Porous Calcium‐Silicate‐Hydrate as a Low‐Cost Nano‐Platform for Ultra‐High CO2 Capture and Storage

Abstract CO 2 capture and storage have been regarded as promising concepts to reduce anthropogenic CO 2 emissions. However, the high cost, inferior adsorption capacity, and higher effective activation temperature of traditional sorbents limit their practical application in efficient CO 2 capture. Here, a C‐S‐H@ZIF‐8 (C‐S‐Z) sorbent is fabricated by in situ growth of the ZIF‐8 shell on the C‐S‐H (calcium‐silicate‐hydrate) surface for ultra‐high CO 2 adsorption and storage. Among the C‐S‐Z, the outer ZIF‐8 shell acts as a transport channel that promotes CO 2 absorption toward the underlying C‐S‐H substrate for accelerated carbonation while preventing nitrogen and water from reaching the interior C‐S‐H. As a consequence, C‐S‐Z possesses the merits of ample pyrrolic nitrogen, porous structure, and ultra‐high surface area (577.18 m 2 g −1 ), that contribute to an ultra‐high CO 2 capture capacity, reaching 293.6 mg g −1 . DFT calculations show a high CO 2 adsorption energy and the mineral carbonation is dominant by the adsorption process. In particular, the advantages of the outstanding adsorption capacity, low cost, and high CO 2 selectivity make this C‐S‐H‐based sorbent hold great potential in the practical application for direct air CO 2 capture and storage.