Dynamic CO₂ sequestration: from global emission challenges to sustainable capture through geopolymer technologies.

Carbon capture and storage (CCS) has emerged as a pivotal technology to mitigate anthropogenic CO₂ emissions and advance toward global net-zero emission targets. Despite its potential, CCS implementation faces persistent challenges, including high costs, technological uncertainties, energy penalties, environmental risks, and issues of public acceptance. This review highlights the critical linkage between rising CO₂ emissions and the rise in global temperature. Special attention is given to advances in dynamic adsorption techniques, alongside an assessment of the limitations of conventional materials such as ordinary Portland cement (OPC) for well injection. The urgent need to curb rising CO₂ emissions has spurred interest in novel geopolymer-based materials for carbon capture and storage (CCS). Recent research suggests that fly ash-based geopolymers offer a promising alternative, enabling the dual benefit of industrial waste stabilization and CO₂ mitigation. This review critically examines fly ash-based geopolymers as dual-function CCS materials: (1) as solid sorbents capturing CO₂ via physisorption and chemisorption and (2) as durable well-cement materials for storing CO₂ in subsurface reservoirs. The comparative analysis with conventional sorbents (zeolites, MOFs, amine solvents) demonstrates that geopolymers possess superior thermal and chemical stability as well as cost-effectiveness. The study concludes that by outlining field-scale deployment prospects and challenges, geopolymers can replace OPC in well-cementing for CCS with superior long-term integrity and low carbon emissions. Thus, the present review uniquely integrates mechanistic insights, durability under CCS conditions, and environmental implications, highlighting geopolymers as dual-function materials for CO₂ capture and storage.