The GrO@HKUST-1 composites can be rapidly prepared at room temperature within 1 min.
The GrO@HKUST-1 composites have a higher surface area compared to its parent HKUST-1.
Its CO2 adsorption capacity reached 9.02 mmol/g at 1 bar and 273 K, with an increase of 32% compared to HKUST-1.
Its CO2/N2 adsorption selectivity reached 186 at 1 bar, 1.8 times that of HKUST-1.