13^th International Conference on Electrochemistry May 27- 28, 2019 Barcelona, Spain

Biography:

Kent Kammer Hansen has completed his PhD at the age of 31 years from the Technical University of Denmark. He is a senior researcher at the Technical University of Denmark. He has published more than 100 papers in reputed journals and has been serving as an reviwever for several journals.

Abstract:

Electrolysis of water is a convenient way to store energy as hydrogen. The PEM Electrolysis Cell (PEMEC) has many advantages; Compactness, operation in a wide power range, and the possibility of deliver high purity H₂. However, the use of expensive iridium on the anode side (oxygen electrode), makes large scale operation of the PEMEC too costly. In order to reduce the cost it is necessary to either replace or at least lower the use of iridium. Here we for the first time report the use of Mg-doped LaCrO₃ as a possible support material for the PEMEC oxygen electrode. The chromates are synthesized using aqueous solutions of metal-nitrates, evaluated by powder XRD, tested for corrosion stability in acid and finally the total conductivity is measured.

The compounds show good corrosion stability and sufficient conductivity.

Biography:

Wojciech Grochala (b.1972) studied chemistry at the University of Warsaw (Poland) and received his Ph.D. in molecular spectroscopy under the supervision of Jolanta Bukowska. After postdoctoral work in theoretical chemistry with Roald Hoffmann (Cornell, US), and in experimental inorganic and materials chemistry with Peter P. Edwards (Birmingham, UK) he returned to Poland. He obtained his habilitation at the University of Warsaw in 2005, and in 2011 he was appointed Full Professor. Wojciech Grochala received the Kosciuszko Foundation Fellowship (US), Royal Society of Chemistry Postdoctoral and Research Fellowships (UK), The Crescendum est Polonia Foundation Fellowship (Poland), and Świętosławski Prize 2nd degree (Polish Chem. Soc., Warsaw section). In 2014 he was granted titular professorship from the President of Poland. Since 2005 Grochala heads the Laboratory of Technology of Novel Functional Materials, currently with some 30 group members. He has published more than 150 papers in reputed journals.

Abstract:

The standard redox potential of the Ag(II)/Ag(I) redox pair reaches some 2 V vs. NHE, which renders Ag(I) notoriously difficult to oxidize in aqueous environment due to preceding oxidation of water. However, Ag(II) species may easily be obtained in non-aqueous media, and in some they may be sufficiently short-lived to enable preparation of genuine Ag(II) salts. Here we will discuss our recent attempts to understand electrochemistry of Ag(II) in anhydrous H₂SO₄ [1,2] and HF [3]. It turns out that oxidation of Ag(I) in H₂SO₄ leads to [Ag(II)(HSO₄)₂(H₂SO₄)₂] complex partly soluble in the solvent; the formal redox potential in 30% oleum reaches +2.9 V vs. NHE, which is the largest experimentally determined value for fluorine-free system. Upon prolonged electrolysis black residue of Ag(II)(SO₄) semiconductor precipitates from the solution.

Similar experiments carried out in anhydrous HF lead to formation of AgF₂. This compound is currently considered to be the only known analogue of parent compounds of oxocuprate superconductors and intense research is carried out worldwide in attempts to dope this system. Success of preparative elecrosynthesis of AgF₂ opens new route towards doped and mixed-valence systems which are of immense important for solid state physics. Further efforts in this direction might lead to expansion of the family of the Ag(II)/F systems known to date.

Biography:

Mohammad Tavakkoli completed his PhD in the Department of Chemistry and Materials Science at Aalto University in Finland in November 2017. In 2018, he was awarded the Gustav Komppa Award which is annually given by the Finnish Chemical Society to the best doctoral dissertation of the year in Finland in the field of chemistry and related disciplines. He has been working on the development of catalyst materials for a wide range of electrochemical reactions as well as electrode materials for batteries and supercapacitors. He has also devised a few facile synthesis methods to produce high-performance nanomaterials for the electrochemical energy applications. He is currently a Postdoctoral Researcher in Nanomaterials Group (NMG), Department of Applied Physics, Aalto University. His current research areas are: development and rational design of electrode materials for electrochemical energy devices; synthesis, characterization, and functionalization of functional carbon nanomaterials; and development of transparent conductive thin films for use in flexible electro-optical devices.

