• 文献标题:   pH-Dependent adsorption of aromatic compounds on graphene oxide: An experimental, molecular dynamics simulation and density functional theory investigation
  • 文献类型:   Article
  • 作  者:   TANG H, ZHANG SY, HUANG TL, CUI FY, XING BS
  • 作者关键词:   graphene oxide, aromatic compound, ph, molecular dynamics simulation, density functional theory
  • 出版物名称:   JOURNAL OF HAZARDOUS MATERIALS
  • ISSN:   0304-3894 EI 1873-3336
  • 通讯作者地址:   Xian Univ Architecture Technol
  • 被引频次:   2
  • DOI:   10.1016/j.jhazmat.2020.122680
  • 出版年:   2020

▎ 摘  要

This work provides a comprehensive understanding for the pH-dependent adsorption of aromatic compounds (ACs) on graphene oxide (GO). Isothermal and kinetics experiments indicated both adsorption capacity and adsorption rate were suppressed at higher pH, and the mechanisms were revealed by molecular dynamics simulations and density functional theory calculations. More specifically, pi-pi, hydrogen bond, vdWs, and water-mediated steric hindrance interactions were examined to reveal how pH affected the adsorption capacity, and microscopic dynamic adsorption process was captured to reveal how pH affected the adsorption rate. Results showed the reduced adsorption capacity at higher pH was mediated by increased electrostatic repulsion, weakened Tr-TC interaction, and increased water-mediated steric hindrance. The pH-dependent behaviour of GO was responsible for the effect of pH on adsorption rate. Self-aggregation of GO at lower pH helped to capture ACs and created more favourable adsorption sites. Upon the adsorption of ACs on GO, GO/water/AC/water/GO sandwich-like structure formed, which was also mediated by solution pH. Overall, pH affects the adsorption of ACs on GO by regulating driving forces, adsorption process, and the configuration property of GO-AC complex.