State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Qingdao 266580, Shandong, People's Republic of China. College of Science, China University of Petroleum, Qingdao 266580, Shandong, People's Republic of China.
Nanotechnology. 2017 Mar 1;28(13):135703. doi: 10.1088/1361-6528/aa5fae.
Development of low energy cost membranes for separating helium from natural gas is highly desired. Using van der Waals-corrected first-principles density functional theory (DFT) calculations, we theoretically investigate the helium separation performance of divacancy-defective germanene. The 555 777 divacancy-defective germanene presents a 0.53 eV energy barrier for helium, which is slightly larger than the energy threshold value of gas molecule penetration of a membrane (0.5 eV). Thus, the 555 777 divacancy-defective germanene is difficult for helium to permeate, except under high temperature or pressure. However, the 585 divacancy-defective germanene presents a surmountable energy barrier (0.27 eV) for helium, and it shows extremely high helium selectivities relative to other studied gas molecules. Especially, the He/Ne selectivity can be as high as 1 × 10 at room temperature. Together with the acceptable permeance for helium, the 585 divacancy-defective germanene can be used for helium separation with remarkably good performance.
开发用于从天然气中分离氦气的低能耗膜是非常需要的。使用经范德华修正的第一性原理密度泛函理论（DFT）计算，我们从理论上研究了双空位缺陷锗烯的氦气分离性能。555777 双空位缺陷锗烯对氦气的分离能垒为 0.53 eV，略大于膜中气体分子渗透的能量阈值（0.5 eV）。因此，除了在高温或高压下，555777 双空位缺陷锗烯很难让氦气渗透。然而，585 双空位缺陷锗烯对氦气具有可逾越的能量势垒（0.27 eV），并且相对于其他研究的气体分子表现出极高的氦气选择性。特别是，在室温下，He/Ne 的选择性可以高达 1×10。结合对氦气的可接受渗透性，585 双空位缺陷锗烯可用于具有优异性能的氦气分离。