Abstract:

The development of efficient and low-cost electrocatalysts in electrocatalytic reactions plays an essential role because the catalyst determines not only the overall reaction efficiency but also the cost. We have developed a few synthesis methods to synthesize novel and low-cost electrocatalysts developed by carbon nanotubes (CNTs). CNTs are known for their exceptional properties in various applications. Here, I will further show that CNTs can be also utilized to create highly active and durable electrocatalysts [1-6]. In this talk, the focus is to design active catalysts for electrochemical water splitting by which highly pure hydrogen (as a clean energy carrier) and oxygen are produced from water. However, these novel and highly active designed electrocatalysts can be also utilized in other electrochemical energy devices.

We have developed a one-step chemical vapor deposition synthesis process to grow carbon-encapsulated iron nanoparticles (CEINs) supported on CNTs, as efficient electrocatalysts for catalyzing hydrogen production through electrochemical hydrogen evolution reaction [1]. The structure of CEINs can be also electrochemically modified to make them active for catalyzing another half-reaction in water electrolysis devices which is oxygen evolution reaction [2]. I further introduce single-walled CNTs as promising supports to stabilize individual atoms or subnano clusters of Pt in order to produce much cheaper Pt catalysts with almost a similar activity to that of bulk Pt for electrochemical hydrogen production. I show how our recently developed electroplating technique can strongly immobilize Pt atoms on small diameter CNTs, suggesting a facile method to produce single-atom catalysts [3].  I also remark the promising performance of multi-walled CNTs for the covalent functionalization with organometallic compounds [4] and non-covalent modification with nitrogen-enriched polymers [5,6] to produce stable electrocatalysts for catalyzing reactions occurring under harsh oxidizing conditions.

Finally, I also mention some of our other recent achievements in the design of advanced porous carbon nanomaterials which show promising performance for catalyzing various electrocatalytic reactions of importance for fuel cells and hydrogen production

Biography:

A. Kusior received her MSc in a filed of materials science and Ph.D. in chemistry from AGH University of Science and Technology, Kraków, Poland in 2015. Since 2015 she has been working as Assistant at Faculty of Materials Science and Ceramics at AGH. Her scientific research concerns the physicochemical properties of nanomaterials for photoelectrochemical and sensing applications. She has published more than 15 papers in reputed journals.

Abstract:

Photoelectrochemical water splitting is a promising technology to produce renewable fuels like hydrogen by using solar energy photon for the chemical reaction. Designed and controlled synthesis of nanostructures with well-defined morphology has recently gained increased attention, especially in the case of the material/liquid interface. The relationship between structure and property is one of the central issues in materials chemistry.  Nevertheless, the photoelectrode material must be able to absorb sunlight efficiently and have the right band alignment.

Cuprous oxide Cu₂O is a p-type semiconductor, which can be operated at relatively low temperatures. It posses high stability and good electrocatalytic characteristics. The conductivity of Cu₂O is mainly determined by the hole carrier density of the inter-granular contact region. Moreover, Cu₂O remains an attractive alternative to silicon due to the non-toxic nature, narrow band gap of about 2.0 eV, with an estimated theoretical efficiency approaching 12%.

Presented work aims to fabrication and characterization of copper oxide based photocathodes for photoelectrochemical applications. Different morphologies of Cu_2-xO were synthesized by the electrochemical deposition onto a Ti foil using alkaline and acidic cupric sulfate solutions stabilized by lactate ions. The morphology of obtained materials was analyzed by SEM observation. The XRD and Raman spectroscopy measurements were carried out for phase analysis. Measurements of the photocurrent versus voltage over the UV-ViS range of the light spectrum were performed.

Biography:

Jacob Sagiv is a Professor in the Weizmann Institute Department of Materials and Interfaces. He received the BSc in Chemistry and Physics from the Hebrew University of Jerusalem, and PhD (1975) from the Weizmann Institute. As postdoctoral fellow (1975-1978, with Prof. Hans Kuhn) at Max Planck Institute for Biophysical Chemistry, Göttingen, J. Sagiv pioneered the modern research area of monolayer self assembly (J. Chem. Phys. 1978, 69, 1836-1847; J. Am. Chem. Soc. 1980, 102, 92-98). The term “self-assembling monolayer” was coined in 1983 (New Scientist 1983, 98, 20) with reference to the advancement by Sagiv group at WIS of the concept of chemically controlled layer-by-layer self-assembly (J. Am. Chem. Soc. 1983, 105, 674-676). The nondestructive chemical patterning of highly ordered self-assembled mono- and multilayers and special applications based on such purpose-designed synthetic structures have been central topics of Sagiv group’s research at WIS.

