bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Ti|IrO2-SnO2-Sb2O3 electrodes without Chloride Precursors and Their Electrochemical Applications
Authors: Reyes Adrián , Sánchez David , Serrano Ricardo Agustín , Medel Alejandro , González-Fuentes Miguel A. , Méndez Erika 
Published: February 2020

Electrochemical oxidation depends enormously on the electrode materials used during electrolysis. Dimensionally Stable Anodes (DSA) represent a good option for electrochemical oxidation applied to wastewater treatment due to the ability of generating hydroxyl radicals. These radicals are strong, non-selective oxidizing agents, which are able to react with organic pollutants and mineralize them. However, this kind of electrodes is commonly synthesized from chloride precursors, which represents an environmental problem, because they can form undesirable chlorinated by-products during the electrolysis. Some DSA electrodes such as PbO2, SnO2-Sb2O5 and TiO2 are promising anodes due to their high over-potential for oxygen evolution, which leads to the ability of OH radical production; however, their main drawback is the low chemical stability [1, 2]. This disadvantage prevents their use in environmental applications and causes the search for other materials with better properties. In this work we present the synthesis as well as its electrochemical application of a DSA electrode composed of Ti|IrO2-SnO2-Sb2O3. The purpose is enhancing the chemical stability and prolonging the electrode lifetime. The Pechini concept was used to this material, but with the advantage that no chloride precursors were employed [3]. Cyclic voltammetry (CV), X-ray diffraction (DRX), Energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) were used to characterize the as-prepared electrode. The electrocatalytic properties were evaluated by electrochemical degradation of tartrazine in aqueous media as well as dibenzothiophene in organic media. Results showed that noncracked oxide layers were obtained and that the electrode has a great capability for the electrochemical degradation of both molecules.
Keywords: DSA electrode, Ti|IrO2-SnO2-Sb2O3, tartrazine, dibenzothiophene

X. Chen, G. Chen, Anodic oxidation of dyes at novel Ti/B-diamond electrodes, Chem. Eng. Sci. 58 (2003) 995.

X. Chen, G. Chen, F. Gao, P. Yue, High-performance Ti/BDD electrodes for pollutant oxidation, Environ. Sci. Technol. 37 (2003) 5021.

M. H. P. Santana, L. M. Da Silva, L. A. De Faria, (2003). Investigation of Surface Properties of Ru-Based Oxide Electrodes Containing Ti, Ce and Nb. Electrochim. Acta, 48 (13), 1885.
Electrodeposition of Mg-Based Alloys for Anti-Corrosion and Energy Storage Applications
Authors: Castro Pardo Samuel , Ganguli Babu , Vajtai Robert , Ajayan Pulickel M 
Published: February 2020

Magnesium has gained a lot of attention due to its inherent properties such as light-weight with a density of 1.7 g/cm3 and the highest strength to weight ratio. Such unique properties make magnesium a suitable candidate for various applications including vehicles, aerospace projects, construction, energy storage applications and medical implants. One of the crucial issues with the use of magnesium on these applications is the tendency of the material to corrode. This is due to the high chemical activity of magnesium, its standard equilibrium potential of Mg/Mg2+ is -2.4 V vs. NHE. To prevent these problems, there have been reported strategies such as formation of alloys with noble metals or inert elements and the protection of the metal with a coating film.1 From the mentioned solutions, the most suitable solutions to prevent corrosion on magnesium without compromising its properties are the formation of alloys using passive elements such as Al, Ni or Cr and the protection of magnesium with a coating film. 2,3

