Day 1 :
Technical University of Munich, Germany
Keynote: How neutrons as a probe for in situ and in operando measurements support the understanding of electrochemistry in Li-ion battery research
Time : 09:30-10:00
Ralph Gilles a Senior Scientist, has his expertise in neutron scattering methods for studying energy materials as batteries and high-temperature alloys. Especially, the use of in situ, in operando methods (very often combined with non-destructive measurements) on real bulk samples enables a powerful tool on energy related topics. In his group methods as neutron diffraction, small-angle neutron scattering, grazing incidence small-angle neutron scattering, imaging, neutron depth profiling and neutron induced prompt gamma activation analysis are applied for battery research. He is an Industrial Coordinator of Heinz Maier-Leibnitz Zentrum, Coordinator of the Materials Science group and Head of the Materials Science Laboratory.
For a better understanding of the electrochemistry in batteries a huge demand emerge for in situ and in operando characterization methods. Due to the high penetration depth and high sensitivity of neutrons to light elements as lithium such a probe is more and more attractive in the last decade. This contribution gives an overview how neutrons with their unique properties contribute in the development of new battery cells. During charging and discharging of NMC/graphite cells the intercalation of Li in the graphite layers can be observed in situ with neutron diffraction (ND) as such measurements are sensitive to detect LiCx phases as LiC6 and LiC12 during the intercalation/de-intercalation process. Under fast charging conditions and low temperatures the appearance of Li plating can be studied. A correlation of C-rates and Li plating is investigated by means of voltage relaxation and in situ ND. Batteries consisting of lithium iron phosphate (LFP) are often used for stationary energy storage systems. Here neutrons provide the answer why various types of graphite result in losses of the storage capacity. On larger scales of >50 micrometer neutron imaging (radiography and tomography) enables a non-destructive view inside the cell to make visible for example how the electrolyte filling with the distribution of the electrolyte in the cell between the layer stacks in a pouch cell takes place. The use of neutron induced prompt gamma activation analysis (PGAA) is a powerful tool to describe the capacity loss of the cell caused by tiny metal deposition on the graphite anode after charging/discharging processes. The method of neutron depth profiling (NDP) is suited to study near surface phenomena as the Li distribution in electrodes. A new set-up for NDP is currently under development to improve the space resolution and to measure with a time resolved mode.
Austrian Institute of Technology, Austria
Keynote: Polyelectrolyte multilayer assemblies and brushes on reduced graphene oxide field-effect transistors for sensing applications
Time : 10:00-10:30
W Knoll earned his PhD degree in Biophysics from the University of Konstanz in 1976. From 1991-1999 he was the Laboratory Director for Exotic Nanomaterials in Wako, Japan, at the Institute of Physical and Chemical Research (RIKEN). From 1993 to 2008, he was Director at the Max Planck Institute for Polymer Research in Mainz, Germany. Since 2008, he is the Scientific Managing Director of the AIT Austrian Institute of Technology. Since 2010 he is a Regular Member of the Austrian Academy of Sciences. He received an Honorary Doctorate from the University of Twente, the Netherlands in 2011 and became a Member of the Academia Europaea in 2017.
Graphene, a two-dimensional zero band gap semiconducting material, has gained considerable interest in material science, energy storage and sensor technology, due to its remarkable electronic and mechanical properties. It’s high carrier mobility and ambipolar field effect, together with a great sensitivity towards changes in environmental conditions makes graphene perfectly suitable as transducing material for the use in various types of sensors. In this report, we first describe a novel biosensor exploiting the pH dependence of liquid gated graphene-based field-effect transistors for the enzymatic detection of urea. The channel between the interdigitated source-drain microelectrodes was non-covalently functionalized with bilayers of poly (ethylene imine) and urease using the layer-by-layer approach, providing a LoD below 1 mM urea. Next, we present a sensor based on a reduced graphene oxide field effect transistor (rGO-FET) functionalized with the cascading enzymes arginase and urease as recognition elements in a layer by layer assembly with poly (ethylene imine). The build-up of this nano-architecture was monitored by surface plasmon resonance spectroscopy. L-arginine was quantitatively detected by the change in current between source and drain electrode due to electrostatic gating effects conferred by the formation of OH- ions upon enzymatic hydrolysis of the analyte L-arginine. And finally, we will describe first results on the coupling of calcium-responsive polymer brushes to graphene field-effect transistors. The presence of Ca+2 ions neutralize the charge of the phosphate groups leading to a change of the Dirac point by electrostatic gating effects. A formalism using the Langmuir adsorption model and the Grahame equation is used to obtain the surface coverage from the change of the Dirac point.
