Haonan Qi¹, Sylvain Picaud², Michel Devel³, Enwei Liang¹, and Zhao Wang¹
Astrophysical Journal 867, 133 Link to Article [DOI: 10.3847/1538-4357/aae4e4]
¹Guangxi Key Laboratory for Relativistic Astrophysics, Department of Physics, Guangxi University, Nanning 530004, People’s Republic of China
²Institut UTINAM, CNRS UMR 6213, Université Bourgogne Franche-Comté, F-25030 Besançon, France
³FEMTO-ST institute, UBFC, CNRS, ENSMM, 15B avenue des Montboucons, F-25030 Besançon, France

Using atomistic simulations, we characterize the adsorption process of organic molecules on carbon nanoparticles, both of which have been reported to be abundant in the interstellar medium (ISM). The aromatic organics are found to adsorb more readily than the aliphatic ones. This selectivity would favor the formation of polycyclic aromatic hydrocarbons (PAHs) or fullerene-like structures in the ISM due to a structural similarity. In our simulations, we also observed that the molecules form a monolayer over the nanoparticle surface before stacking up in aggregates. This suggests a possible layer-by-layer formation process of onion-like nanostructures in the ISM. These findings reveal the possible role of carbon nanoparticles as selective catalysts that could provide reaction substrates for the formation of interstellar PAHs, high fullerenes, and soots from gas-phase molecules.