Based on these two solutions, we propose to use aluminum as the second element for the alloy formation to prevent corrosion of magnesium and to enhance its structural, thermal, and electrical performance. In our study, we’ve been able to produce magnesium alloys by electro-co-deposition which have demonstrated to have a lower corrosion behavior compared to pristine magnesium films. Similarly, magnesium-based materials are gaining interest in energy storage application due to two-electron transfer per a reaction and thus a high volumetric capacity compared to the state-of-art Li-ion batteries. Also, they have shown to be safer than Li since Mg during cycling do not form dendrites.4 Herein, we explore the use of electro-co-deposited Mg-Al alloy as electrodes to construct high energy rechargeable Mg batteries.
References
(1) Esmaily, M.; Svensson, J. E.; Fajardo, S.; Birbilis, N.; Frankel, G. S.; Virtanen, S.; Arrabal, R.; Thomas, S.; Johansson, L. G. Fundamentals and Advances in Magnesium Alloy Corrosion. Prog. Mater. Sci.
2017, 89, 92–193.
(2) Liu, R. L.; Scully, J. R.; Williams, G.; Birbilis, N. Reducing the Corrosion Rate of Magnesium via Microalloying Additions of Group 14 and 15 Elements. Electrochim. Acta
2018, 260, 184–195.
(3) Yuwono, J. A.; Birbilis, N.; Liu, R.; Ou, Q.; Bao, Q.; Medhekar, N. V. Aqueous Electrochemical Activity of the Mg Surface: The Role of Group 14 and 15 Microalloying Elements. J. Electrochem. Soc.
2017, 164 (13), C918–C929.
(4) Bucur, C. B. Challenges of a Rechargeable Magnesium Battery A Guide to the Viability of This Post Lithium-Ion Battery, 1st editio.; Spinger Briefs in Energy, 2018.
Reaction Mechanism for the Formation of Magnetite Nanoparticles Via Electrochemistry
Authors: Reséndiz Ramírez Rubí , Antaño López René , Rodríguez López Aarón , Larios Duran Erika Roxana , Torres-González Julieta 
Published: February 2020

Magnetite is an iron oxide composed of ferrous-ferric oxide, because of its magnetic properties is used in different areas. In literature there are proposals of reaction mechanisms for the formation of magnetite when it is produced electrochemically, however, these do not seem to be very clear since there are inconsistencies in their formulation. In electrochemical synthesis metallic iron is used as a cathode and as an anode in an electrolytic solution, the necessary potential is applied to oxidize iron to form magnetite (Fe3O4). The most stable oxidation state of iron is (III), some authors report that they oxidize to iron III and later reduce one part to iron II to form magnetite. One of the reported inconsistencies is the existence of solids that are formed in the anode that later diffuse to the cathode to be reduced to form the magnetite, other authors support the fact that magnetite is formed in the solution and that the hydrogen is one of the main reactants. In this work we propose a simple mechanism for the formation of magnetite:
Fes + 2(OH-) →Fe(OH)2ads+2e-

3Fe(OH)2ads+ 2(OH-)→ Fe(OH)2•2Fe(OH)3ads+2e-

Fe(OH)2•2Fe(OH)3ads →Fe3O4+4H2O
This mechanism was proposed to be analyzed by EIS with the reaction mechanisms approach. This approach consists of formulating the impedance expression, starting with charge and mass balances using mathematical models, to be able to use this approach it is necessary to have intermediaries adsorbed in the mechanism. With this approach it is possible to obtain a simulated spectrum as a function of the potential by means of theoretical assumptions of the parameters involved, which can be sustained experimentally.
Molybdenum Carbide Electrocatalyst/Support Synthesis and Characterization
Authors: Benavidez Angelica D , Nayak Shanti Kiran , Coker Eric , Garzon Fernando H 
Published: February 2020

Transition metal carbides are increasingly gaining attention as electrocatalysts/supports due to their unique properties including structural durability, electronic conductivity, and an electron structure which is somewhat similar to that of noble metals[1]. Molybdenum carbide has shown to be an active catalyst and as a noble metal support, however it is difficult to prepare in high surface area nanoparticle form[2,3]. Most nanoparticle synthesis methods produce residual carbon that blocks surface access. In order to improve materials performance, high surface area, impurity-free molybdenum carbides are needed. With the aid of thermochemical modeling and gas equilibration studies, we have developed a synthesis method that yields high surface area MoC nanoparticles of the metastable cubic phase. These 2-3 nm MoC nanoparticles have surface areas of up to 360m2/g and have been characterized using TEM, XRD, EDS, XPS, and BET. The nanoparticles were tested for their effectiveness for both electrochemical and heterogeneous synthesis of ammonia.
[1] Y. Liu, T.G. Kelly, J.G. Chen, W.E. Mustain, Metal Carbides as Alternative Electrocatalyst Supports, ACS Catal. 3 (2013) 1184–1194. doi:10.1021/cs4001249.
[2] M. Patel, J. Subrahmanyam, Synthesis of nanocrystalline molybdenum carbide (Mo2C) by solution route, Materials Research Bulletin. 43 (2008) 2036–2041. doi:10.1016/j.materresbull.2007.09.025.
[3] A.M. Gomez-Marin, E.A. Ticianelli, Analysis of the electrocatalytic activity of a-molybdenum carbide thin porous electrodes toward the hydrogen evolution reaction, Electrochimica Acta. 220 (2016) 363–372. doi:10.1016/j.electacta.2016.10.101.

