V_(2)CO_(2)MXene从CO_(2)/N_(2)混合气体中选择性吸附CO_(2)的第一性原理计算

First-principles calculation of the selective adsorption of CO_(2)by V_(2)CO_(2)MXene from CO_(2)/N_(2)mixture

二氧化碳作为温室气体中最重要的组成部分,其含量的变化将直接影响全球气候变化,在燃烧后气体中选择性捕获CO_(2),对减缓因CO_(2)浓度过高引发的环境问题具有十分重要的意义.本文采用第一性原理计算的方法,研究了V_(2)CO_(2)MXene材料对CO_(2)的选择性吸附性能.首先研究了不同官能团V_(2)CT_(X)MXene材料的结构和性质,发现V_(2)CO_(2)具有良好的稳定性.后研究了V_(2)CO_(2)对CO_(2)的吸附行为,结果表明,当CO_(2)被水平吸附时,V_(2)CO_(2)对CO_(2)气体分子的吸附能力较强且均满足在高性能吸附剂表面吸附CO_(2)的理想值(-0.42 eV-0.82 eV),可以适用于探测/捕获CO_(2)气体分子.此外,进一步研究了相同条件下V_(2)CO_(2)对N_(2)气体分子的吸附行为,结果表明V_(2)CO_(2)对N_(2)分子的吸附很弱.因此V_(2)CO_(2)可以选择性地从CO_(2)/N_(2)混合气体中吸附CO_(2),有望成为在燃烧后气体中选择性吸附CO_(2)的候选材料.

As the most important component of greenhouse gases,the change of carbon dioxide content will directly affect global climate change.Selective capture of CO_(2)in post combustion gases is of great significance to mitigate environmental problems caused by excessive CO_(2)concentration.In this paper,the first principle calculation method was used to study the selective adsorption performance of V_(2)CO_(2)MXene material for CO_(2).Firstly,the structures and properties of V_(2)CO_(2)MXene materials with different functional groups were studied.It was found that V_(2)CO_(2)had good stability.Later,the adsorption behavior of V_(2)CO_(2)on CO_(2)was studied.The results showed that when CO_(2)was horizontally adsorbed,V_(2)CO_(2)had a strong adsorption capacity for CO_(2)gas molecules,which met the ideal value(-0.42 eV-0.82 eV)of CO_(2)adsorption on the surface of high-performance adsorbent,and could be suitable for detecting/capturing CO_(2)gas molecules.In addition,the adsorption behavior of N_(2)on V_(2)CO_(2)under the same conditions was further studied.The results showed that the adsorption of V_(2)CO_(2)on N_(2)was very weak.Therefore,V_(2)CO_(2)can selectively adsorb CO_(2)from CO_(2)/N_(2)mixture,which is expected to be a candidate material for selective adsorption of CO_(2)in post combustion gases.