Day 1 :
Researcher, Institute of Materials Science of Mulhouse (IS2M-CNRS), France
Keynote: Design of Pd-based nanoalloy particles confined into mesoporous carbon: Size, composition and confinement effects on the interactions with hydrogen
Time : 10:00-10:30
Camelia Matei Ghimbeu is a Researcher at Institute of Materials Science of Mulhouse (IS2M-CNRS), France. She received her PhD from University of Metz in 2007, France and TU Delft, The Netherlands and her Habilitation in 2015 from University of Haute Alsace, France. She is the author of 55 articles and about 100 communications, her research interests are focused on the design of carbon hybrid materials with controlled characteristics for energy storage and environmental applications. She is animating the research axe “Carbon and Hybrid Materials” at IS2M, and she is member of French Network of Electrochemical Storage of Energy (RS2E).
Supported metal nanoparticles (NPs) with well controlled size, dispersion and shape are of great interest in many fields of applications. They exhibit large surface to volume ratio, faster molecular diffusion pathways and synergetic effects rising from the interaction with the support. Mesoporous carbons are widely employed to support such particles affording good stabilization through nanoconfinement effects leading to small and well dispersed NPs. Supported Pd-based alloys with noble or transition metals on carbon are tremendously studied in catalysis while hydrogen storage studies are scarce. In the present work two main strategies were developed to synthesize a series of Pdx-M100-x alloys NPs (where M=Co, Ni, Rh, Pt and x=10, 25, 50, 75, 90) having different compositions, tunable particle size and location in the carbon network. The first approach is the incipient wetness impregnation of carbon host with a metallic solution, followed by hydrogen reduction at 300-500°C while the second approach is a one-pot method where the metallic particles are formed in-situ during the synthesis of carbon framework at 600°C. The optimization of NPs size was achieved by tuning several metal salt type, carbon precursors, cross-linkers and thermal reduction temperature while their location was directed mainly by the type of synthesis approach. The impregnation
favor the NPs location into the pores, while the one-pot in the walls of carbons. For several studied systems, alloy particles were formed in the whole composition range as highlighted by the linear relationship between the lattice parameter and the composition (Fig. 1a). Small particles with sizes ranging between 1.5 and 50 nm were prepared (Fig.1), the incipient method allowing obtaining always smaller particle sizes than the one-pot method (Fig. 1left). The hydrogen interactions with the nanoalloys were strongly influenced by their composition, size and confinement in the carbon network.
CSIC Research Professor, Catalan Institute of Nanoscience and Nanotechnology, Spain
Keynote: Nanofluids for energy applications
Pedro Gomez-Romero has completed his PhD in Chemistry from Georgetown University, USA in 1987 with Distinction. He served as a Full Professor and Group Leader
of NEO-Energy lab at ICN2 (CSIC), Sabbatical at the National Renewable Energy Laboratory, USA (1998-99), Vice-director of MATGAS Technological Center (2010-2013)
and leads projects on nanomaterials for energy storage and conversion (lithium batteries, supercapacitors, graphene, flow batteries, solar-thermal energy, nanofluids). He is author of more than 200 publications, scientific editor of the books "Functional Hybrid Materials" P Gómez-Romero, C Sanchez (Eds.) (Wiley-VCH 2004) and “Metal Oxides in Supercapacitors” (Elsevier, 2017, D Dubal, P Gomez-Romero) (in preparation) and author of three award-winning popular science books. He is member of MRS, ECS, ISE, EuroScience and the Royal Society of Chemistry and Fellow of the Royal Society since 2014.
Nanofluids are homogeneous dispersions of nanoparticles in conventional base fluids which constitute an emerging type of unique liquid materials within the field of Nanoscience and Nanotechnology. They have been proposed and used for a variety of applications with very special emphasis on thermal properties and heat-transfer applications. Indeed, solids present better thermal conductivity and specific heat capacities than liquids but dispersing solid micro particles in fluids leads to clogging, a problem which is solved with nanoparticles. On the other hand, other energy-related applications are possible for nanofluids which have not been explored until very recently. In our group we are developing two different research lines dealing with nanofluids i) nanofluids for thermal applications and ii) Electroactive Nanofluids (ENFs) for energy storage in novel flow cells. The latter type includes a wide variety of nanofluids containing nanoparticles able to store electrical energy, whether through redox or capacitive mechanisms. We will present an overview of the use of nanofluids in the field of energy, from thermal to electroactive nanofluids with some final focus on our own recent results, including the first example of the application of ENF materials for the development of fast energy storage in flow cells. In this case, we have used a capacitive nanofluid based on graphene which would be the flow-cell analog of solid-electrode graphene supercapacitors.
Catalan Institution for Research and Advanced Studies, Spain
Jordi Arbiol graduated in Physics at Universitat de Barcelona (UB). He also obtained his PhD (European Doctorate and PhD Extraordinary Award) in the field of Transmission Electron Microscopy (TEM) applied to nanostructured materials. He was an Assistant Professor at UB. He has served as a Group Leader at Institut de Ciència de Materials de Barcelona, ICMAB-CSIC. He is currently the Vice President of the Spanish Microscopy Society (SME), apart from being a leader of the Group of Advanced Electron Nanoscopy at Institut Català de Nanociència i Nanotecnologia (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST). He has been awarded with the 2014 EMS Outstanding Paper Award, the EU40 Materials Prize 2014 (E-MRS), listed in the Top 40 under 40 Power List (2014) by The Analytical Scientist and the PhD Extraordinary Award in 2001 (UB).
Technology at the nanoscale has become one of the main challenges in science as new physical effects appear and can be modulated at will. Superconductors, materials for spintronics, electronics, optoelectronics, sensing, energy applications and new generations of functionalized materials are taking advantage of the low dimensionality, improving their properties and opening a new range of applications. As developments in materials science are pushing to the size limits of physics and chemistry, there is a critical need for understanding the origin of these unique physical properties (optical and electronic) and relate them to the changes originated at the atomic scale, e.g.: linked to changes in (electronic) structure of the material. In the present work, I will show how combining advanced electron microscopy imaging with electron spectroscopy, as well
as cathodoluminescence in an aberration corrected STEM will allow us to probe the elemental composition and electronic structure simultaneously with the optical properties in unprecedented spatial detail. The talk will focus on several examples in advanced nanomaterials for optical, plasmonic and energy pplications. In this way the latest results obtained by my group on direct visualizing and modeling materials at atomic scale will help to understand their growth mechanisms (sometimes complex) and also correlate their physical properties (electronic and photonic) at sub-nanometer with their atomic scale
structure. The examples will cover a wide range of nanomaterials: Quantum structures self-assembled in a nanowire - quantum wires (1D) and quantum dots (0D) and other complex nanowire-like morphologies for photonic and energy applications (LEDs, lasers, quantum computing, single photon emitters, water splitting cells, batteries), nanomembranes and 2D sheets; as well as metal multiwall nanoboxes and nanoframes for 3D plasmonics.