CARBON 2016 - the World Conference on Carbon
Pennsylvania, United States
Our partner Ferdinand Hof from CNRS will participate at the CARBON 2016 - the World Conference on Carbon which will be helded in Penn State University, USA from the 10-15 July .
On Thurdays 14 at 15:40 to 16:40, "GICs of Nanocarbons and their Role as Effective Reducing Agent" will be presented by:
Ferdinand Hof1,2, Kai Huang1,2, Alessandro Boni3, Giovanni Valenti3, Katerina Kampioti1,2, Alain Derré1,2, Catharina Paukner4, Francesco Paolucci3, Alain Penicaud1,2*
1CNRS, Centre de Recherche Paul Pascal (CRPP), UPR 8641, F-33600 Pessac, France.
2Université Bordeaux, CRPP, UPR 8641, F-33600 Pessac, France.
3Dipartimento di Chimica “G. Ciamician”, Università di Bologna, 40126 Bologna, Italy.
4FGV Cambridge Nanosystems, CB5 8HY Cambridge, United Kingdom.
Graphite intercalation compounds (GICs) can be readily exfoliated to monolayer graphene in organic solvents without sonication treatment by stirring. These GIC solutions are composed of charged graphene layers.1,2 Due to their size and surface area, graphitic nano carbons are an interesting and promising carbon alternative for various applications. In this study, sustainable synthetic graphitic nano carbons have been used as starting material to synthesize metal nanoparticle/nano carbon composite materials with remarkable electrocatalytic activity.
We will demonstrate that graphitic nano carbons can be intercalated by potassium metal. The intercalated graphitic nano carbon can directly be solvated in THF by stirring and these solutions have been characterized intensively. Additionally, their reducing character has been exploited to generate metal nanoparticles attached to the framework of the carbon. The characteristics of the as generated composite materials have been studied in detail by various techniques such as HR-TEM, TGA, XRD, XPS among others and their catalytic properties in terms of the oxygen reduction reaction (ORR) have been explored.
RESULTS AND DISCUSSION
A rigorous study on nano sized graphitic material will be presented. It will be demonstrated that graphitic nano carbons with lateral sizes bellow 50 nm, in analogy to large flake size graphite, can be intercalated successfully by potassium metal. This material can be dissolved in absolute organic solvents by the aid of stirring and these solutions are thermodynamically stable.
Nanoparticle graphene composite have attracted interested due to the synergistic effects of properties of the graphene as well as nanoparticles.3 Up to date, the vast majority of examples published on the generation of NP/graphene composites rely on surfactant/water baseddispersions of graphene or graphene oxide and on the addition of metal salt as well as reducing agent to that dispersion.4 It has been demonstrated that potassium intercalated GICs are an excellent reducing agent used to generate platinum nanoparticles attached to graphitic surface.5
GICs made out of the nano sized graphitic material can be efficiently used to synthesize nanoparticles (NP). The presented procedure has advantages over the conventional methods, as the reduction of the metal takes place in close proximity of the carbon lattice. Furthermore, the addition of any further reduction agent can be avoided, because the charged graphene itself serves as a reducing agent in the generation of the nanoparticles.
Carbon nano materials are promising materials for electro catalytic application thanks to their high surface areas, electrical conductivity and stability in acidic or basic aqueous solutions.6
This as-produced material exhibits a unique size distribution and interesting morphology. The conductivity within the composite is ensured by the graphene layers connecting the nanoparticles to the electrodes. Therefore, high electro catalytic activity in the oxygen reduction reaction (ORR), electron transfer numbers close to four and long term stability have been observed for this nano carbon / nano particle composite material.
Funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement No 603488 (Plascarb project) is acknowledged.
1. Pénicaud A., et al. (2013). Acc. Chem. Res. 46 (1), 129–137.
2. Vallés C., et al. (2008) J. Am. Chem. Soc. 130, 15802–15804.
3. Xia, W., et al. (2016) Angew. Chem. Int. Ed. 55 (8) 2650-2676.
4. Yin, P. T., et al (2015) Chem. Rev. 115 (7), 2483–2531.
5. Furstner, A., et al (1989) J. Catal. 118 (2), 502–506.
6. Mazzaro, R., et al (2015) ChemistryOpen 4 (3), 268-273.