Layered double hydroxides (LDHs) with a hierarchical meso-structure are successfully synthesized on mesoporous silica foams by simple impregnation and hydrothermal treatment. The as-synthesized LDH/silica foam nanocomposites show well-defined mesostructures with high surface areas, large pore volumes, and mesopores of 6–7 nm. The nanocomposites act as carbon dioxide (CO₂) sorbents under simulated flue gas conditions. They also exhibit significantly enhanced CO₂ capacities under high-pressure conditions and high CO₂/N₂ and CO₂

/CH4 selectivities.