Acetone adsorption on hierarchically porous carbon foams: effect of nitrogen doping and oxygen functional groups

Porous carbons are promising materials for volatile organic compound (VOC) capture, but the interplay between pore structure and surface chemistry remains poorly understood. Here, we report the synthesis of graphene-like carbon foams (CFs) with ultra-high surface area (2563 m² g⁻¹) and tunable surface functionalities for efficient acetone vapour adsorption. Using sodium ethoxide as a precursor, we prepared pristine CFs and systematically modified them via oxygen and nitrogen doping. Moderate oxygen doping (~11 at.%) preserved microporosity, resulting in exceptional acetone uptake (1206 mg g−1), superior N₂/acetone selectivity (~11,500) and excellent regeneration stability compared to undoped CF samples. In contrast, aggressive oxidation (~26 at.% O) and high nitrogen doping (7–13 at.%) significantly reduced porosity and adsorption capacity, with the most heavily doped samples showing the poorest performance. Near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) was employed to gain further insight into the adsorption mechanisms, which were dominated by pore filling and weak electrostatic interactions from surface groups enhancing low-pressure uptake. Our findings establish a clear structure – function relationship, highlighting the critical balance between porosity and surface chemistry for VOC capture. These results also position CFs as scalable, regenerable adsorbents for industrial air purification and environmental remediation. Furthermore, the work provides a robust platform for engineering next-generation adsorbents with tailored performance, contributing to cleaner air technologies and sustainable chemical engineering solutions.