skip to main content

This content will become publicly available on March 24, 2015

Title: Enhanced gas adsorption on graphitic substrates via defects and local curvature: A density functional theory study

Using van-der-Waals-corrected density functional theory calculations, we explore the possibility of engineering the local structure and morphology of high-surface-area graphene-derived materials to improve the uptake of methane and carbon dioxide for gas storage and sensing. We test the sensitivity of the gas adsorption energy to the introduction of native point defects, curvature, and the application of strain. The binding energy at topological point defect sites is inversely correlated with the number of missing carbon atoms, causing Stone–Wales defects to show the largest enhancement with respect to pristine graphene (~20%). Improvements of similar magnitude are observed at concavely curved surfaces in buckled graphene sheets under compressive strain, whereas tensile strain tends to weaken gas binding. Trends for CO2 and CH4 are similar, although CO2 binding is generally stronger by ~4 to 5 kJ mol–1. Furthermore, the differential between the adsorption of CO2 and CH4 is much higher on folded graphene sheets and at concave curvatures; this could possibly be leveraged for CH4/CO2 flow separation and gas-selective sensors.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [3]
  1. Indian Institute of Science, Bangalore (India)
  2. Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore (India); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  3. Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore (India)
Publication Date:
OSTI Identifier:
1325864
Report Number(s):
LLNL-JRNL-643967
Journal ID: ISSN 1932-7447
Grant/Contract Number:
AC52-07NA27344
Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 118; Journal Issue: 15; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; 03 NATURAL GAS; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 25 ENERGY STORAGE