Experimental realization of two-dimensional boron sheets

Feng, Baojie; Zhang, Jin; Zhong, Qing; Li, Wenbin; Li, Shuai; Li, Hui; Cheng, Peng; Chen, Lan; Wu, Kehui

doi:10.1038/nchem.2491

Cited by 1,608 publications

(1,556 citation statements)

References 33 publications

Supporting

103

Mentioning

1,378

Contrasting

Unclassified

Order By: Relevance

“…According to the data of Petrović et al [27], the ribbons organize upon cooling at around 1220 K, either through condensation of B adatoms or segregation of B that had been dissolved in the selvage after h-BN decomposition. The boron sheets realized by Feng et al [66] through boron molecular beam epitaxy on Ag(111) display a similar striped appearance as the ribbons observed here, which may be a hint for a similarity in structure. We note that nitrogen stemming from the decomposition of h-BN will rapidly desorb as N 2 [67,68].…”

Section: A Decomposition Of H-bn and Blister Effects After Annealingsupporting

confidence: 58%

Annealing of ion-irradiated hexagonal boron nitride on Ir(111)

et al. 2017

View full text Add to dashboard Cite

Annealing of a monolayer of hexagonal boron nitride destroyed by Xe ion irradiation gives rise to rich structural phenomena investigated here through a combination of scanning tunneling microscopy, low-energy electron diffraction, x-ray photoelectron spectroscopy, and density functional theory calculations. We find selective pinning of vacancy clusters at a single specific location within the moiré formed by hexagonal boron nitride (h-BN) and the Ir substrate, crystalline Xe at room temperature of monolayer and bilayer thickness sealed inside h-BN blisters, standalone blisters only bound to the metal at temperatures where boron nitride on Ir (111) decomposes, and finally a pronounced threefold symmetry of all morphological features due to the preferential formation of boron-terminated zigzag edges that firmly bind to the substrate. The investigations give clear insight into the relevance of the substrate for the damage creation and annealing in a two-dimensional layer material.

show abstract

Section: A Decomposition Of H-bn and Blister Effects After Annealingsupporting

confidence: 58%

Annealing of ion-irradiated hexagonal boron nitride on Ir(111)

et al. 2017

View full text Add to dashboard Cite

show abstract

“…For example, while all existing 3D boron allotropes are semiconducting at standard conditions, borophenes show metallic characteristic [30][31][32] , which also distinguishes them from other well studied 2D materials usually having bandgaps. Among the properties borophenes may offer, their mechanical properties are of particular interest and importance.…”

mentioning

confidence: 99%

“…Towards the synthesis of borophenes, several theoretical works [28][29] have suggested using metal substrates, such as Ag or Cu that may screen only a few of 2D boron structures. Very recently, two independent experiments have reported the successful synthesis of borophenes on Ag(111) by using molecular beam epitaxy methods [30][31] .…”

mentioning

confidence: 99%

“…40 The experimentally realized borophenes were characterized to be in different lattice phases. The triangular (v=0) and v 1/6 sheets were proposed as atomic models for a stripped phase 30,41 while the v 1/5 sheet was proposed for a phase showing a brick-wall pattern 31 in scanning tunneling microscopy images. The relaxed triangular sheet displays a washboard-like buckling structure due to an excess of electrons (Figure 1a), whereas the v 1/6 and v 1/5 sheets are purely planar because of their high HH concentrations making them both electron-deficient (Figure 1b and 1c).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Elasticity, Flexibility, and Ideal Strength of Borophenes

