A review on controllable preparation and applications of biomass-based carbon aerogels

Biomass-based carbon aerogels have emerged as sustainable porous carbon materials with ultralow density, high surface area, and tunable surface function groups. However, precise regulation toward different applications remains a significant challenge for maximum optimizing their performance. In this review, a comprehensive overview of the diverse methods for the controlled synthesis of biomass-based carbon aerogels from renewable feedstocks was provided, with emphasis on precursor selection, gelation chemistry, drying strategies, carbonization, and activation processes. The relationships between structure and application performance properties are systematically discussed, highlighting how heteroatom doping, hierarchical porosity, and defect engineering influence adsorption, electrochemical energy storage, electrocatalysis, sensors, microwave absorption and thermal insulation. Specially, the mechanism of each application was given, linking biomass-based carbon aerogels properties with application performance. Furthermore, the key challenges and future directions are proposed for the scalable development of high-performance biomass-based carbon aerogels. Perspectives on life cycle assessment and future trends are also outlined, aiming to provide guidance for the rational design and large-scale deployment of biomass-derived carbon aerogels.