bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) X-Ray Spectroscopy of Energy-Relevant Material in Operando Condition
Authors: Dong Chung-Li
Published: February 2020

A new age of human demand for renewable energy is coming and material scientists are devoted to developing new functional materials to produce clean and sustainable energy. It has always been a great challenge to improve the energy conversion/generation/storage efficiency of current energy material. In many important energy material systems such as nanostructured catalysts, artificial photosynthesis, smart materials, and energy storage devices, it is essential to determine the atomic/electronic structures near the interfacial region under the real working environment. Without comprehending the fundamental properties such as chemical states, atomic and electronic structures and how they alter near the interfacial region during the physical/chemical reaction, it is difficult to better design the material for advancing performance in an effective approach. Synchrotron x-ray spectroscopies, including x-ray absorption and x-ray emission spectroscopies are very powerful characterization tools to determine the local unoccupied and occupied electronic states. Exploiting the in situ/operando approach, the way to track the modification of atomic and electronic structures of the energy material under operational environment now becomes accessible. This presentation will report the in situ/operando characterization on energy relevant materials by synchrotron x-ray spectroscopy, including soft- and hard-x-ray absorption spectroscopy. Emerging characterization tool, recent progress of in situ technique development, and a number of recent studies will be presented in this talk.
(Keynote) Artificial Photosynthesis from First Principles
Authors: Carter Emily A.
Published: February 2020

Someday the world’s liquid fuels needed for ships and airplanes will come from sustainable sources and low-energy processing. We are far from that day. While that fact is unfortunate, it opens up exciting opportunities for researchers from many different fields to work together to realize that vision. I will report on some of my research group’s contributions toward this goal, as we develop and apply quantum mechanics based simulation methods to unravel mechanisms associated with (photo)electrochemical water oxidation and carbon dioxide reduction at semiconductor electrodes. As an example, we believe we have finally identified – after six years of work - the crucial aromatic-amine-derived catalytic intermediate involved in CO2 reduction to methanol at illuminated compound-semiconductor electrodes. Knowledge of this intermediate lends itself to proposed design principles to enhance the efficiency of this promising photoelectroreduction process.
High Performance p-Si/Ni3S2 Photocathode for Photoelectrochemical Hydrogen Evolution in Neutral Solution
Authors: Jia Qing , Yu Chunlin , Zhang Xingwang
Published: February 2020

In the renewable energy field, solar-driven photoelectrochemical (PEC) water splitting into H2 which has features of high energy density, high conversion efficiency and non-pollution is an efficient, inexpensive way to relieve the energy crisis. Silicon, with a bandgap of 1.1eV as an earth-abundant and efficient solar light absorption material is considered to be one of the most promising candidates for hydrogen generation in PEC devices. However, at present, most of the hydrogen evolution reactions are studied in heavily acidic condition such as 0.5M H2SO4, as for practical application, acid condition is high-cost and not environment-friendly. It’s necessary and challenging to explore photocathodes which can be used in neutral solution. The low-cost and stable transition metal sulfides materials as electrocatalysts for water splitting have grabbed more attention of researchers in recent years. Their suitable bandgap can make them absorb light over a wide range so that the solar energy can be fully used. In this study，it was found that Ni3S2 was an excellent electrocatalyst for hydrogen evolution in neutral solution. Moreover, p-Si /Ni3S2 core/shell array shows an enhanced PEC performance due to the cooperation of p-Si array’s excellent light harvesting and the optical properties of flake-like Ni3S2. By tuning the material’s composition, morphology and structure, their optical properties and stability can be optimized and applied in neutral solution. This work will generate significant new knowledge of the stable and unique core-shell nanostructure and make a meaningful contribution to the industrial application of potential hydrogen energy.
Pilot Electrodeposition of Aluminium for Microelectronics, Aerospace and Automotive Applications
Authors: Stiemke Frank M , Iliev Boyan , von Czarnecki Peter , Schubert Thoms J.S.
Published: February 2020

Ionic liquids are salts which have per definition a melting point below 100 ° C. They are non-flammable and have a high thermal stability as well as a very low vapor pressure. Many ionic liquids are characterized by a wide electrochemical window of up to seven volts, which in principle also allows the deposition of metals with high reduction potentials. Since most ionic liquids are aprotic solvents, this results in another important advantage over aqueous electroplating systems: the lack of hydrogen evolution and the corresponding hydrogen embrittlement of the deposited metal layer.

Due to its high reduction potential, aluminum cannot be deposited from aqueous solutions in pure state. However, there are very interesting applications for aluminum coatings in the area of corrosion protection or in the design sector. For example, in the (automotive) design area, chromium coatings can be replaced by shiny aluminum layers. Even in the electronics industry, homogeneous aluminum coatings on different substrates open up new possibilities for increased efficiency, e.g. copper printed circuit board tracks are replaced by corresponding aluminum ones with similar conductivity. This saves, among other things, costs for raw materials and reduces the weight of the component, which can be a significant advantage in this industry. A galvanic coating with aluminum from non-flammable ionic liquids is therefore promising from the technical point of view.

In a European joint project, the automated aluminum deposition from ionic liquids on plastic and metal substrates for the automotive industry and turbine construction could now be successfully demonstrated in a pilot plant.

