Size and dispersion control of Pt nanoparticles grown upon graphite-derived nanosheets

This is the latest version of this item.

Official URL: http://dx.doi.org/10.1080/00986445.2014.968714

Graphite oxide (GO) nanosheets, graphene nanosheets (GNS), and nanocomposites comprising of GO or GNS coated with polypyrrole (PPy) were prepared and assessed for their ability to influence the surface deposition and growth of Pt nanoparticles. GO was obtained from graphite via oxidation and exfoliation, and GNS was obtained from GO in a subsequent reduction. Both GO and GNS were coated with PPy via in situ polymerization of pyrrole (Py), forming surface-enhanced materials. Scanning electron microscope, energy-dispersive x-ray, transmission electron microscopy, electron energy loss spectroscopy, Raman, and atomic force microscope findings showed that the Pt nanoparticle loading, agglomeration size, aggregate morphology, and surface dispersion varied according to the nanosheet surface, nanocomposite type, and Py= nanosheet feed ratio. Surface oxygen functionalization along GO, GNS, and their nanocomposites influenced the loading, dispersivity, and morphology of nanoparticle agglomerates. PPy= GO nanocomposites yielded an improved nanoagglomerate surface dispersion and loading compared to samples. The PPy-coated substrates offered a greater intrinsic propensity for redox processes, resulting in higher Pt loadings. Additionally, these nanocomposites provided more surface reduction sites compared to bare nanosheets, and the additional sites contributed toward forming smaller, more homogeneously dispersed Pt nanoparticle agglomerates. Bringing together the electrical properties of PPy and physicomechanical traits of carbon nanosheets, it follows to reason that the nanocomposites produced, particularly GO-based nanocomposites, offer promise as a nanoparticle support material for use in catalysis, electrocatalysis, and hydrogen storage.