Oxidation of a two-dimensional hexagonal boron nitride monolayer: a first-principles study.
Oxidation of a two-dimensional hexagonal boron nitride monolayer: a first-principles study.
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DOI：
10.1039/c2cp40081b
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发表时间：
2012-03
期刊：
影响因子：
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通讯作者：
Yu Zhao;Xiaojun Wu;Jinlong Yang;X. Zeng
中科院分区：
文献类型：
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作者：
Yu Zhao;Xiaojun Wu;Jinlong Yang;X. Zeng
二维 (2D) 六方氮化硼氧化物 (h-BNO) 是氧化石墨烯的结构类似物。受最近氧化石墨烯实验研究的启发，我们研究了二维 h-BN 片的化学氧化以及 h-BNO 的相关电子特性。特别强调了原子氧化学吸附的最有利位点，氧原子跳跃到 h-BN 表面顶部、桥或中空位点的迁移势垒，以及氧分子在 h-BN 表面解离的最可能途径。我们发现，当氧原子在 h-BN 表面迁移时，它最有可能在 N 原子上方，但受到三个相邻 B 原子的限制（形成三角环）。一般来说，氧原子的化学吸附会拉伸B-N键，在某些条件下甚至可能破坏B-N键。根据第一个化学吸附 O 原子的初始位置，随后的氧化往往会在 h-BN 片上形成 O 结构域或 O 链。后者可能导致一种沿锯齿形方向解开 h-BN 片材的合成策略。更好地了解 h-BN 片材的氧化对于调整 h-BN 片材的应用性能具有重要意义。
Two-dimensional (2D) hexagonal boron-nitride oxide (h-BNO) is a structural analogue of graphene oxide. Motivated by recent experimental studies of graphene oxide, we have investigated the chemical oxidation of 2D h-BN sheet and the associated electronic properties of h-BNO. Particular emphasis has been placed on the most favorable site(s) for chemisorption of atomic oxygen, and on the migration barrier for an oxygen atom hopping to the top, bridge, or hollow site on the h-BN surface, as well as the most likely pathway for the dissociation of an oxygen molecule on the h-BN surface. We find that when an oxygen atom migrates on the h-BN surface, it is most likely to be over an N atom, but confined by three neighbor B atoms (forming a triangle ring). In general, chemisorption of an oxygen atom will stretch the B-N bond, and under certain conditions may even break the B-N bond. Depending on the initial location of the first chemisorbed O atom, subsequent oxidation tends to form an O domain or O chain on the h-BN sheet. The latter may lead to a synthetic strategy for the unzipping of the h-BN sheet along a zigzag direction. A better understanding of the oxidation of h-BN sheet has important implications for tailoring the properties of the h-BN sheet for applications.