bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Impact of Carbon Surface Functionalities on the Electrochemical Detection of Hemoglobin
Authors: Andreas Heather Anne , Tom Justin 
Published: February 2020

The electrochemical biosensing of hemoglobin (Hb) may provide a relatively fast method of detection with the possibility of developing point-of-care diagnostics or at-home monitoring; however, obtaining a Hb electrochemical signal is often slow and difficult because the four redox active heme groups are buried in the interior hydrophobic regions of the protein. Ideally, the biosensor electrode would be inexpensive and formed from environmentally sustainable materials, such as carbon. However, the electroactivity of Hb is inconsistent on different carbon electrode materials. Additionally, Hb electroactivity is strongly dependent on whether the Hb is immobilized on the electrode surface or is in a solution-based sample. Clearly, for a point-of-care diagnostic, it would be useful to be able to measure the Hb concentrations within a liquid phase, and therefore a carbon material which evidences Hb-electroactivity is required.
Until this work, there was little understanding of the role that carbon-oxygen surface functional groups (from the carbon electrode) played in Hb electroactivity. We examine Hb electroactivity of several carbons are examined through cyclic voltammetry and differential pulse voltammetry in a neutral phosphate buffered electrolyte. Carbon-oxygen surface functionalities were characterized using X-ray photoelectron spectroscopy (XPS), thermal programmed desorption (TPD) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR).
Our findings show that Hb electroactivity is inhibited by ether and carbonyl surface groups present on the carbon electrode. Using this information, a Hb-inactive carbon (Vulcan XC-72) was made active for Hb detection by removal of these surface groups (see figure). Ultrasonication removed the ether functionalities, resulting in a significant increase in the Hb electroreduction. The amount of reduction was increased further if the ultrasonication was followed by a relatively simple 15 minute electroreduction at -1.95 V vs. Hg/Hg2SO4 (saturated K2SO4) in stirred 10 mM phosphate electrolyte (pH 5.03) purged with N2. The electroreduction was shown to selectively remove the carbonyl and quinone functionalities, resulting in the increase Hb electroactivity.
The knowledge of carbon-oxygen surface functionalities is essential to better understand hemoglobin’s electroactivity on carbon and influences the choice of carbon electrode materials for further development of hemoglobin electrochemical biosensors.
Figure: Representative CVs (a) and DPVs (b) of glassy carbon (dotted green curve), ultrasonicated Vulcan XC-72 on glassy carbon (dashed purple curve) and ultrasonication+electrochemically reduced Vulcan XC-72 on glassy carbon (solid purple curve) in 0.1 M PB containing 0.2 g L-1 BHb from at least three replicate trials.

Figure 1
(Invited) Polyoxometalate Modified Biomass Carbon for Supercapacitor Electrodes
Authors: Genovese Matthew , Lian Keryn 
Published: February 2020

Biomass waste carbon materials have been emerging as high performance and low cost electrodes for energy storage such as supercapacitors. Addition of thin layers of redox active pseudocapacitive materials onto biomass activated carbon can leverage the strength of the electrochemical activity of the former and the high surface area as well as the low cost of the latter. In our study, several biomass carbon materials, including corncobs and pine cones, have been investigated as substrates for adsorption of electrochemically active and highly reversible polyoxometalates (POM) clusters. In this talk we will compare these two carbons to show the influential factors on the adsorption of POM clusters.
Among various chemical and structural properties of biomass activated carbons, we have found that POM adsorption is highly favored within a carbon matrix possessing pore diameters in the 1-2 nm range. These large micropores are big enough to accommodate the large POM cluster, while still being small enough to effectively trap and hold the molecule. Pine cone activated carbon with this optimal pore arrangement demonstrated ultra-high loading of the PMo12O40
3- (PMo12) molecule resulting in carbon-POM hybrid materials consisting of over 55 wt. % PMo12. This large POM loading imparted tremendous redox activity to the already high double layer capacity of the carbon substrate, leading to a high areal capacitance of 1.19 F cm-2 for the hybrid material, close to 2.5 times larger than for unmodified carbon. We have also demonstrated that a mixed molecular coating combining multiple POM chemistries can be adsorbed onto the activated carbon substrate to create a more ideally capacitive charge storage profile. These results demonstrate a promising method for the design of high performance yet cost effective hybrid energy storage electrodes.
The Improvement of Boron-Doped Diamond Anode System in Electrochemical Oxidation and Fenton Coupling System Degradation of p-Nitrophenol By Sensing Electrode of Iron
Authors: Xing Xuan 
Published: February 2020