The 2005 Prize for Excellence of the Israel Chemical Society, “for pioneering contributions to modern surface science by developing the self-assembly method of ordered arrays of molecules on surfaces.” The 2010 Kolthoff Prize in Chemistry, awarded by the Technion - Israel Institute of Technology. The 2015 Prize for Excellence in Research of the Israel Vacuum Society.

Abstract:

We report recent results of ongoing efforts devoted to the advancement of unconventional approaches to the in-situ functionalization of self-assembled OTS monolayers,¹ which enable effective nondestructive chemical patterning of such inert monolayers on length scales from centimeters down to less than 10 nanometers. The developed methodology exploits novel electrochemical transformations confined at the interface between two solid materials, here the to-be-patterned OTS monolayer and a thin film coating that acts as a site-activated reagent/catalyst upon exposure to electrons.² Site-targeted nanoscale exposure to electrons is achieved either by the use of a conductive AFM tip³ or a focused electron beam⁴. Our findings demonstrate the equivalence of the monolayer surface chemical transformations induced by the electrical AFM and the e-beam lithography approaches. Besides circumventing the need of ex-situ synthesis of functional monolayer components, this nondestructive electrochemical patterning methodology offers a number of unique features that allow realization of surface channels exhibiting unusual ionic and electronic transport⁵ along planned surface paths with precisely designed layouts that may reach centimetre lengths with widths down to less than 20 nm. Such channels represent a novel trype of inherently patternable single-layer functional material with tunable electrical properties.

Biography:

Syeda Wishal Bokhari graduated from Shanghai Jiao Tong University with an MS degree in Materials Science and Engineering. She was awarded the prestigious Excellent International Student Award (2016-17) and Outstanding MS dissertation Award (2018) of SJTU based on her excellent academic and research performance. She was offered many prestigious fully funded scholarships from the University of Manchester, University of Alberta, University of Melbourne, University of Auckland and the Tsinghua University. She has 10 peer-reviewed journal articles under her belt. Her research focuses on the development of graphene-based composites, transition metal oxides, 2D materials with applications in electrochemistry and energy storage.

Abstract:

The high power density, long life cycle and very short charging time make supercapacitor a desirable energy storage system.1 One of the limitations, however, is their low energy density as compared to the batteries.2 The best approach so far to overcome this problem is to design hybrid electrodes by comibining the capacitor type and battery type materials.3 Such hybrid electrodes use carbon materials as a conductive backbone and the transition metal oxides as an electroactive components.4 As a result, a synergistically high performance is obtained which originates from the high conductivity and long life cycle of carbon materials and the high specific capacitance of TMOs.5 Herein, we report two hybrid ternary electrode systems by using graphene-CNTs and graphene-CNCs as conductive matrix and combining them with bimorph Akaganeite (β-FeOOH) and Manganese dioxide (α-MnO2) nanoparticles respectively via a simple hydothermal self assembly method. When used as electrode in symmetirc and asymmetric supercapacitors (2V) in an aqeous electrolyte system, the hybrid electrodes gave an excellent energy-power profile, high specific capaictance and remarkable cylic stability of upto 99.8% after 10,000 galvanostatic chargedischarge cycles. This high performance is attibuted to a dominant capacitive charge storage mechanism and the well-structuring of the hybrid electrodes. This system approcah can be useful in desiging high performance electrodes for long life supercapacitor systems with high energy and power desnsities.

Biography:

Abstract:

The lead-free ferroelectric ceramics with the formula of (1-x)Na0.5Bi0.5TiO3-xK0.5Bi0.5TiO3 (x = 0.00, 0.12, 0.16, 0.17, 0.18, 0.19, 0.20 and 0.30) were synthesized by conventional solid-state method. The binary system has been designed based on the phase diagram. The XRD patterns recorded at room temperature proved the phase formation of the samples. Using Rietveld refinement method which allow us to verify the morphotropic phase boundary (MPB) at x=0.12-0.18. The limits of rhombohedral and tetragonal solid solutions were successfully formed, as well as the evolution of their lattice parameters as a function of composition and temperatures were revealed. From the Scanning Electron Microscopy (SEM) analysis, have revealed uniform distribution of grains and change in grain size with the increase in K0.5Bi0.5TiO3 concentration. Presence of functional groups has been determined by Raman Spectroscopy at room-temperature. Electrical properties of ceramics are systematically modified by the K0.5Bi0.5TiO3 content. Electromechanical coupling factor kp = 0.291 are ameliorated at x = 0.12. The photocatalytic activity for the decolorization of methylene blue under visible light irradiation of NBT powder was evaluated. In consequence, it can be considered as a potential system in photocatalytic devices.

