Abstract In this study, density functional theory calculations were performed to study the CO2 capture and separation on calcite surface with charge-modulated. The results indicate that calcite surface can be used experimentally for charge modulation and is very stable under charged conditions. At the critical charge density of 18.56 × 1013 e−/cm2, the adsorption energy of a single CO2 on calcite surface can be dramatically enhanced, reaching −6.23 eV. Moreover, reversible processes of CO2 adsorption/desorption are exothermic without any energy barrier, and thermodynamic properties demonstrate that CO2 spontaneously adsorbs on the charged calcite surface at the temperature below 900 K. In practical application, calcite can achieve more adsorption capacity (4.95 × 1014 cm−2) at minimum charge density (8.04 × 1013 e−/cm2) compared with two-dimensional materials. In addition, charged calcite has highly selective for separating CO2 from N2, H2 and CH4. Importantly, the optimal charge density range for CO2 capture and separation is determined from 8.04 × 1013 to 18.56 × 1013 e−/cm2. These results not only demonstrate the feasibility of cheap calcite as an excellent reversible CO2 collector by charge-modulated method but also provide a direction on natural minerals as candidate gas-adsorbent materials.

中文翻译：

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电荷调制方解石上的 CO2 捕获和分离

摘要 本研究通过密度泛函理论计算研究了电荷调制条件下方解石表面CO2的捕获和分离。结果表明方解石表面可以实验用于电荷调制，并且在带电条件下非常稳定。在临界电荷密度为 18.56 × 1013 e-/cm2 时，单个 CO2 在方解石表面的吸附能显着增强，达到 -6.23 eV。此外，CO2 吸附/解吸的可逆过程是放热的，没有任何能量障碍，热力学性质表明 CO2 在低于 900 K 的温度下自发吸附在带电的方解石表面。在实际应用中，方解石可以实现更大的吸附容量（4.95 × 1014 cm−2) 在最小电荷密度 (8. 04 × 1013 e-/cm2) 与二维材料相比。此外，带电方解石对于从 N2、H2 和 CH4 中分离 CO2 具有高度选择性。重要的是，CO2 捕获和分离的最佳电荷密度范围确定为 8.04 × 1013 至 18.56 × 1013 e-/cm2。这些结果不仅证明了廉价方解石作为一种优良的可逆 CO2 收集器的可行性，而且为天然矿物作为候选气体吸附材料提供了方向。