Adsorption of HCN on reduced graphene oxides: a first-principles study.

The interactions between HCN and reduced graphene oxides (rGO) are investigated using first-principles calculations with M06-2X functional. The results show that the adsorption of HCN on rGO is generally stronger than that on graphene, which is due to the presence of the active defect sites in rGO, such as the hydroxyl, epoxide, and carboxyl functional groups and even the carbon atom near these groups. The interaction between HCN and rGO with oxygen-containing group can result in the formation of hydrogen bonds, N · · · H and O · · · H. The adsorption of HCN on rGO depends on the type and location of oxygen-containing group in rGO. Carboxyl group on rGO is much more attractive for HCN than hydroxyl and epoxide group. The adsorption of HCN is much stronger in rGO with oxygen-containing group on the surface than that at the edge. The adsorption of HCN on rGO with carboxyl attached to vacancy on the surface is the strongest.