Zhang

Yang

Penev

et al. 2017

Adv Funct Materials

273

199

View full text Add to dashboard Cite

ABSTRACT:We study the mechanical properties of two-dimensional (2D) boron-borophenes -by first-principles calculations. The recently synthesized borophene with 1/6 concentration of hollow hexagons (HH) is shown to have in-plane modulus C up to 210 N/m and bending stiffness as low as D = 0.39 eV. Thus, its Foppl-von Karman number per unit area, defined as C/D, reaches 568 nm -2 , over twofold higher than graphene's value, establishing the borophene as one of the most flexible materials. Yet, the borophene has a specific modulus of 346 m 2 /s 2 and ideal strengths of 16 N/m, rivaling those (453 m 2 /s 2 and 34 N/m) of graphene. In particular, its structural fluxionality enabled by delocalized multi-center chemical bonding favors structural phase transitions under tension, which result in exceptionally small breaking strains yet highly ductile breaking behavior. These mechanical properties can be further tailored by varying the HH concentration, and the boron sheet without HHs can even be stiffer than graphene against tension. The record high flexibility combined with excellent elasticity in boron sheets can be utilized for designing composites and flexible systems.

show abstract

“…Very recently, borophenes have been successfully synthesized by atomic deposition on a silver surface [11,12]. These rapid progresses in experimental syntheses and theoretical studies have paved the way for possible applications of borophenes in nanoscience and nanotechnology.…”

mentioning

confidence: 99%

Perfectly planar CoB 18 – as a motif for metallo-borophenes

2016

Nano Res.

View full text Add to dashboard Cite

Over the past decade, extensive collaborative experimental and theoretical researches have systematically elucidated the structures and chemical bonding of boron clusters as a function of size and have revealed an intriguing set of structures, ranging from planar hydrocarbon-analogs to nanotubular and fullerenelike structures (borospherenes) [1][2][3][4][5][6][7]. Small boron clusters have the propensity for planarity with delocalized  and  electrons over the whole molecular plane, giving rise to the concept of multiple aromaticity. Particularly, the discovery of the planar B 36 with a central hexagonal vacancy [8] has been a major landmark in the study of boron clusters, because it can be viewed as the basis for the formation of monolayer two-dimensional (2D) boron materials and provided the first indirect evidence for the viability of 2D borons with hexagonal holes [9,10]. This momentous finding prompted the proposal of a new name "borophene" for the new 2D boron [8], in analogy with graphene, by Jun Li and Lai-Sheng Wang.The reason that the name borophene was coined, rather than borene, was because the later had already been used in chemistry to represent R-B=B-R types of organoboron molecules. Very recently, borophenes have been successfully synthesized by atomic deposition on a silver surface [11,12]. These rapid progresses in experimental syntheses and theoretical studies have paved the way for possible applications of borophenes in nanoscience and nanotechnology. Now, a team led by Prof. Jun Li from Tsinghua University and Prof. Lai-Sheng Wang from Brown University reported the first perfectly planar transitionmetal doped boron cluster (CoB  18 , Fig. 1) implying a promising future for "hetero-borophenes" [13]. The CoB  18 cluster was studied thoroughly by both photoelectron spectroscopy and quantum chemistry, and it was found to consist of a seven-membered ring of boron atoms with a central Co atom that has rather strong covalent interactions with the boron surrounding. The Co atom at the center holds the highly flexible boron structure so that a perfect plane can be formed without any defect in the boron framework. The B-B lengths on the periphery of the cluster are shorter than the internal ones due to dangling bonds in the periphery. The team performed chemical bonding analyses, which indicate that Co interacts with the surrounding B 7 ring via six four-centered, two-electron (4c-2e)  bonding orbitals. The inner B 7 ring bonds with the outer B 11 ring via both  and  type bonding, thus ensuring electronic stability of the framework. There are ten  electrons delocalized over the whole plane, suggesting unique  aromaticity (Fig. 2) for the planar CoB  18 cluster. They also showed that the central Co atom has a rare oxidation state of +1 with d 8 electron configuration due to the strong covalent interactions between Co and

show abstract

Experimental realization of two-dimensional boron sheets

Cited by 1,608 publications

References 33 publications

Annealing of ion-irradiated hexagonal boron nitride on Ir(111)

Annealing of ion-irradiated hexagonal boron nitride on Ir(111)

Elasticity, Flexibility, and Ideal Strength of Borophenes

Perfectly planar CoB 18 – as a motif for metallo-borophenes

Contact Info

Product

Resources

About