Citation:

Abstract:

Single walled carbon nanotubes has been identified as a potential material for CO2 gas sensing, capture and storage, however, comprehensive understanding of adsorption/desorption mechanisms that drives these application is still lacking yet such knowledge is essential for mainstream application of SWCNT in the identified areas. In this work, we use Density Functional Theory to study CO2 storage and sensing on SWCNTs with the aim of unraveling how such applications can be enhanced with the introduction of dopants with emphasis on Al, B, N and S as potential dopants. It is observed that doping SWCNT with N and B can be easily achieved compared to Al and S, which reported high and positive formation energies thus, can only be achieved under non-equilibrium condition. N doping improves SWCNT interaction with CO2 molecules and when subjected to thermal treatment the adsorbed CO2 is release to the atmosphere at 423 K thus a reusable sensing element can be achieved. It was further observed that the diffusion of molecular CO2 within the proximity of Al and S dopants in SWCNT matrix is not favored, while N and B doped SWCNT tend to have lower barrier energies to CO2, thus can offer better control of carbon storage. Our finding can assist in the design and optimization of SWCNT for energy and environmental applications.