Boron-doped diamond (BDD) electrodes are promising anode materials in electrochemical oxidation system in degradation of wastewater containing toxic and bio-refractory organic pollutants due to their corrosion resistant ability and strong oxidation ability. In order to further improve the performance of BDD anode system, electrochemical oxidation of p-nitrophenol(PNP) was initially investigated in BDD anode system with the presence of sensing electrode. The results showed that the performance of the synthetic system was improved under neutral conditions with the joint actions of anode oxidation (64.6%) and H2O2 which was produced by oxygen reduction at carbon fiber cathode (11.9%). Under acid conditions, the degradation efficiency of PNP was further improved from 41.8% of the traditional system to 84.5% of the synthetic system. The strong oxidation ability was due to the anode oxidation (24.5%) and Fenton reaction by H2O2 and Fe2+ releasing from sensing electrode (66.7%). Moreover, under alkaline conditions, the results showed that the combined system was also improved by the coagulation of iron flocs formed from sensing electrode besides anode oxidation. Furthermore, hydroxyl radicals and H2O2 which were dominated oxidants were detected and quantified for the oxidation mechanism explanation.
Electrochemical Kinetics and Dimensional Considerations at the Nanoscale
Authors: Yamada Hidenori , Bandaru Prabhakar R 
Published: February 2020

A critical understanding of thermodynamics inherent to charge transfer is necessary for scientific insights, as well as for applications ranging from biochemical reactions, electrocatalysis, and charge storage in capacitors and batteries. In this letter, we first examine issues related to conventional classical reaction rate theories, such as the Marcus-Hush models for homogeneous electron transfer, and the extensions by Chidsey to heterogeneous electron kinetics. While the foundational attributes have almost always been reckoned in terms of one-electron based charge transfer, much of the theoretical and experimental analysis has only obliquely referred to dimensionality considerations.
We have found a major role of the dimensionality dependent density of states (DOS) in mesoscale and nanoscale materials in modulating electron kinetics. We have then discovered several novel characteristics that have never been reported before, such as, (i) the observation of DOS dependent reaction rate constant and electrical current oscillations, coupled with (ii) the prediction of tests of dimensionality/quasi-dimensionality. We posit a chirality dependent electron transfer rate constant in nanotubes and graphene-like structures, considering the coupling of the energy level spacing in the nanostructured electrode with that in the ambient, e.g., electrolyte. The manifestation of novel features in electron transfer kinetics as a function of dimensionality probes new frontiers in the tunability of electrochemical characteristics. We expect our work to generate very wide interest in the scientific community due to the importance of heterogeneous charge transfer across a variety of disciplines.
Effects of Electrolyte Composition on AC-Driven Electrochemiluminescence from Anthracene Derivatives Having Blue Emission
Authors: Tsuneyasu Shota , Ichikawa Takuya , Nakamura Kazuki , Kobayashi Norihisa 
Published: February 2020

Electrochemiluminescence (ECL) is a light emitting phenomenon of excited species which is generated from electrochemical reaction at electrodes. ECL reaction has attracted great interest to utilize as the novel kinds of light emitting devices. We have reported that the ECL device can be integrated with reflective displaying devices based on liquid crystal[1] or organic electrochromic[2] technologies. Moreover, the ECL emission colors from the ECL electrolyte solution dissolving 9, 10-diphenylanthracene (DPA) and rubrene in N-methyl-2-pirroridone (NMP) can be controlled by changing the frequency of alternating current (AC) voltage.[3]

Here, we focused on the blue emission of AC-driven ECL (AC-ECL) systems because the ECL intensity and long-term stability were unsatisfactory in present stage. One of the reasons for the issue is that the balance of redox species in the device did not exactly match. In this study, we introduced mixed solvent of propylene carbonate (PC)-toluene system (volume ratio = 1:1) for achieving the stable blue ECL from DPA molecule. PC is well known as the electrochemically stable solvent; toluene can also dissolve the large amount of aromatic compound such as DPA. We measured the electrochemical and optical properties of the DPA in NMP or PC/toluene electrolyte solution in order to discuss the effect of stabilities of redox species on the AC-ECL properties. As a result, it was found that the composition of electrolyte affected the stability of oxidized and reduced species. Moreover, the emission properties of the AC-ECL device were strongly depended on the stability of redox species. From these results, to achieve the good performance of the blue ECL device, it is required that the exactly matched balance of redox species in the device.

