Boronic acid-functionalized graphene aerogels for selective catechol removal in complex multicomponent phenolic aerosols

Selective adsorption in complex multicomponent aerosols remains challenging because structurally similar molecules often compete for identical adsorption sites. Herein, a boronic acid-functionalized three-dimensional graphene aerogel was developed as a selective adsorbent for phenolic compounds. Following 1,2-benzenediboronic acid modification, the specific surface area of graphene aerogel increased from 380.69 to 539.88 m 2 g −1 . In dynamic multicomponent aerosol experiments, the detected catechol amounts after filtration through B-14/CA and B-18/CA were 65.94 and 65.21 μg/cig, respectively, compared with 106.13 μg/cig for the conventional cellulose acetate filter. Other representative phenolic compounds exhibited responses distinct from that of catechol, demonstrating differential filtration in the competitive system. Density functional theory calculations showed that the optimized catechol complex did not correspond to a conventional boronate ester. Instead, a noncovalent B···O contact of approximately 2.06 Å closed a seven-membered pseudo-cyclic adsorption configuration without dehydration. The similar adsorption energies of catechol and guaiacol, −0.34319 and −0.34799 eV, respectively, indicated that a single optimized adsorption energy was insufficient to explain the experimental difference. These results suggest that the combination of hierarchical porous transport and configuration-dependent noncovalent recognition contributes to preferential catechol retention in multicomponent aerosols.