CO2 Capture on h-BN Sheet with High Selectivity Controlled by External Electric Field
CO2 Capture on h-BN Sheet with High Selectivity Controlled by External Electric Field
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由外部电场控制的高选择性 h-BN 片上的 CO2 捕获
DOI：
10.1021/acs.jpcc.5b00681
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发表时间：
2015-03-26
影响因子：
3.7
通讯作者：
Yang, Jinlong
中科院分区：
文献类型：
--
作者：
Guo, Hongyan;Zhang, Wenhua;Yang, Jinlong
开发用于从气体混合物中分离和捕获二氧化碳的高效吸附剂材料对于减少二氧化碳对环境的影响至关重要。基于色散校正的密度泛函理论计算，我们表明六方氮化硼片（h-BN）在外部电场作用下可以成为有效的二氧化碳捕获吸附剂。在没有电场的情况下，CO2 分子被物理吸附在 h-BN 片上。在外部电场作用下，CO2分子在h-BN单层上的吸附可以得到强烈加强。与 CO2 相比，h-BN 片上对 H-2、N-2、CH4、CO 或 H2O 的吸附明显较弱，表明在电场下，h-BN 片上 CO2 的捕获优先于其他气体分子。计算得出CO2与其他气体分子的吸附速率常数之比可高达10(5)。而且，h-BN片上CO2分子的捕获是可逆的；也就是说，可以通过关闭施加的电场来释放吸附的CO2。这项研究表明h-BN片材不仅可以用于二氧化碳捕获，还可以作为高选择性的气体储存材料。选择性程度可以通过施加的外部电场来控制。
Developing highly efficient sorbent materials for CO2 separation and capture from gas mixture is most important for reducing impact of CO2 on the environment. On the basis of density functional theory calculations with dispersion correction, we show that hexagonal boron nitride sheet (h-BN), when under an external electric field, can become an effective sorbent for CO2 capture. In the absent of the electric field, CO2 molecules are physisorbed on the h-BN sheet. Under the external electric field, the adsorption of CO2 molecules on h-BN monolayer can be strongly strengthened. Compared to CO2, the adsorption of H-2, N-2, CH4, CO, or H2O on h-BN sheet is notably weaker, indicating that the capture of CO2 on h-BN sheet under the electric field is highly preferred over other gas molecules. The calculated ratio of adsorption rate constant of CO2 to other gas molecule can be as high as 10(5). Moreover, the capture of CO2 molecule on h-BN sheet is reversible; that is, the adsorbed CO2 can be released by shutting down the applied electric field. This study suggests potential application of h-BN sheet not only for CO2 capture but also as a gas-storage material with high selectivity. The degree of selectivity can be controlled by an applied external electric field.