Yoon Hee Wook, Lee Tae Hoon, Doherty Cara M, Choi Tae Hwan, Roh Ji Soo, Kim Hyo Won, Cho Young Hoon, Do Si-Hyun, Freeman Benny D, Park Ho Bum
Department of Energy Engineering, Hanyang University, Seoul 04763, Republic of Korea.
McKetta Department of Chemical Engineering, University of Texas at Austin, 200 East Dean Keeton Street Stop C0400, Austin, Texas 78712, United States.
J Phys Chem Lett. 2020 Mar 19;11(6):2356-2362. doi: 10.1021/acs.jpclett.0c00204. Epub 2020 Mar 10.
Graphene oxide (GO) is a promising 2D material for adsorbents and membranes, in particular, for the CO separation process. However, CO diffusion and sorption in GO and its layered structures are still not well understood because of its heterogeneous structure. Here we report CO sorption in GO and its derivatives (e.g., reduced GO (rGO)) in powders and films. These CO sorption behaviors reveal that GO is highly CO-philic via complex CO-functional-group-surface interactions, as compared with graphite and rGOs. Even in highly interlocked, lamellar GO films, CO molecules above a certain threshold pressure can diffuse into GO interlayers, causing GO films to swell and leading to dramatic increases in CO sorption. Intercalated water in GO interlayers can be removed by preferential CO sorption without any changes in the GO chemical structure. This finding helps to explain the origin of CO affinity with GO and has implications for preparing anhydrous GO assemblies for various applications.
氧化石墨烯（GO）是一种很有前景的二维材料，可用于吸附剂和膜，特别是用于CO分离过程。然而，由于其结构的不均匀性，CO在GO及其层状结构中的扩散和吸附仍未得到很好的理解。在此，我们报告了粉末和薄膜形式的GO及其衍生物（如还原氧化石墨烯（rGO））对CO的吸附情况。这些CO吸附行为表明，与石墨和rGO相比，GO通过复杂的CO-官能团-表面相互作用对CO具有高度亲合性。即使在高度互锁的层状GO薄膜中，高于一定阈值压力的CO分子也能扩散到GO层间，导致GO薄膜膨胀，并使CO吸附量急剧增加。GO层间的插层水可通过优先吸附CO而去除，且GO的化学结构不会发生任何变化。这一发现有助于解释CO与GO之间亲和力的来源，并对制备用于各种应用的无水GO组件具有启示意义。