- Theoretical and Computational Electrochemistry | Batteries and Energy Storage Sensors Physical and Analytical Electrochemistry | Photoelectrochemistry | Electrochemical Energy Electrochemical Engineering | Electrochemical Water Treatment | Electronic Materials and Processing Dielectric Science and Materials
Location: Olimpica 1
Max Planck Institute for Chemical Physics of Solids, Germany
Max Planck Institute for Solid State Research, Germany
Thomas F Jaramillo
Stanford University, USA
Title: Design and development of catalyst materials for the production of fuels and chemicals in a sustainable manner
Thomas F Jaramillo is an Associate Professor of Chemical Engineering at Stanford University and the Deputy Director of Experiments at the SUNCAT Center for Interface Science and Catalysis, a partnership between the School of Engineering at Stanford and the SLAC National Accelerator Laboratory. He earned his BS in Chemical Engineering at Stanford, followed by MS and PhD degrees in Chemical Engineering from the University of California at Santa Barbara. He then conducted research at the Technical University of Denmark as a Hans Christian Ørsted Postdoctoral Fellow prior to joining Stanford’s Faculty in 2007. His research efforts are aimed at developing materials and processes for sustainable chemical transformations related to energy conversion. He has earned a number of honors and awards for his efforts, including the Presidential Early Career Award for Scientists & Engineers (PECASE, 2011
Statement of the Problem: The vast majority of fuels and chemicals that are produced and consumed across the globe today are derived from fossil fuels: oil, coal, and natural gas. The long list includes conventional liquid fuels such as gasoline, diesel, and jet fuel, in addition to many other products such as plastics (e.g. polyethylene) and fertilizer (i.e. ammonia, NH3). Society has benefitted tremendously from the science and engineering efforts that have brought these crucial products to market at a global scale, however continuing to use fossil-based resources at such high rates could potentially lead to troubling consequences ahead. This motivates the development of new chemical processes to produce the same kinds of fuels and chemicals that we rely on, using renewable energy and sustainable feedstocks instead.
Methodology & Theoretical Orientation: We seek to employ solar and wind energy to power the production of fuels and chemicals in a sustainable manner, largely motivated by the dropping costs of renewable electricity, the growing penetration of renewables into energy markets, and the need for storing variable electricity.
Findings: Catalyst materials have been developed capable of driving important chemical transformations in a sustainable manner involving electricity. Specific examples include the production of hydrogen (H2), carbon-based products (e.g. hydrocarbons, alcohols), ammonia (NH3) fertilizer, and hydrogen peroxide (H2O2).
Conclusion & Significance: The development of catalysts with appropriate properties can serve as the basis of new, renewable pathways to produce the large-scale fuels and chemicals that could play a major role in reaching sustainability goals for the globe.
Max Planck Institute for Chemical Physics of Solids, Germany
Title: Interfacially engineering topological semimetal MoP into a superior electrocatalyst for hydrogen evolution
Guowei Li received his Master’s degree in Materials Science from Jiangsu University in 2011 with Prof. Changsheng Li. He then moved to the University of Groningen, the Netherlands, and was awarded the PhD degree under the supervision of Dr. Graeme R Blake and Prof. Thomas T M Palstra in 2016. Since then, he joined the Max Planck Institute for Chemical Physics of Solids, Dresden as a Postdoctoral Fellow in the group of Prof. Claudia Felser. His research interests focus on the magnetic and electrical transport properties of chalcogenides and topological materials, from synthesis to applications in clean energy harvesting and conversion.
Materials in topological states are endowed with many exotic properties such as extremely large magnetoresistance, high conductivity, and intrinsic Hall effects. However, the effect of such appealing properties on electrocatalysis still remains elusive. Recently, the observation of exceedingly high conductivity and Weyl nodes in MoP provide us with a modeling catalyst for revealing the correlation between topological states and electrocatalytic activity and designing high-performance electrocatalyst for hydrogen evolution reaction (HER). MoP encapsulated in Mo, P co-doped carbon layer (MoP@C) was thus synthesized and exhibits outstanding electrocatalytic HER performance with an extremely low overpotential of only 49 mV at a current density of 10 mA/cm2 and a decreased Tafel slope of 54 mV/dec. in alkaline medium. Such superior HER activity of the MoP@C exceeds those of the-state-of-art non-noble metal-based HER electrocatalysts and even comparable to that of the Pt/C catalyst. As a topological semimetal, MoP manifests a very high conductivity (8.2 μΩ at 300 K) and mobility (up to 10 cm2/VS at 300 K) due to the topologically protected triple point fermions and complex Fermi surface. Meanwhile, the rich P-C and Mo-C bonds in the interfaces between the carbon layer and MoP modulates the band structure of MoP@C and eventually facilitates the fast electron transfer, accumulation, and subsequent de-localization, which are responsible for the excellent HER activity.
Silesian University of Technology, Poland
Title: Electrochemistry of bipolar s-tetrazine derivatives
M Lapkowski is a Full Professor of Silesian University of Technology and Director of Department of Physical Chemistry of Polymers, Faculty of Chemistry, Polish Academy of Science. His fields of research activity are the synthesis of electronic conducting polymers, the physicochemical characterization of polymers, oligomers and composite materials, synthesis and characterization of new organic materials for optoelectronics and photovoltaic. He was an Assistant Professor in l'Université de Nantes, (France), and Invited Professor in l’Ecole Normale Superieur de Cachan, (France), University of Sao Paolo, Brazil, University of Woolongong, Australia and Tohoku University, Japan. He is a Member of International Society of Electrochemistry since 2005.
