Interactions of Li, Ca, and Al with aromatic carbon materials: An <i>ab initio</i> study

Zhao, Yanling; Lin, Chensheng; Zhang, R. Q.; Wang, R. S.

doi:10.1063/1.1898209

Cited by 10 publications

(8 citation statements)

References 33 publications

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“…The conclusion emerging from this test is that weak Cainteractions are considerably underestimated using the GGA͑PBE͒-DFT method. Related computational studies carried out by Sun et al 62 and Zhao et al 63 on Ca-doped aromatic hydrocarbon systems, showed similar underestimation of the electronic correlations using the GGA͑B3LYP͒-DFT method. An interesting question that raised while carrying out the present benchmark test was, is the Ca-C 24 H 12 system physically similar to Ca-decorated graphene?, or in other words, is it correct to extrapolate conclusions found in the Ca-C 24 H 12 system to Ca-decorated nanostructures?…”

Section: Computational Outline and Test Of The Methodssupporting

confidence: 56%

First-principles study of the stability of calcium-decorated carbon nanostructures

2010

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In view of the interest in calcium-decorated carbon nanostructures motivated by potential biotechnological and nanotechnological applications, we have carried out a systematic and thorough first-principles computational study of the energetic and structural properties of these systems. We use density-functional theory ͑DFT͒ and ab initio molecular dynamic simulations to determine minimum energy configurations, binding energy profiles and the thermodynamic stability of Ca-decorated graphene and carbon nanotubes ͑CNT͒ as function of doping concentration. In graphene, we predict the existence of an equilibrium ͑ ͱ 3 ϫ ͱ 3͒ R30°commensurate CaC 6 monolayer that remains stable without clustering at low and room temperatures. For carbon nanotubes, we demonstrate that uniformly Ca-decorated zigzag ͑n Յ 10, 0͒ CNT become stable against clustering at moderately large doping concentrations while Ca-coated armchair ͑n , n͒ CNT exhibit a clear thermodynamic tendency for Ca aggregation. In both Ca-doped graphene and CNT systems, we estimate large energy barriers ͑ϳ1 eV͒ for atomic aggregation processes, which indicates that Ca clustering in carbon nanosurfaces may be kinematically hindered. Finally, we demonstrate via comparison of DFT and Møller-Plesset second-order perturbation calculations that DFT underestimates significantly the weak interaction between a Ca dopant and a coronene molecule, and also that the Ca-coronene system is not physically comparable to Ca-doped graphene due to lack of electronic-d orbitals hybridization near the Fermi energy level.

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Section: Computational Outline and Test Of The Methodssupporting

confidence: 56%

First-principles study of the stability of calcium-decorated carbon nanostructures

2010

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“…54 A similar conclusion has been obtained by ab initio calculations for the Li-C 6 H 6 system. 55 These theoretical results support our expectation, although, to our knowledge, there is no theoretical report on the K -C 6 H 6 system.…”

Section: Formation and Thermal Stability Of K Clusterssupporting

confidence: 91%

Potassium-benzene interactions on Pt(111) studied by metastable atom electron spectroscopy

Sogo

Sakamoto

Aoki

et al. 2010

The Journal of Chemical Physics

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Electron emission spectra obtained by thermal collisions of He(∗)(2(3)S) metastable atoms with C(6)H(6)/Pt(111), C(6)H(6)/K/Pt(111), and K/C(6)H(6)/Pt(111) were measured in the temperature range of 50-200 K to elucidate the adsorption/aggregation states, thermal stabilities of pure and binary films, and local electronic properties at the organic-metal interface. For C(6)H(6)/Pt(111), the He(∗)(2(3)S) atoms de-excite on the chemisorbed overlayer predominantly via resonance ionization followed by Auger neutralization and partly via Penning ionization (PI) yielding weak emission just below the Fermi level (E(F)). We assigned this emission to the C(6)H(6) π-derived states delocalized over the Pt 5d bands on the basis of recent density functional calculations. During the layer-by-layer growth, the C(6)H(6)-derived bands via PI reveal a characteristic shift caused by the final-state effect (hole response at the topmost layer). C(6)H(6) molecules chemisorb weakly on the bimetallic Pt(111) (θ(K)=0.1) and physisorb on the K multilayer. In both cases, the sum rule was found to be valid between the K 4s and C(6)H(6)-derived bands. The band intensity versus exposure plot indicates that the C(6)H(6) film grows on the K multilayer by the Volmer-Weber mechanism (island growth), reflecting the weak K-C(6)H(6) interactions. In case of K/C(6)H(6)/Pt(111), the K atoms are trapped on the topmost C(6)H(6) layer at 65 K, forming particlelike clusters. The surface plasmon satellite was identified for the first time and the loss energy increases with increasing cluster size. The K clusters are unstable above ∼100 K due to thermal migration into the C(6)H(6) film. When the cluster coverage is low, the K 4s band extends below and above E(F) of the Pt substrate and the anomaly is discussed in terms of vacuum level bending around the cluster.

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“…Previous studies on the reactions of benzene with reactive metals have been performed in the condensed phase, − in the gas phase, ,− and using matrix isolation. ,, Theoretical studies on these reactions have also been reported. ,,,,− Collectively, this previous work documents reaction through an electron transfer pathway for isolated benzene molecules, and these studies have provided detailed information about the bonding in the metal–benzene complexes so formed. However, no previous work has addressed the details of this reaction chemistry for bulk solid-state benzene wherein proximity of multiple benzene molecules has the potential to alter the reaction pathway or the products formed.…”

Section: Introductionmentioning

confidence: 93%

Raman Spectroscopy of the Reaction of Thin Films of Solid-State Benzene with Vapor-Deposited Ag, Mg, and Al

2011

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Thin films of solid-state benzene at 30 K were reacted with small quantities of vapor-deposited Ag, Mg, and Al under ultrahigh vacuum, and products were monitored using surface Raman spectroscopy. Although Ag and Mg produce small amounts of metalÀbenzene adduct products, the resulting Raman spectra are dominated by surface enhancement of the normal benzene modes from metallic nanoparticles suggesting rapid Ag or Mg metallization of the film. In contrast, large quantities of Al adduct products are observed. Vibrational modes of the products in all three systems suggest adducts that are formed through a pathway initiated by an electron transfer reaction. The difference in reactivity between these metals is ascribed to differences in ionization potential of the metal atoms; ionization potential values for Ag and Mg are similar but larger than that for Al. These studies demonstrate the importance of atomic parameters, such as ionization potential, in solid-state metalÀorganic reaction chemistry.

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Interactions of Li, Ca, and Al with aromatic carbon materials: An ab initio study

Cited by 10 publications

References 33 publications

First-principles study of the stability of calcium-decorated carbon nanostructures

First-principles study of the stability of calcium-decorated carbon nanostructures

Potassium-benzene interactions on Pt(111) studied by metastable atom electron spectroscopy

Raman Spectroscopy of the Reaction of Thin Films of Solid-State Benzene with Vapor-Deposited Ag, Mg, and Al

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