Two-Dimensional Stoichiometric Boron Oxides as a Versatile Platform for Electronic Structure Engineering

Abstract

Oxides of two-dimensional (2D) atomic crystals have been widely studied due to their unique properties. In most 2D oxides, oxygen acts as a functional group, which makes it difficult to control the degree of oxidation. Because borophene is an electron-deficient system, it is expected that oxygen will be intrinsically incorporated into the basal plane of borophene, forming stoichiometric 2D boron oxide (BO) structures. By using first-principles global optimization, we systematically explore structures and properties of 2D BO systems with well-defined degrees of oxidation. Stable B-O-B and OB tetrahedron structure motifs are identified in these structures. Interesting properties, such as strong linear dichroism, Dirac node-line (DNL) semimetallicity, and negative differential resistance, have been predicted for these systems. Our results demonstrate that 2D BO represents a versatile platform for electronic structure engineering via tuning the stoichiometric degree of oxidation, which leads to various technological applications.

Ethanol–ethylene conversion mechanism on hydrogen boride sheets probed by in situ infrared absorption spectroscopy

“…5,6 2D materials comprising boron are considered to possess unique properties owing to the large number of theoretically predicted polymorphs. 7,8 Various 2D boron-containing compounds, including boron chalcogenides, 9 boron oxides, 10,11 boron hydrides, 12,13 and boron phosphides, 14 have also been theoretically predicted to have a large number of polymorphs. Depending on the structure, the bonding strengths of the boron materials with gas molecules are expected to be different, thereby leading to a wide variety of catalytic properties for 2D boron-related materials.…”

Thermodynamic stability of borophene, B2O3 and other B1−xOx sheets

“…6. No other points are on the convex hull and the structures with positive mixing energies represent thermodynamically unfavorable systems, which include honeycomb-like B O 2 [20,26] or other previously considered structures [27,36,37]. The gray diamonds in figure 2 lie above the convex hull.…”

“…These structures show the overall lowest mixing energies of all studied sheets (filled, gray diamonds in figure 2). We also added the energy of the structures studied by Zhang et al [36] and Lin et al [37] to figure 2 (purple symbols). Their mixing energy is significantly higher than the ones of the heterogeneous mixtures, indicating that they are thermodynamically unfavorable.…”

Inorganic Boron-Based Nanostructures: Synthesis, Optoelectronic Properties, and Prospective Applications

“…On the other hand, the 2D boron oxide (BO) structure is also proposed to be stable after experiencing a suitable stoichiometric degree of oxidation. Yang et al [66] studied the structural configurations of the 2D boron oxide sheet by using the first-principle global optimization method, suggesting that they have potential applications in high-speed nanoelectronic devices. Also, Zhang et al [67] investigated the physical properties of the hexagonal borophene oxide sheets in Wu’s work [59], revealing they should possess remarkable mechanical and electronic properties.…”