Electronic and structural properties of ZnO, Fe₂O₃, and Al₂O₃ clusters interacted with graphene oxide: a combined DFT and experimental study

Abstract

The work uses Density Functional Theory (DFT) with the B3LYP/LANL2DZ method to study the electronic and structural characteristics of Graphene Oxide (GrO) combined with ZnO, Fe₂O₃, and Al₂O₃. The research examines how GrO anchoring sites, including hydroxyl (-OH), epoxy (-O), and carboxyl (-COOH) groups, affect the performance of these composite materials. The results show that the hydroxyl site creates the largest conductivity improvement because it decreases the energy gap of GrO from 2.7606 eV to 0.3894 eV in the iron oxide hybrid. The Total Dipole Moments (TDM) of molecules with epoxy (O) interactions reach 8.7375 Debye, which indicates that those molecules have greater chemical sensing sensitivity. For studying the surface and stability of the model molecules, both the Molecular Electrostatic Potential, MESP, and QTAIM are calculated. Both quantities are considered complex and site -dependent electronic behavior; applying these calculations can indeed tune the electronic structure by picking specific functional groups. The research demonstrates that the physical integration of metal oxides with graphene oxide results in the formation of a composite material with enhanced properties, as the experimental data (confirmed by spectroscopic and microscopic analyses) align with the theoretical predictions derived from computational modeling. Results dedicated the studied models and/or materials for sensors and electrodes, as well as for catalytic work.