Figure 1
Electrochemical Methane Activation and Conversion Using Fe, Co, Cu Oxides/ZrO2 Nanocomposites
Authors: Vazquez Juvencio , Mojica Hebert Rodrigo , Molina Paulina , Acevedo-Peña Prospero , Reguera Edilso , González Montiel Marlene 
Published: February 2020

Methane has been widely employed as a feedstock for numerous chemical and electrochemical processes. However, methane activation poses a challenge due to the molecule’s relative inertness, lack of significant polarity and because its bond energy is the highest among all hydrocarbons. Consequently, the ability to activate methane (CH4), or access the C atom to form new bonds is a difficult endeavor [1]. Furthermore, CH4 gas emission has long been ignored and regarded as a trivial matter [2], even though its effect as a greenhouse gas is over 30 times more potent than that of CO2 [3]. In this regard, the oxidation and conversion of CH4 to liquid alcohols is an economical and energy efficient alternative with academic and industry interest.
The present study shows the synthesis and characterization of Fe, Co, Cu oxides/ZrO2 nanocomposites used as bifunctional electrocatalyst for the electrochemical activation of methane, which in conventional alkaline electrochemical systems is always performed at room temperature.
Fe, Co, Cu oxides/ZrO2 nanocomposites were synthesized using an aqueous-phase precipitation technique and their structural, spectroscopic, magnetic and electrochemical characteristics were evaluated.
Methane was electrochemically activated over the three functional electrocatalysts here synthesized. Carbonate anions were used as an oxygen donator to facilitate methane activation while ZrO2 adsorbed and donated carbonate anions to active sites on Fe, Co and Cu oxides where methane was adsorbed and activated. Products formed were studied by gas chromatography.
References:
[1] R. Bergman, Nature, 446, 391 (2007).
[2] A. R. Brandt, G. A. Heath, E. A. Kort, F. O. Sullivan, G. Petron, S. M. Jordaan, P. Tans, J. Wilcox, A. M. Gopstein, D. Arent, S. Wofsy, N. J. Brown, R. Bradley, G. D. Stucky, D. Eardley, R. Harriss, Science, 343, 733 (2014).
[3] D. T. Shindell, G. Faluvegi, D. M. Koch, G. A. Schmidt, N. Unger, S. E. Bauer, Science, 326, 716 (2009).
[4] Neil Spinner and William E. Mustain, Journal of The Electrochemical Society, 160 (11) F1275-F1281 (2013).
Isolating Surface Reactivity of High Energy Cathode Materials through Model Thin Films
Authors: Phillip Nathan Dale , Veith Gabriel M. , Ruther Rose E. , Wood David L 
Published: February 2020

Increasing demands for improved energy density in lithium ion batteries for electric vehicles and grid storage has spurred the development of high energy cathode materials. Ni-rich LiNixMnyCozO2 (x > 0.5, x + y + z = 1) cathode systems are frontrunners among the next-generation of Li-ion battery cathode active materials. Despite the material’s high theoretical capacity (~200 mAh/g), commercial adoption has been hindered by a lack of understanding of complex interactions between the electrolyte and the binder, conductive additives, and active material present in composite electrodes. In this study, we isolated the surface reactivity of LiNi0.6Mn0.2Co0.2O2 (NMC622) by physical vapor deposition of thin film electrodes (thickness < 1.5 µm) for characterization and electrochemistry without influence from conductive additives and binders.
Radio Frequency Magnetron Sputtering of homemade NMC622 targets was used to deposit thin films of NMC622 onto Pt-coated Al2O3 substrates which were annealed to achieve the desired layered structure. LiCoO2 thin films were deposited in a similar manner as a baseline for the process. The dependence of crystal structure and stoichiometry on deposition and annealing conditions of these films were determined by XRD, Raman, and ICP-AES. Cathodes were cycled against Li metal in a standard commercial electrolyte of 1.2 M LiPF6 in EC:EMC (3:7 wt%) and extracted in an inert atmosphere glove box for surface characterization after rinsing in DMC. Ex situ XPS and FT-IR analysis of pristine and cycled cells traced a substantial difference in surface species dependent on annealing environments and cycling conditions of thin films. This provided a model system to investigate the influence of thin film coatings such as Al2O3, LiPON, and ZrO2 on the active material alone. The approach developed here may be extended to other promising cathode systems for which the surface chemistry of the active material is not well understood.

