The adsorption characteristics of CO, NO and NO2 on two dimensional metalloporphyrin porous nanosheets: A first-principles study

[Display omitted] •Prediction of 2D organic single-atom catalysts with high-density.•The adsorption mechanism of CO, NO and NO2.•Sensitive gas sensors for detecting and removing CO, NO and NO2.•The detection of toxic gases by detecting magnetic property without direct contact. The toxic gas molecules (TGMs) emitted from coal burning have caused great damage to environment and people’s health, so it is urgent to design effective gas sensors to detect and remove TGMs. In this work, two-dimensional metalloporphyrin porous grid nanosheets (MPP-Grids) with transition metal atom center (M = Fe, Co and Zn) were predicted to be stable structures with sufficient and high-density active sites, which could adsorb and detect toxic gases. Based on density functional theory, the bonding characteristics, temperature effect, electronic and magnetic properties of MPP-Grids adsorbed with CO, NO and NO2 were investigated. FePP-Grid was the best adsorbent for removing CO, NO and NO2 simultaneously with larger adsorption energies. According to different magnetic moment changes from −1.71 μB to 0.00, 0.96 and 0.01 μB, FePP-Grid could detect and distinguish CO, NO and NO2 in the way of detecting magnetic properties without direct contact. And ZnPP-Grid could detect and distinguish NO and NO2 in the same way. Therefore, FePP-Grid and ZnPP-Grid were promising gas sensors, which could be used for the detection of CO, NO and NO2.