Li修饰的Si6C14和Si8C12纳米笼作为有前景的储氢介质的可行性：一项计算研究
Feasibility of Li decorated Si6C14 and Si8C12 nanocages as promising hydrogen storage media: A computational study
AI总结：
本文利用DFT计算研究了Li修饰的Si6C14和Si8C12纳米笼的储氢性能，发现其储氢质量密度分别达13.73 wt%和9.08 wt%，且在300K下可逆解吸，优于US-DOE目标，是有前景的储氢介质。
摘要：
本文利用密度泛函理论（DFT）研究了Li修饰的Si6C14和Si8C12的可逆储氢容量。通过HOMO-LUMO能隙以及化学硬度和亲电性指数等多种整体反应性描述符，研究了所设计的Si6C14Li6和Si8C12Li4纳米笼的化学稳定性。我们的研究表明，修饰在所设计的Si6C14和Si8C12纳米笼上的每个Li原子最多可吸附5个H2分子，吸附能处于0.14-0.085 eV的最佳范围内，从而分别产生13.8%和9.2%的总质量密度。研究发现，吸附的H2分子与Li金属位点之间的相互作用是通过非共价和闭壳型相互作用发生的。H2分子以准分子形式被吸附，且键长略有伸长。分子动力学研究表明，在300K下，大多数H2分子从所设计的主纳米笼中解吸，而未引起任何显著的结构变化，这证实了它们的可逆性。当吸附和解吸条件分别设定为100K/60bar和240K/1bar时，Si6C14Li6和Si8C12Li4笼的实际储氢质量密度估计分别为13.73 wt%和9.08 wt%，与US-DOE（美国能源部）到2020年设定的5.5 wt%的目标相比相对较高。因此，通过计算设计的Si6C14Li6和Si8C12Li4纳米笼可被视为储氢应用领域的潜在系统。
英文摘要：
This article presents the reversible hydrogen storage capacities of Li-decorated Si6C14 and Si8C12 using Density Functional Theory (DFT). The chemical stabilities of the designed Si6C14Li6 and Si8C12Li4 nanocages are investigated using HOMO-LUMO gaps and various global reactivity descriptors such as chemical hardness and electrophilicity index. Our study reveals that each Li atom decorated over the designed Si6C14 and Si8C12 nanocages can hold up to 5H2 molecules with adsorption energy lying in the optimum range of 0.14-0.085 eV, thereby yielding an overall gravimetric density of 13.8% and 9.2% respectively. The interaction between adsorbed H2 molecules and the Li metal sites is found to occur via non-covalent and closed shell type of interaction. The H2 molecules are adsorbed in a quasi-molecular fashion with elongated bond length. The molecular dynamics study reveals that most of the H2 molecules get desorbed from the designed host nanocages at 300K without causing any significant structural changes, which confirms their reversibility. When the adsorption and desorption conditions are set at 100K/60bar and 240K/1bar respectively, the practical storage gravimetric densities of Si6C14Li6 and Si8C12Li4 cages are estimated to be 13.73 wt% and 9.08 wt%, which are relatively high in comparison to the US-DOE target of 5.5 wt% by the year 2020. Hence, the computationally designed Si6C14Li6 and Si8C12Li4 nanocages can be regarded as prospective systems for hydrogen storage applications.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