Figure 1
Electrochemical Technologies for Developing Countries
Authors: Petrovic Slobodan 
Published: February 2020

Batteries and photovoltaics are critical technologies for enabling electrical power for the rural areas in developing countries. The solar PV systems with battery storage are considered the only hope for almost 2 billion people without access to electricity. These forgotten people need electricity for improved basic life necessities such as reading at night, refrigerating food, or charging cell phones for communication.
Solar Hope (www.solar-hope.org) is a unique, non-profit organization that has accomplished over 120 solar PV installations in Africa and South America since 2010. The PV installations were installed for schools, hospitals, orphanages, and for water pumping for whole villages. The volunteers for the organization are the students from the Electrical Engineering and Renewable Energy Engineering program at the Oregon Institute of Technology. A unique concept involves PV system design in classroom and implementation in the field. Through Solar Hope, the students participate in the design, component build, and training, prior to joining the expeditions to remote areas of Africa. Solar Hope has made a huge impact so far by affecting with the installations in the excess of 300,000 people, mostly children. The efforts by Solar Hope also save lives by enabling better treatment of patients in the hospitals and by preventing fires from burning fossil fuels inside.
Solar Hope requires help from the electrochemical community in form of component donations (e.g., batteries, Solar PV panels, charge controllers, inverters, etc.) as well as monetary contributions to enable the use of electrochemical technologies in developing countries and help improve lives of millions.
A 1D Mathematical Model to Study the Effects of Adhesive Strength on the Electrochemical Performance of Silicon Electrodes for Advanced Lithium Ion Batteries
Authors: Appiah Williams Agyei , Park Joonam , Byun Seoungwoo , Cho Inseong , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

In recent times, commercially available lithium ion batteries (LIBs) employ graphite, with a theoretical capacity of 372 mAh g-1, as their anode material. To enhance the energy density of LIBs, alternative anode materials with higher capacities, such as Li metal, Si, and various alloys, have been extensively exploited. With its advantages of a higher theoretical capacity (4200 mAh g-1), environmental friendliness, and terrestrial abundance, Si is particularly well-suited as an anode material for this purpose. Nevertheless, Si suffers from large volume variations (up to 300%) during lithiation/delithiation processes, leading to pulverization, low cycling efficiency, unstable solid electrolyte interphases (SEI), and permanent capacity losses.
There have been several scientific investigations and strategies to solve the issues related to the large volume changes in Si. Relevant breakthroughs have been made with the help of advanced nanotechnologies in terms of enhancing the cycle life and improving the cycle rate performance. Notable among them is the use of binding materials with improved adhesive properties, such as copolyimide, alginate, poly(acrylic acid) (PAA), carboxymethyl cellulose, polyamide-imide, polyimide, and polymers that form cross-linked networks. Moreover, enhancing the adhesive strength between the Si composite electrode and Cu current collector by coating the latter’s surface with a very thin polymeric layer has significantly enhanced the electrochemical performance of Si anodes. However, the mechanism underlying this improvement in performance was not clearly addressed.
In this presentation, a coupled chemo-mechanical model which considers the contact resistance as well as the influence of the attractive forces inside the contact area between the electrode and current collector was developed to study the effects of the adhesive strength of a binding material on the electrochemical performance of silicon-based lithium-ion batteries. The model predictions were validated with experimental data from coin-type half-cells composed of Li metal, Si electrodes, and Cu current collectors coated with binding materials with different adhesive strengths. The proposed model was used to investigate the effects of the adhesive strength and various cell design parameters on the specific capacity of the Si-based Li-ion cells.
Controllable Synthesis of Circular Graphene Domains By Atmosphere Pressure Chemical Vapor Deposition
Authors: Dai Gui-Ping , Vinodgopal Kizhanipuram , Wu Marvin H. , Jiang Bang-Bang 
Published: February 2020

