The effect of both Pt decoration and the defects on the adsorption of graphene for SO₂

We systematically investigate the combined effect of both the defects, including single vacancy defects (SV) and Stone-Wales defects (SW), and the decoration of Pt atom on the structural, electronic, and adsorption properties of graphene for SO₂ molecule using the density functional theory (DFT). The calculations reveal that Pt atom can be stably combined on both SV defected graphene (SVG) and SW defected graphene (SWG) with the high-binding energy of −7.03 and −2.61 eV, respectively. In addition, the SO₂ molecule is chemically adsorbed on Pt-decorated graphene with SV defects and SW defects, their adsorption energies are −1.402 and −1.891 eV, respectively. The adsorption of SO₂ can significantly change the conductivity of the adsorbed system, which shows that Pt decorated SVG and SWG have good sensitivity to SO₂. Moreover, compared with Pt decorated SVG, Pt decorated SWG has better adsorption ability for SO₂ gas molecules, which corresponds to larger adsorption energy, strong orbital hybridization, and the obvious increase of conductivity. These results indicate that the combination of defects and Pt atom decoration can tune the electronic and adsorption properties of graphene, and provide insight into the application of graphene-based gas sensors for SO₂ gas molecules.