bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microbial Fuel Cell for Energy Generation and Wastewater Treatment
Authors: Ulyanova Yevgenia , Singhal Sameer 
Published: February 2020

According to a number of reports about 90% of “used” water or wastewater remains untreated, and is pumped back into the environment, causing global pollution. Proper treatment is needed prior to releasing this water back into the ecosystem or re-purposing it for alternate uses.
To meet the above-described need, a microbial fuel cell (MFC) has been developed, that can simultaneously generate energy from wastewater while also removing contaminants and allowing for its reuse, thereby greatly offsetting the net energy costs of water treatment. A MFC is a device that directly converts chemical energy, derived through microbial metabolism, to electrical energy. Specifically for this system the organic contaminants are processed at the anode, while heavy metal (ex. hexavalent chromium) contamination is removed at the cathode. This configuration of the MFC presents the novelty in the system’s design as compared to existing MFC technologies.
The method for bioremediation of organic and heavy metal contaminants in wastewater is different. Organic contaminants are oxidized during wastewater treatment to carbon dioxide, whereas heavy metals are typically reduced to a safe metallic form. Therefore, separate types of bacteria are employed for anode and cathode fabrication. The bioanode bacteria, Shewanella
oneidensis strain MR-1
[
1
], has been widely studied[
2
] for the use in MFC. Bacterial attachment is facilitated by entrapment in biopolymers with carbon nanomaterials (including high surface area porous carbons and graphene) followed by incubation to allow for biofilm growth. Previous work has shown that these composite electrodes form very stable bioelectrodes that can be used for months without degradation[
3
]. Spectroscopic activity assays (Figure 1) along with amperometric activity assays for oxidation of organic substrates are employed to study the effects of bacterial immobilization and catalytic performance at modified bioelectrodes.
Low Energy High Rate Anaerobic – Aerobic Digestion (HRAAD) and Applications
Authors: Cooney Michael John 
Published: February 2020

Conventional aerobic technologies based on activated sludge processes have been widely applied for the treatment of domestic wastewater due the high efficiency realized, the possibility for nutrient removal, and high operational flexibility [1]. Unfortunately, the high capital and operation costs that coincide with the introduction of aeration-based technologies likewise impose significant financial constraints upon city and county that process large amounts of dilute wastewater [2]. The dissolution of oxygen is energy intensive, and results in the growth of significant quantities of biomass known as sludge, which requires further treatment/stabilization prior to disposal [3]. As such; reliable, unsophisticated, and cost effective treatment technologies have been proposed, including anaerobic treatment under anoxic conditions, as well as combined forms of anoxic with anaerobic treatment [4]. Of these, anaerobic pretreatment is perhaps the simplest and most conceptually attractive approach for domestic wastewater due to its relatively low construction and operational cost, operational simplicity, low production of excess sludge, production of energy in the form of biogas and applicability in small or large scale [5].
Anaerobic digestion can also be used as a pretreatment step prior to facilitate the use of low energy aerobic treatments used as a polishing step - reducing the organic load flowing into the aeration treatment basins can result in the production of less sludge that will, in turn, will reduce the amount of energy used in sludge handling (e.g., pumping, dewatering through belt presses, drying, trucking, and placing in landfills) [6]. In this presentation on-going research to design high rate anaerobic –aerobic digestion (HRAAD) reactors will be presented, as will results from their deployment in industry at demonstration scale. Commentary on how the HRAAD can be integrated into businesses to achieve sustainable use of fresh water supplies in isolated city communities will also be presented along with the application of sand filtration to this system to produce an R1 effluent for agriculture. Finally, the design of a novel unit operation that combines the elements of both a sand filter and a microbial fuel cell will also be discussed.
________________________________________________________________________________________
1. Gavrilescue, M., et al., Acta Biotechnology, 19(2), 111-145 (1999).
2. Kassab, G., et al., Bioresource Technology, 101(10), 3299-310 (2010).
3. Dufresne, L., et al., Evaluation of Energy Conservation Measures for Wastewater Treatment Facilities. 2010, Environmental Protection Agency: Washington D.C.
4. Chan, Y.J., et al., Chemical Engineering Journal, 1(55), 1-18 (2009).
5. Lettinga, G., Antonie van Leeuwenhoek, 67, 3-28 (1995).
6. Gohil, A., et al., Bioresource Technology, 97, 2141-2152 (2006).
Electron and Ionic Transport in Microbial Anode Respiration and Their Importance in Microbial Electrochemical Cell Applications
Authors: Popat Sudeep , Parameswaran Prathap , Torres César 
Published: February 2020

Anode-respiring bacteria (ARB) catalyze the complete oxidation of organic compounds (e.g. acetate, glucose) into electrical current and carbon dioxide. ARB produce a biofilm at the electrode surface, where even cells on the outer part of the biofilm are participating in current production. Our team uses a variety of electrochemical techniques in order to characterize electron transport responses from various ARB. Through these experiments, we have observed a complex response to anode potential that allows ARB, such as G. sulfurreducens, to optimize their efficiency in electron transport. Identifying this complex behavior allows us to better understand and predict the response of ARB to different conditions in microbial electrochemical cells (MXCs).
While the topic of electron transport is the focus of most ARB research, ionic transport is the most important factor in determining rate-limiting and potential loss processes. ARB require near-neutral pH in the medium to grow, differing from chemical fuel cells commonly employed, which run under acidic or alkaline conditions. This pH requirement results in a major transport limitation, as H+ ions (now in mM range) should be transported from anode to cathode to achieve electron neutrality. In an MXC anode, H+ ions accumulate in the ARB biofilm, creating an acidification that limits current generation. We have identified and characterized ARB that work outside the neutral pH range, including Geoalkalibacter ferrihydriticus and Thermoanaerobacter pseudethanolicus, that allow us to operate MXCs at either acidic or basic conditions. Meanwhile, at the cathode, local gradients leading to pH > 12 is typical in MXC operation. As a consequence, the pH gradient results in Nernstian concentration overpotential of > 300 mV. Thus, understanding and controlling ionic transport in MXCs is essential to ensure an efficient operation. I will discuss our current efforts to characterize and overcome ionic transport limitations in order to develop efficient MXC processes.
Aqueous Phase Synthesis of CuIn Alloy Nanoparticles and Its Application for CIGS Solar Cell
Authors: Takahashi Hideyuki , Fujiki Hironari , Yokoyama Shun , Tohji Kazuyuki 
Published: February 2020

Among various low cost solar cells with high efficiency, CIGS (Cu(In,Ga)Se2) type solar cell shows attractive performances. These CIGS type solar cell is synthesized by gas phase method or liquid phase reduction method in organic solvents. However, in the case of former, productivity is relatively low, since vaporizing temperature of three or more elements is extremely different, which read the large amount of waste of resources. On the other hand, in the case of later, synthesis costs become increase because of the use of organic solvents. Thus, to decreasing the cost of CIGS type solar cell, synthesis method with high recovery rate and without the using of organic solvents is required.
Until now, we reported that the synthesis of uniform and well crystallized alloy nanoparticles, such as Pd20Te7 and Bi2Te3 by restrict controlling the homogenization of metallic complexes in the aqueous solution under room temperature [1]. In this method, reduction rate of the metal species can be controlled under the room temperature, nevertheless ternary, or more, alloy nano materials with uniform and well crystallized structure was not synthesized until now.
Therefore, in this study, CI nanoparticles were synthesized by obeying the calculation results and reduction potential measurements. CIS semiconductor was tried to synthesize through selenided reaction of CI nanoparticles synthesized. Solar cell ability was also investigated.
Metallic complexes in the aqueous solution was restricted to homogenized species by utilizing the theoretical calculation method using the critical stability constants. Detailed calculation procedure was summarized in Ref. 1. Amine-based and/or carboxyl-based complexing reagent, were used for the complex reagents. Reduction potential of Cu (and/or In) complexes was measured, and synthesized materials were analyzed by XRD.
Calculation was performed for various system, such as the Cu-NO3-OH-glycine system (dissolution of Cu(NO3)2 and glycine). By obeying the calculation results and also electrochemical potential measurement, various copper complexes was successfully restricted to single species, such as [(Cu2+)(Gly)2], at the pH range over 10, and relationship between stability constants of complex reagents and reduction potential were summarized. As a results, CuIn nanoparticles can be successfully synthesized.
CuInSe semiconductor materials were also synthesized by gas phase selenided reaction of the CuIn thin film on the substrate. XRD mesurments shows that synthesized materials were single phase of CuInSe alloy. Synthesized CuInSe thin film on the substrate shows the voltage under the irradiation of light. Thus, by using this easy methods, solar cell can be constructed.
This work was supported by the Grant-in-Aid for Challenging Exploratory Research (No. 25550085).
References: [1]H. Takahashi, et.,al; Applied Catalysis A: General 392, 80-85 (2011)
Electrochemical Study of the Effect of Adsorbates and Precursors in the Synthesis of Well-Defined Platinum Nanoparticles Using Water-in-Oil Microemulsion
Authors: Martínez-Rodríguez Roberto Alexis , Vidal-Iglesias Francisco José , Solla-Gullón José , Montiel Vicente , Cabrera Carlos R , Feliu Juan 
Published: February 2020

Intensive research has been focused on the study of the production of well-defined structured nanoparticles. This is due to the different properties possessed by these materials according to their size/shape. One of the most studied noble metals is Platinum (Pt) due to its catalytic properties and different methods have been reported to prepared. However, it is of great importance to find easy new ways as well as cost effective and scalable method to synthesize them. In a recent communication [1] we have reported, for the first time, the synthesis of cubic Pt nanoparticles with a very high yield using a water-in-oil (w/o) microemulsion method in which HCl was added in the aqueous phase of the w/o microemulsion. This method, unlike others such as the colloidal method, fulfils these previous requirements. This works pretends to explain the effect on the shape of the nanoparticles of different surface modifiers added in the aqueous phase using also different Pt precursors. In addition, bimetallic nanoparticles have been prepared with similar methodology and the effect of the adsorbates will be evaluated. The nanoparticles have been electrochemically characterised by hydrogen and Ge ads/desorption processes, CO monolayer oxidation and ammonia electro-oxidations have been also studied as test reactions in order to determine the efficiency in the catalytic activity.
References
[1] R. A. Martínez-Rodríguez, F. J. Vidal-Iglesias, J. Solla-Gullón, C. R. Cabrera, J. M. Feliu, Synthesis of Pt Nanoparticles in Water-in-Oil Microemulsion: Effect of HCl on Their Surface Structure, J. Am. Chem. Soc. 136 (2014) 1280.
Oxidation State and Local Structure of a High-Capacity LiF/Fe(V2O5) Conversion Cathode for Li-Ion Batteries
Authors: Pohl Alexander , Guda Alexander , Shapovalov Viktor , Witte Ralf , Das Bijoy , Scheiba Frieder , Rothe Jörg , Soldatov Alexander , Fichtner Maximilian 
Published: February 2020

Electrical energy storage becomes increasingly important to extend the range of electric vehicles and to buffer the electricity generated by intermittent energy sources. Recently a lot of effort has been put into finding novel materials with higher energy density and longer cycle life. Especially conversion materials based on fluorides offer a 3-5 fold increase of capacity compared to current state-of-the-art Li-ion batteries based on Li-intercalation [1]. Fluorides have the advantage of a high cell voltage vs. Li due to a large band gap compared to other conversion materials such as oxides and nitrides. For example, FeF3converts reversibly to Fe and LiF upon discharge transferring up to 3 electrons according to
FeF3 + 3Li ↔ Fe + 3LiF E0 = 2.96 V (weighted average), Cth= 712 mAh/g
The traditional approach to enable metal fluorides as cathode materials for Li-ion batteries is to coat the insulating fluoride particles with a conducting carbon shell by high-energy ball milling [2]. The FeF3/C nanocomposites show a very high capacity up to the theoretical maximum in the first few cycles, but cyclic stability is poor due to a pulverisation of the core-shell FeF3/C particles upon prolonged cycling.
We recently prepared an improved LiF/Fe(V2O5) nanocomposite by high-energy ball milling, which shows a high reversible capacity of 420 mAh/g in the first 20 cycles and 270 mAh/g after 50 cycles [3]. The cyclic stability was much improved compared to FeF3/C composites due the addition of V2O5. We used in situ XAS, Mössbauer spectroscopy, ab initio calculation of model XANES spectra and principle component analysis to identify highly amorphous V[FeV]O4 nanograins, which form during ball milling [4]. From the calculations we also identified LixVO2-xFx. Both phases have open crystal structures and the ability to reversibly store lithium in interstitial lattice sites. As the V[FeV]O4 and LixVO2-xFx nanograins are in close contact with LiF and Fe particles, they help to maintain electrical and ionic contact upon prolonged cycling.

J. Cabana, L. Monconduit, D. Larcher, M.R. Palacín, Adv. Mater.
22 (2010), E170.

F. Badway, F. Cosandey, N. Pereira, G.G. Amatucci, J. Electrochem. Soc.
150 (2003), A1318.

B. Das, A. Pohl, K. Chakravadhanula and M. Fichtner (2014), submitted.

H. Pohl, A. A. Guda, V. V. Shapovalov, R. Witte, B. Das, F. Scheiba, J. Rothe, A. V. Soldatov and M. Fichtner, Acta Materialia
68 (2014), 179.
Vanadium Oxide 3-D Nanostructures for Lithium Ion Battery Cathodes
Authors: Gillette Eleanor , Liu Chanyuan , Rubloff Gary W , Lee Sang Bok 
Published: February 2020

Nanostructured electrodes have been a popular area of research in energy storage, where their high surface area and shortened diffusion pathways can provide increased energy and power density over bulk electrodes of the same materials. While a variety of nanostructures have been demonstrated, often these structures are disordered and randomly interconnected, or they must be held together by polymer binder which essentially constitutes a dead weight and volume in the electrode. It can be difficult to draw broadly applicable conclusions to pursue optimized electrode geometries without the ability to test electrodes with systematically variable geometries. As 3-D structures have become of greater interest in energy storage, there is a need to be able to explore the relationship between structure and performance systematically.
Here we present electrodes produced by controllably interlinking an array of uniform nanotubes. The aspect ratio of the nanotubes and the number of interconnecting points can be modified systematically. 3-D branched anodized aluminum oxide (AAO) membranes are used as templates for the atomic layer deposition of vanadium oxide (V2O5). AAO templates have frequently been used to produce uniform high aspect ratio arrays of materials, and the systematic introduction of branch points allows our templates to be expanded into three dimensional networks. The use of an ALD deposition process allows these templates to be uniformly and conformally coated with V2O5, creating nanostructured cathodes whose morphology can be carefully and systematically controlled.
We successfully produced a series of V2O5 cathodes with varying aspect ratios as well as the number and spacing of branch points. These cathodes were then characterized by a variety of electrochemical methods, including cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge. These studies will lay the groundwork for rationally designed 3-D electrodes and full battery devices in the future.
Catalytic Polymer Membranes for Improved Oxygen Evolution Reaction in Lithium-Oxygen Batteries
Authors: Ryu Won-Hee , Gittleson Forrest S , Taylor André D. 
Published: February 2020

Owing to the decline in our fossil fuels reserves and the growing worldwide demand for energy, sustainable energy storage systems are unquestionably needed. The lithium-oxygen battery, an emerging next generation energy storage system, demonstrates an exceptionally high theoretical energy density which is comparable to the available energy density of gasoline.[1] However, the insufficient round trip efficiency and poor cyclability of current lithium-oxygen batteries must be solved before commercialization for large scale energy storage systems (i.e. smart grid) and electric vehicles. A critical step towards advancing the performance is to develop highly efficient catalytic electrodes for oxygen reduction and oxygen evolution reactions, corresponding to the formation and decomposition of insulating Li2O2 products.[2,3] The insulating solid products formed during discharging often deactivate the surface of catalysts on the oxygen electrode, making reversible decomposition of the Li2O2products during charging difficult. Therefore, tailored design and effective positioning of catalyst materials in the oxygen electrode are key to avoiding deactivation.[4]
In this presentation, we report the design of a new cell system including catalytic polymer membranes to improve lithium-oxygen battery performance. The catalytic polymer membrane can be inserted between the oxygen electrode and separator, thereby affording more catalytic sites by geometric positioning of catalyst nanoparticles decorated on the polymer membrane. The polymer membrane scaffold can effectively preserve their catalytic activity after the formation of Li2O2products on the oxygen electrode (discharging), and consequently faciliate oxygen evolution reaction (charging). Here, we will further discuss the unique effects of the catalytic membrane on the performance and charge/discharge characteristics of the lithium-oxygen battery.
[1] Peter G. Bruce, Stefan A. Freunberger, Laurence J. Hardwick, and Jean-Marie Tarascon, Nature Materials 11 (2012) 19.
[2] Won-Hee Ryu, Taek-Han Yoon, Sung-Ho Song, Seok-Woo Jeon, Yong-Joon Park, and Il-Doo Kim, Nano Letters, 13 (2013) 4190.
[3] Forrest S. Gittleson, Ryan C. Sekol, Gustavo Doubek, Marcelo Linardi and André D. Taylor, Physical Chemistry Chemical Physics, 16 (2014) 3230.
[4] Ryan C. Sekol , Xiaokai Li , Peter Cohen , Gustavo Doubek , Marcelo Carmo, and André D. Taylor, Applied Catalysis B: Environmental, 138 (2013) 285.
Investigation of the Performance Improvement of Silicon Electrodes Cycled with Electrolyte Containing FEC or VC
Authors: Lucht Brett L. , Nguyen Cao Cuong 
Published: February 2020

Silicon is one of the most promising candidates for an anode material in LIBs due to the high theoretical capacity, 3580 mAh/g. This theoretical capacity is ~10 times that of commercial graphite (372 mAh/g) currently used in lithium ion batteries. However the silicon electrodes have a very large volume expansion (300–400%) during lithiation resulting in instability of the solid electrolyte interphase (SEI) and poor capacity retention. The two most frequently utilized SEI stabilizing additives are vinylene carbonate (VC) and fluoroethylene carbonate (FEC). A systematic comparison of the effects of added FEC or VC at multiple concentrations is being conducted with uniform silicon nano-particle electrodes.
Capacity retention of Li/silicon nano-particle cells with different concentrations of VC and FEC in 1.2 M LiPF6 in 1:1 EC/DEC have been investigated. The capacity fades very rapidly for the baseline electrolyte. Incorporation of FEC at any of the concentrations investigated (5, 10, 15, or 25 %) results in significant improvements in capacity retention. Interestingly, intermediate concentrations of FEC 10-15 % give the best capacity retention suggesting that lower concentrations do not generate a sufficiently stable SEI while higher concentrations may results in increased cell resistance. Cells containing added VC do not have significantly better performance than the cells containing the baseline electrolyte. Incorporation of 3 % VC results in cells with very similar capacity fade to the baseline electrolyte, while cells containing 6 % VC have an odd intermittent behavior which may be due to high cell impedance as evidenced by electrochemical impedance spectroscopy. The cycling efficiencies correlate very well with the capacity retention. Cells containing 10-15 % FEC have the best efficiencies (~99 % for cycles 10-50), while cells containing the baseline electrolyte or electrolyte with added VC have lower efficiencies (<98 % for cycles 10-50).
Ex-situ surface analysis of the electrodes after cycling via a combination of SEM, XPS and FT-IR will be reported. Structural characterization of the SEI will lead to a better understanding of the source of performance enhancement due to the incorporation of added FEC.

Acknowledgements

This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, Subcontract No 6879235 under the Batteries for Advanced Transportation Technologies (BATT) Program.