Modulation of CO adsorption on 4,12,2-graphyne by Fe atom doping and applied electric field

Adsorption characteristics of CO adsorbed on pristine 4,12,2-graphyne (4,12,2-G) and Fe-doped 4,12,2-graphyne (Fe-4,12,2-G) are studied by first-principles calculations. It is shown that CO is only physically adsorbed on pristine 4,12,2-G. Fe atoms can be doped into 4,12,2-G stably and lead to band gap opening. After doping, the interaction between Fe-4,12,2-G and CO is significantly enhanced and chemisorption occurs. The maximum adsorption energy reaches -1.606 eV. Meanwhile, the charge transfer between them increases from 0.009e to 0.196e. Moreover, the electric field can effectively regulate the adsorption ability of the Fe-4,12,2-G system, which is expected to achieve the capture and release of CO. Our study is helpful to promote applications of two-dimensional carbon materials in gas sensing and to provide new ideas for reversible CO sensor research.