Dept of Materials Science and Engineering, Hanyang University, Seoul 133-791, Korea.
Phys Chem Chem Phys. 2013 Mar 7;15(9):3243-8. doi: 10.1039/c2cp44231k. Epub 2013 Jan 24.
In this article, the imposition of an external electric field is proposed as an effective means to improve the hydrogen storage properties of a promising medium. To demonstrate the feasibility of this concept, the geometric stability and hydrogen capacity of Li functionalized N-doped graphene were investigated in the presence of an electric field using density functional theory (DFT) calculations. For Li decorated pristine and graphitic structures, the binding energy of the Li atom on the surface sheets exceeded the cohesive energy of the Li metal bulk under a positive electric field. From these results, Li adatom dispersion with atomic accuracy is expected for these two unstable structures. Furthermore, the hydrogen adsorption behavior of the pyridinic and pyrrolic structures was changed by the applied electric field in the range of 0.14-0.27 eV. It is therefore anticipated that the adsorption and desorption processes can be easily controlled using suitable field strength and direction.
在本文中，我们提出在外加电场的作用下，可以有效提高有前途的储氢材料的储氢性能。为了验证这一概念的可行性，我们使用密度泛函理论（DFT）计算研究了电场存在时，Li 功能化 N 掺杂石墨烯的几何稳定性和储氢能力。对于 Li 修饰的原始和石墨结构，Li 原子在表面片上的结合能在正电场下超过 Li 金属体的内聚能。根据这些结果，对于这两种不稳定的结构，Li adatoms 可以以原子精度分散。此外，施加的电场改变了吡啶和吡咯结构的氢吸附行为，在 0.14-0.27 eV 的范围内。因此，预计可以通过适当的场强和方向来轻松控制吸附和解吸过程。
