部分氢化法制备“窄”石墨烯纳米带

1D finite-width graphene nanoribbon systems: alkalization and hydrogenation

Graphene is the first truly two-dimensional (2D) material, possessing a cone-like energy spectrum near the Fermi energy and treated as a gapless semiconductor. Its unique properties trigger researchers to find more applications of it, such as high carrier mobility at room temperature, superior thermoconductivity, high modulus and tensile strength, high transparency, and anomalous quantum Hall effect. However, the gapless feature limits the development of graphene nanoelectronics. Making one-dimensional (1D) strips of graphene (i.e., graphene nanoribbons (GNRs)) could be one of the most promisi…

Electronic and Magnetic Properties of Pristine and Hydrogenated Borophene Nanoribbons

The groundbreaking works in graphene and graphene nanoribbons (GNRs) over the past decade, and the recent discovery of borophene draw immediate attention to the underexplored borophene nanoribbons (BNRs). We herein report a density functional theory (DFT) study of the geometric, electronic and magnetic properties of BNRs as a function of orientation (denoted as BxNRs and ByNRs with the orientation along x- and y-axis, respectively), ribbon width (Nx, Ny = 4 to 15), and hydrogenation effects. We found that the anisotropic quasi-planar geometric structure of BNRand its edge states profoundly gov…

锯齿形边缘硼碳氮纳米带的本征巨斯塔克效应

Intrinsic giant Stark effect of boron-carbon-nitride nanoribbons with zigzag edges

采用第一性原理计算研究了锯齿形硼碳氮（BCN）纳米带的电子性质，其中石墨烯纳米带边缘最外层的C原子被B或N原子取代.我们发现，BCN纳米带是金属，因为几个带交叉的费米能级。对于BCN纳米带在一个丰富的H $_2$的环境中，所谓的近自由电子状态出现在费米能级以上，因为固有的巨斯塔克效应，由于内部电场的横向偶极矩。近自由电子态的位置可以通过施加平行于偶极矩的电场来控制。氮原子的氢化是BCN纳米带中巨斯塔克效应出现的必要条件。我们还讨论了双层BCN纳米带中堆积顺序对本征巨斯塔克效应的影响。

Circumventing the Stability Problems of Graphene Nanoribbon Zigzag Edges

Carbon nanostructures with zigzag edges exhibit unique properties with exciting potential applications. Such nanostructures are generally synthesized under vacuum because their zigzag edges are unstable under ambient conditions: a barrier that must be surmounted to achieve their scalable exploitation. Here, we prove the viability of chemical protection/deprotection strategies for this aim, demonstrated on labile chiral graphene nanoribbons (chGNRs). Upon hydrogenation, the chGNRs survive an exposure to air, after which they are easily converted back to their original structure via annealing. W…

二氧化硅上石墨烷中的自旋不对称石墨烯纳米带

Spin-asymmetric graphene nanoribbons in graphane on silicon dioxide

采用从头计算方法研究了氧化硅衬底上氢化石墨烯（graphane）的结构。发现仅在石墨烯层的一侧上具有氢化的结构是稳定的，并且给出了其氢构型。此外，我们通过从外延石墨烷层选择性地去除氢来形成锯齿形石墨烯纳米带。在这些带中，独立的反铁磁锯齿形带的自旋简并被打破，不同大小的带隙出现相反的自旋物种。这种简并断裂是由于带下方的衬底中的电荷不平衡，其通过衬底原子相对于石墨烯带的边缘的不对称对准而引入。

Hydrogen Atoms on Zigzag Graphene Nanoribbons: Chemistry and Magnetism Meet at the Edge

Although the unconventional $π$-magnetism at the zigzag edges of graphene holds promise for a wide array of applications, whether and to what degree it plays a role in their chemistry remains poorly understood. Here, we investigate the addition of a hydrogen atom $-$ the simplest yet the most experimentally relevant adsorbate $-$ to zigzag graphene nanoribbons (ZGNRs). We show that the $π$-magnetism governs the chemistry of ZGNRs, giving rise to a site-dependent reactivity of the carbon atoms and driving the hydrogenation process to the nanoribbon edges. Conversely, the chemisorbed hydrogen at…