A DFT study of H2CO and HCN adsorptions on 3d, 4d, and 5d transition metal-doped graphene nanosheets

The binding of 3d (Sc, Ti, V), 4d (Y, Zr, Nb), and 5d (La, Hf, Ta) transition metals on graphene nanosheet (TM-GNS) with hydrogen-terminated edges and the adsorption of H2CO and HCN molecules on the pristine and TM-doped GNSs were theoretically studied using a density functional theory method. The calculation showed that all TM atoms had strong binding with GNS, in which the Ta atom displayed the strongest interaction with GNS. The H2CO and HCN molecules showed much stronger adsorption on the TM-GNSs than that on the pristine GNS. The H2CO showed stronger interactions with TM-GNSs than that of HCN, in which the Ta-doping displayed the strongest interactions between the GNS and H2CO or HCN. The adsorption interactions induced dramatic changes of TM-GNS electronic properties. The results revealed that the adsorption strength and sensor ability of GNS can be greatly improved by introducing appropriate TM dopants. Therefore, TM-doped GNSs are suitable for application in H2CO and HCN storage and sensor.