Aerogels for Carbon Dioxide Capture: Classification Design, Preparation Strategies, and Capture Scenarios

The global atmospheric CO2 concentration continues to rise, leading to increasingly severe greenhouse effects, ocean acidification, and extreme climate events. Therefore, the development of efficient CO2 capture materials is urgently needed. Aerogels, a class of three-dimensional nanoporous solid materials formed by the crosslinking of nanoparticles or polymer molecular chains via the sol–gel process, exhibit outstanding advantages in CO2 capture due to their high specific surface area, tunable nanopores, and abundant surface functionalizable sites. This paper systematically summarizes the preparation methods, including supercritical drying, ambient pressure drying, and freeze drying, reviews the classification and design strategies of aerogel materials, and analyzes the application status of aerogels in scenarios ranging from direct air capture, post-combustion flue gas capture, and natural gas purification to carbon sequestration. Finally, future development trends are prospected, aiming to provide a reference for the design and large-scale application of high-performance aerogel-based CO2 adsorbents.