Greatly enhanced adsorption of platinum on periodic graphene nanobuds: A first-principles study

The structural and electronic properties of platinum atom adsorbed on periodic graphene nanobuds (PGNBs) have been investigated and compared with graphene by means of density functional theory (DFT) calculations. Our result based on the generalized gradient approximation has been validated by the state-of-the-art B3LYP level of theory for Pt adsorption on the graphene surface. We demonstrate that the bridge site over the C-C bond center intervening between two hexagonal rings of type I PGNB and the hollow site over the nonagonal ring center of type II PGNB serve as the most thermodynamically favorable states amongst several considering starting configurations. The binding energies of about 3.34 and -3.78 eV were obtained for I PGNB and II PGNB, respectively, within the BSSE corrections, which are more stronger than the Pt binding energy of 2.12 eV for a pure graphene. The electronic structures for the most favorite configurations of Pt atom adsorbed on the systems of interest, in terms of the Mulliken population, the electronic density of states (DOS), and the projected density of states (PDOS) analysis have been discussed. The stability of the Pt-PGNBs and Pt-graphene complexes was confirmed within ab initio molecular dynamics simulation carrying out at ambient temperature. We also indicate that oxygen binding energies at the most energetically favorable configurations on the Pt-PGNB I and Pt-PGNB II complexes are weaker than the O-2 binding energy on a Pt-graphene complex. The very desirable Pt binding energy obtained accompanied by high specific surface area (because of fastened C-60 molecules) and relatively weaker O-2 binding energy of PGNBs compared with the pristine graphene lead to experimentally apprehend these novel hybrid nanostructured materials as a superior media for Pt adsorption. Our study recommends possible avenues for intensification the stability and electro-catalytic activity of platinum atoms on PGNB surfaces through hybrid engineering. (C) 2015 Elsevier B.V. All rights reserved.