Photo-assisted regeneration in CO2 capture: mechanisms and materials

CO 2 capture has emerged as a key strategy for mitigating climate change; however, the energy-intensive regeneration of CO 2 adsorbents hinders its widespread deployment. Harnessing solar irradiation for CO 2 adsorbent regeneration offers a sustainable alternative to conventional thermal regeneration methods. Photo-assisted CO 2 desorption generally involves four sequential steps: light absorption, photon-to-energy conversion, energy transfer, and CO 2 release. Based on the photon-to-energy conversion mechanism, photo-driven CO 2 regeneration can be categorized into three distinct pathways: photothermal, photoisomerization, and photochemical. This review systematically compares these three pathways in terms of regeneration efficiency, working capacity retention, and operational stability of CO 2 adsorbents, while elucidating their fundamental regeneration mechanisms and material design principles. Furthermore, key challenges for practical implementation and future research directions for scalable and energy-efficient CO 2 regeneration are discussed. This review offers fundamental insights into photo-assisted CO 2 regeneration and provides material design principles for advanced regeneration technologies.