The adsorption of CO, O 2 and H 2 on Li–doped defective (8,0) SWCNT: A DFT study

LUNA, C.R.; BECHTHOLD, P.; BRIZUELA, G.; JUAN, A.; PISTONESI, C.

APPLIED SURFACE SCIENCE

ELSEVIER SCIENCE BV

Año: 2018 vol. 459 p. 201 - 207

0169-4332

This work presents a theoretical study, based on DFT calculations, about the changes induced when diatomic molecules (CO, O 2 and H 2 ) are adsorbed on defective (8,0) SWCNT doped with a Li atom. The adsorption of one Lithium atom is tested inside and outside of the nanotube containing a single vacancy. The Li atom induces a magnetic moment on the nanotube and an important reduction in its the band gap (E g ). The adsorption energy values (E ads ) for CO, O 2 and H 2 when Li is located inside, are higher than when Li is outside. The H 2 adsorption does not change the magnetic nature of the system. However, the CO and O 2 molecules reduce the magnetic moment from 1.0 µ B to 0.0 µ B . The band gap energy is reduced for CO and O 2 , while increases in the case of H adsorption. The work function (WF) value is reduced in the cases of CO and H 2 ; whereas for O 2 we observed an opposite behavior, then the final charge state of this molecule is negative. Based on our results, the system Li + defective (8,0) SWCNT can be proposed as possible candidate as gas sensor of CO,O 2 and H 2 .