CHEMICAL ENGINEERING TRANSACTIONS VOL. 41, 2014 A publication of The Italian Association of Chemical Engineering www.aidic.it/cet Guest Editors: Simonetta Palmas, Michele Mascia, Annalisa Vacca Copyright © 2014, AIDIC Servizi S.r.l., I SBN 978-88-95608-32-7; I SSN 2283-9216 Synthesis and Characterization of Electrocatalyticgraphene/MoS2/Ni Nanocomposites Maria Sarno*, Claudia Cirillo, Anna Garamella, Paolo Ciambelli Department of Industrial Engineering and Centre NANO_MATES, University of Salerno Via Giovanni Paolo II ,132 - 84084 Fisciano (SA), Italy msarno@unisa.it NiMoS nanohybrid, consisting in nanosheets of MoS 2 mainly covering nanoparticles of NiS, capped by an oleylamine/oleic acid organic coating, has been successfully synthesized, on few layer graphene (FLG) obtained by physical exfoliation of graphite, by thermolysis of suitable precursors in organic solvent in the presence of surfactants. The samples were characterized by Raman Spectroscopy, Electron Microscopy, and X-ray diffraction, and tested for HER activity using a typical three-electrode setup. We obtained excellent HER activity, with a Tafel slope of 45 mV/dec compatible with electrochemical desorption as rate limiting step and high current density values. 1. Introduction Carbon materials are widely used supports for dispersing catalytic metal nanoparticles, due to their high surface area, effective porous structure for transferring reactants and products, good electrical conductivity required for electrochemical reactions (Kou et al., 2011) and energy application (Li et al., 2011). Graphene sheets have been used as template to deposit metal catalysts for electrocatalysis and as building blocks to form metal/graphene supports for catalysts and battery applications (Zhao et al., 2013). On the other hand, MoS 2 is a promising catalyst for electrocatalytic or photocatalytic hydrogen evolution reaction (HER) in aqueous solution (Sarno et al., 2014b), nickel is often used as HER electrocatalyst (Popczun et al., 2013), also commercially. Among the different methods to synthesize nanomaterials, one of the most promising is a “bottom-up” chemical strategy, offering many advantages, such as experimental easiness and potential low-cost fabrication (Altavilla et al., 2011; Altavilla et al., 2013). Here, we report a new one-step synthetic strategy for the preparation of few layer graphene (FLG)/NiMoS nanohybrid, consisting in nanosheets of MoS 2 laying on NiS nanoparticles, capped by an oleylamine/oleic acid organic coating, synthesized by thermal decomposition of precursors in organic solvent in the presence of surfactants, on graphene nanosheets obtained by physical exfoliation of graphite (Hernandez et al., 2008; Sarno et al., 2014a). All the samples obtained were characterized by Raman Spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy – Energy dispersive X-ray spectroscopy (TEM-EDS), thermogravimetric analysis coupled with mass spectromery (TG-DTG-MS), X-ray diffraction (XRD), and tested for HER using a typical three-electrode setup. We found that our catalysts show excellent HER activity, Tafel slope of 45 mV/dec and high current density values. 2. Experimental The synthesis was carried out using standard airless procedures and commercially available reagents. Ethanol (99.8%, Fluka) and hexane (>95%, Sigma-Aldrich) were used as received. Benzyl ether (99%), 1,2-hexadecanediol (97%), oleic acid (90%), oleylamine (70%), nickel (II) acetylacetonate (90%), 1-2- hexadecanediol (90%), ammonium tetrathiomolybdate (99.97% metal basis) were purchased from Aldrich. Graphite powder (microcrystalline, -300 mesh) was purchased from AlfaAesar. DOI: 10.3303/CET1441037 Please cite this article as: Sarno M., Cirillo C., Garamella A., Ciambelli P., 2014, Synthesis and characterization of electrocatalyticgraphene/mos2/ni nanocomposites, Chemical Engineering Transactions, 41, 217-222 DOI: 10.3303/CET1441037 217