Adsorption and Catalytic Activation of O2 Molecule on the Surface of Au-Doped Graphene under an External Electric Field

Abstract

The interaction between oxygen molecule (O2) and metal-doped graphene has always been a heated discussed issue because O2 plays an important role in the graphene-based gas-storage materials, sensing platforms, and catalysts. In this article, the effect of an external electric field on the interaction between O2 and Au-doped graphene is studied using density-functional theory (DFT) calculations. The simulations show that O2 vertically moves away from Au-doped graphene substrate under a positive electric field, whereas under a negative electric field, accompanied by the vertical pushing out movement, O2 also moves toward the specific Au atom horizontally. Besides, the adsorption energy (Ead) of O2 is dramatically changed with electric field. A negative electric field strengthens the interaction between O2 and Au-doped graphene substrate, resulting in an enhanced Ead; the corresponding O–O distance (dO–O) is also elongated, while Ead is decreased and dO–O is shortened under a positive electric field. Because dO–O of the adsorbed O2 correlates with its catalytic activation, the findings can provide a new avenue to tune the O2 adsorption process onto Au-doped graphene substrate and may be useful in the future applications of graphene-based nanocatalyst.