The talk presents our current research results on the development and the scaling up of aluminum deposition from ionic liquids for applications in automotive engineering as well as in the field of microelectronics on circuit boards and Si wafers. We will report on the high requirements that the electrolytes place on plant design and components, the influence of additives or impurities such as water on the quality of the aluminum deposition. In addition, the influence of the post-treatment of the so produced aluminum layers will be presented. A life-cycle analysis of the electrolyte is presented for the economic and ecological consideration of this aluminum deposition process.
Electrochemical Probe of the Acidity in Room Temperature Ionic Liquids Using Quinone/Hydroquinone System
Authors: El kharbachi Abdel , Gilbert Bernard
Published: February 2020

Room temperature ionic liquids (RTILs) have been shown as alternative solvents for greener organic reactions and acid catalyzed processes [1]. High levels of acidity can be reached in acidified ionic liquids [2]. The Brønsted acidity has been first evaluated based on the determination of the Hammett acidity function H0 using UV-Vis spectroscopy in the presence of the adequate indicator [3]. Nevertheless, the uncertainty on the pKa values of the color indicators seems to be solvent dependent. In fact, it has been observed that two different indicators can lead to significant results deviation which may require additional corrections [4]. As a consequence, a novel approach for the assessment of the acidity in RTILs is presented, being based on the R0(H+) Strehlow function and using the Fc+/Fc as an internal reference couple. Protonation features of the addition of p-benzoquinone to an acidified ionic liquid medium is presented. Fig.1 shows the recorded CV redox behavior of p-benzoquinone in BMImBF4 (1-butyl-3-methylimidazolium tetrafluoroborate), along with Fc+/Fc couple without any interference. Hence, the reversible redox waves can be followed for both entities upon the increase of the acidity level. The electrochemical pathways will be addressed, first in a “neutral” and in a gradually acidified media. The results will be discussed and compared to other aprotic solvents, along useful aspects of quinones for the emerging applications (e.g. Li-ion and redox flow batteries).

Acknowledgements

The IFP (Institut Français du Pétrole) is acknowledged for financial support.

References

[1] H. Olivier-Bourbigou, L. Magna, Ionic liquids: perspectives for organic and catalytic reactions, J. Mol. Catal. A: Chem., 182–183 (2002) 419-437.

[2] C. Thomazeau, H. Olivier-Bourbigou, L. Magna, S. Luts, B. Gilbert, Determination of an Acidic Scale in Room Temperature Ionic Liquids, J. Am. Chem. Soc., 125 (2003) 5264-5265.

[3] T. Robert, L. Magna, H. Olivier-Bourbigou, B. Gilbert, A Comparison of the Acidity Levels in Room-Temperature Ionic Liquids, J. Electrochem. Soc., 156 (2009) F115-F121.

[4] T. Robert, H. Olivier-Bourbigou, L. Magna, B. Gilbert, About the Acidity Level in Room Temperature Ionic Liquids, ECS Transactions, 3 (2007) 71-82.

Figure 1
Electrical Double Layer Tuning of Room Temperature Ionic Liquids Towards Developing Stable Affinity Biosensors
Authors: Jagannath Badrinath , Muthukumar Sriram , Munje Rujuta D. , Prasad Shalini
Published: February 2020

This work demonstrates an engineering approach towards modulating the physical and the electrochemical properties of Room Temperature Ionic Liquids (RTILs) to facilitate biosensing in affinity based biosensors. RTILs possess wide electrochemical window and high charge storage capacity making them suitable for electrochemical sensors. The interactions between RTILs and biomolecules such as proteins and enzymes are less understood and therefore important in determining the biomolecule stability. RTILs could form a protective layer around protein, retaining their native confirmation there by, enhancing the protein stability as opposed to protein in aqueous buffer, where the interaction of water molecules could cause protein destabilization. This protective layer enhances the overall charge of the protein which is leveraged towards developing electrochemical immuno-sensors. The Hofmeister series is typically used to characterize the stability of proteins, enzymes. We therefore present in this work RTILs such as BMIM[BF4], Choline[DHP], Choline[TF2N] based on Hofmeister series and their miscibility (hydrophobicity or hydrophilicity) in aqueous buffers such as human sweat and human serum to determine the stability of an immunoglobulin protein, α-cortisol antibody. Optical characterization techniques such as FTIR and dynamic light scattering (DLS) was used to determine the stability of protein in these chosen RTILs. Since RTILs exhibit excellent charge transfer characteristics, we leverage this towards developing RTIL based point-of care biosensor for the detection of cortisol. The performance of the RTIL biosensor is evaluated using electrochemical techniques such as electrochemical impedance spectroscopy (EIS), chronoamperometry. RTILs contribute to the enhancement of the double layer capacitance upon binding of biomolecules in the electrical double layer (EDL). This modulation of EDL quantifies the performance of the biosensor. Further, even small excitation voltage results in a large change in current response due to excellent electrochemical properties of RTIL. All these characteristics in addition to biomolecule stabilization properties makes RTIL an ideal candidate for electrochemical based biosensing applications.
Effect of Dissolved Cellulose on Molar Conductivity and Dynamic Viscosity of 1-Ethyl-3-Methylimidazolium Acetate Solutions
Authors: Fahey Patrick J. , Fox Eric T. , Gobet Mallory , Greenbaum Steven , De Long Hugh C. , Trulove Paul C.
Published: February 2020

