Progress and current challenges for CO2 capture materials from ambient air

As a major component of greenhouse gases, excessive carbon dioxide (CO2) in the atmosphere can affect human health and ecosystems. Therefore, the capture and transformation of CO2 have attracted extensive attention in academic circles in recent years. Direct air capture (DAC) of CO2 is a technology developed in recent years that can capture and collect CO2 directly from the ambient air, which is a potential negative CO2 emission technology. Currently, DAC technology is being promoted worldwide. Therefore, given the lack of a timely review of the latest developments in DAC technology, an appropriate and timely summary of this technology and a comprehensive understanding of it is necessary. In this paper, we review the research progress of adsorbent materials for directly capturing CO2 from ambient air in recent years, including liquid-based absorbent, solid adsorbent, and moisture-swing adsorbent. How their chemical composition, structure, morphology, and modification method affects their performance and long-term use is thoroughly discussed. In addition to efficient CO2 adsorption properties, designing low-cost sustainable materials is critical, especially for practical applications. Therefore, the technical and economic evaluation of CO2 adsorbents directly capturing from ambient air is reviewed. This review is of great significance for researchers to fully understand the development status and future trends of direct capture of CO2 from ambient air. This review provides the latest adsorbents that have been developed and applied to capture CO2 directly from ambient air, and highlights key research challenges.