center. There are two...
#1Bo Gao(SDUST: Shandong University of Science and Technology)H-Index: 8
#2Ruliang Zhang(SDUST: Shandong University of Science and Technology)H-Index: 9
Last. Aiping Cao(SDUST: Shandong University of Science and Technology)H-Index: 1
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Abstract An effective carbon fiber/graphene oxide/carbon nanotubes (CF-GO-CNTs) multiscale reinforcement was prepared by co-grafting carbon nanotubes (CNTs) and graphene oxide (GO) onto the carbon fiber surface. The effects of surface modification on the properties of carbon fiber (CF) and the resulting composites was investigated systematically. The GO and CNTs were chemically grafted on the carbon fiber surface as a uniform coating, which could significantly increase the polar functional group...
CO2 capture, storage, sequestration (CCS), and utilization (CCU) are regarded as the most effective way to slow the pace of global warming. In our present work, the structural stability and catalytic properties for adsorbing CO2 on the surface of isolated Ni clusters and 5–8–5 monovacancy graphene (MGr) supported Ni clusters have been investigated using density functional theory. The results show that, with the increasing of atomic number, the structure of isolated Ni clusters tended to be stabl...
Abstract To distinguish the potential of graphene sensors, there is a need to recognize the interaction between graphene sheet and adsorbing molecules. We used density functional theory (DFT) calculations to study the properties of pristine as well as Pt-decorated graphene sheet upon adsorption of NH3 and CH4 on its surface to exploit its potential to be as gas sensors for them. We found much higher adsorption, higher charge transfer, lower intermolecular distance, and higher orbital hybridizing...
Abstract Adsorption properties of C 2 H 2 and C 2 H 4 gas molecules on Pt-decorated graphene (PtG) have been examined using first-principles density functional theory (DFT) calculations. A particular interesting aspect of PtG is that the Pt atom influences the electronic structure of graphene through coulombic charge-transferring. Upon adsorption of C 2 H 2 and C 2 H 4 on PtG, the C–C axis remains essentially parallel to the surface. We found high values of adsorption energy, low connecting dist...
#1Peng Yi(Kunming University of Science and Technology)H-Index: 3
#2Zuo Xiangzhi(Kunming University of Science and Technology)
Last. Lijuan Zhang(SCUT: South China University of Technology)H-Index: 32
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Abstract null null Hypothesis. null Organic co-solvents, which are universally employed in adsorption studies of hydrophobic organic chemicals (HOCs), can inhibit HOC adsorption by competing for active sites on the adsorbent. The adsorbent structure can influence co-solvent interference of HOC adsorption; however, this effect remains unclear, leading to an incomplete understanding of the adsorption mechanism. null null null Experiments. null In this study, dioctyl phthalate (DOP) was used to inv...
Abstract null null MgO-based mixture is a promising candidate for CO2 capture due to its high theoritical capture capacity, non-corrosiveness, low cost and wide availability. In this work, the effects of preparation methods and sorption conditions on the characteristics of MgO-Na2CO3 are studied. A stable MgO conversion of 0.32 for CO2 sorption is obtained during the 30-cycle tests at 400 °C, 2 MPa, where the material exhibits a strong skeleton structure with increased specific surface area when...
Last. Zeyan Wang(SDU: Shandong University)H-Index: 56
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Abstract null null The water gas shift reaction is an important reaction for H2 production in various industrial applications. The presence of CaO can promote the reactivity of the water gas shift reaction without any catalysts, but the enhancement mechanism of CaO in this reaction is difficult to determine just by the experiment. In this work, the water gas shift reaction along four possible pathways on the CaO surface were studied by density functional theory (DFT) analysis. The energy barrier...
#1Xiaopeng Li(SWUST: Southwest University of Science and Technology)
#2Run Zhang(SWUST: Southwest University of Science and Technology)
Last. Hongping Zhang(SWUST: Southwest University of Science and Technology)H-Index: 27
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Abstract null null The potential hazards of glyphosate on human health and ecological system cause widespread concern while being extensively accepted as a low side effects herbicide. Carbon based adsorbents are promising candidates for removal glyphosate. In this study, the ab initio calculations are carried out to explore the effects of ten different elemental dopants on the glyphosate capture ability of graphene. The results indicate that elemental doping can be an effective way to improve th...
#1Qiuyue Sheng(Northeastern University (China))H-Index: 4
#2Bin Yang(Northeastern University (China))H-Index: 12
Last. Keqiang Chen(Northeastern University (China))H-Index: 3
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Abstract This paper investigated the adsorption mechanism of cupferron on the malachite (−2 0 1) surface and the implications for flotation via X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FTIR) measurements, density functional theory (DFT) calculations, and microflotation tests. The XPS and FTIR analyses confirmed the adsorption of cupferron on the malachite surface. The DFT calculations indicated that the adsorption was mainly due to the reaction between O atoms in cupfe...
Last. Guoqing Wang(NPU: Northwestern Polytechnical University)
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To improve the pyrolytic carbon (PyC) deposition rate of Carbon/Carbon (C/C) composites prepared by the traditional chemical vapor infiltration (CVI) method, the 3D Ni/wood-carbon (3D Ni/C) catalyst was introduced into the CVI process. The effects of catalyst on the density of C/C composites were studied, and the deposition rate and morphologies of PyC were investigated after catalytic CVI. The morphologies of catalyst and PyC were characterized by scanning electron microscope and polarized ligh...
#1Renhui Zhang(ECJTU: East China Jiaotong University)H-Index: 12
#2Mengyue Zhu(ECJTU: East China Jiaotong University)
Last. Liping Xiong(ECJTU: East China Jiaotong University)H-Index: 4
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Abstract In this work, using first-principles calculations, the adsorption behavior of benzotriazole anion on defective graphene (DG) surface was investigated, the adsorption of benzotriazole anion on DG surface achieved the modification of N onto graphene. The calculated results showed that the benzotriazole anion could absorbed on DG, rather on pristine graphene (PG); the DG superior to PG as protective coating could stably anchor on Cu surface; Cu was easily oxidized by oxygen, the absorption...
Abstract Within the exploring for a sensitive sensor of Methyl isocyanate (MIC) gas molecule, the adsorption of MIC molecule on pristine and doped graphene sheets was investigated by DFT calculations. The adsorption of MIC gas molecule was monitored on the Si, Ge and B-OH doped graphene and the results showed that B(OH)- doped graphene was better than intrinsic, Si-doped and Ge-doped graphene for the MIC gas sensing with acceptable adsorption energy (-18.15 kcal.mol-1), work function changes (-4...