He Xiang, Walter Michael, Jiang De-En
Department of Chemistry, University of California, Riverside, CA, 92521, USA.
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, Jiangsu, 210008, China.
Small. 2021 Jul;17(27):e2004808. doi: 10.1002/smll.202004808. Epub 2021 Jan 15.
Bulk Ag hydrides are extremely challenging to make even at very high pressures, but they may become stable as the particle size shrinks to the nanometer regime. Here, the formation and electronic structure of Ag nanohydrides are investigated from a superatomic perspective by density functional theory. It is found that as the coverage increases, adsorption energy of hydrogen atoms on Ag cluster to form Ag H nanohydride (n is from 1 to 15) can be energetically favorable with respect to bare Ag and H . Furthermore, the adsorbed hydrogen atoms contribute their 1s electrons to the superatom electron count and behave as a metal instead of a ligand. The electronic structure of the silver nanohydrides follows the superatomic complex model, leading to magic or relatively more stable compositions such as Ag H , Ag H , and Ag H , which correspond to 40-electron, 58-electron, and 68-electron shell closings, respectively. Angular momentum analyses of the superatomic orbitals suggest a convoluted interaction of geometry, symmetry, and orbital splitting.
即使在非常高的压力下，块状银氢化物的制备也极具挑战性，但随着粒径缩小到纳米尺度，它们可能会变得稳定。在此，通过密度泛函理论从超原子角度研究了银纳米氢化物的形成和电子结构。研究发现，随着覆盖率的增加，相对于裸银和氢原子，氢原子在银团簇上吸附形成银纳米氢化物（n为1至15）在能量上是有利的。此外，吸附的氢原子将其1s电子贡献给超原子电子数，并表现为金属而非配体。银纳米氢化物的电子结构遵循超原子复合模型，导致出现如AgH₈、AgH₁₄和AgH₁₅等具有神奇或相对更稳定组成的结构，它们分别对应于40电子、58电子和68电子的壳层闭合。对超原子轨道的角动量分析表明，几何结构、对称性和轨道分裂之间存在复杂的相互作用。