Reference

[1] S. Tsuneyasu, K. Nakamura, N. Kobayashi, Chem. Lett., 45, 949 (2016).
[2] S. Tsuneyasu, L. Jin, K. Nakamura, N. Kobayashi, Jpn. J. Appl. Phys., 55, 041601 (2016).
[3] T. Nobeshima, M. Nakakomi, K. Nakamura, N. Kobayashi, Adv. Optical Mater., 1, 144 (2013).
Electrodeposition with Nanoparticles As Nano-Bioplar Electrodes
Authors: Crouch Garrison , Han Donghoon , Fullerton Susan , Go David B. , Bohn Paul W. 
Published: February 2020

Bipolar electrochemistry has been used in examination of electrochemical effects under high electric fields, optically-coupled experiments, and geometries where conventionally-connected electrodes would be prohibitively complex. In macro-scale bipolar electrochemistry, the difference in electric potential between the electrode and the surrounding electrolyte provides the driving force for a chemical reaction. This research extends on previous work by examining the kinetics and underlying mechanistic behavior of nanoscale bipolar electrodeposition to create conductive filaments, which behave differently due to inherent limitations of nanoscale mass transport. Nanoscale conductive filaments, usually associated with resistive memory or memristor technology, may also be used for chemical sensing and in the creation of nano-patterned electro-optic or electronic materials. Realistic implementation of the technology requires precise knowledge of the conditions that control the formation and dissolution of filaments. A silver (Ag) conductive filament is created by electrodeposition in a nanoscale gap between two electrodes, creating an atomic-scale junction. In this work, Ag conductive filaments are formed through a polymer electrolyte using a conductive atomic force microscope (C-AFM). Statistical analysis shows that the distribution of formation times exhibits Gaussian behavior, which can be modified by changing electrical parameters, polymer electrolyte thickness, and surface functionalization. Further, Ag nanoparticles have been embedded into the polymer electrolyte film, to serve as nanoscale bipolar electrodes, and statistical analysis suggests that bipolar electrochemical processes at the Ag nanoparticles slows filament formation compared to polymer films without nanoparticles. Dissolution time distributions are lognormal, and repeated re-formation of filaments from previously formed structures is characterized by rapid re-growth. The experiments demonstrate a direct-write bipolar electrochemical deposition/dissolution strategy developed as an approach to reconfigurable, non-contact in situ wiring of nanoparticle arrays – thereby enabling applications where actively-controlled connectivity of nanoparticle arrays is used to manipulate nanoelectronic and nanophotonic behavior. With application areas ranging from massively-parallel chemical sensing arrays to non-contact tunable metamaterials, increasing the repeatability and mechanistic understanding of bipolar nanoelectrodeposition is important to advancing the use of similar technology in real-world devices.
This work was supported by a NASA Space Technology Research Fellowship NNX16AM45H and the Defense Advanced Research Projects Agency FA8650-15-C-7546.
(Invited) Robust Internal Temperature Sensing of Large-Format Li-Ion Cells
Authors: Zhang Guangsheng , Ge Shanhai , Leng Yongjun , Yang Xiao-Guang , Marple Dan , Wang Chao-Yang 
Published: February 2020

Large temperature difference arises in big-size Li-ion cells (e.g. 94Ah Samsung cells) due to low thermal conductivity of battery materials, especially under extreme conditions like high C rate operation at low temperatures or abuse conditions [1]. Previous research [2,3] has attempted to embed micro thermocouples in 18650-format cylindrical cells (1.6 Ah) and demonstrated that internal temperature sensing is more useful than surface temperature sensing in early detection of abnormal thermal behaviors for safety enhancement. For practical applications of this technique, internal temperature sensors must be robust and durable to survive battery life cycle and must be low cost. In this study we developed a new resistance temperature device (RTD) based on nickel foil that meets both criteria. Embedded in 10Ah pouch cells, these in-cell temperature sensors still function well after the cells experienced 2,500 cycles. It is believed that low-cost, durable and reliable in-cell temperature sensors have finally arrived to enable substantial improvement in the Li-ion battery’s high-temperature safety and thermal management.
References:

X.G. Yang, T. Liu and C.Y. Wang, Innovative heating of large-size automotive Li-ion cells, Journal of Power Sources, accepted for publication, 2017.

