Due to the continuous growth of global carbon dioxide emissions, the development of cost-effective carbon dioxide capture technology has attracted extensive attention. Amino-modified chitosan aerogels with lamellar porous structures are good candidates as carbon dioxide adsorbents because of their degradable properties and low energy consumption. Polyethylene polyamine-modified chitosan aerogels (PEPA-CSs) were prepared through a process of crosslinking and freeze-drying using a chitosan solution, polyethylene polyamine (PEPA), and epichlorohydrin (ECH) as raw materials. The amino group of PEPA was proven to be successfully grafted on the chitosan surface by FITR and XPS. The SEM and TEM analysis showed a rich three-dimensional porous structure and a good rigidity and bearing capacity of the PEPA-CS. The adsorption capacity was significantly increased by PEPA grafting with a maximum value of 1.59 mmol/g at 25 °C and 1 bar through both physical and chemical interactions, which indicates a potential for broad application prospects in industrial CO₂-capture applications.

The conversion of CO₂ into high-value-added chemicals and fuels using electricity generated from renewable energy sources is one of the most promising methods to reduce the dependence of human society on fossil fuels and to alleviate environmental problems. The performance of catalysts is one of the most important factors restricting the development of this technology, and in recent years, carbon materials have been the hot spot of research in the field of CO₂ electrocatalytic reduction catalysts. In this paper, the progress of the application of carbon materials in CO₂ electrocatalytic reduction reaction (ECR) is reviewed in detail. Three aspects of carbon materials directly as metal-free carbon material catalysts for CO₂ reduction, metal-centered coatings in metal catalysts, and support for metals, are comprehensively described, respectively, including the preparation strategy of catalysts, the mechanism of action and structural characteristics of catalysts, the distribution of products and the catalytic performance of catalysts. Finally, the problems and challenges faced by the field are summarized, and the outlook is presented in various areas, including catalyst preparation, performance enhancement, and deepening mechanism research.