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Lai KC, Han Y, Spurgeon P, Huang W, Thiel PA, Liu DJ, Evans JW. Reshaping, Intermixing, and Coarsening for Metallic Nanocrystals: Nonequilibrium Statistical Mechanical and Coarse-Grained Modeling. Chem Rev 2019; 119:6670-6768. [DOI: 10.1021/acs.chemrev.8b00582] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- King C. Lai
- Department of Physics & Astronomy, Iowa State University, Ames, Iowa 50011, United States
- Division of Chemical & Biological Sciences, Ames Laboratory − USDOE, Iowa State University, Ames, Iowa 50011, United States
| | - Yong Han
- Department of Physics & Astronomy, Iowa State University, Ames, Iowa 50011, United States
- Division of Chemical & Biological Sciences, Ames Laboratory − USDOE, Iowa State University, Ames, Iowa 50011, United States
| | - Peter Spurgeon
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Wenyu Huang
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Patricia A. Thiel
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
- Department of Materials Science & Engineering, Iowa State University, Ames, Iowa 50011, United States
| | - Da-Jiang Liu
- Division of Chemical & Biological Sciences, Ames Laboratory − USDOE, Iowa State University, Ames, Iowa 50011, United States
| | - James W. Evans
- Department of Physics & Astronomy, Iowa State University, Ames, Iowa 50011, United States
- Division of Chemical & Biological Sciences, Ames Laboratory − USDOE, Iowa State University, Ames, Iowa 50011, United States
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McKee WC, Patterson MC, Frick JR, Sprunger PT, Xu Y. Adsorption of transition metal adatoms on h-BN/Rh(111): Implications for nanocluster self-assembly. Catal Today 2017. [DOI: 10.1016/j.cattod.2016.09.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Han Y, Gaudry É, Oliveira TJ, Evans JW. Point island models for nucleation and growth of supported nanoclusters during surface deposition. J Chem Phys 2016; 145:211904. [PMID: 28799390 DOI: 10.1063/1.4954410] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Point island models (PIMs) are presented for the formation of supported nanoclusters (or islands) during deposition on flat crystalline substrates at lower submonolayer coverages. These models treat islands as occupying a single adsorption site, although carrying a label to track their size (i.e., they suppress island structure). However, they are particularly effective in describing the island size and spatial distributions. In fact, these PIMs provide fundamental insight into the key features for homogeneous nucleation and growth processes on surfaces. PIMs are also versatile being readily adapted to treat both diffusion-limited and attachment-limited growth and also a variety of other nucleation processes with modified mechanisms. Their behavior is readily and precisely assessed by kinetic Monte Carlo simulation.
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Affiliation(s)
- Yong Han
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - Émilie Gaudry
- Institut Jean Lamour, UMR CNRS 7098, Université de Lorraine, 54011 Nancy Cedex, France
| | - Tiago J Oliveira
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - James W Evans
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
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Han Y, Evans JW. Adsorption and diffusion of Ru adatoms on Ru(0001)-supported graphene: Large-scale first-principles calculations. J Chem Phys 2016; 143:164706. [PMID: 26520542 DOI: 10.1063/1.4934349] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Large-scale first-principles density functional theory calculations are performed to investigate the adsorption and diffusion of Ru adatoms on monolayer graphene (G) supported on Ru(0001). The G sheet exhibits a periodic moiré-cell superstructure due to lattice mismatch. Within a moiré cell, there are three distinct regions: fcc, hcp, and mound, in which the C6-ring center is above a fcc site, a hcp site, and a surface Ru atom of Ru(0001), respectively. The adsorption energy of a Ru adatom is evaluated at specific sites in these distinct regions. We find the strongest binding at an adsorption site above a C atom in the fcc region, next strongest in the hcp region, then the fcc-hcp boundary (ridge) between these regions, and the weakest binding in the mound region. Behavior is similar to that observed from small-unit-cell calculations of Habenicht et al. [Top. Catal. 57, 69 (2014)], which differ from previous large-scale calculations. We determine the minimum-energy path for local diffusion near the center of the fcc region and obtain a local diffusion barrier of ∼0.48 eV. We also estimate a significantly lower local diffusion barrier in the ridge region. These barriers and information on the adsorption energy variation facilitate development of a realistic model for the global potential energy surface for Ru adatoms. This in turn enables simulation studies elucidating diffusion-mediated directed-assembly of Ru nanoclusters during deposition of Ru on G/Ru(0001).
