Direct Chemical Vapor Deposition Synthesis of Porous Single‐Layer Graphene Membranes with High Gas Permeances and Selectivities
Direct Chemical Vapor Deposition Synthesis of Porous Single‐Layer Graphene Membranes with High Gas Permeances and Selectivities
复制标题
直接化学气相沉积法制备高透气性和高选择性多孔单层石墨烯膜
DOI：
10.1002/adma.202104308
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发表时间：
2021-09
影响因子：
29.4
通讯作者：
Zhe Yuan;Guangwei He;S. Faucher;Matthias Kuehne;S. Li;D. Blankschtein;M. Strano
中科院分区：
文献类型：
--
作者：
Zhe Yuan;Guangwei He;S. Faucher;Matthias Kuehne;S. Li;D. Blankschtein;M. Strano
含有分子大小的面内孔的单层石墨烯由于其原子厚度和低气体传输阻力而被认为是用于高性能气体分离的有前途的膜材料。然而，典型的基于蚀刻的孔生成方法不能解耦孔成核和孔生长，导致高面孔密度和高选择性之间的权衡。相比之下，在化学气相沉积期间形成的石墨烯中的固有孔不是通过蚀刻产生的。因此，本质上多孔的石墨烯可以表现出高的孔密度，同时保持其气体选择性。在这项工作中，首次系统地控制了固有石墨烯孔的密度，同时精确地保持了用于气体筛分的适当孔径。因此，通过控制生长温度、前体浓度和石墨烯表面的非共价修饰，制造了具有迄今为止记录的最高H2/CH 4分离性能（H2渗透性> 4000 GPU和H2/CH 4选择性> 2000）的单层石墨烯膜。此外，研究发现，在实验条件下，气体分离过程中石墨烯表面的纳米级分子结垢（其中石墨烯孔在实验条件下被碳氢化合物污染物部分堵塞）控制了选择性和温度依赖性渗透率。总的来说，多孔单层石墨烯的直接合成利用了其作为高性能气体筛分膜的巨大潜力。
Single‐layer graphene containing molecular‐sized in‐plane pores is regarded as a promising membrane material for high‐performance gas separations due to its atomic thickness and low gas transport resistance. However, typical etching‐based pore generation methods cannot decouple pore nucleation and pore growth, resulting in a trade‐off between high areal pore density and high selectivity. In contrast, intrinsic pores in graphene formed during chemical vapor deposition are not created by etching. Therefore, intrinsically porous graphene can exhibit high pore density while maintaining its gas selectivity. In this work, the density of intrinsic graphene pores is systematically controlled for the first time, while appropriate pore sizes for gas sieving are precisely maintained. As a result, single‐layer graphene membranes with the highest H2/CH4 separation performances recorded to date (H2 permeance > 4000 GPU and H2/CH4 selectivity > 2000) are fabricated by manipulating growth temperature, precursor concentration, and non‐covalent decoration of the graphene surface. Moreover, it is identified that nanoscale molecular fouling of the graphene surface during gas separation where graphene pores are partially blocked by hydrocarbon contaminants under experimental conditions, controls both selectivity and temperature dependent permeance. Overall, the direct synthesis of porous single‐layer graphene exploits its tremendous potential as high‐performance gas‐sieving membranes.