Metal-organic frameworks for CO2 capture: Tailoring structure and function through modification strategies

The challenge posed by greenhouse gases, particularly carbon dioxide (CO₂), represents one of the most pressing environmental crises confronting modern society. Carbon capture, as a crucial process within the carbon cycle, demands materials with specific properties. However, the development of carbon capture materials that comprehensively satisfy these criteria remains an arduous task. Current investigations reveal metal-organic frameworks (MOFs) as promising materials for tackling this environmental challenge. Due to the structural diversity of MOFs, their adsorption properties can be tailored through modifications, such as metal doping and functional group introduction, etc. This review aims to provide a comprehensive overview and update on the development of MOFs modification for CO₂ adsorption. In this review, we identify the changes in MOFs before and after modification, comparing monometallic and bimetallic MOFs, as well as MOFs with various functional groups (e.g., -NO₂, -OH, -COOH, -SO₃H, etc.), and composite MOFs. By evaluating the advantages and disadvantages of different modification methods, the modification strategies can be further optimized to improve the adsorption properties and selectivity of MOFs. Additionally, we discuss the synthesis and adsorption mechanisms that contribute to achieving higher capture capacities and selectivity, as well as their costs and regeneration performance. In short, it is essential to consider multiple factors when designing materials that balance both selectivity and adsorption capacity.