Fig. 2: CO₂ adsorption isotherms of GS and corresponding structural changes.

a CO₂ adsorption and desorption isotherms of α-GS activated at 353 K and 453 K under vacuum, respectively, at 273 K with an equilibrium time of 600 s. b CO₂ sorption isotherms of α-GS activated at 453 K with various equilibration conditions at 273 K. c The CO₂ adsorption isotherms of α-GS activated at 453 K at various temperatures with equilibration time of 1800 s. d Variable-temperature powder X-ray diffraction (VT-PXRD) patterns of α-GS recorded from 373 to 473 K. The red dashed lines highlight the shift and disappearance of characteristic peaks corresponding to the α phase, while the blue dashed lines indicate the β phase. e Powder X-ray diffraction (PXRD) patterns of α-GS were collected for three distinct states: simulated patterns based on single-crystal X-ray diffraction (SCXRD) data of methanol (MeOH)-recrystallized samples, thermally transformed phases at 393 K, and experimentally obtained MeOH-recrystallized samples. f In situ PXRD patterns monitoring the phase transition from β-GS to CO₂@γ-GS under 100 kPa CO₂ at varying exposure times of 278 K (The red dashed lines indicate the emerging diffraction peaks corresponding to CO₂@γ-GS).