This study determined the effect of dissolved cellulose on the ion conductivity, dynamic viscosity, and density of 1-ethyl-3-methylimidazolium acetate (EMIAc). Cellulose solutions were prepared with three different solvents and two different sources of cellulose. The solvents were pure EMIAc, EMIAc combined in a 1:1 mole ratio with water, and EMIAc combined in a 1:1 mole ratio with acetonitrile. The cellulose sources were microcrystalline cellulose (MCC) and cotton. MCC was tested at 0, 0.001, 0.005, 0.01, and 0.03 g (g solution)-1 and cotton was tested at 0, 0.001, 0.005, and 0.01 g (g solution)-1. Each solution was evaluated over the range of 20 to 60°C. Both MCC and cotton increased the dynamic viscosity and decreased molar conductivity (with several small exceptions) for all three solvent types. The fractional changes (from zero cellulose content) for dynamic viscosity were large compared to the fractional changes in molar conductivity. The source of cellulose had a large impact on the resulting change in dynamic viscosity, as cotton increased dynamic viscosity drastically more than MCC for a given cellulose mass fraction for all solvents. For comparison, solutions were also made with glucose and cellobiose instead of cellulose in order to remove the inherent movement constraints on anhydroglucopyranose moieties within the cellulose chain. These comparisons help to understand why the addition of cellulose polymer affects dynamic viscosity more than molar conductivity by one or more orders of magnitude. Knowledge of the ion transport phenomena will allow a more thorough understanding of why ionic liquids like EMIAc are capable of dissolving biopolymers like cellulose.
Increasing Electrode Utilization and Developing a Robust Charging Method for Silver-Zinc Rechargeable Button Cell Batteries
Authors: Pourdarvish Reza , Powers Timothy W , Ortega Jeffrey Vincent , Dueber Ross Eugene
Published: February 2020

Recently, silver-zinc (AgZn) rechargeable batteries have become commercially available in small sizes which have greater capacity and energy densities over comparatively sized rechargeable Li-ion and Li-polymer batteries. Silver-zinc batteries typically do not utilize 100% of their stored capacity; therefore, an accurate charging procedure needs to be employed to prevent overcharging and undercharging events. Charging the cell properly will increase the performance and cycle life. However, charging a cell without a battery management system is a considerable challenge since it is normally required to determine the state of charge of the battery accurately. This work provides a new robust charge algorithm which utilizes a two-zone charging approach. Silver-zinc rechargeable batteries have two voltage plateaus during discharge (Figure 1). Zone 1 is utilized when the cell is discharging in the lower plateau prior to charge (OCV~1.59V). Zone 2 is utilized when the cell was discharging in the upper plateau or transition zone prior to charge (OCV~1.82V). The cell is charged using a CC-CV (constant current-constant voltage) algorithm with a maximum charge current and a maximum charge voltage. Also, the use of additives in different electrolytes was explored and characterized with respect to increasing electrode utilization, charge rate capability, and cycle life improvement in silver-zinc rechargeable button cell batteries.

Figure 1: Discharge voltage profile for Silver-Zinc button cell batteries

Figure 1
Synthesis, Electrochemical Properties of Sns/Rgo Nanocomposite As a Negative Electrode Material for Na-Ion Batteries
Authors: Kim Joo-Hyung , Jung Young Hwa , Yun Jong Hyuk , Kim Do Kyung
Published: February 2020

To date, there has been much research on electrochemical study of lithium ion batteries. However, the question has also been raised for depletion of lithium resources, causing interest in Na-ion batteries (NIBs). While extensive investigations on various transition metal oxides and chalcogenides as an anode material for NIBs have been carried out, few of them have been able to utilize their high specific capacity in sodium-based systems. Here, the mixed Sn-S nanocomposites on reduced graphene oxide are prepared via a facile hydrothermal synthesis and a unique carbo-thermal reduction process, producing ultrafine nanoparticle with a size of under 2 nm. It has been confirmed to overcome the intrinsic properties of tin sulfides such as large volume change and sluggish diffusion kinetics by experimental results, which demonstrating an outstanding electrochemical performance; excellent specific capacity of 1230 mAh g-1, impressive rate capability (445 mAh g-1 at 5000 mA g-1) and cycling stability. The electrochemical behaviors of conversion-alloying reactions for the anode materials are also investigated revealing both the structural transition and the chemical state in the discharge/charge process. Comprehension of the reaction mechanism for the mixed Sn-S/rGO hybrid nanocomposites makes it a promising electrode material and provide a new perspective on the anode field for Na ion batteries.
Ti Substitution into P2-Type Na0.67CoO2 for Structural Stabilizer and Facile Kinetics of High Energy Na-Ion Batteries
Authors: Kang Seok Mun , Sung Yung-Eun
Published: February 2020

