Aminosilane-modified wood sponge for efficient CO2 capture

Wood sponges obtained by structure-retaining delignification of natural wood sheets are promising for CO 2 storage. Herein, lignin in balsa wood is selectively removed through chemical treatment, leading to a highly porous structure. To boost the CO 2 adsorption capacity, amine agents are grafted on the delignified wood via a condensation reaction. The resulting amine-grafted wood sponges exhibit hierarchical porosity and are mechanically resilient. A relatively high CO 2 uptake of 1.22 mmol g −1 (25 °C, 1 bar) is achieved due to the physisorption of hierarchical pores and chemisorption of high amine group loading. Such amine-grafted wood sponges fabricated from top-down strategy hold great potential to serve as renewable CO 2 capture materials.