▎ 摘　　要

The gas-adsorption behaviors of O-2 and H-2 on penta-graphene (PG) and Pt single atom@penta-graphene (Pt-PG) were investigated using density functional theory calculations. To illustrate the importance of the van der Waals (vdW) interactions, in addition to popular local density approximation (LDA) and semilocal Perdew-BurkeErnzerhof generalized gradient approximation (GGA-PBEsol) functionals, two non-local (vdW-DF2 and rev-vdW-DF2) functionals were investigated through the correlation between energetic, structural, and electronic properties. On the surface of the PG (band gap 2.3 eV), O-2 was strongly physisorbed, which reduced the O-2/PG band gap to similar to 0.75 eV and created a p-type semiconductor. The H-2 was very weakly physisorbed without any changes in the band gap. On the semimetal Pt-PG (zero band gap), the H-2 and O-2 were strongly chemisorbed which was dissociative for H-2. H-2 adsorption opens a band gap of 1.45 eV, making the H-2/Pt-PG system a semiconductor. But the O-2/Pt-PG system remains semimetal. The PG can be used for the detection of O-2 but not for H-2. The presence of the Pt atoms allows the Pt-PG system to detect the H-2 very well. LDA is suggested for investigating H-2 adsorption on both the PG and Pt-PG systems, but the non-local vdWs must be used for the O-2 adsorption study.