Vicioxite: A carbon material containing adjacent OH groups for CO2 and H2O capture

Developing efficient carbon-based adsorbents for CO2 and H2O capture is critical for mitigating climate change.Although functionalization of carbon materials is essential for efficient adsorption, the structural control of carbon materials remains challenging.While oxygen functional groups can enhance surface polarity, conventional oxidation methods lack control over group arrangement and often degrade the carbon framework.This study successfully synthesized "Vicioxite", a carbon material with controlled struc-tures and adjacent oxygen sites (especially OH groups) via catalysts-free synthesis to elucidate the effective configurations for CO2 and H2O capture.We synthesized model materials using coronene-coated activated carbon fibers (ACFs) via a regioselective two-step bromination and hydrolysis process.This method successfully introduced adjacent OH groups while preserving the π-conjugated basal plane.Computational analyses revealed that the specific edge topology of coronene energetically favors the formation of adjacent OH pairs, whereas steric hindrance restricts their formation on armchair edges.Experimental characterization, including 13 C nuclear magnetic resonance, confirmed these structures.Crucially, CO2 temperature-programmed desorption demonstrated that samples rich in adjacent OH groups exhibited superior CO2 adsorption capacity compared to untreated ACF.These results suggest that adjacent OH groups induce interactions, demonstrating that controlling the local spatial arrangement of functional groups is essential for designing high-performance adsorbents.