Functional group-directed self-installing doors in porous graphene: a theoretical study

• Published in: Journal of materials science Vol. 55; no. 12; pp. 5111 - 5122
• Main Authors: Li, Yuanzhen, Li, Chenchen, Linghu, Yaoyao, Wu, Chao
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2020; Springer; Springer Nature B.V
• Subjects: Analysis; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Computation & Theory; Computer simulation; Crystallography and Scattering Methods; Density functional theory; Density functionals; Functional groups; Gas mixtures; Graphene; Graphite; Installation; Materials Science; Methane; Polymer Sciences; Porosity; Selectivity; Solid Mechanics
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-020-04367-2

The pores in porous graphene sheets are usually passivated by atoms and functional groups including H, N, F, and OH. It is expected that some small molecules can adsorb with sufficient strength to the functionalized pores to change their properties, which can be undone by heating. We have employed the density functional theory simulations to verify that CF 3 CH 2 OH molecules can strongly adsorb to pores passivated by both N and H atoms (e.g. the pore16-1N1 model). Actually, the CF 3 CH 2 OH molecule can be used as a self-mounting “gate” to reversibly adjust the shape, size, and separation property of the pore. For example, the gas mixture (H 2 , CH 4 , n -C 4 H 10 , and i -C 4 H 10 ) passing freely through a pore with diameter of 7–8 Å can now be separated by pre-adsorbing a CF 3 CH 2 OH molecule. Larger components such as n -C 4 H 10 , and i -C 4 H 10 are completely blocked, and the small mixture of H 2 /CH 4 can be well separated with a selectivity of 10 11 :1. The “self-installing door” mechanism opens up a new way to flexibly transform large pores according to the needs.