Plasma-assisted catalysis for graphene pre-nucleation: the role of high-index nickel nanocrystal surfaces

The reactivity of high-index Ni nanocrystal surfaces is critical for catalytic carbon nanostructure synthesis. We used reactive molecular dynamics to probe C₂ and C₂H radical interactions with Ni(111), Ni(210), and Ni(331) surfaces under acetylene plasma conditions. While high-index surfaces showed enhanced reactivity, the Ni(331) facet proved superior, promoting both rapid pre-nucleation and the subsequent growth of a high-quality crystalline layer. This performance stems from an optimal balance of low carbon-diffusion barriers and suppressed C₂ dissociation, yielding the lowest activation energies for C₄ chain and C₆ ring formation. These findings establish engineered surface faceting as a promising route toward superior catalysts.