bluuebunny/crossref_metadata_2025_split huggingface dataset:
Redox Active Molecule Induced Metal-Organic Framework Thin Film on Optical Fiber Towards Chemical Sensing of Carbon Dioxide
Authors: Kim Ki-Joong , Culp Jeffrey , Ohodnicki Paul R , Cvetic Patricia , Goodman Angela 
Published: February 2020

Sensing of carbon dioxide (CO2) has proven to be a challenging area of research over the few last decades. Although nondispersive infrared absorption sensors are widely used as gas sensors, these are unsuitable for mobile sensing applications due to the necessity of a bulky and expensive optical system. In the case of chemi-resistive sensors based on metal oxides, elevated temperatures are required to promote reaction of surface-bound chemical species and they exhibit cross-sensitivity and significant baseline drift over the life of the sensors. Therefore, it is necessary to explore new types of sensing materials and systems that provide a sensitive, selective, and stable response for CO2 gas as well as sensing at atmospheric conditions.
Waveguide-based optical fiber sensors have unique characteristics and flexible designs which make them well-suited to remote monitoring applications due to their inherent long- range transmission of light. Integrating functional materials such as metal-organic frameworks (MOFs) into optical fibers enable the measurement of optical property changes by adsorbing guest molecules and has led to the potential approach for the fabrication of chemical sensors due to their exceptional sorption capacity and high degree of reversibility even at near-ambient temperatures. Recently, efforts have also demonstrated the ability to infiltrate guest molecules into the pores of MOFs to induce emergent properties (guest-host interaction) which are important advantages for MOFs for use in optoelectronic devices such as chemical sensors. Examples of such properties include enhanced electronic conductivities compatible with chemi-resistive sensing platforms as well as increased optical absorption relevant for optical waveguide-based sensors.
In the present work, MOF thin films were coated on an uncladded optical fiber through a simple solution method at room temperature, which is critical for manufacturability of optical fiber-based sensor devices. Then, the redox-active molecules, 7,7,8,8-tetracyanoquinodimethane (TCNQ), was introduced into MOF pores, achieving enhanced electronic conductivity and optical absorption as well as selective closing of MOF pores and enhanced stability in water. It is observed that the activation of pristine MOF at different temperatures greatly affects the coordination of TCNQ guest molecule into pristine MOF pores.
Sensing responses of TCNQ infiltrated MOF deposited on optical fibers showed a linear relationship between partial pressure of CO2 gas and the light transmission, indicative of a guest molecule-induced optical response modification. Furthermore, the sensors show high sensitivity to CO2 with rapid response time and excellent reversibility. A method for fabricating guest molecule induced MOF films on optical fibers and the capabilities of these sensor to reversibly detect a wide range of concentrations of CO2 gas will be presented.
(Invited) Gamma Irradiated WO3 Nanostructures for Electrochemical Sensing of Multiple Depression Biomarkers
Authors: Sekar Chinnathambi , A C Anithaa 
Published: February 2020

Ability of smart sensors to monitor critical biomarkers even at very low concentration paves the way for further progression in precision medicine initiatives. Hence, many attempts have been made to improve sensing performances by suitably modifying the electrode materials. Surface modification by radiation (e.g. neutrons, ions, electrons and γ-rays) leads to production of lattice defects such as vacancies, defect clusters and dislocations and these induced defects act as recombination centres by trapping the generated carriers. In the present work, we report the synthesis of nanostructured WO3 and its surface modification by gamma ray and swift heavy ion irradiation with different doses and its application for electrochemical sensors applications.
Identification and detection of easily obtainable biomarkers that accurately diagnoses depression are imperative for improving mental health of patients. Here, the gamma and swift heavy irradiated WO3 nanoparticles have shown very high electrocatalytic activity towards a number of neurochemicals including dopamine, serotonin, epinephrine, norepinephrine, acetylcholine, and melatonin [1-4]. For example, nicotinamide adenine dinucleotide (NAD) immobilized gamma irradiated WO3 NPs modified glassy carbon electrode has exhibited simultaneous electrochemical determination of NEP and MEL with the lowest detection limits of 1.4 nM, and 2.6 nM respectively over a wide dynamic range of 0.010 to 1000 µM in phosphate buffer solution at physiological pH of 7.0. The major improvements in the electrocatalytic activity of the fabricated electrode towards the oxidation of analytes is due to the induced high surface density defects, larger electroactive surface area, higher conductivity and fast electron kinetics. Interestingly, these electrodes exhibited excellent anti-interference 5ability against a number of active biological species and metal ions with good stability and reproducibility. Furthermore, fabricated sensors could be successfully applied for real sample analysis with human blood serum, and pharmaceutical samples and the results will be discussed in detail.
References

