西北大学Mark C. Hersam团队报道了通过硼烯氢化合成硼烯晶型物。 相关研究成果发表在2021年3月12日出版的《科学》。

合成的二维多晶型硼或硼酚由于其各向异性的金属丰度、相关的电子现象和多样的超晶格结构而备受关注。虽然硼酚的异质结构已经理解，但硼酚的有序化学改性尚未见报道。

在超高真空条件下，利用原子氢对硼烯进行氢化反应合成“硼烷”多晶型物。通过原子尺度成像，光谱学和第一性原理计算，最普遍的硼烷多晶型物显示出具有两个中心的双电子硼氢键和三个中心的两个电子硼氢硼键的组合。

硼烷多晶型物是具有修饰的局部功函数的金属，并且可以通过氢的热脱附而可逆地返回到原始的硼酚。因为在环境暴露后硼酚的氧化率会降低两个数量级以上，因此氢化还提供化学钝化。

附：英文原文

Title: Synthesis of borophane polymorphs through hydrogenation of borophene

Author: Qiucheng Li, Venkata Surya Chaitanya Kolluru, Matthew S. Rahn, Eric Schwenker, Shaowei Li, Richard G. Hennig, Pierre Darancet, Maria K. Y. Chan, Mark C. Hersam

Issue&Volume: 2021/03/12

Abstract: Synthetic two-dimensional polymorphs of boron, or borophene, have attracted attention because of their anisotropic metallicity, correlated-electron phenomena, and diverse superlattice structures. Although borophene heterostructures have been realized, ordered chemical modification of borophene has not yet been reported. Here, we synthesize “borophane” polymorphs by hydrogenating borophene with atomic hydrogen in ultrahigh vacuum. Through atomic-scale imaging, spectroscopy, and first-principles calculations, the most prevalent borophane polymorph is shown to possess a combination of two-center–two-electron boron-hydrogen and three-center–two-electron boron-hydrogen-boron bonds. Borophane polymorphs are metallic with modified local work functions and can be reversibly returned to pristine borophene through thermal desorption of hydrogen. Hydrogenation also provides chemical passivation because borophane reduces oxidation rates by more than two orders of magnitude after ambient exposure.

DOI: 10.1126/science.abg1874

Source: https://science.sciencemag.org/content/371/6534/1143