Spontaneous formation of metallic nanostructures on highly oriented pyrolytic graphite (HOPG): an ab initio and experimental study

Abstract

We have investigated the decoration of step-edges of HOPG by Ag, Au and Pt using experimental and theoretical approaches. Metallic nanowires can be formed on bare or functionalized step-edges. Energy dispersion analysis indicates the presence of oxygenated groups. The experiments showed that nanowires can be obtained with the three metals along the step-edges, but the shapes and morphologies are very different. We have found that the interaction between the metal wires and the carbon follows the sequence: Pt > Au > Ag. The electronic redistribution between the atoms participating in the bond between the metallic nanowire and the step-edges shows a complicated pattern. The density of electronic states projected on the different atoms indicates that there are different orbitals participating in the bonds.

Surface-Limited Electrodeposition of Continuous Platinum Networks on Highly Ordered Pyrolytic Graphite

“…Spontaneous deposition of Pt agglomerates, nanoparticles, and networks on HOPG was induced from water as well as non-aqueous polar solvents [ 24 , 25 , 26 ] and was explained in terms of the reduction of Pt by oxidized defect sites on the surface and step-edges [ 24 ]. However, the mechanism appears to be more complex, involving not only graphite step-edges, but also hydrogenated sites [ 27 , 28 ]. As a consequence, Pt nuclei may be already present before the application of the overpotential to the electrode [ 28 ].…”

Electron microscopy dataset for the recognition of nanoscale ordering effects and location of nanoparticles

“…Caused by specific particle-surface interactions, ordering of metal nanoparticles and formation of specific geometrical arrangements/patterns has been observed in a variety of nanoscale materials [14][15][16][17][18][19][20] . However, it is difficult to isolate such unique structural arrangements in a stable form for collection of datasets.…”

Spontaneous selective deposition of iron oxide nanoparticles on graphite as model catalysts

“…[46][47][48] Metal seed sites could be used as a way to selectively deposit material using activated areas to plant nucleation sites for further growth assemblies of nanoparticles. Many groups have utilized physical vapor deposition via metal evaporation 47,[49][50][51][52][53][54][55][56] or electrodeposition to deposit metal nanoparticles on carbon supports. [57][58][59] Soluble metallic precursors have been used previously to deposit and reduce metal nanoparticles onto graphitic materials such as graphite, graphene and carbon nanotubes.…”