Abstract
Mitigating the most extreme potential effects of climate change due to fossil fuel burning requires unprecedented global carbon sequestration. The materials used for carbon capture must be renewable, economically feasible, abundant, and recyclable with the ability to recover the adsorbed gas. Carbon quantum dots (CQD) are evaluated as materials to decorate the interior pore space of model carbon surfaces to achieve selective carbon dioxide adsorption from gas mixtures. We used classical molecular dynamics (MD) simulation to evaluate the effect of CQD size and composition on the selectivity of CO2 relative to N2 and O2. The CQDs are modified either through nitrogen doping of the interior aromatic structure or functionalization of the edges with amine groups. CQDs show selective adsorption for CO2 relative to N2 and O2 in all cases. The magnitude of the selectivity is a function of CQD size and the amount of doping and functionalization. In this exploratory study, a maximum CO2:N2 selectivity of 4.3 and CO2:O2 selectivity of 3.1 were obtained on isolated CQDs at 300 K without structural optimization. This preliminary computational study sets the framework for optimizing the CQD atomic architecture on a CQD/AC adsorbent.
Original language | English |
---|---|
Pages (from-to) | 13639-13650 |
Number of pages | 12 |
Journal | Journal of Physical Chemistry C |
Volume | 127 |
Issue number | 28 |
DOIs | |
State | Published - Jul 20 2023 |
Externally published | Yes |
Funding
This research was supported by a grant from the U.S. Department of Agriculture AFRI Grants.gov no. GRANT13390059. M.B. received partial support from the Center for Materials Processing, a Tennessee Higher Education Commission (THEC). D.H. acknowledges support from the USDA National Institute of Food and Agriculture, Hatch Project 1012359.