DFT Insights into the Interfacial Chemical Behavior of Hybrid LDH/GO Nanocomposites

Hybrid layered double hydroxides (LDHs)/graphene oxide (GO) nanocomposites are novel two-dimensional (2-D) materials applied in extensive fields, which take advantages of the synergistic effect of LDH and GO at the composite interface. However, the interfacial interaction mechanism determining the LDH/GO nanocomposite properties still remains to be explored. Herein, we used density functional theory to comprehensively illustrate interfacial interactions, as well as structural and electronic properties of Mg/Al LDH/GO nanocomposites. Our results, for the first time, reveal that there exists unique water-generated chemical interaction during the LDH/GO combining process. The generated interfacial water molecules play a key role in maintaining the nanocomposites by forming complicated and diverse interfacial hydrogen bond structures. Moreover, the transfer of the hydrogen atom from LDH to the epoxy group resulting in hydroxyl was also observed. The results provide hints for interpreting previous experimental observations. There is interfacial charge transfer from LDH to GO and water molecules. The electrical properties of the LDH component in the composite can be modulated by properly varying the epoxy/ hydroxyl ratio on GO. The current results might prove to be instrumental in the design of 2-D heterostructural LDH/GO composites.