Molecular dynamics study at N₂/H₂O-rGO interfaces for nitrogen reduction reaction

It is an emerging trend to develop synthetic ammonia via nitrogen reduction reaction(NRR) by using simple, economical and efficient catalysts under mild conditions. Due to the intrinsic rich-functional groups of the surface, its versatile tailorability and the true stability among all the two-dimensional materials, reduced graphene oxide (rGO) is drawing a rising attention of researchers to the NRR application. However, due to the hydrophobicity of C and hydrophilicity of oxygen-containing groups of rGO, the interface dynamics between rGO surface and N₂ and H₂O molecules, which are two basic precursors for catalytic NRR are still unclear up to date. Herein, we propose to explore this problem by constructing a hierarchical model for rGO-N₂/H₂O interface interaction and conducting molecular dynamics (MD) simulation at ambient conditions. We find a way to tune the function groups to maximize the adsorption of N₂ and H₂O molecules at the same time. H₂O molecules are more likely to form hydrogen bonds with oxygen-containing groups of rGO in the near range. While in the remote region, N₂ molecules tend to form non-bonding interactions with pure C atoms without oxygen-containing groups of rGO. These results will provide theoretical guidance for NRR based on rGO and rGO based materials.