Adsorption of 3d transition-metal atoms on two-dimensional penta-graphene: A first-principles study

The adsorption of single 3d transition metal (TM) atoms (from Sc to Zn) on a (3 × 3) penta-graphene (PG) sheet has been systematically studied by means of density-functional theory calculations. We particularly study the effect of the TM adatom on the structural, electronic, and magnetic properties when adsorbed on the PG sheet. Our calculations have shown that most of the TM adatoms are preferably adsorbed on the T₂ site (i.e., the top of the C₂ atom located at the bottom layer), while Cr, Zn, and Ni are preferably adsorbed on different B sites. The calculated band structures demonstrate that all TM-PG systems remain semiconductors such that the gap between the valence and conduction bands moves to a lower energy state relative to the Fermi level. For this reason, an apparent narrowing in the band gap values for the TM-PG systems has been predicted (0.11 – 0.97 eV) compared to the band gap of the isolated PG sheet (2.23 eV). Additionally, our results indicate that most of the TM-PG systems are magnetic, with the exception of Ni-PG and Zn-PG systems. Consequently, the engineering of the electronic properties of the TM-PG systems implies that such systems might be promising candidates for different applications.