New research in reducing CO2 emissions is ongoing to mitigate global warming. New ways are continuously sought to efficiently capture flue gases emitted by industries, one of which is using porous adsorbents like aerogels. The use of chemical initiators is the traditional way of synthesizing aerogels for CO2 capture; however, it pollutes the environment to some extent. This study finds an initiator-free method of synthesizing the aerogel which is faster and more stable yet green. The method involves exposing oil-in-water emulsions containing monomer mixtures along with other chemicals to a radiation dose of 10�50 kGy range using an electron accelerator. The polymeric aerogel was formed within 5 min after exposure to optimum dosage, which was then characterized to evaluate the physio-chemical changes. The test revealed that the aerogel synthesized at 40 kGy EB radiation dose exhibits the maximum PEI loading capacity of 4.1 g/g of aerogel. Furthermore, the CO2 adsorption performance of an optimized amine-impregnated polymeric aerogel was 4.45 mmol/g at 30 °C. Interestingly, this aerogel was able to preserve the initial capacity without significant decrease even after five adsorption-desorption cycles. The proposed method is likely to be of great significance in the field of CO2 capture. © 2024 Elsevier Ltd