A DFT study of defects in SnO monolayer and their interaction with O2 molecule

[Display omitted] •The origin of magnetism by impurity defects in SnO monolayer is investigated by density functional theory.•Both the Sn and O vacancy reduce the band gap and shows semiconductor behavior.•The substitution of B and N demonstrates the ferromagnetic semiconductor nature of the SnO monolayer.•The vacancies significantly enhance the chemical activity towards O2 molecule in the defective SnO monolayer.•The adsorption strength of the O2 molecule may be beneficial for catalysis like an oxygen reduction reaction (ORR). In this study, we have employed the first-principles calculations to investigate the influence of various point defects such as vacancy and impurities in SnO monolayer (ML) through the electronic and magnetic properties. Our results demonstrate the magnitude of the formation energy decreases in the order of B > C > N, which may be influenced by the different electronegativities. All these defective systems, defects could induce some defect energy levels in the band gap and significantly enhance the adsorption strength for capture O2 molecule. The analysis of adsorption energy of O2 molecule and electronic properties reveal the strong interaction of free O2 with the defective monolayer. These findings may provide useful information to understand the origin of magnetism in the SnO monolayer in the presence of defects. Moreover, our work may provide a useful way to use of SnO ML as a catalyst in oxygen reduction reaction and gas sensor devices.