Heterojuncions of Graphene and Pd and Pd/Pt Alloy Nanoparticles: H2 Sensing and Potential Catalytic Applications

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

Campinas

Congreso; 26th Annual User Meeting LNLS/CNPEM (RAU); 2016

Graphene is the first two-dimensional (2D) crystalline material with outstanding properties. This has opened new avenues towards various applications including the construction of sensitive platforms. In this particular matter, decorating graphene with transition-metal catalyst nanoparticles (NPs) seems to be quite promising platform to explore into the electronic properties of the heterojunction. Thereare multiple applications which include H2 sensing, H2 storage and heterogeneous catalysts. In this work we addressed some of the aforementioned applications by chemically synthesizing alkylaminecoated Pd and Pd/Pt NPs and assembling them as films on Graphene and aminopropyl-triethoxysilane (APTES)-modified Si substrates for H2 sensing and potential catalytic applications. 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. In order to explore into the Pd-H and Pt-H interaction, we performed X-ray absortion near edge structure (XANES) in an atmosphere with and without H2. The results showed distinct film behavior depending on both; the type of NPs (Pd versus Pd/Pt alloys) and the nature of substrates. Finally, we will show some preliminary results of their catalytic reactivity.