Graphene, as a perfect two-dimensional crystalline structure, has attracted much attention in the research community, owing its unusual mechanical strength (>1Pa), optical transparency and high carrier mobility for various promising applications. Several methods have been used to develop to obtain graphene, such as mechanical exfoliation, thermal decomposition of SiC and chemical vapor deposition (CVD). Among these methods, CVD is considered to be the most promising way for graphene industrial development and scale-up production due to its convenience and economic efficiency. In a CVD process, growth on Cu substrates is particularly attractive since the growth occurs via a self-limiting mechanism, attributed to the negligible carbon solubility in copper.
Yet the CVD graphene shows a lower carrier mobility of a few hundred to a few thousand cm2/(Vs) compared with exfoliated graphene obtained from natural graphite, because of the presence of growth defects and boundaries. In order to attain the predicted theoretical values for graphene, it is critical to improve graphene film quality. Previous studies have shown that seamless merging of graphene domains during CVD is an ideal route to reducing defects and domain boundaries, and produce single crystal graphene to enable further applications. Furthermore, the morphology and edge structure of individual graphene domains strongly influence its properties. It is very important to understand the nucleation stage and the expansion mechanism of the graphene domains to control the morphology of graphene films.
Recent advances in the CVD method yields various interesting graphene domain shapes. Pentagonal, triangular, rectangular, snow-like graphene, twelve-pointed and four-lobed, graphene domains have been successfully obtained. The various shapes of these graphene domains can be achieved by optimizing growth parameters, such as precursor composition, flux, and choice of substrate. However, all of these methods either require liquid-state copper as the substrate or yield irregular circular or other shapes with one or very few separate circular graphene domain. Hence, it would be quite advantageous to grow graphene on a solid-state copper substrate via the simultaneous large scale growth and seamless merging of circular-shaped graphene domains. This provides a very good platform to observe and investigate the growth mechanism leading to large area single crystal graphene sheets.
In this presentation, I will report the first successful large-scale growth of single-crystal “circular” graphene domains on a solid-state copper substrate during the early stage of CVD operated under atmosphere pressure. The individual circular graphene domains have smooth edges as well as axisymmetric and centrosymmetric shapes which permit seamless merging of adjacent graphene without the effect of orientation.

Figure 1
(Invited) Gel Behavior of Sugar-Based Polymers and Their Composites
Authors: Imae Toyoko 
Published: February 2020

Cellulose is a linear sugar-based polymer and a main component of wood pulp which are a material of paper. In this decade, the cellulose nano-fibers are gathering attentions in the material science because of their mechanical properties and environmental suitability. In particular, the 2,2,6,6-tetramethyl-1-piperdinyloxy free radical (TEMPO)-oxidized cellulose nano-fiber (TOCNF) is the ultrafine fiber and have many carboxyl groups on its surface, which are suitable for the chemical modifications. From this viewpoint, we have examined the modifications of TOCNF to develop absorbers. It was demonstrated that the nanocomposites of nanoparticle/dendrimer/TOCNF allowed the diffusion of small molecules in their matrix, although the simple TOCNF formed a film with powerful gas-barrier function. Thus, the availability of these nanocomposites for absorbers were verified; however, the detailed structures of these nanocomposites were not yet confirmed.
In this study, The TOCNF was hybridized with amine-polymers (poly(amido amine) dendrimer and poly(ethyleneimine) with different molecular weights). The hybrids formed transparent gels, and especially the dendrimer led to a homogeneous viscoelastic gelation in the wide range of mixing ratio. The number binding ratios of polymers per TOCNF suggested that the dendrimer partially covered the surface of TOCNF, facilitating the cross-linking, while the poly(ethyleneimine) could vary their conformations to cover the TOCNF at the different concentrations.