The synergistic effect of water and lattice oxygen on CO2 mineralization in γ‐dicalcium silicate

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Abstract In this work, we clarify the roles of lattice oxygen and water in the carbonation reaction of γ‐C₂S by the well‐defined ab initio calculations. Two distinct carbonation mechanisms, dry carbonation and water‐assisted carbonation, are identified and analyzed. Findings reveal that lattice oxygen on the γ‐C₂S (010) surface, particularly the unsaturated oxygen, is crucial in both carbonation types. In dry carbonation, the unsaturated oxygen atom reacts with CO₂ to form carbonate, while in water‐assisted carbonation, it facilitates H₂O dissociation. Water, when bonded to Ca atoms on the γ‐C₂S (010) surface, aids in Ca atom dissolution. In the water‐assisted process, hydroxyl groups from H₂O dissociation combine with CO₂ to produce HCO₃⁻, which ultimately forms CO₃2⁻ on the γ‐C₂S (010) surface. This study offers a new perspective on the impact of lattice oxygen and water in γ‐C₂S carbonation and aims to inspire advancements in developing novel low‐carbon materials.