CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics and National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing, 100049, China.
Nanoscale. 2011 Nov;3(11):4824-9. doi: 10.1039/c1nr10741k. Epub 2011 Oct 14.
Through first-principles calculations, we found doping carbon atoms onto BN monolayers (BNC) could significantly strengthen the Li bond on this material. Unlike the weak bond strength between Li atoms and the pristine BN layer, it is observed that Li atoms are strongly hybridized and donate their electrons to the doped substrate, which is responsible for the enhanced binding energy. Li adsorbed on the BNC layer can serve as a high-capacity hydrogen storage medium, without forming clusters, which can be recycled at room temperature. Eight polarized H(2) molecules are attached to two Li atoms with an optimal binding energy of 0.16-0.28 eV/H(2), which results from the electrostatic interaction of the polarized charge of hydrogen molecules with the electric field induced by positive Li atoms. This practical carbon-tuned BN-Li complex can work as a very high-capacity hydrogen storage medium with a gravimetric density of hydrogen of 12.2 wt%, which is much higher than the gravimetric goal of 5.5 wt % hydrogen set by the U.S. Department of Energy for 2015.
通过第一性原理计算，我们发现将碳原子掺杂到 BN 单层（BNC）中可以显著增强该材料上的 Li 键。与 Li 原子和原始 BN 层之间较弱的键强度不同，我们观察到 Li 原子强烈杂化并将其电子贡献给掺杂的衬底，这是增强结合能的原因。吸附在 BNC 层上的 Li 可以作为一种高容量的储氢介质，而不会形成团簇，并且可以在室温下回收。八个极化的 H(2)分子附着在两个 Li 原子上，最佳结合能为 0.16-0.28 eV/H(2)，这是由氢分子的极化电荷与正 Li 原子诱导的电场之间的静电相互作用产生的。这种实际的碳调 BN-Li 配合物可以作为一种非常高容量的储氢介质，其氢的重量密度为 12.2wt%，远高于美国能源部为 2015 年设定的 5.5wt%氢的重量目标。
