Hierarchically porous wood/CuBTC/GO composites for efficient and selective CO2 capture

A composite adsorbent material for CO ₂ capture was prepared using low-density, high-porosity balsa wood (BW) as the matrix, with the introduction of CuBTC and graphene oxide (GO). Characterization via scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Raman spectroscopy, and X-ray diffraction (XRD) confirmed the uniform synthesis of octahedral CuBTC within the wood pores. The introduction of GO increased the loading of CuBTC by 28.3%, with the final loading reaching 46.67%. FTIR analysis revealed interfacial interactions—hydrogen bonding and Cu ²⁺ coordination. Compared to pure CuBTC, the composite exhibited higher thermal stability (up to 500 K) and excellent water resistance, with minimal structural changes after 6 hours of immersion. Its microporous surface area was 229.19 m ² ·g ^-1 , pore volume was 0.12 cm ³ ·g ^-1 , and average pore diameter was 2.01 nm. Under conditions of 298 K and 1 bar, the CO ₂ adsorption capacity reached 1.93 mmol·g ^-1 , and it exhibited excellent cycling stability. The average CO ₂ adsorption heat was 32.13 kJ·mol ^-1 , indicating that the adsorption mechanism was primarily physical adsorption, i.e., wood acted as a high-speed channel for CO ₂ transport, while the unsaturated copper sites exposed on CuBTC in the wood pores interacted electrostatically with the quadrupole moment of CO ₂ . Additionally, this composite material exhibited high CO ₂ /N ₂ (up to 71), outperforming pure CuBTC, highlighting its potential for application in CO ₂ capture. This study is valuable for the functionalization of wood.