On the Mechanism of Formation of Metal Nanowires by Self‐Assembly

“…These truncated octahedral NPs with fcc structure were located in 2.5×2.5×2.5 nm large periodically repeated cells with the ≥0.9 nm separation between adjacent particles. Interactions of metal NPs at such distances are shown to be negligible [32].…”

Section: Computational Detailsmentioning

confidence: 99%

Using density functional calculations to elucidate atomic ordering of Pd-Rh nanoparticles at sizes relevant for catalytic applications

Vega

Aleksandrov

Neyman

2019

Chinese Journal of Catalysis

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“…74 Moreover, such properties as average cohesion energy and average metal-metal bond distance reveal scalability with respect to size up to the bulk limit. 66,75 These nanoparticles can ideally complement the slab models, enabling the study of interactions with defect sites (at edges, corners, etc.…”

Section: Computational Details and Modelsmentioning

confidence: 99%

Carbon on Platinum Substrates: From Carbidic to Graphitic Phases on the (111) Surface and on Nanoparticles

2009

Self Cite

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The formation of carbonaceous deposits on Pt(111) surfaces and Pt nanoparticles has been studied using suitable models and density-functional calculations. The study addresses a broad range of processes, from the very first stage of carbon deposition up to a final building of graphene monolayers (ML) defined as a 1:1 ratio of the number of C atoms to surface Pt atoms. A carbidic phase is formed below a coverage of approximately 0.3 ML, when negatively charged carbon atoms are strongly adsorbed preferentially on fcc hollow sites. On Pt nanoparticles, the adsorption of carbon atoms seems to be enhanced near particle edges due to the special flexibility of defect sites. Above a coverage of approximately 0.3 ML, the formation of small C(n) aggregates becomes possible. Interestingly, thermodynamics favors the formation of C(3) trimers at a coverage of 0.33 ML, whereas the formation of C(2) dimers requires a higher coverage of 0.5 ML. The covalently bonded C(2) species is supposed to be the key fragment for the formation of benzene-like rings at coverages above 0.6 ML. These rings are expected to be the building blocks for the graphene monolayer. However, the typical electronic structure of graphene is not observed until a coverage above approximately 1.8 ML is reached. We corroborated the experimentally suggested carbon double-layer to be stable. It is proposed to consist of a monolayer of carbidic atoms C adsorbed on Pt with a graphene layer adsorbed on the carbidic layer. Some of the carbidic atoms serve as anchors for the graphene layer, with noticeably strong covalent bonds formed. This double-layer model would imply a much higher adhesion of the graphene layer than in the single-layer model.

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On the Mechanism of Formation of Metal Nanowires by Self‐Assembly

Cited by 56 publications

References 18 publications

How to determine accurate chemical ordering in several nanometer large bimetallic crystallites from electronic structure calculations

How to determine accurate chemical ordering in several nanometer large bimetallic crystallites from electronic structure calculations

Using density functional calculations to elucidate atomic ordering of Pd-Rh nanoparticles at sizes relevant for catalytic applications

Carbon on Platinum Substrates: From Carbidic to Graphitic Phases on the (111) Surface and on Nanoparticles

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