Sodium ion batteries (NIBs) have attracted much attention as promising alternatives of lithium ion batteries (LIBs) for large scale energy storage systems. This is because sodium is cheap and abundant throughout the world contrary to lithium. However, low gravimetric/volumetric energy density of NIBs hinders its practical use. For sodium layered oxide, Na+/vacancy ordering appears at certain Na concentration, which is caused by energy minimization of electrostatic interactions between cations. This ordering leads to first-order transition that acts as kinetic barrier in battery application. In order to investigate how Na+/vacancy ordering affects battery performance, we report P2-type Na0.67Co1-xTixO2 (x≤0.2) cathode with different ordering characters. The Ti-substituted cathode utilize more Na+ ions through expanded cut-off potential, whereas Na0.67CoO2 suffers a severe capacity loss at the same condition. Also, as the ordering is mitigated, rate capability of the sample is improved. In this study, we will discuss the detailed mechanism of the improvement through TEM, in-situ XRD, and electrochemical methods.
Co, N-Doped Carbon Nanomaterial As a High-Performance Catalyst for Oxygen Reduction Reaction
Authors: Zierath Rani , Li Wenyue , Zou Shouzhong
Published: February 2020

As one of the most promising clean energy conversion systems, fuel cells (FCs) have been demonstrated to be an efficient technology to resolve intercorrelated fossil fuel depletion and climate change issues. However, sluggish oxygen reduction reaction (ORR) at the cathode side of the FCs cripples the overall device performance. Commercial Pt/C catalysts show good catalytic activity toward ORR, but their prohibitive price, limited supply and inferior stability hinder the application of FCs in a large scale. In this work, we used polyaniline modified Co-based metal organic framework (ZIF-67) as a precursor to obtain cobalt/nitrogen-doped carbon composite (Co/N-doped C) which shows outstanding ORR catalytic activity, long-term stability and high methanol poison resistance. Based on the results of control experiments, we propose that the impressive electrochemical performance originates from the nitrogen substituted carbon sites tuned by cobalt nanoparticles. Future work will be focused on further enhancing the performance of Co/N-doped C and dissecting the catalytic mechanisms.
Three-Dimensional Pore-Controlled Nitrogen-Doped Graphene Hydrogels for High-Performance Supercapacitor Developed through Properly Modulating By Formamide
Authors: Wang Yao , Wei Zidong
Published: February 2020

In recent years, three-dimensional (3D) graphene has emerged as front runners to solve the restacking issues of two-dimensional (2D) graphene in the hope of achieving a high capacity in supercapacitors. Nevertheless, the traditional 3D graphene still reveals an unsatisfactory capacitance property on account of the simplex macropore structure and un-optimized surface properties; in addition, simultaneously optimizing structure as well surface properties by one-step procedure also faces significant challenges. Herein, formamide was inventively employed as a modulator of pore structure and meanwhile a dopant of nitrogen to ameliorate the surface properties. As expected, it has been found that the supercapacitor performance of optimized 3D nitrogen-doped graphene have been remarkably boosted compared with the traditional 3D graphene. An initial capacity of 275 F g-1 at the current densities of 0.5 A g-1 was achieved. Moreover, the few capacitance fade after 2000 charge–discharge cycles at a current density of 20 A g−1 has been demonstrated. This work provided a new clue that how to design the porous graphene framework for supercapacitors and beyond with simple method.

Figure 1
Phase-Field Modeling of pH-Dependent Corrosion Reactions at an Iron/Aqueous Solution Interface
Authors: Tsuyuki Chisa , Yamanaka Akinori , Ogimoto Yasushi
Published: February 2020

There has been a growing demand for corrosion prediction. To describe the time-space evolution of a metal/aqueous solution interface, a phase-field (PF) method is promising because of its suitability for simulating moving interfaces. Yet, only a few attempts are reported concerning the PF simulation of corrosion reactions. Here we propose a PF modeling of pH-dependent general corrosion of iron in an aqueous solution. Our PF model consists of three governing equations: First one is the Allen-Cahn equation derived from the Butler-Volmer electrochemical reaction kinetics, in which the activity of OH- ions is taken into account in order to express the pH-dependent motion of an iron/solution interface as proposed by Bockris [J. O’ M Bockris et al., Electrochimica Acta 4,325-361 (1961)]. Second is the Cahn-Hilliard equation that describes the diffusion of ions in the solution. And the last one is the Poisson equation to calculate the distribution of an electrostatic potential. As for the simulation parameters, the diffusion coefficients of ions, the corrosion potential, and the corrosion current density to estimate the mobility of the interface, are given by Corrosion Analyzer software (OLI Systems Inc.). Using the proposed PF model, we can successfully reproduce the pH-dependent general corrosion of pure iron in an HCl solution. Simulation results demonstrate that the PF model is available to predict the iron dissolution and the evolutions of Fe2+, H+, and OH- ions concentrations in the solution.
Macroscale Films of Highly Ordered Periodic 3D Semiconductor Nanostructures Generated Via Lithography-Free Photoelectrodeposition
Authors: Carim Azhar I , Batara Nicolas A. , Premkumar Anjali , Atwater Harry A , Lewis Nathan S
Published: February 2020

