Pd AND Pd/Pt ALLOY NANOPARTICLES ON GRAPHENE USED FOR H2 SENSING

MARIA CELESTE DALFOVO; CRISTIÁN HUCK IRIART; VESNA STANIC; LISANDRO GIOVANETTI; FELIX G. REQUEJO; FRANCISCO J. IBAÑEZ

La Plata

Congreso; XI Reunión Anual de la AACr; 2015

Solid-state films containing Pd nanoparticles (NPs) are used in applications such as H2 sensing,[1],[2] H2 storage[3] and heterogeneous catalysts (hydrogenation reactions),[4]. Since the discovery of Graphene (G), the first two-dimentional (2D) crystalline material, new avenues have opened towards the construction of sensitive platforms. Graphene?s π-electrons which are exposed in 2D surface exhibit unusual and unique chemical/electronic properties compared to its counterpart, graphite.[5] The G film demonstrated the ability to be spontaneously decorated with NPs coated with organic stabilizers[6] forming a new class of nanomaterials known as heterojunctions. In this work we chemically synthesized alkylamine-coated Pd and Pd/Pt nanoparticles (NPs) and assembled them as films on Graphene/Si and aminopropyl-triethoxysilane (APTES)/Si substrates for H2 sensing. Here, we performed small-angle X-ray scattering (SAXS) and grazing incidence small-angle X-ray scattering (GISAXS) experiments in order to explore into the shape, order and size of NPs solutions and in solid-state films, respectively. Real-time GISAXS was used to monitor interparticle distance, NPs size and film structure upon H2 sensing. Preliminary results showed distinct film behavior depending on both; the type of NPs (Pd versus Pd/Pt alloys) and the nature of substrates. The main goal of this work is explore into the NPs film restructuring during the H2 sensing and correlate them with the same type of NPs films in chemiresistive H2 sensors.References: [1] Ibañez F.J. et al. J. Am. Chem. Soc., vol. 130, n.o 2, pp. 622-633, 2008. [2] Moreno, M. et al. J. Am. Chem. Soc., vol. 133, n.o 12, pp. 4389-4397,2011. [3] Yamauchi, M. et al. ChemPhysChem, vol. 10, n.o 15, pp. 2566-2576, 2009. [4]