Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronics, Xiangtan University , Xiangtan, Hunan 411105, P. R. China.
Integrated Materials Design Centre (IMDC), School of Chemical Engineering, UNSW Australia , Sydney, New South Wales 2052, Australia.
ACS Appl Mater Interfaces. 2017 Jun 14;9(23):19825-19830. doi: 10.1021/acsami.7b03676. Epub 2017 Jun 1.
Ideal carbon dioxide (CO) capture materials for practical applications should bind CO molecules neither too weakly to limit good loading kinetics nor too strongly to limit facile release. Although charge-modulated switchable CO capture has been proposed to be a controllable, highly selective, and reversible CO capture strategy, the development of a practical gas-adsorbent material remains a great challenge. In this study, by means of density functional theory (DFT) calculations, we have examined the possibility of conductive borophene nanosheets as promising sorbent materials for charge-modulated switchable CO capture. Our results reveal that the binding strength of CO molecules on negatively charged borophene can be significantly enhanced by injecting extra electrons into the adsorbent. At saturation CO capture coverage, the negatively charged borophene achieves CO capture capacities up to 6.73 × 10 cm. In contrast to the other CO capture methods, the CO capture/release processes on negatively charged borophene are reversible with fast kinetics and can be easily controlled via switching on/off the charges carried by borophene nanosheets. Moreover, these negatively charged borophene nanosheets are highly selective for separating CO from mixtures with CH, H, and/or N. This theoretical exploration will provide helpful guidance for identifying experimentally feasible, controllable, highly selective, and high-capacity CO capture materials with ideal thermodynamics and reversibility.
理想的二氧化碳（CO）捕获材料应既能有效结合 CO 分子，又不会因结合过强而限制其释放。虽然电荷调制型可切换 CO 捕获被认为是一种可控的、高选择性的、可逆的 CO 捕获策略，但开发实用的气体吸附剂材料仍然是一个巨大的挑战。在这项研究中，我们通过密度泛函理论（DFT）计算，研究了导电硼烯纳米片作为电荷调制型可切换 CO 捕获的有前途的吸附材料的可能性。结果表明，向吸附剂中注入额外电子可以显著增强负电荷硼烯对 CO 分子的结合强度。在饱和 CO 捕获覆盖率下，负电荷硼烯的 CO 捕获容量高达 6.73×10 cm。与其他 CO 捕获方法相比，负电荷硼烯上的 CO 捕获/释放过程是可逆的，动力学较快，通过开关硼烯纳米片所携带的电荷，很容易进行控制。此外，这些负电荷硼烯纳米片对从 CH、H 和/或 N 的混合物中分离 CO 具有很高的选择性。这项理论研究为识别具有理想热力学和可逆性的实验可行的、可控的、高选择性的、高容量 CO 捕获材料提供了有益的指导。
