Perspectives on water-facilitated CO2 capture materials

Efficient separation of CO 2 from other gases has become an issue of world-wide concern. Intrigued by the fascinating carbonic anhydrase-catalysed CO 2 hydration and deprotonation in biological organisms, researchers have found that water can play a significant role in fast and selective CO 2 transport ( e.g. facilitating transport, salting-out effect, swelling, synergic sorption, etc. ) and have managed to fabricate super CO 2 capture materials by judiciously introducing water into solids. Considering that water usually exists in industrial CO 2 resources and often acts as a negative impurity due to competitive sorption and pore blockage, exploring CO 2 capture materials with the aid of water has become an important emerging strategy to provide general and excellent paradigms for practical CO 2 capture technologies. In this sense, we propose a new concept, "water-facilitated CO 2 capture (WFCC) materials", which refers to solid materials (either adsorbents or membranes) with a remarkable improvement in CO 2 capture performance due to entrapped water. In this way, we endeavor to answer an important question: when and how water contributes to this drastic enhancement. Strategies to avoid the negative effects of water and to enable WFCC are also tentatively proposed. This review firstly proposes the concept of water-facilitated CO 2 capture materials. The strategies of avoiding the negative effects of water and maximizing the positive effects of water are tentatively proposed.