Electrodeposition of Se-Te alloy films under illumination spontaneously generates nanopatterned films with significant periodic order. The feature sizes, periodicities, anisotropies, and orientations of the nanoscale pattern are a function of the exact nature of the optical excitation. Isotropic morphologies consisting of ordered arrays of nanopores were generated using unpolarized illumination whereas linearly polarized light resulted in highly-anisotropic lamellar morphologies with the long axes of the patterns aligned along the E-field vector. The use of two non-orthogonal polarized sources simultaneously generated patterns oriented along the average E-field vector and with degrees of anisotropy related to the difference in orientation between the two input E-field vectors and the phase correlation between the sources. The pattern periodicity was encoded by the illumination spectral profile. A single periodicity in single spatial direction was only generated even with the use of broadband and multimodal spectral profiles and multiple polarization inputs and the periodicity was found to be sensitive to all investigated tuning of such profiles. The incidence of the illumination set the direction the material grew from the substrate, mimicking natural phototropism: grazing illumination resulted in growth at significant angle to the surface normal. Also, additional 3D morphological complexity could be directed by utilizing temporal changes in the illumination; for example, zig-zag structures resulted from oscillation of the illumination incidence back and forth across the surface normal and woodpile structures were generated by periodically switching between orthogonal polarization states.

The nanopatterning process occurred without the use of any type of physical or chemical templating agents: no photomask, patterned substrate nor surfactants/ligands were used to influence the morphology. Modeling of the growth using a combination of full-wave electromagnetic simulations of light absorption and scattering coupled with Monte Carlo simulations of mass addition successfully reproduced the experimentally observed morphologies and indicated that morphology development was a consequence of the fundamental light-matter interactions during growth.
Local Structure of Highly Conductive Vanadate Glass Containing Tinoxide Studied By RT-MöSsbauer Spectrum
Authors: Oka Nobuto , Fujita Yuki , Izumi Tomoka , Kubuki Shiro , Nishida Tetsuaki
Published: February 2020

Barium iron vanadate glass, e.g., 20BaO‧10Fe2O3‧ 70V2O5 (in mol %), and its analogs show high electrical conductivity amounting to the order of 10-1 Scm-1 [1-4]. This is brought about by the isothermal annealing for only several ten minutes at a given temperature higher than its glass transition temperature or crystallization temperature. The electrical conductivity are tunable from the order of 10-6 to 10-1 Scm-1 by changing the condition of isothermal annealing. The marked increase in the electrical conductivity was attributed to the structural relaxation of the “3D-network” which was preferable for the small polaron hopping from VIV to VV. Substitution of CuI (3d10), ZnII (3d10) and CuII (3d9) for FeIII (3d5) caused a further increase in the electrical conductivity [2-4], e.g., 20BaO‧5Cu2O‧5Fe2O3‧70V2O5 glass annealed at 450 °C for 30 min showed an increase of the electrical conductivity from 5.1×10–6 Scm–1 to 2.0×10–1 Scm–1, which was one order of magnitude larger than that of non-substituted vanadate glass (3.4×10–2 Scm–1) [2-4].

In this study, we investigated the substitutional effect of SnIV (4d10) and SnII (5s2) on the structure and the electrical conductivity of barium iron vanadate glass annealed at 500℃ for 0 - 300 min. The electrical conductivity of the annealed vanadate glass containing SnO (20BaO‧5Fe2O3‧5SnO‧70V2O5) was three orders of magnitude smaller than that of the conventional conductive vanadate glass (20BaO‧ 10Fe2O3‧70V2O5). Figure shows RT-Mössbauer spectrum of conductive vanadate glasses annealed at 500℃ for 60 min. The quadrupole splitting (Δ) of FeIII increase from 0.57 to 0.66 mms−1 as the composition of SnO increase, which reflected a decreased symmetry or an increased distortion of FeO4 and VO4tetrahedra [2-4]. Such a local distortion of the network should decrease the carrier mobility, and be contributed to the lower conductivity.

References:

1) Fukuda, A. Ikeda and T. Nishida, Solid State Phenom., 90/91, 215-220 (2003).

2) Nishida, S. Kubuki, K. Matsuda and Y. Otsuka, Croat. Chem. Acta
88(4) 427-435 (2015).

3) K. Matsuda, S. Kubuki and T. Nishida, AIP Conf. Proc. (msms2014), 1622, 3-7 (2014).

4) T. Nishida, Y. Izutsu, M. Fujimura, K. Osouda, Y. Otsuka, S. Kubuki and N. Oka, Pure and Appl. Chem. (2017). [DOI: https://doi.org/10.1515/pac-2016-0916]

Figure 1
Synthesis and Application of Nickel Terephthalate MOF for Hydrogen Generation
Authors: Messegee Zachary , Osborn Justin , Abdel-Fattah Tarek M
Published: February 2020

In the last decade, the push towards reliable, economical, and environmentally clean power systems for energy production has seen an increase in demand. Development of the hydrogen fuel cell has supplied the desired green energy source demanded but the cells lack in safety and efficiency. To increase efficiency and reduce the need for unsafe pressurized hydrogen, efficient catalysts need to be developed for the hydrogen fuel cell process. MOFs (metal organic frameworks) are becoming popular catalysts of interest due to their distinct properties as efficient energy converters and high capacities to store energy. The metal salt, NiCl2•6H2O, was coordinated to the organic ligands of disodium terephthalate (C8H4Na2O4) to synthesize the nickel terephthalate (Ni[C6H4(COO)2]•4H2O) MOF. The MOF was synthesized at 22 °C with crystal formation occurring between one and a half to two weeks. The efficiency of the MOF catalyst was also tested in aqueous solution with sodium borohydride (NaBH4) at room temperature. The hydrogen produced was collected and weighed using a previously described water displacement system [1,2]. With one micromole of MOF material, the catalyst produced 55 mL of hydrogen within a 120 minute period. The reaction rate constant was consistently 63.54 L mol-1 hr-1.

