Synergistic chemi-physisorption in NH2-MIL-125/graphene aerogel composites for efficient H2S abatement in heritage conservation environments

Abstract Cultural artifacts suffer irreversible degradation from trace hydrogen sulfide (H 2 S), requiring advanced abatement technologies. To overcome the limitations of conventional adsorbents—inadequate capacity, slow kinetics, and poor cyclability—this study develops a synergistic NH 2 -MIL-125/graphene aerogel composite (NH 2 -MIL-125/GA). The mesopores of the reduced graphene oxide aerogel facilitate rapid H₂S diffusion, while the MOF micropores, together with Ti 4+ clusters and amine groups, enable high-capacity chemisorption. Structural integration ensures uniform MOF dispersion, enhancing surface area and mechanical robustness. The composite exhibits superior H 2 S adsorption capacity under static conditions and maintains high efficiency in dynamic breakthrough tests. Excellent regenerability over multiple cycles is achieved, with π–π stacking and hydrogen bonding preventing MOF agglomeration. Spectroscopic and DFT analyses confirmed dual mechanisms: H-bonding with amines and Ti–S coordination. Oddy tests demonstrate effective suppression of silver tarnishing and lead pigment blackening, establishing a scalable material for preventive conservation.