1,2,4,5-tetrazine, especially 3,6-disubstituted derivatives are very well known materials, in particular, in the field of the energetic chemistry. However, s-tetrazine ring has a number of other interesting properties. It is electroactive, with a very high electron affinity, furthermore it is highly colored. It is the smallest fluorophore, which makes s-tetrazine derivatives very promising molecules for active layers in optoelectronics devices such as organic light emitted diodes (OLED), electrofluorochromic and electrochromic windows. The functionalization of the ring with electron-donating group leads to obtain the donor-acceptor-donor (D-A-D) type of structure, which can serve as both: electron as well as hole transporting materials. Electrochemistry is a suitable method for characterization of new electroactive organic materials for optoelectronic and electronic applications. It provides lots of information about redox properties, stability, the conversion and storage of energy, etc. It also allows to determine the electron affinity and ionization energy of investigated compounds, parameters which are correlated with energies of HOMO and LUMO level, which need to be determined if materials are investigated towards optoelectronic applications. In this work we present the electrochemical and spectroelectrochemical characterization of bipolar s-tetrazine derivatives. The characterizations of studied compounds were performed using: electrochemical techniques including cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurements; spectroelectrochemical investigations such as UV-Vis, EPR, Raman and fluorescence spectroelectrochemistry. The electrochemical characterization indicated that a few of studied s-tetrazine derivatives undergo electrochemical polymerization (oligomerization) which is rarely observed in this group of compounds. Hence, monomers as well as electrochemical obtained polymers were studied. Their redox processes have been investigated by in situ UV-Vis and EPR spectroscopy. A huge effect of chemical structure on the electrochemical properties was observed. Introduction of oxygen atom as a linker between donor and acceptor part of molecules resulted in obtained thin polymer layer with unique properties.
Vladimir S Bystrov
Keldysh Institute of Applied Mathematics RAS, Russia
Title: Computational studies of ferroelectric composites and thin films containing polyvinylidene fluoride (PVDF) and graphene/graphene oxide
Vladimir S Bystrov has completed PhD, Dr. Habil.Phys. Dr.Sci. Phys. & Math. from Russian Academy of Sciences. Since 1993, he has his expertise in various fields of computational molecular modeling, computational exploration and computer simulation of nonlinear multifunctional nanomaterials and different organic & bio-molecular nano-structures such as: bioferroelectric & polymer PVDF/PVDF-TrFE thin ferroelectric films, graphene/oxide graphene and related polar composite nanomaterials; amino acids (glycine, etc.), peptides nanotubes, thymine & DNA; hydroxyapatite (HAP) & nanoparticles, etc. Computational studies of nanostructures were made using the molecular mechanics, quantum-chemical calculations (ab initio, DFT, semi-empirical methods), molecular dynamics (MD) on the base of various software (HyperChem, AIMPRO, VASP, etc.) and clusters in Russia IMPB & KIAM, Linux cluster in University of Aveiro, Portugal. He is a Head of the Group for Computer Modelling of Nanostructures and Biosystems of IMPB-KIAM RAS, Pushchino.
Computational molecular investigations and experimental studies of the ferroelectric properties of new composite nanomaterials based on polymer ferroelectrics and graphene/graphene oxide are presented. Main results of the computational molecular modeling of various nanostructures and the piezoelectric properties of the composites from polyvinylidene fluoride (PVDF)/poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) films and graphene/graphene oxide (G/GO) were reviewed and analyzed in comparison with the experimental data at the nanoscale, particularly with atomic force and piezo-response force microscopy (AFM/PFM) data. The performed computational molecular modeling of the graphene/graphene oxide (G/GO) and PVDF ferroelectric polymer composite nanostructures were studied by the different methods using HyperChem tool: molecular mechanics (MM) methods (BIO CHARM), quantum mechanical (QM) calculations based on density functional theory and semi-empirical PM3 method. Experimentally the switching behavior, piezoelectric response, dielectric permittivity and mechanical properties of the films were investigated and found to depend on the presence of G/GO concentration variation. Experimental results qualitatively correlate with those obtained in the calculations. Particularly, computed data of the piezoelectric coefficients d33 for developed PVDF-G/GO models are in line with observed experimental behavior with concentration changes of GO components. Further development with several multilayered GO nanostructures and inserted PVDF chain and layers, having new curved structures after optimization are considered and discussed. The properties of these investigated nanostructures with the GO content dependence for these composites are analyzed. The results obtained in the reviewed and analyzed present study provide important insights into our understanding of the mechanisms of piezoelectricity in such new nanocomposites give us new prospective for further creation, development and applications of novel ferroelectric polymer–graphene/graphene oxide nanocomposites as multifunctional nanomaterials.
E Fillis Tsirakis
Max Planck Institute for Solid State Research, Germany
Title: Integration of functional liquids in solid-state electronic circuits
E Fillis Tsirakis completed his studies in Max Planck Institute for Solid State Research, Germany.
Field-effect gating with solid dielectrics is the basis of modern electronics. It is a technique that is most successfully used in integrated circuits. Here, we present our work on realizing solid-state heterostructures with fully integrated liquids, opening a brand new phase-space of materials for integrated circuits. Gating with liquid electrolytes in field-effect transistors offers clean contact-electrolyte interfaces and higher polarizations than in conventional, all-solid-state architectures. We demonstrate the fabrication of electronic devices such as capacitors and field-effect transistors with integrated, patterned aqueous-NaCl solutions, which are of equal quality or even outperform standard, bulk electrolyte devices. Our work opens a new route to the exploitation of solid–liquid interfaces in integrated functional devices.
M E Henry Bergmann
Anhalt University of Applied Sciences, Germany
Title: (Electro)chemical water disinfection – challenges for the 21st century
M E Henry Bergmann has his 35-years expertise in electrochemical engineering that is recently focused on methods of drinking and process water disinfection. His technological approach for small and medium-size treatment devices respects the new European Biocide Regulation and the practical needs as well - against the background of avoiding or minimizing chlorination, and the formation of hazardous by-products. New (electro)chemical technologies are suggested basing on the use of chlorine dioxide, physically or electrochemically generated ozone, and combined methods.
