Probing the structure of carbon nanohorn aggregates by adsorbing gases of different sizes

We explore the adsorption behavior of Ne and CF4 in as-produced carbon nanohorn aggregates using adsorption measurements and computer simulations. Despite the difference in specific surface area observed for these gases, the isotherms for both gases show the presence of two substeps before monolayer completion. With the aid of computer simulations, we conclude that this universal behavior is the result of adsorption in interstitial spaces of varying dimension in the aggregates.