Steam explosion-derived hollow hierarchical porous balsa wood-based carbon skeleton/MOF-199 composites for indoor formaldehyde removal

To develop highly-efficient indoor formaldehyde adsorbents derived from biomass skeleton, the hollow hierarchical porous balsa wood-based carbon skeleton/copper-based metal organic framework (MOF-199) composites were prepared by steam explosion, mild carbonization, and in-situ growth. The steam explosion process, conducted at 1.2 MPa for 180 s, facilitated the formation of a hollow hierarchical macropore structure, including 1603 nm, 7240 nm, and 144616 nm, in balsa wood, while preserving the integrity of its three-dimensional skeleton. Mild carbonization at 400 °C allowed for the regulation of pore structure and the reconstruction of surface hydroxyl and carboxyl groups. The in-situ grown MOF-199 onto the carbonized balsa wood-based skeleton introduced micropores and potential chemical active sites. An excellent formaldehyde adsorption capacity was reached to 166.5 mg g −1 by the synergistical enhancement of hydrogen bonding, Van der Waals force, and chemical capture, with a theoretical maximum adsorption capacity (287.9 mg g −1 ), approximately 22 times that of commercial activated carbon. This study provides an effective and promising method for the preparation of efficient biomass-based formaldehyde adsorbents. Synopsis: Highly efficient formaldehyde adsorbents derived from balsa wood were fabricated via a combination of steam explosion, mild carbonization, and in-situ growth of MOF-199. • A combining strategy of steam explosion, carbonization, and in-situ growth was used. • A hollow hierarchical macropore microstructure of balsa wood was formed. • Mild carbonization regulated pore structure and the surface functional groups. • In-situ grown MOF-199 introduced micropores and potential chemical active sites. • The maximum adsorption capacity was 22 times higher than that of commercial AC.