AC. Anithaa, K. Asokan, C. Sekar, Biosensors and Bioelectronics (2019)

AC Anithaa, K Asokan, C Sekar, J. Taiwan Inst. Chem. Eng. 84 (2018) 11-18

AC. Anithaa, K. Asokan , C. Sekar, Sens.Actuators B: Chem. B 238 (2017) 667–675

AC. Anithaa K. Asokan, C. Sekar, Electrochim. Acta, 167 (2015) 294; 237 (2017) 44-53
Study on the Structural and Surface Changes during Lithiation/Delithiation Processes in Copper Sulfide
Authors: Nam Jae Seok , Lee Jung-Hun , Hwang Soo Min , Kim Young-Jun 
Published: February 2020

Rechargeable batteries have been considered as one of efficent routes for energy conversion and storage. Li-ion batteries (LIBs) have been empolyed as major power sources for both mobile and stationary and applications. However, the energy densities of conventional, intercalation-based LIBs are insufficient to meet the demands for high-energy-densities enabling long distance driving electric vehicles and large-scale energy storage [1]. Transition metal sulfides based on conversion and/or alloying reactions have drawn considerable interest due to their abundance and high specific capacities [2]. Among them, copper sulfide (CuS) has a theoretical capacity of 560 mAh g-1 (CuS + 2Li+ + 2e‒ ↔ Li2S + Cu) and good electronic conductivity of ~10-3 S cm-1 [3,4]. Nevertheless, CuS shows poor cycling stability, owing to the dissolution of lithium polysulfides (Li2Sn, 2<n≤8) in the organic electrolytes and the insulating nature of Li2S products. To improve the irreversibility issues, it is highly required to understand the electrochemical behavior of CuS during lithiation and delithiation processes.
In this work, we conducted in-situ and ex-situ analysis studies to investigate the electrochemical behavior of CuS during lithiation and delithiation in a carbonate-based electrolyte in the potential range of 0.05 – 3.0 V vs. Li+/Li. The structural and phase evolution of the CuS electrode were in-situ monitored by X-ray diffraction (XRD) and Raman spectroscopy during the lithiation and delithiation processes. In addition, the ex-situ XRD measurement was carried out to probe the phase transition of the CuS during the electrochemical processes and the result was correlated to the in-situ XRD patterns for characteristic lithiation/delithiation potentials. Furthermore, the changes in the chemical binding energies and the formation of the solid-electrolyte interphase layer on the CuS surface were analyzed by ex-situ X-ray photoelectron spectroscopy. It was found that CuS experiences a two-step lithiation reaction of insertion, followed by conversion; however, from the in-situ data, the CuS appears to convert into Li2S and Cu phases without forming distinct intermediate phases, such as Cu1.8S, Cu1.96S, and Cu2S, by lithiation process, which is contrast from the ex-situ data. Based on the above results, we showed the improved battery performance in the carbonate-based electrolyte through nano-engineering of CuS electrode, demonstrating the promise as a high-capacity LIB electrode.
[1] O. Grӧger, H. A. Gasteiger, and J.-P. Suchsland, J. Electrochem. Soc., 162, A2605‒A2622 (2015).
[2] X. Xu, W. Liu, Y. Kim, and J. Cho, Nano Today
9, 604‒630 (2014).
[3] J.-S. Chung and H.-J. Sohn, J. Power Sources
108, 226‒231 (2002).
[4] A. Débart, L. Dupont, R. Patrice, and J.-M. Tarascon, Solid State Sci.
8, 640‒651 (2006).
Improved Gas-Phase Detection of Volatile Organic Compounds Using a Solid-State Conductive Polymer Electrolyte
Authors: Willis Christina Nicole , Saffary Yalda , Misra Mano , Mohanty Swomitra K. , Tripathy Anurag 
Published: February 2020

