Open AccessMultipulsed Millisecond Ozone Gasification for Predictable Tuning of Nucleation and Nucleation-Decoupled Nanopore Expansion in Graphene for Carbon Capture
Author(s) -
Kenneth J. Hsü,
Luis Francisco Villalobos,
Shiqi Huang,
HengYu Chi,
Mostapha Dakhchoune,
Wan-Chi Lee,
Guangwei He,
Mounir Mensi,
Kumar Varoon Agrawal
Publication year - 2021
Publication title -
acs nano
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.554
H-Index - 382
eISSN - 1936-086X
pISSN - 1936-0851
DOI - 10.1021/acsnano.1c02927
Subject(s) - nucleation , materials science , nanopore , millisecond , permeance , etching (microfabrication) , graphene , yield (engineering) , nanotechnology , nanoporous , carbon fibers , chemical engineering , selectivity , layer (electronics) , chemical physics , chemistry , composite material , organic chemistry , composite number , physics , astronomy , engineering , catalysis
Predictable and tunable etching of angstrom-scale nanopores in single-layer graphene (SLG) can allow one to realize high-performance gas separation even from similar-sized molecules. We advance toward this goal by developing two etching regimes for SLG where the incorporation of angstrom-scale vacancy defects can be controlled. We screen several exposure profiles for the etchant, controlled by a multipulse millisecond treatment, using a mathematical model predicting the nucleation and pore expansion rates. The screened profiles yield a narrow pore-size-distribution (PSD) with a majority of defects smaller than missing 16 carbon atoms, suitable for CO 2 /N 2 separation, attributing to the reduced pore expansion rate at a high pore density. Resulting nanoporous SLG (N-SLG) membranes yield attractive CO 2 permeance of 4400 ± 2070 GPU and CO 2 /N 2 selectivity of 33.4 ± 7.9. In the second etching regime, by limiting the supply of the etchant, the nanopores are allowed to expand while suppressing the nucleation events. Extremely attractive carbon capture performance marked with CO 2 permeance of 8730 GPU, and CO 2 /N 2 selectivity of 33.4 is obtained when CO 2 -selective polymeric chains are functionalized on the expanded nanopores. We show that the etching strategy is uniform and scalable by successfully fabricating high-performance centimeter-scale membrane.