Yang Ning, Liu Zhenyu, Zhou Yunlong
College of Energy and Power Engineering, Northeast Electric Power University, Jilin, 132012, China.
J Mol Model. 2023 Jan 31;29(2):60. doi: 10.1007/s00894-023-05464-0.
The massive emission of carbon dioxide in the world causes global warming and a series of increasingly serious ecological problems. It is urgent to find efficient adsorbent for large-scale CO capture. Graphene as a solid adsorbent has exhibited great potential and development prospects in gas adsorption. Doping atoms at defect sites in composite graphene is considered as one of the promising approaches to enhance the gas adsorption ability. Nevertheless, composite graphene doping with different atoms has not been explored to a large extent so far.
In this work, vacancy graphenes with single C-vacancy (VI-G) and with double C-vacancies (VII-G) are doped with nitrogen atoms and metal atoms M (M = Co, Mo, Mn, Fe) to form composite configurations. The Perdew-Burke-Ernzerho (PBE) functional is used under the generalized gradient approximation (GGA) basis set. A comprehensive study of the adsorption effect and charge transfer characteristics of CO molecule on different composite graphene configurations is carried out through DFT calculation. By analyzing the adsorption energy, adsorption distance, energy band structure, and atomic Mulliken population, it is found that the composite graphene doped with metal atoms such as Co-3N-VI, Mo-3N-VI, Mn-3N-VI, Fe-3N-VI, and Mo-4N-VII significantly enhanced the CO adsorption. Further analysis of charge density and density of states (DOS) demonstrates that CO adsorption on M-3N-VI and M-4N-VII reached the same conclusion. Thus, it is concluded that appropriate metal atoms can enhance the adsorption characteristics.
全球大量的二氧化碳排放导致全球变暖以及一系列日益严重的生态问题。迫切需要找到用于大规模二氧化碳捕获的高效吸附剂。石墨烯作为一种固体吸附剂在气体吸附方面展现出了巨大的潜力和发展前景。在复合石墨烯的缺陷位点掺杂原子被认为是增强气体吸附能力的一种有前景的方法。然而，到目前为止，不同原子掺杂的复合石墨烯尚未得到充分研究。
在这项工作中，具有单碳空位（VI-G）和双碳空位（VII-G）的空位石墨烯被氮原子和金属原子M（M = Co、Mo、Mn、Fe）掺杂以形成复合结构。在广义梯度近似（GGA）基组下使用佩德韦-伯克-恩泽霍（PBE）泛函。通过密度泛函理论（DFT）计算对CO分子在不同复合石墨烯结构上的吸附效果和电荷转移特性进行了全面研究。通过分析吸附能、吸附距离、能带结构和原子穆利肯布居，发现掺杂有Co-3N-VI、Mo-3N-VI、Mn-3N-VI、Fe-3N-VI和Mo-4N-VII等金属原子的复合石墨烯显著增强了CO吸附。对电荷密度和态密度（DOS）的进一步分析表明，CO在M-3N-VI和M-4N-VII上的吸附得出了相同的结论。因此，得出结论，适当的金属原子可以增强吸附特性。