Rapid screening of tuberculosis by evaluation of associated volatile organic compounds (VOCs) in breath has been shown to be a promising technology that is significantly faster and more convenient than traditional sputum culture tests. Methyl nicotinate and methyl p-anisate have been isolated as specific biomarkers for the mycobacterium tuberculosis, as they are not found in high concentrations in ambient air or the breath of healthy patients, but should be readily present in all patients with active TB. These VOCs can be electrochemically detected using a solid-state sensor based on metal-functionalized 3D titanium dioxide nanotube arrays (TNAs), as shown by Bhattacharyya et. al. [1]. This chronoamperometric method uses a two-electrode system, in which the pure titanium back of the sensor functioned as both the counter and reference electrode, meaning that the applied current is highly dependent on the resistance of the nanotubes and difficult to reproduce from sensor to sensor. This work will discuss two improvements to the current method: 1) a move to a three-electrode system using a solid electrolyte, and 2) potential scanning electrochemical methods used for detection.
To improve reproducibility and specificity of the sensor, the platform has been modified to use a solid-state, conductive electrolyte in order to create a gas phase three-electrode system. A conductive polymer of known resistance is used to separate the functionalized TNA from the silver-painted counter and reference electrodes. Doing this ensures more consistent interactions with the analyte of interest between sensors. In addition to the electrode changes, new scanning potential methods such as cyclic voltammetry (CV) and square wave voltammetry (SWV) have shown promise in detecting the analytes more specifically than chronoamperometry. For example, running cyclic voltammetry using cobalt functionalized sensors shows a reduction peak at about -0.5 V vs a silver quasi-reference electrode when exposed to methyl nicotinate vapor. Results comparing different electrochemical methods and specific responses to the biomarkers will be presented.

[1] D. Bhattacharyya, Y. R. Smith, S. K. Mohanty, and M. Misra, “Titania Nanotube Array Sensor for Electrochemical Detection of Four Predominate Tuberculosis Volatile Biomarkers,” J. Electrochem. Soc., vol. 163, no. 6, pp. B206–B214, 2016.
(Invited) The Role of Advanced Characterisation in Understanding the Initiation and Propagation of Failure in Li-Ion Batteries
Authors: Shearing Paul R. 
Published: February 2020

Recent years have witnessed a number of high profile failures of Li-ion batteries; from cell-phones to aircraft, it is essential to improve understanding of failure mechanisms in order to design solutions to effectively mitigate the risks of cell thermal runaway. The increasingly diverse and demanding range of applications for Li-ion batteries necessitates a redoubling of efforts to tackle safety issues. Here, we apply a suite of in-situ and operando characterisation tools to understand safety and failure criteria over a range of time and length scales.
At the electrode length scale, we utilise high resolution X-ray computed tomography to examine the complex, heterogeneous microstructures characteristic of Li-ion batteries. These can be effectively combined with imaged based modelling tools to explore the local electrochemical and physical behaviour, which can be correlated with electrochemical and thermal measurements. We can extend these investigations into the fourth dimension to explore the change in electrode morphology with time, to evaluate the role of microstructure evolution on cell degradation and failure.
At the cell length scale, we utilise a combination of high-speed X-ray imaging, thermal imaging, calorimetry and acoustic spectroscopy, to understand the nucleation and propagation of failure in devices.
In concert, these tools provide unique insight into degradation and failure process from the particle to the cell scale, from sub-second thermal runaway, to long term in-situ degradation studies. Increasingly we are equipped to evaluate new innovations in Li-ion battery technology, and moreover to effectively design and optimise next generation battery chemistries.
Investigation of Lithium-Ion Battery Interface Degradation Mechanism through EIS Analysis Under Various Cycling Conditions
Authors: Dong Bo , Li Yige , Ozkan Cengiz , Ozkan Mihri 
Published: February 2020