G.S. Zhang, L. Cao, S. Ge, C.Y. Wang, C. E. Shaffer and C. D. Rahn. In situ measurement of radial temperature distributions in cylindrical Li-ion cells, Journal of The Electrochemical Society, 2014, 161: A1499-A1507

G.S. Zhang, L. Cao, S. Ge, C. Y. Wang, C. E. Shaffer and C. D. Rahn. Reaction temperature sensing (RTS)-based control for Li-ion battery safety, Scientific Reports, 2015, 5: 18237
Solid Electrolyte Interphase Formation and Failure Mechanisms in Lithium–Ion Batteries: In-Situ AFM Imaging
Authors: Huang Zhuangqun , Kumar Ravi , Yermolenko Ivan , De Wolf Peter , Xiao Xingcheng , Sheldon Brian W. 
Published: February 2020

The lifetime and performance of lithium-ion batteries depend significantly on the formation and evolution of the solid electrolyte interphase (SEI) layer. Si has almost 10 times theoretical specific capacity compared to current state-of-the-art graphite anode materials in Li-ion batteries, which is highly attractive for electric vehicle applications. However, this energy advantage comes with a ~300% volume change during voltage cycling, which causes substantial deformations to SEI. The mechanical integrity of SEI on Si electrodes is highly important in developing commercial Si-based batteries. For R&D, directly probing the SEI evolution is challenging due to 1) SEI thickness is from 10 to 100s of nm; 2) SEI is fragile, which requires a gentle probing force; 3) in situ and operando measurements in electrolyte and under ambient control are needed; 4) multimodal information to clarify the convoluted topographical, mechanical, electrical and electrochemical properties is desired; and 5) a well-defined specimen configuration is needed to interpret the deformation. We have addressed these issues by applying controlled strains to the SEI layer using patterned Si island electrodes and by monitoring these electrodes during voltage cycling on a PeakForce electrochemical AFM system housed inside an Ar-filled glove box (< 1ppm O2 and H2O contents). From this study, we verified that 1) SEI crack formation occured during lithiation, which has been predicted but not directly observed previously; 2) additional SEI formation at low potentials did not fill these cracks, which directly contradicts some prior speculation; 3) SEI had a layered structure, the individual layer of which could be differentiated by the quantitative nanomechanical probing. We are also using Scanning electrochemical microscopy (SECM) to detect local electrochemical differences at stable and unstable SEI sites. Our comprehensive studies not only provide a new in-depth understanding of the in
operando SEI formation, evolution and its mechanical response, but also offer guidance to tailor passivation layers for optimal battery performance.

Figure 1.(A)-(D) AFM images of surface topographic evolution of the SEI layer during lithiation-dethiation cycles. (E) SEM image of a PeakForce SECM nanoelectrode probe. The probe is fully insulated with only the Pt-coated tip apex exposed.
Reference:
[1] Tokranov et al.,
ACS Appl. Mater. Interfaces, 2014, 6, 6672
[2] Tokranov et al., Adv. Energy Mater., 2016, 6, 1502302
[3] Kumar et al., ACS Energy Lett., 2016, 1, 689

Figure 1
(Invited) Characterizing Battery Safety on Aged Cells
Authors: Santhanagopalan Shriram , Cao Lei , Hartig Julia , Wu Zenan 
Published: February 2020

