• 文献标题:   Molecular Mechanisms of CO2 Adsorption in Diamine-Cross-Linked Graphene Oxide
  • 文献类型:   Article
  • 作  者:   CAI JS, CHEN JE, ZENG PM, PANG ZF, KONG XQ
  • 作者关键词:  
  • 出版物名称:   CHEMISTRY OF MATERIALS
  • ISSN:   0897-4756 EI 1520-5002
  • 通讯作者地址:   Zhejiang Univ
  • 被引频次:   10
  • DOI:   10.1021/acs.chemmater.9b00688
  • 出版年:   2019

▎ 摘  要

Graphene oxides (GOs) are layered carbon materials composed of a mixture of oxygenated functional groups that can react with different molecules. Alkyl diamine molecules (ethylenediamine, butanediamine, or hexanediamine) can insert into the layers of GO and systematically expand its interlayer spacing from 0.762 nm to over 1.030 nm. In this work, we found that CO2 uptake maximizes at the interlayer spacing of 0.860 nm in GOs cross-linked by diamines. We characterized the subtle chemical and compositional differences among samples by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and solid-state NMR. In situ C-13 NMR was applied at variable temperatures to investigate the adsorption mechanisms of CO2, which revealed both physically and chemically adsorbed CO2 in diamine-cross-linked GO matrices. In particular, we observed the unique state of CO2 that are physically trapped in GO layers with 0.860 nm spacing by van der Waals interactions. This state of CO2 was not observed in GOs with either smaller or larger interlayer spacings.