  Purpose: We investigated the interaction of O and O2 on monolayer Niobium
Diselenide (NbSe2) to provide theoretical predictions about the electronic
properties of the complexes using First principles calculations in Quantum
Espresso 6.7. As known, considering impurities in pristine nanomaterials like
NbSe2 is very important as it can alter some of its properties.
  Method: In this paper, we performed some topological analyses on the
electronic densities and electronic structures calculations to O- and O2-NbSe2
complexes. Charge Density Difference (CDD) and Bader charge analysis reveal
that O and O2 acted as oxidizing agents and accumulated electronic charges from
the NbSe2.
  Results: The electronic properties calculations of the complexes showed that
the metallic behavior of NbSe2 is preserved after O and O2 adsorption.
Calculations of the net charge transfer revealed that the atomic and molecular
oxygen has accumulated electronic charges while the NbSe2 has depleted
electronic charges. These results showed the possibility of tailoring the
electronic properties of NbSe2.
  Conclusion: The interaction of O and O2 with the monolayer NbSe2 caused
charge redistributions while maintaining the metallicity of the NbSe2. In all
circumstances, the results are consistent with the established works which show
the possibility of modifying the electronic properties of NbSe2 that could open
some potential applications in nanotechnology and other nanoelectronics-related
devices.
