The effect of Fe doping on adsorption of CO2/N2 within carbon nanotubes: a density functional theory study with dispersion corrections

A review on production of metal organic frameworks (MOF) for CO2 adsorption

The environment sustenance and preservation of global climate are known as the crucial issues of the world today. Currently, the crisis of global warming due to CO₂ emission has turned into a paramount concern. To address such a concern, diverse CO₂ capture and sequestration techniques (CCS) have been introduced so far. In line with this, Metal Organic Frameworks (MOFs) have been considered as the newest and most promising material for CO₂ adsorption and separation. Due to their outstanding properties, this new class of porous materials a have exhibited a conspicuous potential for gas separation technologies especially for CO₂ storage and separation. Thus, the present review paper is aimed to discuss the adsorption properties of CO₂ on the MOFs based on the adsorption mechanisms and the design of the MOF structures. In addition, the main challenge associated with using this prominent porous material has been mentioned.

DFT, QTAIM, and NBO investigations of the ability of the Fe or Ni doped CNT to absorb and sense CO and NO

The structures and intramolecular interactions of complexes (FeCNT-CO, FeCNT-NO, NiCNT-CO, and NiCNT-NO) formed by the Fe or Ni doped single-wall carbon nanotube (FeCNT or NiCNT) and gas CO or NO were studied using density functional theory, quantum theory of atom in molecule (QTAIM), and natural bond orbital methods. The adsorption processes of CO and NO on surfaces of FeCNT and NiCNT are chemisorption, energetically favored, exothermic, and spontaneous. High temperature is not good for adsorption. Introducing NO more obviously elongates the distances between Fe/Ni and C atoms and decreases ∠CFe(Ni)C than adding CO. QTAIM analysis shows that the covalent bonding interactions of FeCNT-NO (NiCNT-NO) are stronger than that of FeCNT-CO (NiCNT-CO). NO plays a role of electron acceptor while CO is electron donator in complexes. Electrostatic interaction of FeCNT-NO (NiCNT-NO) is stronger than that of FeCNT-CO (NiCNT-CO). The stronger intramolecular interactions of FeCNT-NO and NiCNT-NO reveal that FeCNT and NiCNT are more effective to adsorb and sense NO than CO. CO and NO considerably change the electronic properties of FeCNT and NiCNT, which is useful for designing sensors for CO and NO.

Electrocatalytically switchable CO2 capture: first principle computational exploration of carbon nanotubes with pyridinic nitrogen

Carbon nanotubes with specific nitrogen doping are proposed for controllable, highly selective, and reversible CO2 capture. Using density functional theory incorporating long-range dispersion corrections, we investigated the adsorption behavior of CO2 on (7,7) single-walled carbon nanotubes (CNTs) with several nitrogen doping configurations and varying charge states. Pyridinic-nitrogen incorporation in CNTs is found to induce an increasing CO2 adsorption strength with electron injecting, leading to a highly selective CO2 adsorption in comparison with N2 . This functionality could induce intrinsically reversible CO2 adsorption as capture/release can be controlled by switching the charge carrying state of the system on/off. This phenomenon is verified for a number of different models and theoretical methods, with clear ramifications for the possibility of implementation with a broader class of graphene-based materials. A scheme for the implementation of this remarkable reversible electrocatalytic CO2 -capture phenomenon is considered.