References

T. Dushatinski, C. Huff, and T. Abdel-Fattah, Applied Surface Science, 385, 282 (2016).

2. C. Huff, T. Dushatinski, A. Barzanji, N. Abdel-Fattah, K. Barzanji, and T. Abdel-Fattah, ECS J Solid State, 6, M69-M71 (2017).
(Invited) Innovations at the Nexus of Food, Energy, and Water Systems (INFEWS) and Beyond
Authors: Jones James W.
Published: February 2020

Food, energy, and water are essential to survival and well-being of humankind. Recently, there have been shortages of these essential resources that led to food and energy price spikes and fresh water shortages. These shortages and price spikes have occurred at different spatial and temporal scales and in different contexts; some have even led to social unrest that threatens food, energy, and/or water security. Such insecurity issues are likely to worsen in the future due to continued population growth and limited sources of fossil fuels, water, and land. Furthermore, a changing climate and threats to soil health in many areas could alter our capabilities to provide these necessities.

Most research has been conducted to assess these food, energy, and water security issues individually. Such studies are mostly done without considering important interactions that occur among food, energy, and water subsystems, limiting the robustness of results and solutions. In response to the need to more holistically address these resources, the National Science Foundation (NSF) developed a cross-discipline initiative called INFEWS (Innovations at the Nexus of Food, Energy, and Water Systems). FEW systems incorporate physical, natural, biological, and social/behavioral processes in addition to cyber elements. Investigations of these complex systems may produce discoveries that cannot emerge from research on food or energy or water systems alone. It is the synergy among these components in the context of sustainability that will open innovative science and engineering pathways to produce new knowledge, novel technologies, and predictive capabilities to solve the challenges of scarcity and variability.

Although several established NSF programs prioritize this area of research, NSF’s major emphasis is a multi-Directorate solicitation for proposals to address FEW systems (https://www.nsf.gov/publications/pub_summ.jsp?WT.z_pims_id=505241&ods_key=nsf17530) with 3 tracks: understanding and modeling, cyber systems for decision support, and solution inspired research. NSF and USDA-NIFA jointly manage this initiative.

This presentation will highlight some INFEWS projects as well as some of the challenges associated with these large transdisciplinary research efforts. It will also include comments about some of NSF’s 10 Big Ideas for future research investments and another multi-Directorate, multi-Agency transdisciplinary effort that is being considered.
SOFC Co-Generation of Electricity and Clean Water
Authors: Wachsman Eric D. , Hays Thomas H
Published: February 2020

Energy and water are basic necessities for human civilization. For too long these basic necessities have been provided by separately designed and operated independent large-scale infrastructures. In contrast the co-generation of electric power and potable water provides for significant improvement in system efficiency as well as the possibility for smaller distributed co-generation. One approach to do this is to not only use the electricity generated by solid oxide fuel cells (SOFCs), but also use the heat generated to drive water purification technology, as well as capture the H2O in the SOFC exhaust. By leveraging both electrical and thermal energy, very high system efficiency is possible. Moreover, the fuel flexibility, modularity, and solid-state nature of SOFCs make them ideal for operation in remote areas.

Addressing this at the local level with a strategy of distributed water purification powered by local fuel resources will be very effective. Using methane derived from agricultural waste, durable small scale SOFC units can generate significant amounts of electricity and heat. Electrical and thermal outputs from a biogas fueled SOFC were measured and total cell efficiency calculated to inform design criteria for the proposed power units. SOFC stability to sulfur contamination was improved using anode infiltration and evaluated in long term tests. Using the information gathered from these tests an analysis of the system size and fuel requirements necessary for a developing world community system were determined.
(Invited) The NIH BRAIN Initiative – the Road Thus Far and into the Future
Authors: Langhals Nick Brandon
Published: February 2020

Nick B. Langhals, Ph.D. serves as the Program Director for Neural Engineering at the National Institute of Neurological Disorders and Stroke (NINDS), where he manages a portfolio of grants focused on the development and translations of neurotechnologies. He is heavily involved in the Brain Research through Advancing Innovative Neurotechnologies® (BRAIN) Initiative teams focused on both implantable and non-invasive technologies for recording and modulating neural activity. He also serves as the NINDS lead for the Bioengineering Research and Stimulating Peripheral Activity to Relieve Conditions (SPARC) programs at NIH. Within this talk, he will discuss many of the recent advances in neural interface materials, devices, electronics, and instrumentation that have been developed through NIH BRAIN funding in many of these areas. Further, he will also discuss a vision for future opportunities in research and development in these areas and where the electrochemical community could play an active role.
(Invited) From Flexible Fibers to Nanomagnetics: Minimally Invasive Sensors and Actuators of Neural Activity
Authors: Anikeeva Polina
Published: February 2020