Biography:

Chandra Mohan obtained his PhD degree in the field of “Schiff based metal complexes and their applications as Chemical Sensors” from Guru Gobind Singh Indraprastha University, Delhi, India. He has done M.Phil in Inorganic Chemistry from Delhi University and performed his research work on “Heteropoly acid intercalated clays as catalysts” in 2009. He has keen interest in research and development activities. He has 6 years of teaching experience and about 8 years of research experience. He has published 10 research papers in reputed journals and has presented 10 research papers in various conferences and workshops held in India. He is an awardee of a national fellowship from University Grant Commisiion Delhi for his Ph.D. degree. He was also invited for a lecture from Sensor Lab, University of the Western Cape, Bellville, South Africa in May 2015 and as keynote speaker in the International conference at Imperial College London, UK in September 2018. Presently he is a reviewer & editorial member of 7 International Journals and 8 scientific bodies in India and abroad.

Abstract:

Chemical Sensors are used for monitoring structural integrity of reactor containment buildings and nuclear waste repository, control of nuclear power plants, pollution monitoring and leakages of toxic gases/chemicals. Present work is based on developing ion selective electrodes (ISEs) based on PVC membrane, which includes Schiff base ligands and their complexes, macrocyclic ligands as ionophores for sensing different metal ions. Ion selective electrodes have been prepared and the electrodes performance was optimized by varying the amounts of PVC, plasticizers, ionophores and cation/anion excluders. Various characteristic features of these proposed chemical sensors with different parameters such as response time, selectivity, lifetime and pH effect on sensor response have been studied. The semicarbazide and thiosemicarbazide based Schiff base ligands and their metal complexes have been synthesised and used for the fabrication of electrochemical sensors or ion- selective electrodes. The proposed ISEs were successfully applied for the determination of various cations and anions in water samples and also as an indicator electrode in potentiometric titrations.

Biography:

Abstract:

Lithium batteries are characterized by high specific energy, high efficiency and long life. These unique properties have made lithium batteries the power sources of choice for the consumer electronics market with a production of the order of billions of units per year. These batteries are also expected to find a prominent role as ideal electrochemical storage systems in renewable energy plants, as well as power systems for sustainable vehicles, such as hybrid and electric vehicles.

In order to develop the Li-ion battery technology Indigenously, C-MET has initiated and is actively working for the development of Active materials (cathode and anode) and has developed an entire battery fabrication and testing facility for button/coin type and pouch / rectangular cells under one roof (Fig.1 a). The development of materials for high energy batteries is a continuous process and C-MET is working for the development of novel materials for the high charge capacity and energy density. The facility has already been created for the large scale synthesis of active materials (500 gm batch level) using spraydryer (Fig.1 b). Lithium cobalt oxide (LiCoO2) and Lithium iron Phosphate (LiFePO4) has been synthesised and optimized via Sol-gel and hydrothermal synthesis method and used as a cathode materials. Lithium titanium oxide (Li4Ti5O12) as an anode material has been synthesized via solid-solid combustion process. The nanostructured spherical hard carbon (anode material) has been synthesized using novel natural sources (potato, banana and sweet potatoes) and one Indian patent has been filed based on this invention. These developed cathode and anode materials were compared with the commercially available active materials (Aldrich and MTI, Corporation USA make) and fabricated prototype button/coin (2032type) cells and pouch/rectangular cells using the active materials developed by C-MET. The electrochemical performances of these cells are found to be similar to that of the commercially available active materials. We also have successfully developed thin, flexible & light weight batteries and also working for the development of polymer based electrolyte for Li-Polymer batteries. We have also initiated the activities for the development of Li-Air and Li-S batteries and Na-ion batteries for hybrid/electric vehicles for smart, green & clean transportation

Biography:

Ali Rıza Özkaya received his undergraduation, master’s degree and PhD from Marmara University, in 1980, 1984 and 1990, respectively, and became professor at the same university in 2005. He is the head of Physical Chemistry Department at Marmara University since 2012. His research interest ranges from electrochemical redox, in-situ spectroelectrochemical, electrochromic and electrocatalytic properties of organic and inorganic based macrocyclic compounds, especially phthalocyanines, to electrochemical energy convertion and storage. He has published more than 100 papers with total citations higher than 2000 in SCI journals. He has been serving as an editorial board member and electrochemistry topic editor of Turkish Journal of Chemistry.

