Density functional theory study of water splitting on ZnO catalyst adsorbed on Graphene Oxide

We discuss results from density functional theory (DFT) calculations of water splitting on ZnO surfaces using the hybrid B3LYP exchange functional and the 6-311G basis sets. The production of H₂ and O₂ occurs through the formation of a Zn-H bond generated from the hydrolyzed product of ZnO. We discuss the Transition state of the reaction using the Synchronous Transit-Guided Quasi-Newton (STQN) method following calculations of the Intrinsic Reaction Coordinate (IRC) using the same level of theory. We discuss an extension of our work using RB3LYP/DGDZVP method for water splitting on ZnO adsorbed on graphene oxide (GO) surface (GO-ZnO) which forms a p-n hetero junction enhancing the rate of H₂ evolution as it does for a GO-TiO₂. GO sheet can facilitate exciton formation and acts as an electron sink to store the separated electrons. Hydrogen production was observed on the GO-ZnO surface using five different GO models.