Whereas worldwide hundreds of millions of people do not have access to safe drinking water, in developed countries current research and practice are oriented towards problems of micropolutants and disinfection by-products formed at µmole-per litre level. Another special subject of activities is the low-chemical disinfection of process waters in recirculation and cooling systems. Although direct electrochemical drinking water disinfection is applied for decades of years, conditions for avoiding over chlorination and disinfection by-products could only be clarified in the recent years. A new approach is the electrochemical generation of chlorine dioxide (ClO2) at mm concentration level. It is well known that ClO2 has much lower organic by-product formation potential compared to free active chlorine. The challenge is to minimize chlorite, chlorate and perchlorate in the solutions obtained. The high chlorite reactivity often causes maxima in ClO2 formation. Highly active anodes dramatically reduce the generation of chlorine dioxide due to parasitic reactions. Solutions for inorganic electrolysis and disinfection by-products can be found by analysing and studying influence parameters such as temperature, electrode material, counter electrode material and cell construction. ClO2--to-ClO2 yields of 75% are possible at the moment. Furthermore, it is discussed if combined methods may contribute to lower by-product formation. A simple variant is the combined chlorine-chlorine dioxide formation. The combination of ozone and chlorine dioxide in situ is another interesting option. First own experiments have shown that all initial chlorite can be converted to chlorine dioxide. Lower temperatures in the range of 5℃ are preferred reaction conditions. It can be stated that in the future improved regulations and inline analysis methods have to be applied for safer disinfection. Means of digitalization could support the process.
University of Poitiers, France
Title: Oxygen evolution reaction at the surface of nickel cobaltites: The impact of surface restructuring phenomena on the activity
Aurélien Habrioux (Associate Professor) has an expertise in electrocatalysis and in materials science. His research interests deal with the design and development of novel non-noble electrocatalysts for reactions such as oxygen reduction reaction and oxygen evolution reaction in alkaline medium. He is especially interested in scrutinizing and explaining surface restructuring phenomena affecting catalysts surface and occurring upon working conditions. He has been coordinating researches aiming at developing transition metal oxides supported heteroatom doped graphene-based materials for the reversible air electrode of high energy density Li-air and Zn-air batteries. He has also been working on the understanding of the effect of the active phase/substrate interaction on the electrocatalytic activity.
The storage of intermittent renewable energies requires the implementation of efficient energy storage systems. These systems must allow converting renewable energies into sustainable energetic vectors (hydrogen, electron). For this purpose, the oxygen evolution reaction (OER) plays an important role. OER possesses a sluggish kinetics that can be enhanced by using a catalyst exhibiting reliable surface composition and morphostructural properties. To limit the use of scarce noble metals, the synthesis of effective 3d transition metal oxide-based catalysts is of interest. As activity and stability of materials depend on their composition and morphostructural properties, the synthesis of well-defined catalysts is of utmost importance. To this end nanocasting approach constitutes an interesting pathway. In this study, NixCo3-xO4 materials have been synthesized by replicating ordered mesoporous silica templates. Materials were investigated using numerous physico-chemical techniques such as x-ray induced photoelectron spectroscopy (XPS), high resolution transmission electron microscopy, x-ray diffraction and Raman spectroscopy. Evidences from XPS and Raman measurements reveal that the different catalysts surfaces are hydroxylated. A particular attention was paid to restructuring phenomena occurring upon potential cycling and responsible for greatly improving the OER activity. These restructuring phenomena were evidenced using post-mortem Raman spectroscopy and XPS. It was observed that the intrinsic activity of the different restructured catalysts depends on the incorporated nickel amount and correlates with the CoIII/CoIV peak potential. The modulation of CoIII/CoIV peak potential is explained by changes in the chemical environment of surface Co atoms and results in the formation of nickel/cobalt oxy-hydroxide. Nickel indeed modulates the electronic properties of the Co active site and allows improving the OER activity of electrode materials. The catalysts described in this presentation are moreover very efficient since after surface restructuring, the over potential at 10 mA.cm-2 is as low as 310 mV.
Italian Institute of Technology, Italy
Title: New poly(3,4-ethylenedioxythiophene) coatings for neural recording and stimulation
Stefano Carli has completed MSc and PhD in Chemistry from the University of Ferrara, Italy. He has devoted his PhD investigations to the development of new photochromic dyads. From 2009 to 2016 his research activity was oriented on dye sensitized solar cells, perovskite solar cells, as well as on new catalysts for light-induced water splitting. Currently he is a Postdoctoral Researcher at the Italian Institute of Technology and his research is focused on the development of new smart materials for neural sensing and stimulation. One of the main concerns of his research is the reduction of tissue inflammation as a consequence of neural probes implantation. For this purpose, new drug release systems from conductive polymers (PEDOT) are under investigation.
