Adsorption of H2O Molecules Mechanism on Graphene-Like ZnO Monolayer with Promoted Humidity Sensing Performance

Density functional calculations have been used to investigate the structure and energies of water adsorbed on the graphene-like zinc oxide monolayer (g-ZnO) in its pristine and defected configuration. The most stable adsorption configuration, charge transfer, and adsorption energy theoretically predicted the improvement on humidity sensing performance. Both adsorption energy and charge transfer of g-ZnO exhibit strong dependency on its structure change and molecule adsorption. It is observed that the H₂O molecule is weakly adsorbed on the g-ZnO surface and act as charge acceptors for pristine g-ZnO system. However, it is strongly expose adsorption of H₂O on the monolayer ZnO when introducing a Zn vacancy in the system. The partial density of states (PDOS) upon different configurations performed to analyze water molecule adsorption mechanism. This improved adsorption energy of H₂O on monolayer ZnO could help in realizing the physical properties and chemical activity of g-ZnO for H₂O capture.