Thermal management is a critical component of battery safety. Extensive amount of research has been done on the thermal aspects of battery safety,electrochemical stability of the cell components, initiation of internal electrical failure due to short-circuits, inadvertent inclusion of impurities during the fabrication process, and swelling of cells due to chemical reactions. However, limited results have been reported on how the safety of lithium ion cells changes with aging of the cells. The lowering of capacity as the cell ages may contribute to marginal improvements to the abuse performance of the cells; whereas the increase in resistance and changes to the mechanical and thermal stability window of the components result in narrower windows for safe operation.
In this talk, we present some results on how the thermal, electrical and mechanical properties of lithium ion cells change under different cycling conditions. The testing on the components was performed after careful disassembly of large format (40 Ah) lithium ion cells. Thermal conductivities were measured using the xenon nanoflash technique. Compression and tensile tests were performed on cell components harvested from the cells before and after cycling. Electrochemical resistance build up was characterized using impedance spectroscopy. Cycling conditions included different depth of discharge windows, cycling temperatures as well as charge/discharge rates. Initial results (Fig. 1) show that for the cells tested, under the cycling conditions we used, the anode undergoes a significant amount of degradation in terms of thermal and mechanical properties. The subsequent build up of electrochemical resistance and over heating of the cells lead to lowering of the safety threshold.
We then proceed to integrate the properties of cell components that were experimentally measured, into mathematical models that are used to assess cell-level performance under abuse. The models are used to perform several what-if analyses to identify safety thresholds for the individual cell components for our cell design. We conclude with case studies illustrating how safety thresholds for each cell component is different, how the different factors interact with each other to determine the outcome of cell-level safety, and how to best incorporate these findings to design safer lithium ion cells.

Figure 1
Electrochemical Detection of Sulfanilamide at MWCNT Coated Conducting Polymer Modified Electrode
Authors: Khan Shirinaz , Chillawar Rakesh , Digal Pradesh , Motghare Ramani V 
Published: February 2020

Oxidation of sulfanilamide (SN) at the Glassy Carbon Electrode (GCE) modified with a thin layer of electropolymerized Eriochrome Black-T (EBT) and multi walled carbon nanotubes (MWCNT) was investigated voltammetrically. The performance of layer by layer modified composite electrode was compared with bare GCE, p(EBT)/GCE, and MWCNT/GCE using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). An enhanced current response and lower peak potential were observed for SN oxidation at the layered composite electrode compared to rest of the electrodes. Hence, it was employed for analytical determination of SN after optimization of experimental parameters. Under optimized condition, the oxidation peak current increased linearly with concentration of SN over the range of 2 Χ10-8 to 5 Χ 10-6 M. The limit of detection was calculated to be 1.2 Χ 10-8 M. The electrode showed good selectivity, repeatability and reproducibility. It was also successfully applied for the determination of SN present in spiked human serum and ground water samples.

Figure 1
Fabrication of Porous Current Collectors for Li Ion Capacitor with Pico-Second Pulse Laser and Acceleration of Li+ Ion Pre-Doping Reaction to Laminated Graphite/Porous Current Collector Anodes
Authors: Tsuda Takashi , Ando Fuma , Mochizuki Yasumasa , Gunji Takao , Tanabe Toyokazu , Kaneko Shingo , Ohsaka Takeo , Itagaki Kaoru , Soma Naohiko , Matsumoto Futoshi 
Published: February 2020

The fabrication process of porous copper (Cu) current collectors having the pore diameter (3-50 mm) and the rate of opening area (1-4 %) was developed with a system constructed with a pico-second pulse laser and a polygon mirror. The fabricated porous Cu current collectors (Fig. 1) were used to evaluate the porous design on the Cu current collector for exhibiting higher Li+ doping reaction rate with cells in which graphite electrodes were laminated with separators and the laminated graphite anode opposites to Li metal through a separator (Fig. 2). It was found in this study that the conditions of hole diameter (5 mm) and the rate of opening area (1%) is the best one to realize high Li+ doping rate and that the rate determining step of the pre-doping reaction is the diffusion of Li+ion in the pore of the Cu porous current collectors.

Fig. 1 Surface SEM images of prepared porous Cu current collectors. Magnified SEM image of a pore: (A) a view from the plane of incidence of a laser, (B) a view from the plane of emission of a laser. Opening rate of pore on the current collectors: (C) 1 and (D) 2.5 %. The pore size is a constant of 20 mm in all SEM images.

Fig. 2 Schematic description of a cell for pre-doping reaction with graphite layer/porous current collector anodes and a Li metal.

Figure 1