Statement of the Problem: The development of implantable neural microelectrodes has revolutionized the field of biomedical applications by enabling bidirectional communication with the nervous system at high resolution. Unfortunately, one of the main concerns related to chronically implanted neural microelectrodes is related to the adverse reaction of the surrounding tissue, which is known to encapsulate the neural microelectrodes after few weeks post implantation, leading to significant worsening of recording/stimulation quality. Among various approaches aimed to minimize inflammatory reaction and gliosis while preserving the electrochemical integrity of microelectrodes, the possibility of delivering anti-inflammatory drugs from the surface of neural implants represents a challenging strategy. For this purpose, the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT), is commonly electrodeposited onto the microelectrodes in conjunction with the negatively charged dexamethasone sodium phosphate (Dex-P). Following this methodology, the drug release can be promoted by applying a cathodic trigger that reduces PEDOT to its neutral state, while enabling the free diffusion of the drug. Unfortunately, the inclusion of Dex-P as a dopant has been reported to negatively affect both electrochemical properties and stability of PEDOT coatings.
Methodology & Theoretical Orientation: In this study, for the first time, the anti-inflammatory drug dexamethasone (Dex) was chemically anchored to the surface of electrodeposited PEDOT, thereby enabling the drug release upon the hydrolysis of the chemical bond between Dex and the PEDOT film. This approach would account for a self-adjusting release system that promotes the delivery of the drug by local changes in the biologic environment.
Conclusion & Significance: The big challenge of this study was to realize self-adjusting release of drugs by neural implants, as a consequence of post implantation inflammatory biological triggers. Here we found that the covalent bond between Dex and PEDOT composite coatings can account for a biologically controlled drug release system.
César Pascual García
Luxembourg Institute of Science and Technology, Luxembourg
Title: Electrochemical regulation of the acidity in miniaturized electrochemical cells: The route to increase flexibility and multiplexing of chemical control
César Pascual García graduated in Solid State Physics from the Universidad Autónoma of Madrid in Spain with a dissertation of electronic optical transitions in III-V semiconductors. He obtained his PhD in Condensed Matter Physics in 2007 from the Scuola Normale Superiore of Pisa in Italy with the thesis: “Low lying excitations of few electrons quantum dots”. At the beginning of his career he collaborated in fundamental topics centered on the electron correlations of semi- and super- conductor materials, but then his interest shifted to biology-applied topics as he started working as Scientific Officer at the Institute for Health and Consumer Protection of the European Commission. Currently he is an ATTRACT fellow and Lead Research Scientist at the Luxembourgish Institute of Science and Technology where he leads the activities for electrochemical sensors and actuators for medicine applications at the Materials Research and Technology Department. His current research focus is semiconductor nanowires for bio-sensing and the miniaturized control of chemical reactions.
Better computer controlled systems to perform nanoscale chemical tasks is a demand for the fabrication of high-throughput microarrays and reprogrammable sensors dedicated to precision personalized medicine. The very limited tools that we have today to control chemical reactions in miniaturized devices is one of the main barriers for the control of massive multiplexing (>1 Mega spots). The proton concentration is one of the building blocks that could be used to control the kinetics of chemical reactions. Currently the multiplexed systems for high-yield in-situ synthesis of commercial microarrays are driven by optically triggered acid-labile groups. The electrochemical control of the proton release would be a natural way to control the acidity due to the high speed efficiency of redox processes, and would allow combining microarrays and programmable electrochemical sensors. However, only a couple of attempts can be found in literature to control chemical reactions in miniaturized environments by an electrochemically driven proton concentration. The limited surface to volume ratio of the electrodes and the fast diffusion of protons decreased the performance of these systems. Here we present our studies to control reversibility of redox processes that can be used to change the pH in microfluidic environments during many cycles, and a microfluidic design to control the fast diffusion of protons. With our system we show a pH swing comparable to the highest achieved by electrochemical systems of few millilitres, but in a device where the acid is confined in nano-litter volumes. The design promises high yield in-situ chemical synthesis since the system is compatible with lateral resolutions in the micron range assuring the stability of acid contrast between close spots.
Ulrike Langklotz works in the field of Electrochemistry, mainly for applications in the field of energy storage, for ten years. The general attempt bases on the complementation of electrochemical results with suitable non-electrochemical measuring methods, e.g. spectroscopy. Main topics are the preparation and characterization of thin dielectric oxide films as well as the investigation of electrode materials used in lithium ion and lithium sulphur batteries. Recently, the investigation of nanostructured silicon as anode material was one main topic
Carbon coated silicon nanowires (SiNW) are the nanostructure of choice for binder-free high capacity anodes. These anodes with adjusted active mass loading and advanced morphology were grown by chemical vapor deposition (CVD). The high mass loadings (up to 6 mgSi/cm²) in combination with the lightweight carbon foil used as substrate and current collector predestines these anodes for applications where high energy densities are required, e.g. for automotive applications. The requirements in high power devices are especially challenging with respect to the (de)lithiation reactions. Thus, (complex) carbon coated SiNW anodes with varying morphology and mass loading are examined regarding their performance as well as the kinetics of the charge-discharge reactions. The specific capacity and cycle stability as well as the achievable C-rates strictly depend on these parameters. The anodes offer capacities up to 2 mAhcm-2, initial coulomb efficiencies higher than 80% and capacity fading of less than 10% over 100 cycles. The established process with high uniformity allows detailed examinations of the charge-discharge curves of samples with tuned properties and clearly shows an effect of the SiNW morphology on the phase transitions in the initial cycles, which in turn can be crucial regarding the degradation behavior of the anodes. Finally, galvanostatic intermittent titration technique (GITT) is applied to analyze the charge transfer and diffusion overpotentials of the (de)lithiation reaction. The overpotentials are basic kinetic parameters of these reactions, and they enable the estimation of the rate determining processes.
