Limits...
Conductive Graphitic Carbon Nitride as an Ideal Material for Electrocatalytically Switchable CO2 Capture.

Tan X, Kou L, Tahini HA, Smith SC - Sci Rep (2015)

Bottom Line: At saturation CO2 capture coverage, the negatively charged g-C4N3 nanosheets achieve CO2 capture capacities up to 73.9 × 10(13) cm(-2) or 42.3 wt%.In addition, these negatively charged g-C4N3 nanosheets are highly selective for separating CO2 from mixtures with CH4, H2 and/or N2.These predictions may prove to be instrumental in searching for a new class of experimentally feasible high-capacity CO2 capture materials with ideal thermodynamics and reversibility.

View Article: PubMed Central - PubMed

Affiliation: Integrated Materials Design Centre (IMDC), School of Chemical Engineering, UNSW Australia, Sydney, NSW 2052, Australia.

ABSTRACT
Good electrical conductivity and high electron mobility of the sorbent materials are prerequisite for electrocatalytically switchable CO2 capture. However, no conductive and easily synthetic sorbent materials are available until now. Here, we examined the possibility of conductive graphitic carbon nitride (g-C4N3) nanosheets as sorbent materials for electrocatalytically switchable CO2 capture. Using first-principle calculations, we found that the adsorption energy of CO2 molecules on g-C4N3 nanosheets can be dramatically enhanced by injecting extra electrons into the adsorbent. At saturation CO2 capture coverage, the negatively charged g-C4N3 nanosheets achieve CO2 capture capacities up to 73.9 × 10(13) cm(-2) or 42.3 wt%. In contrast to other CO2 capture approaches, the process of CO2 capture/release occurs spontaneously without any energy barriers once extra electrons are introduced or removed, and these processes can be simply controlled and reversed by switching on/off the charging voltage. In addition, these negatively charged g-C4N3 nanosheets are highly selective for separating CO2 from mixtures with CH4, H2 and/or N2. These predictions may prove to be instrumental in searching for a new class of experimentally feasible high-capacity CO2 capture materials with ideal thermodynamics and reversibility.

No MeSH data available.


The adsorption energies of a CO2 on negatively charged g-C4N3 and the charge transfer between CO2 and g-C4N3 as functions of charge densities.The gray area indicates the adsorption region.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4664948&req=5

f5: The adsorption energies of a CO2 on negatively charged g-C4N3 and the charge transfer between CO2 and g-C4N3 as functions of charge densities.The gray area indicates the adsorption region.

Mentions: Figure 5 shows the adsorption energies of a CO2 on negatively charged g-C4N3 and the charge transfer between CO2 and g-C4N3 as functions of charge densities. For small charge density case (<13.9 × 1013 cm−2), the adsorption energy of CO2 is small (0.24 ~ 0.35 eV), and charge transfer between CO2 and g-C4N3 is less than 0.06 e−. When charge density is larger than 13.9 × 1013 cm−2, the adsorption energy of CO2 and the charge transfer from g-C4N3 to CO2 increase dramatically with increasing charge density, indicating the CO2 molecule can only adsorb on negatively charged g-C4N3 with large charge density. Considering the adsorption energies of CO2 on other high-performance adsorbents is 0.4−0.8 eV 6, we define the minimum charging density for CO2 capture on negatively charged g-C4N3 is about 17.0 × 1013 cm−2.


Conductive Graphitic Carbon Nitride as an Ideal Material for Electrocatalytically Switchable CO2 Capture.

Tan X, Kou L, Tahini HA, Smith SC - Sci Rep (2015)

The adsorption energies of a CO2 on negatively charged g-C4N3 and the charge transfer between CO2 and g-C4N3 as functions of charge densities.The gray area indicates the adsorption region.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664948&req=5

f5: The adsorption energies of a CO2 on negatively charged g-C4N3 and the charge transfer between CO2 and g-C4N3 as functions of charge densities.The gray area indicates the adsorption region.
Mentions: Figure 5 shows the adsorption energies of a CO2 on negatively charged g-C4N3 and the charge transfer between CO2 and g-C4N3 as functions of charge densities. For small charge density case (<13.9 × 1013 cm−2), the adsorption energy of CO2 is small (0.24 ~ 0.35 eV), and charge transfer between CO2 and g-C4N3 is less than 0.06 e−. When charge density is larger than 13.9 × 1013 cm−2, the adsorption energy of CO2 and the charge transfer from g-C4N3 to CO2 increase dramatically with increasing charge density, indicating the CO2 molecule can only adsorb on negatively charged g-C4N3 with large charge density. Considering the adsorption energies of CO2 on other high-performance adsorbents is 0.4−0.8 eV 6, we define the minimum charging density for CO2 capture on negatively charged g-C4N3 is about 17.0 × 1013 cm−2.

Bottom Line: At saturation CO2 capture coverage, the negatively charged g-C4N3 nanosheets achieve CO2 capture capacities up to 73.9 × 10(13) cm(-2) or 42.3 wt%.In addition, these negatively charged g-C4N3 nanosheets are highly selective for separating CO2 from mixtures with CH4, H2 and/or N2.These predictions may prove to be instrumental in searching for a new class of experimentally feasible high-capacity CO2 capture materials with ideal thermodynamics and reversibility.

View Article: PubMed Central - PubMed

Affiliation: Integrated Materials Design Centre (IMDC), School of Chemical Engineering, UNSW Australia, Sydney, NSW 2052, Australia.

ABSTRACT
Good electrical conductivity and high electron mobility of the sorbent materials are prerequisite for electrocatalytically switchable CO2 capture. However, no conductive and easily synthetic sorbent materials are available until now. Here, we examined the possibility of conductive graphitic carbon nitride (g-C4N3) nanosheets as sorbent materials for electrocatalytically switchable CO2 capture. Using first-principle calculations, we found that the adsorption energy of CO2 molecules on g-C4N3 nanosheets can be dramatically enhanced by injecting extra electrons into the adsorbent. At saturation CO2 capture coverage, the negatively charged g-C4N3 nanosheets achieve CO2 capture capacities up to 73.9 × 10(13) cm(-2) or 42.3 wt%. In contrast to other CO2 capture approaches, the process of CO2 capture/release occurs spontaneously without any energy barriers once extra electrons are introduced or removed, and these processes can be simply controlled and reversed by switching on/off the charging voltage. In addition, these negatively charged g-C4N3 nanosheets are highly selective for separating CO2 from mixtures with CH4, H2 and/or N2. These predictions may prove to be instrumental in searching for a new class of experimentally feasible high-capacity CO2 capture materials with ideal thermodynamics and reversibility.

No MeSH data available.