Liu Jiaman, Jin Lei, Allen Frances I, Gao Yang, Ci Penghong, Kang Feiyu, Wu Junqiao
Environmental Science and New Energy Technology Engineering Laboratory, Shenzhen Geim Graphene Center (SGGC), and Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen 518055, China.
Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States.
Nano Lett. 2021 Mar 10;21(5):2183-2190. doi: 10.1021/acs.nanolett.0c04989. Epub 2021 Mar 1.
Defective graphene holds great potential to enable the permeation of gas molecules at high rates with high selectivity due to its one-atom thickness and resultant atomically small pores at the defect sites. However, precise control and tuning of the size and density of the defects remain challenging. In this work, we introduce atomic-scale defects into bilayer graphene via a decoupled strategy of defect nucleation using helium ion irradiation followed by defect expansion using hydrogen plasma treatment. The cotreated membranes exhibit high permeability and simultaneously high selectivity compared to those singly treated by ion irradiation or hydrogen plasma only. High permeation selectivity values for H/N and H/CH of 495 and 877, respectively, are achieved for optimally cotreated membranes. The method presented can also be scaled up to prepare large-area membranes for gas separation, e.g. for hydrogen purification and recovery from H/CH and H/N mixtures.
由于其单原子厚度以及缺陷部位产生的原子级小孔，有缺陷的石墨烯具有使气体分子以高选择性高速渗透的巨大潜力。然而，对缺陷尺寸和密度的精确控制和调节仍然具有挑战性。在这项工作中，我们通过使用氦离子辐照进行缺陷成核、随后使用氢等离子体处理进行缺陷扩展的解耦策略，将原子级缺陷引入双层石墨烯中。与仅通过离子辐照或氢等离子体单独处理的膜相比，协同处理的膜表现出高渗透性和同时高选择性。对于最佳协同处理的膜，H/N和H/CH的高渗透选择性值分别达到495和877。所提出的方法还可以扩大规模以制备用于气体分离的大面积膜，例如用于从H/CH和H/N混合物中纯化和回收氢气。