Osaka University, Japan
Title: Verification of photo-splitting of H2O to HOOH and H2 as initial photoproducts
Shozo Yanagida is an Emeritus Professor of Osaka University and a Research Director of Research Association for Technological Innovation of Organic Photovoltaics (RATO) of University of Tokyo. Since he was promoted to a Professor of newly established Koza (research course) of Graduate School of Engineering in Osaka University (1980), he had contributed to photochemical conversion of solar energy, e.g., excellent photocatalysis of both nano-sized (quantized) ZnS and poly- & oligo-paraphenylene. When he was staying at SERI (now ENREL) as a Visiting Professor of Dr. A. Nozik’s group in 1984, he understood that organic molecules and their aggregates are kinds of quantum dots themselves. He has his expertise in evaluation of dye-sensitized solar cells, i.e., molecular structured photovoltaics, and enthusiasm in improving photo-conversion efficiency and long-term durability of solar cells on the basis of density-functional theory based molecular modeling.
Most electrochemists and biochemists had a mindset that water oxidation yields oxygen molecules. However, Nosaka and his wife reports on generation and detection of reactive oxygen species such as HO. and HOOH in photocatalysis. We verified on the basis of density functional theory-based molecular modeling (DFT/MM) for photoelectrochemical H2O photo-splitting systems that formation of HOOH only under photo-irradiated and highly negative bias conditions. Further literature survey revealed that, in alkali aqueous solutions (pH 8~11.5), Pt-loaded nc-TiO2 catalyzes effective H2O photo splitting to HOOH and H2 as initial products. Figure 8 shows successful DFT/MM for an aggregate induced by van-der-Waals-Coulomb interactions (vdW&Clmb) between HOTi9O18H as a model of nc-TiO2 photocatalyst, HO-&H2O as an alkali water model, and Pt6 as platinum cluster model. Effective photoelectron transfer is verified from [HO-&H2O] to Pt6 for production of H2 on Pt and hydroxyl radical of [HO. & H2O] on nc-TiO2. Figure 1 shows DFT/MM for exothermic one-electron oxidation of alkali water model of hydrated hydroxide anion, [HO- & H2O] to hydroxyl radical of [HO. & H2O]. Figure 2 shows DFT/MM for exothermic vdW&Clmb- induced dimerization of the radical of [HO. & H2O], verifying that oxidation of [HO- & H2O] to HOOH & (H2O)2 via vdW&Clmb dimerization on nc-TiO2. Driving force of photo splitting will be verified as due to highly exothermic electron transfer reaction to Pt6 on nc-TiO2
Guanajuato University, Mexico
Title: Electrodialysis and electrodeionization applied to remove Cr (III)
Lucía Alvarado has her expertise in Electrochemical Separation Systems which as Electrodialysis and Electrodeionization and green chemistry. She had contribute in works testing and characterizing new carbon materials and nanomaterials. The main research is designing treatment systems to remove metallic ions from wastewater and getting pure water. Currently, her adscription is as full professor in Guanajuato University, Mex., Department of Mining, Metallurgy and Geology. She is active member in the International Society of Electrochemistry and has been reviewer for Elsevier: Electrochimica Acta and Separation and Purification Technology, also reviewer of some projects for the National Council of Science of Technology in Mexico
The development of new strategies to remove ionic metals from wastewater has been became in a global need. To design closed circuits that avoid release these compounds to the environment, from the environmental and production point of view, become each time more necessary. In this way, different kind of methods to remove metals are utilized, such as are the membranes systems. In this context, Electrodialysis and Electrodeionization are electrochemical process of membranes, which them have the capability to remove ionic species. This is why, both methods are available to be use as treatment of water polluted with heavy metals, without to generate wastes. In this way, the aim of the present work is to show the results of the use of these technologies applied to the remove of Trivalent Chromium from synthetic solutions, and evaluate their performance. Commercial membranes and resins were tested during the respective process in order to get advantages or disadvantages, when is used 100 or 1000 ppm Cr (III) solutions. The results presents some advantages for ED using bigger concentrations, meanwhile EDI is much better working low concentrations, spending less energy.
University of Natural Resources and Life Sciences, Austria
Title: S-layer protein lattice as a key component in biosensor development
Bernhard Schuster holds an Associate Professor position for Molecular Nanotechnology and Biomimetic at the Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Vienna, Austria. His main research interests focus on biomimetics, nanobiotechnology, cell envelope mimics and in particular functional supported lipid membranes and bio-inspired S-layer protein- and membrane protein-based sensors. His skills include recrystallization and modification of S-layer proteins, formation techniques for model lipid membranes, surface -sensitive and electrochemical techniques and the reconstitution and analysis of membrane-active peptides and membrane proteins. He is an Editorial Board Member of seven international peer-reviewed journals and filed two international patents. He published about 100 papers in peer-reviewed journals and book chapters and gave more than 120 (invited) contributions to international conferences. His total citations are 1.808; average citation per item: 27; h-index: 27. He serves as Ad-Hoc Reviewer of more than 20 papers per year.
