Stabilization of platinum nanoparticles on graphene by non-invasive functionalization

We have performed DFT-LDA calculations on the interaction of graphene with benzyl mercaptan, and on the role of the mercaptan in the adhesion of Pt nanoparticles. Our calculations indicate that Pt nanoparticles adhere more strongly to defect-free graphene than does benzyl mercaptan, which is essentially physisorbed. The role of the physisorbed mercaptan is to offer an abundance of -SH sites, to which the Pt bonding energy is greater than to graphene. This would lead to a higher deposition density of nanoparticles, which are decorated with chemisorbed mercaptan. The presence of benzyl mercaptan on the surfaces of Pt particles should also contribute to hindering the metallic phase coalescence. (C) 2009 Elsevier Ltd. All rights reserved.