▎ 摘　　要

The chelating groups N- ( trimethoxysilylpropyl ) ethylenediamine triacetic acid ( EDTA-silane ) were linked to graphene oxide ( GO ) surfaces through a silanization reaction, and this modified GO ( GO-EDTA ) was used to remove the heavy metal in the solution. By using molecular dynamics simulation at the molecular level, the absorption distribution, dynamic properties of Pb2+ on the GO-EDTA surface were investigated, the different absorption behaviors of Pb2+ and Na+ between GO and GO-EDTA systems were compared. At the same time, the interaction between GO-EDTA and Ca2+ was simulated, which was comparable to the adsorption behavior of Pb2+. The simulation result shows that: ( 1 ) the adsorption sites of Pb2+ and Na+ are the carboxyl groups in the GO. EDTA system, rather than the hydroxyl groups on graphene oxide surface; ( 2 ) the absorption conformations of Pb2+ and Na+ to carboxyl groups are different. For Pb2+ ions, they form the 2 : 1 type with carboxyl group, i. e. one Pb2+ ion combines with two carboxyl groups; while for Na+ ions, it is the 1 : 1 type, i. e. one Na+ ion combines with one carboxyl group; ( 3 ) comparison with Ca2+ and Na+ ion, the energy barrier of forming COO--Pb2+ ion pair conformation is lowest while the energy barrier to break this con. formation is higher. This result indicates that the Pb2+ ions are adsorbed well on GO and GO-EDTA films.