Statement of the Problem: Combining biological with electronic components is a very challenging approach because it allows the design of ultra-small biosensors with unsurpassed specificity and sensitivity. However, many biomolecules lose their structure and/or function when randomly immobilized on inorganic surfaces. Hence, there is a strong need for robust self-assembling biomolecules, which attract great attention as surfaces and interfaces can be functionalized and patterned in a bottom-up approach.
Methodology: Crystalline cell surface layer (S-layer) proteins, which constitute the outermost cell envelope structure of bacteria and archaea, are very promising and versatile components in this respect for the fabrication of biosensors. S-layer proteins show the ability to self-assemble in-vitro on many surfaces and interfaces to form a crystalline two-dimensional protein lattice.
Findings: The S-layer lattice on the surface of a biosensor becomes part of the interface architecture linking the bioreceptor to the transducer interface, which may cause signal amplification. The S-layer lattice as ultrathin, highly porous structure with functional groups in a well-defined spatial distribution and orientation and an overall anti-fouling characteristics can significantly raise the limit in terms of variety and ease of bioreceptor immobilization, compactness and alignment of molecule arrangement, specificity, and sensitivity. Moreover, mimicking the supramolecular building principle of archaeal cell envelopes, comprising of a plasma membrane and an attached S-layer lattice allow the fabrication of S-layer supported lipid membranes. In the latter, membrane-active peptides and membrane proteins can be reconstituted and utilized as highly sensitive bioreceptors.
Conclusion & Significance: S-layer proteins bridge the biological with the inorganic world and hence, fulfill key requirements as immobilization matrices and patterning elements for the production of biosensors. This presentation summarizes examples for the successful implementation of bacterial S-layer protein lattices on biosensor surfaces in order to give an overview on the application potential of these bioinspired S-layer protein-based biosensors.
Beijing University of Chemical Technology, China
Title: Surface chemistry and electrode design for high performance Li-S battery
Wen Liu has completed his studies at Beijing University of Chemical Technology, China
Based on the reaction of 16Li+S8↔8Li2S, Li-S battery reaches a high theoretical energy density of 2600 Wh/kg, which is several times higher than that of traditional lithium ion batteries (LIBs). The low cost, high capacity as well as environment-benignity makes Li-S battery as a strong candidate for next generation energy storage. However, the development of Li-S battery is severely hindered by several problems, including the low conductivity of sulfur cathode, volume variation during charge/discharge and dissolution of lithium polysulfide (LiPS). These drawbacks cause low utilization of sulfur and poor cycling performance of batteries. To overcome these obstacles, researchers pay attention to regulating the construction of sulfur cathode, using mesoporous materials, core-shell types carbon and graphene oxide etc. The carbon based materials have significant benefit on the conductivity of the electrode and suppress the polysulfide dissolution to some extent. But the nonpolar carbon intrinsically has poor interaction with LiPS and lithium sulfide. Moreover, the lithium dendrite growth and electrode pulverization during cycling gives rise to lower columbic efficiency and safety risks. Hence, the polysulfide trapping chemistry, sulfur electrode design and Li mental electrode protection are the key factors contributing to the cycling performance and stability of Li-S battery. Herein, we propose polar materials including inorganic mental oxides, metal phosphides and organic functional groups, which further hybrid with nano carbons to construct bifunctional host for sulfur electrode. On one hand, the polar sites can strongly absorb LiPS, so that the dissolution of LiPS and shuttling effect can be reduced. On the other hand, polysulfide after absorption can quickly reacted with electrons and Li-ions, therefore improving the reaction kinetics and eliminating the bulky dead sulfur formation. Consequently, the Li-S batteries with the high performance sulfur electrodes can stably run for over 1000 cycles. The mechanism of sulfur trapping chemistry was also revealed by x-ray photoelectron spectroscopy (XPS) characterization and theoretical calculation. In terms of Li metal anode, the huge volume variation during cycling cause electrode pulverization, which is especially serious when paired with high mass loading sulfur cathode. We demonstrate that nanostructuring is one of the key points to realize stable lithium metal anode. Different kinds of scaffold have been constructed with Li mental to reduce the volume variation and suppress dendrite growth. The lithiophilic treatment of scaffold leads to lithium uniformly deposit and nucleate on electrode surface. The dendrite-free lithium deposition also achieved through manipulation of Li-ions transport number by modifying a separator with metal–organic framework materials (MOFs).
Banaras Hindu University, India
Title: Immunosensor for label-free PSA cancer detection on GQDs-AuNRs modified screen-printed electrodes
Rajiv Prakash is a Professor and Coordinator of the School of Materials Science and Technology, Indian Institute of Technology, Banaras Hindu University, India. He has served as Scientist at CSIR lab Lucknow, India for more than 7 years before joining Indian Institute of Technology. He has been recipients of Young Scientist (Council of Science and Technology), Young Engineer Awards (INAE) of India and Materials Society Medal Award of India. His current research interests include synthesis of morphology controlled organic conducting polymers, nanocomposites, fabrication and characterization of organic electronic devices and sensors/biosensors. He is having more than 150 publications in international journals of repute and 17 patents in his credit. He is in Editorial Board of several National and International Journals. He is Member of various national committees including DST-TIFAC for India Vision 2035 and MHRD IMPRINT program.
