The Nanoparticle Size Effect in Graphene Cutting: A “Pac‐Man” Mechanism

Qiu, Zongyang; Li, Song; Zhao, Jin; Li, Zhenyu; Yang, Jinlong

doi:10.1002/ange.201602541

Cited by 11 publications

(15 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…48−50 For example, the Ni− carbon interaction acted as the driving force to cut graphene. 49 Here, we show that, at O 2 atmosphere, low p*O of TM and weak TM−boron binding energy (Au, Pt, and Ag) seem to be the prerequisite conditions toward successful etching of the h-BN sheets. The low p*O of metal is conducive to maintain its metallic state in the O 2 atmosphere and at the high temperature, and the oxidative ability of oxygen is strong enough to break the B−N bonds, even with little assistance of the TM−boron interaction.…”

mentioning

confidence: 62%

“…Based on all this work and reported results, available atmospheric conditions for the oxidative etching of h-BN in TM/h-BN systems are as follows: O 2 for Pt/h-BN, Au/h-BN, and Ag/h-BN; CO 2 for TM/h-BN (TM = Pt, Ru, Rh, Ir, Ni, Fe, and Co) . It has been proven that the interface stability of metal–carbon or metal–boron plays an important role in the etching reaction of graphene or h-BN. − For example, the Ni–carbon interaction acted as the driving force to cut graphene . Here, we show that, at O 2 atmosphere, low p*O of TM and weak TM–boron binding energy (Au, Pt, and Ag) seem to be the prerequisite conditions toward successful etching of the h-BN sheets.…”

mentioning

confidence: 93%

See 1 more Smart Citation

Oxidative Strong Metal–Support Interactions between Metals and Inert Boron Nitride

Song

Dong

et al. 2021

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

The strong metal−support interaction (SMSI) is one of the most important concepts in heterogeneous catalysis, which has been widely investigated between metals and active oxides triggered by reductive atmospheres. Here, we report the oxidative strong metal− support interaction (O-SMSI) effect between Pt nanoparticles (NPs) and inert hexagonal boron nitride (h-BN) sheets, in which Pt NPs are encapsulated by oxidized boron (BO x ) overlayers derived from the h-BN support under oxidative conditions. De-encapsulation of Pt NPs has been achieved by washing in water, and the residual ultrathin BO x overlayers work synergistically with surface Pt sites for enhancing CO oxidation reaction. The O-SMSI effect is also present in other h-BN-supported metal catalysts such as Au, Rh, Ru, and Ir within different oxidative atmospheres including O 2 and CO 2 , which is determined by metal−boron interaction and O affinity of metals.

show abstract

mentioning

confidence: 62%

mentioning

confidence: 93%

Oxidative Strong Metal–Support Interactions between Metals and Inert Boron Nitride

Song

Dong

et al. 2021

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

show abstract

“…As carbon atoms were hydrogenated, the adsorbed Ni nanoparticles penetrated the graphite core with methane (CH 4 ) gas evolution, resulting in a holey structure. Note that it was thermodynamically more favorable for the catalytic gasification of carbon to take place on the edge plane than on the basal plane of graphite 27 – 31 . As a final step, a graphitic carbon shell and an amorphous Si (a-Si) nanolayer were homogeneously distributed on nickel and graphite, respectively, via consecutive CVD processes using C 2 H 2 and SiH 4 gases (details are given in the “Methods” section).…”

Section: Resultsmentioning

confidence: 99%

“…In contrast to earlier approaches, the material design in the current work provided multiple attractive advantages. First, the catalytic reaction primarily activates the Li + -reactive edge plane of graphite 28 – 31 . According to previous studies, the mass-transfer kinetics of graphite can be improved by creating exposed edge sites 32 – 34 .…”