Mammalian nervous system contains billions of neurons that exchange electrical, chemical and mechanical signals. Our ability to study this complexity is limited by the lack of technologies available for interrogating neural circuits across their diverse signaling modalities without inducing a foreign-body reaction. My talk will describe neural interface strategies pursued in my group aimed at mimicking the materials properties and transduction mechanisms of the nervous system. First, I will describe how fiber-drawing methods traditionally used by telecom and photonics industries can deliver neural probes capable of simultaneous electrical neural recording, optical stimulation, and drug and gene delivery into the brain and spinal cord of freely moving subjects. I will then show how these devices can be applied to direct neural growth and activity facilitating repair of damaged nerves. This talk will conclude with the description of an entirely wireless neuromodulation paradigm that relies on heat sensitivity in neurons and hysteretic heat dissipation by magnetic nanomaterials in alternating magnetic fields
(Invited) In Vivo Electroanalytical Measurements of Norepinephrine in the Brain: Current Status and Remaining Challenges
Authors: Park Jinwoo , Bhimani Rohan , Wakabayashi Ken , Bass Caroline
Published: February 2020

Norepinephrine (NE), one of the major catecholamines in the brain, is involved in many physiological processes and behaviors ranging from fear and anxiety to reward. Despite its important roles, NE has largely been unexplored compared to the other central catecholamine, dopamine (DA). This is due in part to the diffuse distribution of NE projections throughout the brain and challenges of its low physiological concentration and anatomy, complicating its detection. Specifically, NE is ordinarily one to two orders of magnitude lower in concentration than that of DA and many rodent brain regions that have appreciable amounts of NE are only a few hundred microns across. Recent studies have demonstrated that fast-scan cyclic voltammetry (FSCV) coupled with carbon-fiber microelectrodes enables the detection of subsecond changes of NE in the brain of anesthetized and awake behaving rats in real time, offering a local view of NE regulation (release and clearance). Although the regulatory mechanisms of NE and DA neurotransmission have many similarities, these studies have revealed that NE has important functional differences compared to DA. These results have provided new insights into the understudied role of NE in reward/aversion processes and drug abuse, and their related behavioral responses for the last decade. However, there are still limitations in the electroanalytical determination of NE in vivo in terms of selectivity and sensitivity. Here, the current state of electrochemical measurements of NE and associated findings are highlighted and the remaining challenges are discussed.
A Novel Soft Sensor Approach for Estimating Individual Biomass in Mixed Cultures with Applications to Agricultural Waste and Wastewater Treatment
Authors: Roberts Nathan , Chin Bryan A , He Q. Peter , Wang Jin
Published: February 2020

Mixed cultures are prevalent in nature, which are biological systems with more than one type of organism sharing or competing for available nutrients. Compared to single cultures, mixed culture present many advantages. For example, when organisms in mixed cultures work symbiotically, the cells’ metabolic pathways complement each other and can result in efficient utilization of substrates and increased product yield. Other advantages include the use of mixed or cheaper substrates, reduction in sterilization and increased robustness to environmental changes. The application of mixed cultures in biotechnology has expanded rapidly in the last a few years, with applications ranging from wastewater treatment, biogas production, soil remediation, to chemical production such as solvent, antibiotics, acids and other valued commodities.

At the same time, many challenges remain for effective mixed culture applications. One of them is how to efficiently and accurately monitor the individual cell populations in a mixed culture. The current approaches on individual cell mass quantification are suitable for off-line, infrequent characterization of mixed cultures. In this work, we propose a fast and accurate ‘soft sensor’ approach for estimating individual cell concentrations in mixed cultures. The proposed approach utilizes absorption spectrum of a mixed culture sample measured by a spectrophotometer over a range of wavelengths. A multivariate linear regression method, partial least squares or PLS, is applied to correlate individual cell concentrations to the spectrum.

The proposed soft sensor is demonstrated using a methanotroph microalgae coculture. Recent findings published in Nature and Nature Geoscience suggest that the coupling of methane oxidation and oxygenic photosynthesis are prevalent in nature and reduce CH4 emissions and reuse CO2. These findings suggest that the coculture of methanotrophs and microalgae represents not only a feasible, but also a highly promising strategy for agriculture waste and wastewater treatment: the biogas and wastewater produced from anaerobic digestion of agriculture waste can be converted by the coculture of methanotroph and microalgae to cell biomass for animal food or biodiesel production, which not only significantly reduces the greenhouse gases emission, but also captures the valuable nutrients contained in digester effluent. Several case studies are presented to demonstrate the effectiveness and robustness of the soft sensor approach.
Dendrimer-Encapsulated Ultra-Small Porous MnO2-Fe3O4 Nanosphere for Clean Water
Authors: Zhu Yan , Yang Wen , Cai Yuxin , Knappenberger Thorsten , Beidaghi Majid , Cheng Zhongyang , Chin Bryan Allen , Chen Pengyu
Published: February 2020

