Hydrogen physisorption channel on graphene: a highway for atomic H diffusion
Hydrogen physisorption channel on graphene: a highway for atomic H diffusion
复制标题
石墨烯上的氢物理吸附通道：原子氢扩散的高速公路
作者：
H. González;E. Cortés;P. Mallet;J. Veuillen;J. J. Palacios;J. Gómez‐Rodríguez;I. Brihuega;F. Yndurain
我们通过结合扫描隧道显微镜实验和第一原理计算来研究原子氢在石墨烯上的吸附。我们的结果揭示了石墨烯层上存在物理吸附通道，该通道由范德华力主导，因此在整个原子晶格中是均匀的，原子氢可以在其中自由移动。这种物理吸附通道对于理解化学吸附在石墨烯上的氢原子的最终构型至关重要。我们发现，即使在低温 (140 K) 下沉积的浓度非常稀 (<0.1%)，约 95% 的化学吸附氢原子也会形成非磁性二聚体。我们的数据表明，这种情况适用于 SiC(0 0 0 − 1)、SiC(0 0 0 1) 和石墨上的单层到多层石墨烯。
We study the adsorption of atomic hydrogen on graphene by combining scanning tunneling microscopy experiments and first principle calculations. Our results reveal the existence of a physisorption channel over the graphene layer, dominated by van der Waals forces and thus homogeneous over the whole atomic lattice, where atomic hydrogen can move freely. Such physisorption channel is essential to understand the final configuration of hydrogen atoms chemisorbed on graphene. We find that ~95% of chemisorbed H atoms form non-magnetic dimers even for very dilute concentrations (<0.1%) deposited at low temperatures (140 K). Our data shows that this scenario holds from mono to multilayers graphene on SiC(0 0 0 − 1), SiC(0 0 0 1) and graphite.