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Affiliation(s)
- Yong Han
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA and Ames Laboratory-U.S. Department of Energy, Iowa State University, Ames, Iowa 50011, USA
| | - James W Evans
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA and Ames Laboratory-U.S. Department of Energy, Iowa State University, Ames, Iowa 50011, USA
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Novotny Z, Netzer FP, Dohnálek Z. Cerium Oxide Nanoclusters on Graphene/Ru(0001): Intercalation of Oxygen via Spillover. ACS NANO 2015; 9:8617-8626. [PMID: 26230753 DOI: 10.1021/acsnano.5b03987] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cerium oxide is an important catalytic material known for its ability to store and release oxygen, and as such, it has been used in a range of applications, both as an active catalyst and as a catalyst support. Using scanning tunneling microscopy and Auger electron spectroscopy, we investigated oxygen interactions with CeOx nanoclusters on a complete graphene monolayer-covered Ru(0001) surface at elevated temperatures (600-725 K). Under oxidizing conditions (PO2 = 1 × 10(-7) Torr), oxygen intercalation under the graphene layer is observed. Time dependent studies demonstrate that the intercalation proceeds via spillover of oxygen from CeOx nanoclusters through the graphene (Gr) layer onto the Ru(0001) substrate and extends until the Gr layer is completely intercalated. Atomically resolved images further show that oxygen forms a p(2 × 1) structure underneath the Gr monolayer. Temperature dependent studies yield an apparent kinetic barrier for the intercalation of 1.21 eV. This value correlates well with the theoretically determined value for the reduction of small CeO2 clusters reported previously. At higher temperatures, the intercalation is followed by a slower etching of the intercalated graphene (apparent barrier of 1.60 eV). Vacuum annealing of the intercalated Gr leads to the formation of carbon monoxide, causing etching of the graphene film, demonstrating that the spillover of oxygen is not reversible. In agreement with previous studies, no intercalation is observed on a complete graphene monolayer without CeOx clusters, even in the presence of a large number of point defects. These studies demonstrate that the easily reducible CeOx clusters act as intercalation gateways capable of efficiently delivering oxygen underneath the graphene layer.
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Affiliation(s)
- Zbynek Novotny
- Fundamental and Computational Sciences Directorate and Institute for Interfacial Catalysis, Pacific Northwest National Laboratory , Richland, Washington 99354, United States
| | - Falko P Netzer
- Surface and Interface Physics, Institute of Physics, Karl-Franzens University , A-8010 Graz, Austria
| | - Zdenek Dohnálek
- Fundamental and Computational Sciences Directorate and Institute for Interfacial Catalysis, Pacific Northwest National Laboratory , Richland, Washington 99354, United States
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Dedkov Y, Voloshina E. Graphene growth and properties on metal substrates. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:303002. [PMID: 26151341 DOI: 10.1088/0953-8984/27/30/303002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Graphene-metal interface as one of the interesting graphene-based objects attracts much attention from both application and fundamental science points of view. This paper gives a timely review of the recent experimental works on the growth and the electronic properties of the graphene-metal interfaces. This work makes a link between huge amount of experimental and theoretical data allowing one to understand the influence of the metallic substrate on the electronic properties of a graphene overlayer and how its properties can be modified in a controllable way. The further directions of studies and applications of the graphene-metal interfaces are discussed.
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Affiliation(s)
- Yuriy Dedkov
- SPECS Surface Nano Analysis GmbH, Voltastrasse 5, 13355 Berlin, Germany
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