Abstract:

The synthesis of a dinuclear ball-type phthalocyanine (BTPc) containing two cofacial ligands and two metal (M) centers was reported for the first time by Zefirov and coworkers in 2002. However, the first article reporting not only synthesis, but also various physicochemical properties of BTPc compounds was published by our group in 2006. This motivated our group to identify electrochemical, spectroelectrochemical and electrocatalytic properties of the newly synthesized examples of these compounds and thus, the relevant studies have been still continuing. Due to the wide range of intermolecular and intramolecular interactions between the face to face Pc rings and/or the two metal centers, these compounds exhibit different and interesting electrochemical and electrocatalytic properties, as compared to their parent monomers. These interactions appear to depend on the nature of the metal centres, bridging links and the presence or absence of axial ligands and thus, can be tuned by changing and/or modifying these species. The enriched ligand and metal-based reduction and oxidation properties of BTPc compounds as a result of the splitting of the classical redox processes of mononuclear Pc compounds lead to their efficiency in electrocatalytic processes. For instance, in aqueous acidic medium, ball-type cobalt and iron Pc complexes usually display high catalytic performance toward oxygen reduction reaction (ORR) which is important for fuel cell applications. The catalytic activities of some BTPc compounds towards ORR have been tested, also in basic aqueous media, in our recent studies. The results encouraged us to test their catalytic performance also in metal-air cells. These studies continues with a project focusing determination of the effect of bridge length and thus, the distance between the two MPc units in BTPc structure on the performance in oxygen electrocatalysis and zinc-air battery.

Biography:

Gyeongseop Lee received his BSc in Chemical and Biological Engineering from the Sogang University in 2014. He is currently pursuing a PhD degree in Chemical and Biological Engineering at the Seoul National University under the supervision of Prof. Jyongsik Jang. His research mainly focuses on zeolitic imidazolate framework-derived materials and their composites for supercapacitor applications.

Abstract:

In this study, a novel hybrid structure of homogeneously distributed Co₃O₄ nanograins on a hexagonal Co(OH)₂ plate (CNG/Co(OH)₂) is synthesized using a one-pot hydrothermal reaction of zeolitic imidazolate framework-67 (ZIF-67). Particularly, because Co-containing ZIF-67 serves as a self-template during the hydrothermal conversion process, various-sized CNG/Co(OH)₂ can be prepared using different sizes of ZIF-67 as the precursor material. The unique structural features of CNG/Co(OH)₂ effectively boost the electrochemical activation of the active materials (i.e., Co₃O₄, Co(OH)₂) by preventing aggregation. Among the various-sized CNG/Co(OH)₂, large-sized CNG/Co(OH)₂ (L_CNG/Co(OH)₂) exhibits the highest capacitance (1284 F g⁻¹ at 1 A g⁻¹), indicating that the electrochemical performance is improved as the size of the hybrid architecture increases. Furthermore, multifarious all-solid-state asymmetric supercapacitors (ASCs) are successfully fabricated with various-sized CNG/Co(OH)₂ as the positive electrode and mesoporous plasma-reduced graphene oxide (MPRGO) as the negative electrode. Owing to the synergistic contributions from the two electrodes, the L_CNG/Co(OH)₂-based ASC delivers a maximum energy density of 41.2 Wh kg⁻¹ at 2.8 kW kg⁻¹, and holds 31.5 Wh kg⁻¹, even at the highest power density of 45 kW kg⁻¹, demonstrating great potential for next-generation energy storage devices.

Biography:

Athil Al-Shihabi Al-Ani is a PhD student at the University of Nottingham/Chemical and Environmental Engineering. She has finished her Master degree in Iraq at the University of Technology/Chemical Engineerin. She is a lecturar at Al-Nahrain Univesity/School of Engineering. She has published 2 papers, recently she submitted a paper to The journal of Physical Chemistry. 