Section: Introductionmentioning

confidence: 99%

Fast-charging high-energy lithium-ion batteries via implantation of amorphous silicon nanolayer in edge-plane activated graphite anodes

et al. 2017

View full text Add to dashboard Cite

As fast-charging lithium-ion batteries turn into increasingly important components in forthcoming applications, various strategies have been devoted to the development of high-rate anodes. However, despite vigorous efforts, the low initial Coulombic efficiency and poor volumetric energy density with insufficient electrode conditions remain critical challenges that have to be addressed. Herein, we demonstrate a hybrid anode via incorporation of a uniformly implanted amorphous silicon nanolayer and edge-site-activated graphite. This architecture succeeds in improving lithium ion transport and minimizing initial capacity losses even with increase in energy density. As a result, the hybrid anode exhibits an exceptional initial Coulombic efficiency (93.8%) and predominant fast-charging behavior with industrial electrode conditions. As a result, a full-cell demonstrates a higher energy density (≥1060 Wh l−1) without any trace of lithium plating at a harsh charging current density (10.2 mA cm−2) and 1.5 times faster charging than that of conventional graphite.

show abstract

“…To solve this puzzle, we performed multiscale simulations of Ni nanoparticle-catalyzed graphene cutting. 48 Reactive MD simulations using the ReaxFF force field 49 at an elevated temperature indicate that at least two Ni atoms are required to break the C−C bond, and intimate contact between the metal nanoparticle and graphene edge is critical. This explains why the more open and flexible armchair edge is easier to etch than the zigzag edge.…”

Section: Ni Nanoparticle-catalyzed Graphene Cuttingmentioning

confidence: 99%

Atomistic Simulations of Graphene Growth: From Kinetics to Mechanism

Qiu

et al. 2018

Acc. Chem. Res.

Self Cite

View full text Add to dashboard Cite

Epitaxial growth is a promising strategy to produce high-quality graphene samples. At the same time, this method has great flexibility for industrial scale-up. To optimize growth protocols, it is essential to understand the underlying growth mechanisms. This is, however, very challenging, as the growth process is complicated and involves many elementary steps. Experimentally, atomic-scale in situ characterization methods are generally not feasible at the high temperature of graphene growth. Therefore, kinetics is the main experimental information to study growth mechanisms. Theoretically, first-principles calculations routinely provide atomic structures and energetics but have a stringent limit on the accessible spatial and time scales. Such gap between experiment and theory can be bridged by atomistic simulations using first-principles atomic details as input and providing the overall growth kinetics, which can be directly compared with experiment, as output. Typically, system-specific approximations should be applied to make such simulations computationally feasible. By feeding kinetic Monte Carlo (kMC) simulations with first-principles parameters, we can directly simulate the graphene growth process and thus understand the growth mechanisms. Our simulations suggest that the carbon dimer is the dominant feeding species in the epitaxial growth of graphene on both Cu(111) and Cu(100) surfaces, which enables us to understand why the reaction is diffusion limited on Cu(111) but attachment limited on Cu(100). When hydrogen is explicitly considered in the simulation, the central role hydrogen plays in graphene growth is revealed, which solves the long-standing puzzle into why H should be fed in the chemical vapor deposition of graphene. The simulation results can be directly compared with the experimental kinetic data, if available. Our kMC simulations reproduce the experimentally observed quintic-like behavior of graphene growth on Ir(111). By checking the simulation results, we find that such nonlinearity is caused by lattice mismatch, and the induced growth front inhomogeneity can be universally used to predict growth behaviors in other heteroepitaxial systems. Notably, although experimental kinetics usually gives useful insight into atomic mechanisms, it can sometimes be misleading. Such pitfalls can be avoided via atomistic simulations, as demonstrated in our study of the graphene etching process. Growth protocols can be designed theoretically with computational kinetic and mechanistic information. By contrasting the different activation energies involved in an atom-exchange-based carbon penetration process for monolayer and bilayer graphene, we propose a three-step strategy to grow high-quality bilayer graphene. Based on first-principles parameters, a kinetic pathway toward the high-density, ordered N doping of epitaxial graphene on Cu(111) using a CNCl precursor is also identified. These studies demonstrate that atomistic simulations can unambiguously produce or reproduce the kinetic information on graphene gr...

show abstract

The Nanoparticle Size Effect in Graphene Cutting: A “Pac‐Man” Mechanism

Cited by 11 publications

References 36 publications

Oxidative Strong Metal–Support Interactions between Metals and Inert Boron Nitride

Oxidative Strong Metal–Support Interactions between Metals and Inert Boron Nitride

Fast-charging high-energy lithium-ion batteries via implantation of amorphous silicon nanolayer in edge-plane activated graphite anodes

Atomistic Simulations of Graphene Growth: From Kinetics to Mechanism

Contact Info

Product

Resources

About