TY - JOUR
T1 - Bottom-up synthesis of graphene films hosting atom-thick molecular-sieving apertures
AU - Villalobos, Luis francisco
AU - Van goethem, Cédric
AU - Hsu, Kuang-Jung
AU - Li, Shaoxian
AU - Moradi, Mina
AU - Zhao, Kangning
AU - Dakhchoune, Mostapha
AU - Huang, Shiqi
AU - Shen, Yueqing
AU - Oveisi, Emad
AU - Boureau, Victor
AU - Agrawal, Kumar varoon
N1 - We acknowledge the host institution École Polytechnique Fédérale de Lausanne (EPFL) for generous support. We gratefully acknowledge Shell for financial support. Parts of the project were funded by the Swiss National Science Foundation, Assistant Professor Energy Grant (PYAPP2_173645), and European Research Council Starting Grant (805437-UltimateMembranes). K.-J.H. acknowledges the Taiwan-EPFL PhD Scholarship program funded by the Ministry of Education, Taiwan. C.V.G. is grateful to Research Foundation Flanders (FWO) for a junior postdoctoral fellowship (12ZQ420N). We thank Aurelien Bornet for his assistance in the NMR analysis.
PY - 2021/9/14
Y1 - 2021/9/14
N2 - Incorporation of a high density of molecular-sieving nanopores in the graphene lattice by the bottom-up synthesis is highly attractive for high-performance membranes. Herein, we achieve this by a controlled synthesis of nanocrystalline graphene where incomplete growth of a few nanometer-sized, misoriented grains generates molecular-sized pores in the lattice. The density of pores is comparable to that obtained by the state-of-the-art postsynthetic etching (1012 cm−2) and is up to two orders of magnitude higher than that of molecular-sieving intrinsic vacancy defects in single-layer graphene (SLG) prepared by chemical vapor deposition. The porous nanocrystalline graphene (PNG) films are synthesized by precipitation of C dissolved in the Ni matrix where the C concentration is regulated by controlled pyrolysis of precursors (polymers and/or sugar). The PNG film is made of few-layered graphene except near the grain edge where the grains taper down to a single layer and eventually terminate into vacancy defects at a node where three or more grains meet. This unique nanostructure is highly attractive for the membranes because the layered domains improve the mechanical robustness of the film while the atom-thick molecular-sized apertures allow the realization of large gas transport. The combination of gas permeance and gas pair selectivity is comparable to that from the nanoporous SLG membranes prepared by state-of-the-art postsynthetic lattice etching. Overall, the method reported here improves the scale-up potential of graphene membranes by cutting down the processing steps.
AB - Incorporation of a high density of molecular-sieving nanopores in the graphene lattice by the bottom-up synthesis is highly attractive for high-performance membranes. Herein, we achieve this by a controlled synthesis of nanocrystalline graphene where incomplete growth of a few nanometer-sized, misoriented grains generates molecular-sized pores in the lattice. The density of pores is comparable to that obtained by the state-of-the-art postsynthetic etching (1012 cm−2) and is up to two orders of magnitude higher than that of molecular-sieving intrinsic vacancy defects in single-layer graphene (SLG) prepared by chemical vapor deposition. The porous nanocrystalline graphene (PNG) films are synthesized by precipitation of C dissolved in the Ni matrix where the C concentration is regulated by controlled pyrolysis of precursors (polymers and/or sugar). The PNG film is made of few-layered graphene except near the grain edge where the grains taper down to a single layer and eventually terminate into vacancy defects at a node where three or more grains meet. This unique nanostructure is highly attractive for the membranes because the layered domains improve the mechanical robustness of the film while the atom-thick molecular-sized apertures allow the realization of large gas transport. The combination of gas permeance and gas pair selectivity is comparable to that from the nanoporous SLG membranes prepared by state-of-the-art postsynthetic lattice etching. Overall, the method reported here improves the scale-up potential of graphene membranes by cutting down the processing steps.
U2 - 10.1073/pnas.2022201118
DO - 10.1073/pnas.2022201118
M3 - Article
SN - 0027-8424
VL - 118
JO - Proceedings of the National Academy of Sciences
JF - Proceedings of the National Academy of Sciences
IS - 37
ER -