Tuning carbon black surface morphology via controlled thermal treatment atmosphere

The surface structure of carbon black (CB) is critically dependent on its preparation and post-treatment conditions. This study investigates the impact of thermal treatment atmosphere – vacuum, hydrogen, and inert gas – on the surface morphology and chemical composition of CB. Detailed structural analysis revealed that vacuum treatment promotes significant smoothing of the carbon surface through micrographite bonding and pore closure, while inert and hydrogen gas treatments exhibited a lesser degree of bonding. Furthermore, hydrogen treatment effectively removed oxygen-containing functional groups (OCFGs) and partially suppressed micrographite bonding, leading to the formation of narrow pores. Isosteric heat of adsorption measurements confirmed these structural changes and highlighted the role of OCFGs in hindering N₂ molecule rearrangement on the carbon surface. These findings demonstrate the tunability of carbon surface properties through controlled thermal treatment atmospheres, offering a pathway for optimizing its performance in applications such as adsorption, catalysis, and energy storage.