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.