The primary food production consumes more than two thirds of all fresh-water abstraction world-wide including the irrigation of crops, livestock watering, and aquaculture production. During this process, water has been identified as a vehicle for the transmission of many harmful agents. This raises emerging needs for solutions that can provide clean water that is essential to human health and is a major resource across a variety of food industrial and agricultural processes. In this research, we present, for the first time, an ultrasonic assisted synthesis method for creating ultrasmall porous MnO2/Fe3O nanocomposites templated on poly(amidoamine) (PAMAM) dendrimer. The prepared nanocomposites were characterized by ultraviolet-visible spectroscopy, dynamic light scattering and transmission electron microscope, showing a uniform size distribution as small as 2 nm. The ultrasmall porous nanostructure can provide high surface to volume ratio, thus high accessible surface area, rendering such nanocomposite a promising candidate removing heavy metal ions, organics and pathogens for clean water in food processing. We examined the hosting and dispersing capacities of dendrimers for heavy metal ions, linear, cyclic, and aromatic hydrocarbons, and major waterborne pathogens, using comprehensive biophysical and analytical methods. The outcomes of this research are expected to provide a rapid, low-cost technology for effective removal of multiple contaminants in the water used for food processing that serve the long-range improvement and sustainability of the US agriculture and food systems.
Detection of Salmonella
Enterica with Magnetoelastic Biosensors in Wash Water Containing Clorox and Chlorine Dioxide
Authors: Chen I-Hsuan , Du Songtao , Liu Yuzhe , Xi Jianguo , Lu Xu , Horikawa Shin , Wikle Howard Clyde , Suh Sang-Jin , Chin Bryan Allen
Published: February 2020

Magnetoelastic (ME) biosensors with phage-displayed oligopeptide probes have been demonstrated to be highly successful in rapid detection of various pathogens, including Salmonella enterica, on the fruit and vegetable surfaces. However, in lieu of testing each produce individually, it is advantageous to detect pathogens in the produce wash water for high-throughput analysis. The sanitizing guidelines of the United States Food and Drug Administration (FDA) suggest adding Clorox and chlorine dioxide to the produce wash water in processing plants to disinfect harmful food-borne pathogens on fruit and vegetable surfaces. Therefore, to determine the efficacy of our ME biosensors in testing for food-borne pathogens in produce wash water, we assessed the stability of our biosensors in the presence of Clorox and chlorine dioxide. Specifically, Enzyme Linked Immunosorbent Assay (ELISA) was used to study the potential effect of Clorox and chlorine dioxide on the S. Typhimurium capturing ability of our phage probe. At concentrations recommended by the FDA for Clorox (100 ppm free chlorine content) and by the United States Environmental Protection Agency for chlorine dioxide (4 ppm), we observed no negative effect of these chemicals on the stability and S. Typhimurium capturing ability of our phage-displayed oligopeptide probe. These data demonstrate the potential efficacy of using our ME biosensors with phage-displayed oligopeptide probes in produce wash waters to determine the presence of food-borne pathogens.
(Invited) The INFEWS Program at the National Science Foundation
Authors: Torgersen Thomas
Published: February 2020

Humanity is reliant upon the physical resources and natural systems of the Earth for the provision of food, energy, and water. It is becoming imperative that we determine how society can best integrate across the natural and built environments to provide for a growing demand for food, water and energy while maintaining appropriate ecosystem services. Factors contributing to stresses in the food and energy and water (FEW) systems include increasing regional and social pressures and governance issues as result of land use change, climate variability, and heterogeneous resource distribution. Interconnections and interdependencies associated with the FEW nexus create research grand challenges for understanding how the complex, coupled processes of society and the environment function now, and in the future. To meet these grand challenges, there is a critical need for research that enables new means of adapting to future challenges. The FEW systems must be conceptualized broadly, incorporating physical processes (e.g., built infrastructure and new technologies for more efficient resource utilization), natural processes (e.g., biogeochemical and hydrologic cycles), biological processes (r.g., agroecosystem structure and productivity), social/behavioral processes (e.g., decision making and governance), and cyber-components (such as sensing, networking, computation and visualization for decision-making and assessment). Investigations of these complex systems may produce discoveries that cannot emerge from research on food or energy or water systems alone. It is the synergy among these components in the context of sustainability that will open innovative science and engineering pathways to produce new knowledge, novel technologies and predictive capabilities to solve the challenges of scarcity and variability.
(Invited) Sensors in Agriculture: Opportunities for Small Businesses
Authors: Melnick Rachel
Published: February 2020

This talk will focus on opportunities for agricultural sensors through USDA National Institute of Food and Agriculture. Dr. Melnick is the USDA NIFA lead for the joint NSF/NIFA program Innovations at the Nexus of Food, Energy and Water Systems as well as manages the Plant Production and Protection – Engineering program are for the USDA Small Business Innovation Research program. The USDA SBIR program offer competitively awarded grants to qualified small businesses to support high quality research related to important scientific problems and opportunities in agriculture that could lead to significant public benefits. The program stimulates technological innovations in the private sector and strengthens the role of federal research and development in support of small businesses. The need to increase agricultural production while reducing the environmental impacts of has led to new and innovative technologies. Smart sensors are a key to precision agricultural production and ensure the security and safety of our food and fiber systems from field to fork.