Abstract:

We report simultaneous under-potential deposition of multiple elements on TiO₂ NTAs arrays (TiO₂ NTAs) to form sensitizer of kesterite (Cu₂ZnSnS₄) to enhance the photo-conversion efficiency of the TiO₂ NTAs. The simultaneous deposition of multiple elements was successfully achieved using the modified electrochemical atomic layer deposition (EC-ALD). We controlled the electrodeposition by manipulating the concentration of the complexing agent (EDTA) and adjusting the pH value of precursor solutions. We emphasized that examine the effect of these two factors (EDTA concentration and pH value) was a key factor to assist the successful deposition of four elements onto the TiO₂ NTAs while maintaining the well-organized structure of NTAs. The electrodeposition process, surface morphology, crystalline structure and photocatalytic activity of the as-prepared and annealed Cu₂ZnSnS₄/ TiO₂ NTAs were discussed. The kesterite crystalline structure of Cu₂ZnSnS₄was successfully deposited as a single phase. In comparison with pure TiO₂ NTAs, an enhancement of 81% in the photo-conversion efficiency was observed, and the band gap was reduced from 3.1 eV to 2.43 eV using the sensitizer Cu₂ZnSnS₄. This approach probably suitable in synthesizing multijunction semiconductor materials for coating of highly structured substrates.

Biography:

Julia Mazurkow has completed his B.Eng. at the age of 22 years from AGH Univeristy of Science and Technology. She is currently Master Student at the same univeristy and pursues her thesis with cooperation with Empa Swiss Federal Laboratories for Materials Science and Technology. Her research interest focuses on nanomaterials synthesis and characterization, as well as their application in the field of electrochemistry (biomolecules detection) and water purification.  

Abstract:

Electrochemical methods are the most commonly used for glucose detection in case of diabetes because of their high accuracy, good sensitivity, quick response, and easy maintenance, which made them suitable and practical for self-testing of patients. The functional principle in commercially available appliances is based on the electrooxidation of glucose present in blood by enzymes (glucose oxidase or dehydrogenase). Generated current is proportional to the amount of this monosaccharide in the sample. However, such systems suffer from stability issues (influence of temperature, pH, and presence of other electroactive species). Likewise, the mass production of them is hindered by low reproducible and high costs. In the majority of cases, test strips are only disposable. As diabetes is on the most widespread diseases in developing countries above disadvantages need to be overcome. An emerging new generation of nonenzymatic electrodes based on the direct transfer of electrons is believed to solve major concerns and contribute to the development of continuous glucose monitoring systems.

Presented work aims to investigate the performance of modified glassy carbon electrode (GCE/CuS) in glucose detection. Copper sulfides in form of nanoflowers were synthesized and characterized (techniques: SEM, XRD, DLS). Electrochemical measurements, cyclic voltammetric and chronoamperometric, were carried out using the three-electrode system in which GCE/CuS electrode was the working one, silver chloride (Ag/AgCl) – reference and platinum wire (Pt) – auxiliary. The influence of polymer type, its concentration and the solvent kind involved in incorporation of copper sulfide nanoparticles on the surface of the electrode was examined. Limit of detection and quantification, as well as measuring range, were determined.

This work has been supported by the European Union and Ministry of Science and Higher Education, project “Najlepsi z najlepszych! 3.0” POWER cofounded by European Social Fund titled "Transition metal compounds with a designed surface for non-enzymatic glucose sensors."

Biography:

Efe Baturhan Orman received his PhD in physical chemistry at Marmara University, Istanbul -TURKEY in 2017. He has been working as a research assistant at Marmara University since 2006. His interests are electrochemical, electrocatalytic and electrocolorimetric properties of organic molecules and their applications in thin films and modified electrodes.

Abstract:

Phthalocyanine (Pc) complexes have attracted considerable attention of many scientists and researchers due to their industrial and technological applications such as dyes and pigments, chemical sensors, photodynamic therapy, solar cells, electrochemical energy conversion and storage, electrochromic devices, photovoltaics, and catalysis. With the conjugated 18- electrons system, Pcs display ligand and/or metal based redox processes. Electrochemical redox behavior of these compounds can be modified in a broad scale by changing the nature and number of peripheral or nonperipheral substituents and the metal ion in the center. The detailed identification of their redox properties has vital importance for the determination of the possibility of the usage of novel Pc compounds in the technological applications.

