Adsorption of single platinum atom on the graphene oxide: The role of the carbon lattice
Journal
Journal of Physical Chemistry C
Journal Volume
115
Journal Issue
24
Pages
12023-12032
Date Issued
2011
Author(s)
Abstract
We present the density functional calculations for the adsorption of a single platinum (Pt) atom on the 2-fold bridged-oxygen (Ob) covered graphene (graphene oxide, GO). We found the incoming Pt at low kinetic energies prefers to interact with only one Ob and the reaction weakens the coupling of the Ob with the underlying two carbon atoms to give rise to an upward tilted Pt�VOa configuration with the Oa singly connected to one of the underlying carbon (C1L) and leaving a semifilled and lone-paired orbital on the other carbon (C*). The highly reactive and long-lived C* plays an important role determining the energy barriers and branching nature of the subsequent reaction pathways. By being long-lived, reactions of the C* spilt into the early- and late-C* pathways depending when the long-lived C* is participated in the reaction. The early-C* pathways involve direct reactions of the C* with either the Pt or the neighboring carbons with low energy barriers (Ea < 0.3 eV) and give rise to stable local minimum states. In contrast, the C* in the late-C* pathways remains a radical such that the product states are less stable and the reactions that follows can again split into the early- and late-C* manifolds. This bifurcation stops when the C* quenches. To our surprise, we found the C*, via a rehybridization from sp3 to sp2 with Ea = 0.23 eV, can attack the C1L that is singly connected to the Pt�VOa on the Oa end to give rise to the ejection of the Pt�VO molecule from the GO surface. This self-cleaning mechanism indicates that a molecule chemisorbed on the carbon-based surface can be removed with an Ea approximately equal to that for the sp3-to-sp2 rehybridization of the carbon lattice.
SDGs
Publisher
American Chemical Society
Type
journal article