Interfacial CO₂ adsorption in geological carbon cycle

Geological carbon cycle (GCC) directly impacts the global carbon cycle and climate change, where CO₂ adsorption is one most critical factor, governs the GCC's efficiency and security. However, the fundamental mechanisms of CO₂ adsorption and its effects on interfacial properties remain inadequately understood due to the inherent complexities of mineral compositions, pore structures, and wettability heterogeneities. To address these challenges, this review systematically explores the theoretical foundations of CO₂ adsorption, providing a mechanistic elucidation of CO₂ adsorption and its effects on interfacial properties. It integrates insights from mathematical modeling, molecular simulations, and experimental methodologies to elucidate the mechanisms of CO₂ sorption and its competitive behavior with other fluid components such as CH₄ and H₂O in geological formations. We critically assess CO₂ adsorption behaviors at diverse interfaces, including solid-fluid interfaces (organic, inorganic, and composite models) and fluid-fluid interfaces (e.g., CO₂-water), and discuss influencing factors, such as pore shape/size, temperature, pressure, moisture, wettability, and external electric fields. Furthermore, the review specifically evaluates the key physicochemical mechanisms underlying CO₂-interface interactions and its implications for interfacial properties, including wettability alteration, interfacial tension changes and adsorption-induced deformation. Meanwhile, we provide a comprehensive understanding of adsorption scenarios within the GCC. Finally, we outline current research challenges and identify prospects to advance the fundamental understanding of how CO₂ adsorption influences mineral interfacial properties and the GCC processes, thereby contributing to global climate governance and carbon neutrality efforts.