LAUSR

The adsorptions of CO and CO2 on pristine and transition metal-doped graphene nanoflakes (GNFs) were theoretically investigated using the density functional theory. Doping of a series of 3d transition metals (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, or Zn) to pristine GNF can significantly enhance the adsorption abilities of GNF, leading to a stronger interaction between gas molecule and GNF. Among all transition metal-doped GNFs, Cr-doped GNF shows the highest adsorption strength toward both of CO and CO2 molecules. Calculated electronic properties for studied systems indicate that TM-doped GNFs present high sensitivity to CO and CO2 molecules. In addition, the adsorptions of the CO and CO2 molecules on TM-doped GNF are influenced on the electronic conductance of the TM-doped GNF. The results of this study may serve to enhance the application of effective CO and CO2 gas storage and sensor to preserve the environment based on GNF. Graphical abstract Graphical abstract