Modulating magnetic characteristics of Pt embedded graphene by gas adsorption (N2, O2, NO2, SO2)

•The effect of gas adsorption on the magnetic properties of Pt-graphene was studied.•N2, O2, NO2, and SO2 gas molecules were chemisorbed on Pt-graphene system.•Spin distribution was different for each chemisorbed gas molecule.•Application of Pt-graphene in gas sensor and spintronic devices is suggested. The effect of gas adsorption on the change in magnetic properties of platinum doped graphene (Pt-graphene) system was investigated using first-principles density-functional theory (DFT). Four chemisorbed gas molecules (N2, O2, NO2, SO2) on Pt-graphene each induced a different type of magnetic properties. For N2 adsorption, there was no spin polarization. However, for the other cases, magnetic properties were altered by occurring spin polarization. O2 adsorption led to local polarization on the gas molecule, and two types of complete polarization were introduced on Pt-graphene by NO2 and SO2 adsorption. Also, in the latter two cases, an interesting difference was found in the spin direction of gas and Pt-graphene. NO2 adsorption induced the same spin direction on the adsorbate and substrate, while SO2 adsorption introduced the opposite spin directions. Thus, these differences in magnetic properties of the Pt-graphene according to the type of adsorbed gas molecules are expected to play a vital role in application as gas sensor or spintronic devices.