In the present work, electrochemical redox behaviors of peripherally and non-peripherally substituted mononuclear metal-free and zinc (II) Pc compounds were investigated by the techniques of cyclic voltammetry and square wave voltammetry on a Pt working electrode in de-aerated nonaqueous solvent medium involving TBAP as the supporting electrolyte. The identified redox data included the half-peak potentials for the redox processes (E_1/2), anodic to cathodic peak potential separations (ΔEp), peak current ratios (I_pa/I_pc for reduction and I_pc/I_pa for oxidation) and the potential difference between the first half-peak oxidation and reduction processes (ΔE_1/2). Electrocolorimetry supported in-situ spectroelectrochemistry of the compounds were also studied since it is not possible to completely identify the nature of the redox processes and the influence of some side-effects such as metal coordination and aggregation.

Biography:

Tarifa Kaniz has completed her Bachelor’s and Master degree from her country, Bangladesh. She is now doing her PhD in Marmara University. During this period, she is also working in a project related with the identification of the electrocatalytic performances of various phthalocyanine compounds for oxygen reduction.

Abstract:

Phthalocyanines (Pcs) have varied chemistry resulting from their rich π -electron system. These compounds have been receiving increasing interest of researchers, due to the presence of various synthetic pathways for their cost-effective preparation and applicability in many areas such as photodynamic therapy, non-linear optics, electrocatalysis, electrochromism and sensors. Another important pluspoint of these complexes is the modification ability of their main skeleton with various central metals and peripheral or non-peripheral substituents. Thus, various functional monomeric MPc derivatives and their dimeric or multimeric derivatives with different kinds of bridging units or linkages could be designed. In this study, the electrochemical redox properties of the novel Pc compounds involving tertiary butyl and oxo bridging groups have been identified by classical voltammetric techniques and in-situ spectroelectrochemistry. These properties allow the determination of the compounds which have the ability to show high catalytic activity and thus, suitable for preparing electrocatalyst for oxygen reduction reaction (ORR). Electrocatalytic performance measurements have been made with cyclic voltammetry, linear sweep voltammetry, chronoamperometry and hydrodinamic rotating disc and rotating ring-disc voltammetry techniques. These measurements were performed with glassy carbon electrodes modified suitably with a Pc compound, a carbon-based supporting material and Nafion as binder. Some catalytic measurements were carried out both in the absence and in the presence of O₂ in solution or Pc compound in the catalyst ink with the aim of evaluating their electrocatalytic ORR performances and the relation with their general surface redox behaviours. Electrocatalytic measurements were performed in both acidic and basic aqueous media in order to understand appliciability in fuel cells and metal-air batteries.

Biography:

Muhammad Nazrul Islam was awarded BS and MS degree in chemistry from University of Chittagong, Bangladesh. Now, he is  final year PhD student in organaic chemistry at Yildiz Technical University, Istanbul, Turkey. Previously, he was a lecturer of chemistry at University of Information Technology and Sciences (UITS), Dhaka, Bangladesh. He has published five papers in reputed journals and presented poster and oral in several national and international coferences. His reseach interests are dendrimer, ring opening polymer (romp), conductive polymers, and antibacterial polymers.

Abstract:

Due to having unique globular shape and possessing multi functional groups on the periphery, Poly(amidoamine) (PAMAM) dendrimers have drawn great attention in recent years. Likewise Graphene Oxide (GO) has also sparked tremendous interest  across many field such as electrochemical, energy and electronic instrument. Nowadays organic-inorganic hybrid materials are being synthesized to be used in highly electroactive material for a better conductivity, dispersion and compatibility. In this study, PAMAM based GO was synthesized from the graphite powder and jeffamine cored 3^rd generation dendrimer.  The chemical structure of PAMAM dendrimer was studied by Fourier Transform Infrared Specroscopy (FT-IR) and Nuclear Magnetic Resonance Spectroscopy (NMR). Then GO-PAMAM dendrimer nanohybrid material were prepared by mixing GO suspension and  PAMAM solution at various ratios. The chemical functionality, surface morphology and structural property of obtained material were investigated via FT-IR, Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) respectively. Finally, a glassy carbon electrode was coated with this hybrid-material and its conductivity was measured by cyclic voltammetry (CV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV).