bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioelectrochemical Systems for Electricity and Hydrogen Production in Biorefinery
Authors: Borole Abhijeet P. 
Published: February 2020

Production of renewable electricity and hydrogen in biorefinery can add a significant value towards development of a sustainable bioeconomy for the 21st century. Here, we investigate bioelectrochemical systems for conversion of biomass and waste using biological fuel cells and electrolysis cells.
The ability to extract electrons from biomass components efficiently can lead to novel pathways for production of energy, fuels and chemicals. Understanding the electron transfer and charge transfer issues is critical in developing functional bioelectrochemical cells. Current production from two biomass-derived streams was investigated determining Coulombic efficiency, cathode efficiency and electrical efficiency. The effect of substrate concentration and loading on performance was studied to understand kinetic vs. mass transfer issues. In addition to the electrochemical aspects, bioconversion aspects become critically important for valorizing complex streams such as bio-derived liquids. In addition to sugars, transformation of furanic and phenolic compounds derived from lignin and hemicellulose is important, since they are rich source of electrons. Removal of furfural, HMF, phenolic acids and acetic acid was demonstrated and conversion efficiencies were calculated. Improvements in current density and coulombic efficiency of the bioanode were studied by varying multiple operational parameters. The electron transfer process was measured against the proton and charge transfer steps to identify mechanistic factors controlling the conversion of the complex substrates to electricity and hydrogen.
Computational Approaches for Rational Design of Electrodes for Biofuel Cells and Biosensors Applications
Authors: Matanovic Ivana , Babanova Sofia , Atanassov Plamen 
Published: February 2020

Redox enzymes have been extensively exploited as electrocatalysts in biofuel cells and biosensors due to the advantages they have over commonly used inorganic catalysts. For example, they often have higher activity and selectivity than the inorganic catalysts and can operate at biologically benign conditions. However, additional improvements have to be made for the development of enzymatic electrodes with high activity, stability, and ease of production that can lead to broader applications of enzyme-based systems. Immobilization and optimal interaction of the proteins with the support material is one of the key components in the design of enzymatic electrodes. Therefore, rational design of the electrode surface provides one of the most promising routes for creating biofuel cells and biosensors with enhanced performances. Such a design, however, demands deeper understanding of the bio-nano interface interactions as well as efficient enzyme orientation, which can be achieved by the use of various computational approaches.
Density Functional Theory (DFT) and docking simulations were used to gain a fundamental understanding of the role of different molecules explored as orienting and/or mediating agents in the design and operation of several enzymatic electrodes. Different computational approaches were first used to explain the role of 1,2-benzoquinone, 1,4-benzoquinone, and ubiquinone on the operation and mechanism of electron transfer in PQQ-dependent soluble glucose dehydrogenase anodes (1, 2). The same approach was also used to understand the role of bilirubin in the bilirubin-modified oxygen reducing bio-cathodes based on bilirubin oxidase. We further studied the interaction of unsubstituted phenothiazine with glucose, lactate and cholesterol oxidases. Namely, it has been shown that the hydrophobic phenothiazine can be utilized for efficient electron transfer in various oxidases. In addition, docking simulations were used to discuss the nature of the interactions between flavins and outer membrane cytochromes of Shewanella spp., which has practical implication in the development of microbial fuel cells.
1. Babanova S, Matanovic I, Atanassov P. Quinone-modified surfaces for enhanced enzyme-electrode interactions in PQQ-dependent glucose dehydrogenase anodes. Chem Electro Chem. 2014;1(11):2017–28.
2. Babanova S, Matanovic I, Chavez MS, Atanassov P. The role of quinones in electron transfer of PQQ-glucose de-hydrogenase anodes – mediation or orientation effect. J. Am. Chem. Soc. 2015;137(24):7754-7762.

Figure 1
Influence of Different Morphology of Three-Dimensional Cuxo with Mixed Facets Modified Air-Cathodes on Microbial Fuel Cell
Authors: Li Kexun , Liu Ziqi 
Published: February 2020

Three kinds of three-dimensional (3D) CuxO catalysts were prepared to modify activated carbon air-cathode using a facile electrochemical method with addition of surfactants. The maximum power density of MFC using SC-Cu air cathode (added sodium citrate into the electrolyte solution in eletrodeposition process) was 1550±47 mW m-2, almost 77% higher than AC cathode. Specifically, the charge transfer resistance significantly decreased by 89% from 9.3980 Ω to 1.0640 Ω compared to the control. Lumphy and mutually embedded filmy sheet structure were observed in SEM, which provided sufficient active sites for oxygen adsorption and diffusion. In XRD and TEM result, CuxO with mixed facets showed special structure which had a better performance. Crystallization condition of electrodeposited materials played a significant role in their nature electrochemical properties, morphology controlled by surfactant of CuxO exhibited high properties on the air-cathode MFC.
Self-Powered Arsenic Biosensor Based on the Inhibition of Laccase By As3+ and As5+
Authors: Wang Tao , Milton Ross D , Abdellaoui Sofiene , Hickey David P , Minteer Shelley D. 
Published: February 2020

Laccase is a multi-copper center enzyme that is able to oxidize phenolic substrates and undergo a four electron reduction of O2 to H2O. The interaction of laccase with different environmental toxins has been reported, whereby laccase can either oxidize pollutants (polyphenols, polyamines and paradiphenols) as fuels or be inhibited by the toxin (mercury and azide).[1] Laccase is also commonly employed within enzymatic fuel cells (EFCs) yielding a biocathode that bioelectrocatalytically reduces O2 to H2O.
Self-powered biosensors are advantageous in terms of portability because they are not reliant on external power sources. In the past, glucose/O2 EFCs have been widely used as self-powered biosensors utilizing laccase as the cathodic biocatalyst.[2] Self-powered biosensors that sense based on enzymatic inhibition by an analyte are an important category of self-powered biosensors and have been extensively studied.[3]

This study reports the first experimental evidence on the inhibition of laccase by two arsenic species (arsenite and arsenate). The mechanism for both inhibitors was determined to follow an uncompetitive inhibition model via UV-Vis assays using 2,2'azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as the oxidant/indicator. Enzymatic inhibition was also studied electrochemically via amperometric i-t experiments. Furthermore, laccase cathodes were employed as part of a conceptual self-powered arsenite/arsenate biosensor, demonstrating sensitivities of 0.91 ± 0.07 mV/mM for arsenite and 0.98 ± 0.02 mV/mM for arsenate.
[1] S. R. Couto, J. L. T. Herrera, Biotechnology advances
2006, 24, 500-513.
[2] E. Katz, A. F. Bückmann, I. Willner, Journal of the American Chemical Society
2001, 123, 10752-10753.
[3] D. Wen, L. Deng, S. Guo, S. Dong, Analytical chemistry
2011, 83, 3968-3972.

Figure 1
Sediment Surface Anodes As a Microbial Fuel Cell Deployment Scheme
Authors: Richter Kenneth Erich , Chadwick Bart David , Kagan Jefferey Scott 
Published: February 2020

Deployment of microbial fuel cells in the marine environment where the anode is buried in the sediment has always been difficult, particularly when anode(s) have been large to maximize power output. Successful burial has required large masses, substantial horsepower resulting in occassional fuel cell damage (Chadwick et al, 2011) and diver support during deployment, confirmation and follow-on maintenance in order to ensure the anodes are sufficiently buried. Successful deployment is never guaranteed and tends to be limited to softer sediments without surface or subsurface obstructions. These issues become more daunting when deployment in deeper water is attempted. Reimers and others appreciated these obstacles early in their field programs and have deployed fuel cell anodes in chambers, open at the bottom, which when lowered to the sediment become sealed and anoxic (Nielsen, et al 2007). Microbial metabolism at the anodes depends on organic compounds diffusing up from the enclosed sediments or even enhanced by nutritional additives.
We present the design and preliminary data from an alternate approach to these deployment obstacles with a focus on scaling. Carbon cloth, functioning as an anode, is attached to one side of a rolled rubber sheet, Carbon cloth, buoyed by small floats also functions as a cathode and is attached to the other (top) side of the sheet. As with other designs, power output depends on diffusion of organic material to the anode surface. The rubber sheet, deployed as a roll on the sediment, is unrolled on the bottom via hydraulic pressure in flexible hose attached along the length of the rolled sheet (think New Year’s Eve party makers). The roll-out is initiated with a battery-powered well pump. The rubber sheet ensures anoxic conditions around the anode(s) on the bottom side of the sheet. Anode/cathode pairs are connected by potentiastats and individual currents recorded.
D.B. Chadwick, J.A. Kagan, A.Q. Wotawa-Bergen and W.C. Davis, "Sled for Benthic Microbial Fuel Cell Deployment with Carbon Fabric Anodes," Oceans 2011, IEEE, (2011).
Nielsen ME1, Reimers CE, and Stecher HA 3rd. 2007. Enhanced power from chambered benthic microbial fuel cells. Environ Sci Technol. 41(22):7895-900.
Fabrication and Evaluation of an Air-Breathing Microfluidic Fuel Cell Employed Enzymatic Electrodes for Lactate Oxidation
Authors: Dector Diana , Hickey David P , Milton Ross , Dector Andres , Arriaga Luis Gerardo , Ledesma-García Janet , Minteer Shelley D. 
Published: February 2020

Lactate is an important biomarker due to its excessive production by the body during anerobic metabolism. Existing methods for electrochemical lactate detection require the use of an external power source. This work present a light air-breathing bio-microfluidic fuel cell (BµFC) operated with 20 mM lactate in phosphate buffer pH 6.5 as fuel and the integration of an air-exposed electrode as cathode enabling oxygen delivery directly from air. FcMe2-LPEI/LOx (dimethylferrocene-modified linear poly(ethylenimine) hidrogel to simultaneously immobilize and mediate electron transfer from lactate oxidase) and An-CNT/BOD (anthracene-modified multi-walled carbon nanotubes, Bilirubine oxidase, 50mM phosphate buffer at pH 6.5, and TBAB-modified Nafion) were employed as electrocatalyst for anode and cathode respectively.
An open circuit potential and maximum power density of 0.855V and 0.125mW cm-2 (at 0.3V) were obtained respectively, meanwhile the maximum current density was 1.01 mA cm_2. Although this air-breathing BµFC requires technological improvements before being tested in a biomedical device, show potential possibilities, it represents the best performance to date for a microfluidic fuel cell using lactate as fuel.
(Invited) Electrodeposition of Yttrium Alloy from Ionic Liquids for High Performance Oxygen Reduction Reaction Catalysts
Authors: Meng Hui , Adzic Radoslav R 
Published: February 2020

The oxygen reduction reaction (ORR) can be greatly improved when the traditional used Pt catalyst is alloyed with yttrium. According to density functional theory calculations, the activity of polycrystalline Pt3Y electrodecan be enhanced relative to pure Pt by afactor of 6-10.[1] Experimental preparation of PtY alloy is limited to physical method such as gas aggregation[2] ormagnetron co-sputtering. [3] The mass activity of ORR at 0.9VRHE is as high as 3.05A mgPt
-1obtained from a PtxY particle of 9nm in diameter.[2]However there is no firm evidence of the possibility of mass production of PtY alloy with high catalytic performance in ORR from chemical method because yttrium reacts with even trace amount of water and oxygen.
To solve this problem, electrodeposition is considered to be a possibility. It is well known that yttrium is extremely basic metal with a reduction potential -2.43VRHE and electroplating of yttrium from aqueous solutions is believedto be unattainable due to intensive hydrogen evolution at such large over potentials. This problem can be solved using ionic liquids as solvent and electrolyte. They are appropriate medium for the electrodeposition of yttrium and its alloys, because the area of electrochemical stability of ionic liquids overlaps the range of reduction potentials of yttrium.[4]

We selected 1-ethyl-3-methylimidazolium tetrafluoroborate to electrodeposit yttrium on glassy carbon substrate.[5]A controlled method is applied to form PtY alloy based on the electrodeposited yttrium. The ORR activity is evaluated by both half cell and full cell characterizations.
References:
[1] J. Greeley, I. E. L. Stephens, A. S. Bondarenko, T. P. Johansson, H. A. Hansen, T. F. Jaramillo, J. Rossmeisl, I. Chorkendorff, J. K. Nørskov, Alloys of platinum and early transition metals as oxygen reduction electrocatalysts, Nature Chemistry, 2009, 1, 552-556.
[2]P. H. Fernandez,F.Masini,D. N. McCarthy,C. E. Strebel,D.Friebel,D.Deiana,P.Malacrida,A.Nierhoff,A.Bodin,A. M. Wise,J. H. Nielsen,T. W. Hansen,A.Nilsson,I. E. L. Stephens, I.Chorkendorff, Mass-selected nanoparticles of PtxY as model catalysts for oxygenelectroreduction, Nature Chemistry, 2014, 6, 732-738
[3]S. J.Yoo , K. S. Lee , S. J. Hwang, Y. H. Cho, S. K. Kim,J. W. Yun, Y. E. Sung, T. H. Lim, Pt3Y electrocatalyst for oxygen reduction reaction in protonexchange membrane fuel cells, International Journal of Hydrogen Energy,2012, 37, 9758-9765.
[4]L. M. Glukhov, A. A. Greish, and L. M. Kustov, Electrodeposition of Rare Earth Metals Y, Gd, Yb in Ionic Liquids, Russian Journal of Physical Chemistry A, 2010, 84, 104-108.
Quantitative Comparison of Atomistic Molecular Dynamics Simulations and X-Ray Scattering of Polymerized Ionic Liquids
Authors: Liu Hongjun , Paddison Stephen J. 
Published: February 2020

Polymerized ionic liquids (polyILs) are touted as the ideal solid-state electrolyte materials for electrochemical devices due to enhanced mechanical characteristics of polymer nature and unique physico-chemical properties inherent from ionic liquids. PolyILs offer great flexibility in designing the task specific media through judicious choosing component cations, anions and polymer structures for a wide range of energy conversion and storage applications, such as dye-sensitized solar cells, lithium ion rechargeable batteries, and alkaline fuel cells. While polyILs enjoy many favorable properties such as low flammability, high thermal/chemical/electrochemical stability, and mechanical strength, they inevitably suffer from the retarded ionic conductivity, one of the detrimental shortcomings in electrochemical applications. PolyILs usually have elevated glass transition temperature Tg and subsequently several orders of magnitude decrease in ionic conductivity with respect to their molecular IL counterparts. Most of previous research involve in finding the optimal polyILs to achieve the maximum accessible ionic conductivity. It is generally accepted that ionic conductivity of polyILs depends on the complex correlations between chemical nature of polymer backbone and counter-ions, glass transition temperature, mesophase morphology, temperature and pressure. Therefore, a molecular-level understanding of the relationship between chemical structure, morphology and ion transport will promote the rational design of polyILs for electrochemical applications.
In present work, we use atomistic molecular dynamics simulations to investigate structural properties of model system poly(1-n-alkyl-3vinylimidzolium bistrifluoromethylsulfonylimide) poly(nVim Tf2N) . X-ray scattering measurement on structural properties of polyILs is elusive. The detailed simulations provide a direct quantitative picture for understanding the structure/morphology of polyILs on the atomic scale. In particular, we present the first direct comparison of structure factors obtained from X-ray scattering and simulations for various alkyl chain length of poly(nVim Tf2N). Excellent agreement is found between the experimental and simulated scattering profiles in terms of peak position and shape, which provides proper validation of our simulation methods. All characteristic distances (backbone-to-backbone, anion-to-anion and pendant-to-pendant) are well reproduced. As the alkyl chain length increases, the backbone-to-backbone peak becomes stronger, moving to larger distance, the anion-to-anion separation slightly increases with vanishing intensity, and the pendant-to-pendant peak hardly changes. This quantitative comparison of X-ray scattering and atomistic simulations is expected to lead to a molecular-level predictive understanding in structure and morphology of polyILs and paves a substantive step towards the rational design of future polyILs for electrochemical devices.
Electrooxidative Polymerization of Aniline in Phosphonium Ionic Liquids and Characterization of the Polyaniline Films
Authors: Tsunashima Katsuhiko , Ito Daiki , Matsumiya Masahiko , Ono Yasushi 
Published: February 2020

Room-temperature ionic liquids (RTILs), i.e. organic molten salts with melting points below 100 ◦C, have been intensively developed for electrolytic media in various electrochemical systems due to the fact that RTILs have unique physicochemical properties such as favorable solubility of organic and inorganic compounds, relatively high ionic conductivity, no measurable vapor pressure, high thermal stability, low flammability, etc. Particularly, RTILs have been regarded as potential electrolytic media for electropolymerization processes.1 Many kinds of RTILs have been investigated for the electropolymerizations; however, highly conductive and stable RTILs based on quaternary phosphonium cations2 have been rarely employed for this application. In this work, we report the electrooxidative polymerization of aniline in triethylpentylphosphonium bis(trifluoromethylsulfonly)amide (P2225-TFSA) and tributylmethylphosphonium bis(trifluoromethylsulfonly)amide (P4441-TFSA) in comparison with the other type of RTILs, characterizing the obtained polyaniline films.
The preparation of the phosphonium RTILs was performed by aqueous ion exchange reaction of the precursor quaternary phosphonium halides with lithium TFSA. The electrooxidative polymerization of aniline in phosphonium RTILs containing 0.1 M H-TFSA was carried out by cyclic voltammetry (CV) method using a three-electrode cell equipped with a Pt disk working electrode. The electrochemical activity of the polyaniline films were evaluated by extended CV scanning technique.
Figure 1 shows typical cyclic voltammograms for the electrooxidative pocesses of aniline. As shown in Fig. 1, it was found that relatively large voltammetric response was observed in P2225-TFSA when compared to that in P4441-TFSA. This seems to be attributed to the relatively low viscosity and high conductivity of P2225-TFSA. In addition, the voltammetric responses were enhanced by cycling, which indicates that ionic species could be efficiently doped into the polyaniline film. The surface morphology based on SEM images of the polyaniline films will be also discussed.
References
1 K. Sekiguchi, et al, J. Electroanal. Chem.
,
557, 1 (2003).
2 K. Tsunashima, et al, Electrochem. Commun., 9, 2353 (2007).

Figure 1
(Invited) Sunlight-Driven Ionic Power Generation from Bipolar Ion-Exchange Membranes Functionalized with Photoacids
Authors: White William , Reiter Ronald S. , Ramirez Claudia P. , Sanborn Christopher D. , Ardo Shane 
Published: February 2020

Bipolar membranes are a class of polymeric ion-exchange materials that consist of a cation-exchange membrane that is in intimate contact with an anion-exchange membrane. They are unique among the ion-exchange membranes in that they that separate and maintain pH differences across the membrane even during passage of ionic current. Moreover, the physics of ion equilibration processes within these membranes resembles that which occurs during equilibration of semiconductor pn-junctions.
In my presentation I will report on my research group’s recent results from measurements of the electrochemical behavior of bipolar membranes under conditions relevant to solar fuels devices. We identified a condition where the energy required to electrolyze water was seemingly less than 1.23 V, which we showed was due to transport of ions other than protons and hydroxide ions. This subtlety will be explained in great detail to clarify misunderstandings in the interpretation of current–voltage behavior of bipolar membranes.
My research group has also recently successfully demonstrated ionic power generation through solar light harvesting in dye-sensitized ion-exchange membranes. Visible light illumination of photoacid-functionalized Nafion membranes drove endergonic excited-state proton transfer and a photovoltage and photocurrent resulted. Photoacid molecules convert the energy in light into a change in the chemical potential of protons via a weakening of protic functional groups on the photoacid, i.e. a drop in its pK
a. Many photoacids absorb visible light poorly and so a secondary research thrust on this project is to develop new visible-light-absorbing photoacids. Toward this, we have developed the first Ir-based inorganic coordination compound photoacids and quantum dot photoacids. Visible-light excitation of these molecules resulted in clear observation of effective photoacid behavior. Calculation of the excited-state pK
a and ongoing work to comprehend the analysis of photoacid behavior in complex systems will be covered.
The applicability and practicality of bipolar membranes in solar fuels devices and as standalone ionic photoelectrochemical devices will also be discussed. As most of these materials, techniques, and analyses are new to the artificial photosynthesis community, we plan to carefully present the results of our studies and provide ample explanations. Collectively, this body of work represents several new directions in artificial photosynthesis research and development that are being pioneered by my research group.