• 文献标题:   Study on the Migration and Transformation Mechanism of Graphene Oxide in Aqueous Solutions
  • 文献类型:   Article
  • 作  者:   SHI L, PANG HW, WANG XX, ZHANG P, YU SJ
  • 作者关键词:   graphene oxide, coagulation, cation, anion, clay mineral
  • 出版物名称:   ACTA CHIMICA SINICA
  • ISSN:   0567-7351
  • 通讯作者地址:   North China Elect Power Univ
  • 被引频次:   1
  • DOI:   10.6023/A19070276
  • 出版年:   2019

▎ 摘  要

Graphene oxide (GO) is widely used in energy chemical, environmental restoration, nanomaterials, liquid phase catalysis, etc. due to its excellent physical and chemical properties. At the same time, GO is inevitably discharged into nature during the application process, and the toxicity released into the environment may lead to instability of the biological sy stem. Therefore, this paper systematically studied several common cations (Na+, K+, Ca2+, Mg2+), anions (PO43-,SO42-,CO32-, HCO3-,Cl-) and clay minerals (montmorillonite, kaolin, bentonite, nano-alumina) on GO coagulation at different concentrations. And FTIR is used to characterize the clay minerals before and after the precipitation of GO. The experimental results show that the cations have strong GO coagulation ability, and the coagulation ability of different valence cations has a large difference. After analysis, the electrical properties of GO in aqueous solution are negative, the cation acts as a counter ion, and the coagulation behavior conforms to the Schulze-Hardy rule. The main reason for the difference in coagulation ability between isovalent cations is electronegativity and ionic hydration. The anion acts to increase the stability of GO, and the coagulation ability of the cation is more effective than the stabilization ability of the anion. The ability of sodium salts with the same valence anion to coagulate GO also differs, mainly because the hydrolysis of HCO3- and CO32- causes a decrease in the negative charges, resulting in a decrease in the ability to stabilize GO. The clay minerals contain hydroxyl and metal-oxygen bonds that interact with GO. According to the maximum removal rate, the clay minerals have the coagulation ability: nano-alumina >kaolin>bentonite>montmorillonite. The main influencing factors are the electrical properties of clay minerals in aqueous solution. This paper is helpful to understand the coagulation behavior of GO in different water environments, and it is of great significance for the future application of graphene engineering in pollution control.