Literature reveals that, in males, prostate cancer is ranked second as leading cause of death out of more than 200 different cancer types. Prostate specific antigen (PSA) is a 33-kDa serine protease, which is largely bound to endogenous protease inhibitors in human blood serum and its concentration in serum is used as indicator for prostate cancer. In healthy males the PSA concentration level ranges from 0 to 4 ng ml-1 in the serum. There are several PSA detection methods available like enzyme-linked immunosorbent assay (ELISA), radioimmunoassay, chemiluminescent immunoassay and SPR based immunosensors but are complicated, costly and time consuming. There is urgent need for the development of low cost, user-friendly and quick sensors for PSA. Recently, we have developed a simple and cost-effective biosensor for detection of PSA based on novel graphene quantum dots decorated with gold nanorods (GQDs-AuNRs) and modified with PSA antibody coated over screen-printed electrodes. The detection of PSA is demonstrated using three electrochemical techniques cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). A typical response for the PSA is shown in the figure based on EIS technique. The modification of screen printed electrodes with novel hybrid of graphene quantum dots-gold nanorods and simultaneous detection using three different techniques makes the sensor sensitive, reproducible and reliable. PSA immunosensor shows 0.14 ng ml-1 limit of detection, which is capable of prediction of any disorder or chances of PSA cancer.
Essen N Suleimenov
Kazakh British Technical University, Kazakhstan
Title: The impact of M Faraday’s work on the development of natural science
Essen N Suleimenov graduated from the Kazakh Mining and Metallurgy Institute, Metallurgy Faculty in 1960 with a specialty of Metallurgical Engineer in the area of non-ferrous, rare and precious metals. He is a Candidate of Technical Sciences (1970), Senior Research Associate (1981), Doctor of Technical Sciences (2005). He is a Fellow of the International Informatization Academy (2004) and Member of the European Academy of Natural Sciences (2007). After graduation he was assigned to work in the Institute of Metallurgy and Ore Beneficiation of the Academy of Sciences of Kazakh SSR. During his work in IMaOB he performed the job duties of a Senior Laboratory Technician (1960-1961); Engineer (1961-1963); Junior (1963-1971) and Senior (1972-1986, 1995-2000) Research Associates; Research Team (multidisciplinary) Leader (1985-1995); Head of Laboratory (2004-2005); Head of Department (2005-2006); Deputy Director for Science (2000-2004) and; Acting Director of the Institute of Metallurgy and Ore Beneficiation (2004).
The scientific heritage of M Faraday in the conditions of the modern crisis in natural science plays a decisive role in the development of ideas about the nature of the chemical bond and the practical use of chemical processes. In the 20th century, a huge experimental material was obtained, which confirms the correctness of M Faraday's views on the effect of electric current on chemical reactions. It was shown in that electrolysis occurs only in the places where the current flows. But electrochemistry has gone on the wrong path, which ultimately led to unjustifiably high losses of funds and labor in developing technologies for extracting metals from complex raw materials. In recent years, researchers have published an increasing number of materials aimed at establishing the principle of the formation of liquid systems and the determination of the mechanism of transport of an electric current through a liquid in the light of the theory of M Faraday. However, in the development of modern natural science the following basic thesis of the works of M Faraday plays: Identity of energy manifestations in the interaction of material objects and; the discrete nature of the electric current. The discrete nature of the electric current makes it possible to use a combination of electrical conditions for organizing unusual chemical reactions. The provision on the identity of energy manifestations of the interaction of material objects provides the basis for the revision of scientific provisions on the mechanism of heat exchange between material objects. Modern science has accumulated a huge amount of experimental material, including the unusual behavior of condensed systems under the influence of various energy effects, which gives grounds for revising the basic fundamental provisions of physical chemistry and theoretical inorganic chemistry.
Costa Rica Institute of Technology, Costa Rica
Title: New approach of flexible electrodes coated with carbon nanotubes/poly(3,4-ethylenedioxythiophene (PEDOT) for mancozeb analysis in water
He has experience in polymers, by profession he is an Industrial Chemist, he has a Master's degree in Industrial Engineering, he is currently a PhD student and works at the Technological University of Costa Rica (TEC), as a Professor at the Materials School and works with the laboratory's chemical regent of polymers of the National Institute of Learning. His research area focuses on standardization of procedures, validation of methods and conducting and nano-structured polymers.
The extensive use of pesticides in crops generates a negative environmental impact affecting water quality and organisms. The intensive use of mancozeb pesticide (MCZ), in developing countries such as Costa Rica can cause severe chronic diseases in people. Therefore, it is paramount to access the residual amount of this agrochemical in water bodies. The purpose of this work is to develop a novel and economical electrode to detect mancozeb in water by electrochemical techniques. The electrodes of poly(3,4-ethylenedioxythiophene) (PEDOT) mixed with CNTs were characterized using thermogravimetric analysis (TGA), atomic force microscopy (AFM) techniques and its recovery after leaching through a sand column. Cyclic voltammetry was applied to characterize the electrochemical behavior of MCZ and its quantification in commercial formulations. The PEDOT/MWCNT electrode provides a robust electrochemical response in the linear range in addition to a faster procedure that can be conducted with fewer solvents and is more environmentally friendly compared to other techniques used to measure MCZ. Measures of this signal intensity as a function of concentration were used to quantify MCZ. Linearity yields a value over R>0.99 in the range from 25 to 150 μmol/L. The recovery value obtained for the tap water was 51.2 μmol/L equivalent to 102%. Speed on signal outputs and the feasible procedure make this new approach a candidate to undertake monitoring programs for ecological, agricultural and hydrological applications.