Adsorption and Desorption of U(VI) on Functionalized Graphene Oxides: A Combined Experimental and Theoretical Study

The adsorption and desorption of U(VI) on graphene oxides (GOs), carboxylated GOs (HOOC-GOs), and reduced GOs (rGOs) were investigated by batch experiments, EXAFS technique, and computational theoretical calculations. Isothermal adsorptions showed that the adsorption capacities of U(VI) were GOs > HOOC-GOs > rGOs, whereas the desorbed amounts of U(VI) were rGOs > GOs > HOOC-GOs by desorption kinetics. According to EXAFS analysis, inner-sphere surface complexation dominated the adsorption of U(VI) on GOs and HOOC-GOs at pH 4.0, whereas outer-sphere surface complexation of U(VI) on rGO was observed at pH 4.0, which was consistent with surface complexation modeling. Based on the theoretical calculations, the…

• NN
  National Natural Science Foundation of China

  Awards: 21207135, 91126020, 21225730, 21207136
• MO
  Ministry of Science and Technology of the People's Republic of China

  Award: 2011CB933700
• PA
  Priority Academic Program Development of Jiangsu Higher Education Institutions
• NS
  Natural Science Foundation of Anhui Province

  Award: 1408085MB28
• HS
  Hefei Science Center, Chinese Academy of Sciences

  Awards: 2015SRG-HSC006, 2015SRG-HSC009