Graphene−Metal Particle Nanocomposites

Xu, Chao; Wang, Xin; Zhu, Junwu

doi:10.1021/jp807989b

Cited by 1,488 publications

(936 citation statements)

References 35 publications

(64 reference statements)

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“…Due to high surface-to-volume ratio (theoretical value of 2630 m 2 /g), graphene is a promising candidate as a substrate for stabilizing metal nanoparticles in heterogeneous catalysis. 7,8 Progress in experimental techniques has made it possible to study the properties of graphene-supported metal nanoparticles such as Pt, Pd and Au, [9][10][11][12] which may offer a new type of carbon-based metal nanocomposite for the next generation of catalysts. 9 Besides the key electrocatalytic role of the Pt catalysts in fuel cells, they have long been used as a promoter in the Fischer-Tropsch (FT) synthesis for conversion of syngas (CO + H 2 ) to liquid fuels.…”

Section: Introductionmentioning

confidence: 99%

Influence of Carbon Support on Electronic Structure and Catalytic Activity of Pt Catalysts: Binding to the CO Molecule

2016

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Single-atom catalysts, especially with single Pt atoms, exhibit potentially improved catalytic activity as compared to metal clusters and metal surfaces. Here, the atop and bridged bondings of the CO molecule on the Pt/C system are studied. Vibrational frequencies, Mulliken populations, charge transfer, charge density differences and density of states are examined to determine the influence of the carbon support on electronic properties and catalytic activity of the Pt adatom and dimer. Comparing orbital populations and the amount of electron transfer to/from the CO molecule show that the net amount of electron transfer to the anti-bonding 2π * orbitals of the CO molecule is higher for the supported Pt dimer than for the substrate-free Pt dimer which leads to a lower vibrational frequency and a larger C−O bond distance. The hybridization between the π orbitals of the polycyclic aromatic hydrocarbons surface and the d orbitals of the Pt adatoms is responsible for enhancing the back donation of electrons to the 2π * orbitals of the CO molecule which results in a larger peak below the Fermi level for the 2π * states of the CO molecule in the corresponding density of state analysis. Therefore, it can be concluded that the carbon support significantly enhances the catalytic activity of the Pt atoms in contact with the surface for activating the CO molecule. The calculated C−O vibrational stretching frequencies provide valuable guidance for experiments considering the use of atom-type catalyst as building blocks for designing new catalysts.

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Section: Introductionmentioning

confidence: 99%

Influence of Carbon Support on Electronic Structure and Catalytic Activity of Pt Catalysts: Binding to the CO Molecule

2016

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“…Metal nanoparticlegraphene hybrid systems have also been fabricated by several groups. 21,[35][36][37] Here, we study a QD-graphene hybrid system, where energy transfer occurs due to the interaction between optical excitations in the QD and graphene nanodisk. The optical excitations in the QD are excitons, which are electron-hole pairs, while those in the graphene nanodisk are surface plasmon polaritons, which are created due to the collective oscillations of conduction-band electrons.…”

Section: Introductionmentioning

confidence: 99%

Dipole-dipole interaction between a quantum dot and a graphene nanodisk

et al. 2012

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We study theoretically the dipole-dipole interaction and energy transfer in a hybrid system consisting of a quantum dot and graphene nanodisk embedded in a nonlinear photonic crystal. In our model, a probe laser field is applied to measure the energy transfer between the quantum dot and graphene nanodisk, while a control field manipulates the energy transfer process. These fields create excitons in the quantum dot and surface plasmon polaritons in the graphene nanodisk which interact via the dipole-dipole interaction. Here, the nonlinear photonic crystal acts as a tunable photonic reservoir for the quantum dot, and is used to control the energy transfer. We have found that the spectrum of power absorption in the quantum dot has two peaks due to the creation of two dressed excitons in the presence of the dipole-dipole interaction. The energy transfer rate spectrum of the graphene nanodisk also has two peaks due to the absorption of these two dressed excitons. Additionally, energy transfer between the quantum dot and the graphene nanodisk can be switched on and off by applying a pump laser to the photonic crystal or by adjusting the strength of the dipole-dipole interaction. We show that the intensity and frequencies of the peaks in the energy transfer rate spectra can be modified by changing the number of graphene monolayers in the nanodisk or the separation between the quantum dot and graphene. Our results agree with existing experiments on a qualitative basis. The principle of our system can be employed to fabricate nanobiosensors, optical nanoswitches, and energy transfer devices.

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“…Most of the existing reports focus on the deposition of nanoparticles of noble metals and oxides, like Au, Pt, Ag and TiO 2 , on the surface of GNSs to impart new functionalities, such as catalytic, energy storage, photocatalytic, sensory and optoelectronic [8][9][10]. Several papers have recently been published on simulation of the GNS/metal (Al, Cu, Ni) interfacial structure and prediction of the mechanical properties of GNS/Al [11][12][13].…”

mentioning

confidence: 99%