General approach to facile synthesis of MgO-based porous ultrathin nanosheets enabling high-efficiency CO2 capture

[Display omitted] •A novel and versatile synthetic methodology is developed for the MgO-based sorbent.•A series of porous ultrathin nanosheets of MgO/C nanocomposites are prepared.•MgO/C nanocomposites display encouragingly extraordinary CO2 capture performance. With increasing concern over environmental issue associated with the anthropological CO2 emission, the exploration of low-cost, efficient and durable solid sorbents for carbon capture and storage technologies (CCS) is actively encouraged. In this work, we present our recent effort in the fine construction of MgO-based sorbents for high-performing CO2 trapping. A general, facile yet effective synthetic protocol is developed to fabricate a new family of MgO/C nanocomposites with porous ultrathin nanosheet architecture by topochemical conversion of Mg-containing coordination polymer precursors from polyol-assisted self-assembly. With rational engineer and manipulation, the resultant MgO/C nanocomposites, composed of ultrafine MgO nanocrystallites dispersed in carbon matrix, are endowed with hierarchical architecture, large surface area, abundant nanoporous structure, and thereby achieving full exposure of a large number of active sorption sites and fast mass transport. With the above benefits, the MgO/C nanocomposites are capable of displaying encouragingly extraordinary CO2 capture performance with ultrahigh sorption capacity (up to 32.0 wt% at 27 °C, 1 bar CO2), rapid sorption kinetics and excellent stability, ranking the best among all the MgO-based sorbents reported so far, and also comparable to the state-of-the-art solid sorbents based on different materials. This work provides a novel, effective and versatile synthetic methodology to develop advanced CO2 solid sorbents based on the inexpensive and earth-abundant elements.