Lithium-ion batteries have attracted enormous attention in the past decade both in the academia and in the industry due to their extreme high energy and power density compared with the conventional battery systems. Stepping into 2019, the lithium-ion battery industry unprecedentedly focuses on the fast charging and diagnosis solutions, especially for the dynamic battery systems. However, the complicated environmental conditions, such as vibration, extreme temperature change, overcharging or overdischraging, fast charging, various testing techniques, combined with insufficient understanding of the State of Health (SOH) of the commercial batteries lead to thermal runaway, aging and explosion issues to the batteries.
Stemmed from that fact, EIS (Electrochemical Impedance Spectroscopy) technique has been proposed to accurately determine the SOH of the commercial batteries. EIS has been proved to be an effective approach to investigate the electrochemical, structual and dynamical properties of the electrochemical systems, especially the interfaces. The study focuses on the effects of one of the most concerning technique "fast charging" and one testing technique, GITT (Galvanostatic Intermittent Titration Technique). Under pre-design conditions, EIS with pre-built equivalent circuit is then implemented at specific conditions to further gather the electrochemical and structural properties of the interfaces inside the battery at proper voltages. Finally, the electrochemical and structual degradation mechanism especially of the interfaces under various conditions is achieved, which inspires further investigation on the comprehensive analysis and determination of the SOH of the lithium-ion batteries. The proposed approach has shown better accuracy and more in-depth analysis compared with the existing techniques.
Long–Term Aging – Overdischarge Degradation Mechanisms Interplay in Li-Ion Pouch Cells
Authors: Juarez-Robles Daniel , Jeevarajan Judith A. , Mukherjee Partha P. 
Published: February 2020

Battery Management Systems (BMS) ensure that cells within a module are cycled appropriately even though the cells may have a different capacity. For large commercial applications, modules may have a few thousand cells making it more challenging to monitor and control each cell individually. A capacity imbalance will not only affect the module performance but it can lead to an overcharge/overdischarge condition on the single cells.
Overdischarge occurs when a Li-ion cell is discharged below its safe electrochemical window. If the cell is extremely overdischarged, a reverse potential condition takes place followed by the dissolution of the copper current collector. In a module without an adequate BMS, overdischarge can occur frequently. Its interaction with the natural aging degradation of the cell may pose a threat to safety issue.
In this work, the interaction between aging and overdischarge in Li-ion cells is studied. The aim is accomplished by aging single pouch cells at different overdischarge levels, prior and after the onset of reverse potential. Electrochemical and morphological characterization of the abused cells will be conducted. Results will provide insights on the interaction of the two degradation mechanisms and the interaction of their corresponding effects.
Post-Chemical Modification of Doped Sites of Locally Functionalized Single-Walled Carbon Nanotubes for Multistep Photoluminescence Modulation
Authors: Shiraki Tomohiro , Shiga Tamehito , Nakashima Naotoshi , Fujigaya Tsuyohiko 
Published: February 2020

Locally functionalized single-walled carbon nanotubes (lf-SWNTs) have local defects on the sp2 carbon networks of the tube structures through chemical modification using ozonization and diazonium chemistry.[1-8] They emit redshifted photoluminescence (PL) with high efficiency compared to original PL (E
11) of pristine SWNTs. The newly generated PL (E
11*) of lf-SWNTs shows PL wavelength variation and selective wavelength shifts based on the modified molecule structures. For example, protonation of amino groups[1] and molecular recognition[6, 7] at the doped sites effectively induced wavelength shifting of E
11* PL. Such external stimuli responsiveness, therefore, is expected to develop advanced sensing and imaging materials and optical devices using the near infrared (NIR) PL functions.
In this study, the doped sites are newly designed as a chemical reaction platform for versatile modulation of the E
11* PL.[8] We employ imine chemistry at the doped sites of lf-SWNTs. Imine bond is formed by a condensation reaction between aldehyde and amine groups. The dynamic bonding feature also allows reversible bond formation and exchange reactions of the bound molecules.
Firstly, aromatic aldehyde-modified lf-SWNTs (lf-SWNTs-CHO) were synthesized. Chemical reactions for imine formation using lf-SWNTs-CHO were examined by mixing various aniline derivatives. The lf-SWNTs-CHO showed a PL peak at 1140 nm (E
11*) which was redshifted than the E
11 PL (980 nm). When p-methylaniline, p-bromoaniline or p-nitroaniline was mixed with the lf-SWNTs-CHO, wavelength shifts of the E
11* PL occurred, which provided different wavelength shift values Dl (= λ(E
11*) − λ(E
11)) of 154, 163, and 165 nm, respectively. The result indicates that the observed wavelength shifts of E
11* depend on the chemical structures of the bound aniline derivatives in the imine bond. Moreover, additional chemical reactions including exchange reactions of the bound aniline derivatives and the Kabachnik-Fields reaction realized further wavelength changes in the E
11* PL of the lf-SWNTs.
Thus, the present approach using post-modification of the doped sites achieves multistep PL modulation based on the local chemical reactions.

References: [1] Schatz, G. C. and Wang, Y. et al., J. Am. Chem. Soc.
2016, 138, 6878. [2] Htoon, H. and Doorn, S. K. et al., Nat. Photon.
2017, 11, 577. [3] Shiraki, T. and Nakashima, N. et al., Sci. Rep.
2016, 6, 28393. [4] Shiraki, T. and Nakashima, N. et al., Nanoscale.
2017, 9, 16900. [5] Shiraki, T. and Nakashima, N. et al., Chem. Commun.
2017, 53, 12544. [6] Shiraki, T. and Nakashima, N. et al., Chem. Commun.
2016, 52, 12972. [7] Shiraki, T. and Nakashima, N. et al., Chem. Eur. J.
2018, 24, 9393. [8] Shiraki, T., Nakashima, N., Fujigaya, T. et al., Chem. Eur. J.
2018, 24, 19162.

Figure 1
Compromised Power Capability of Yarn-Shaped Supercapacitors and Its Mitigation Strategies
Authors: Gao Wei 
Published: February 2020

Supercapacitors are known to have superior power densities over batteries due to their surface-centered charge-discharge processes. Recently, increasing attention has accumulated in the fiber or yarn shaped supercapacitor (FSC) systems, mainly due to their high flexibility and pliable nature, leading to potential applications in wearable electronics, microrobots, medical implants, and smart textiles. However, one of the major limitations that occurs when supercapacitors are made into fiber/yarn shapes, is the increased equivalent series resistance (ESR) due to the fibrous geometry adopted here. For instance, even the best FSC reported will exhibit several hundred ohms of resistance at one-meter length, which however is usually neglected by researchers in their publication.
To directly tackle this issue, here we report our strategies of using a metallic core filament in the yarn supercapacitors development in our lab. With detailed materials and process engineering, we are able to boost the power density by one order of magnitude. Sealing strategies and other alternative solutions for this issue will also be discussed.
Ba0.5Sr0.5CoxFe1-XO3-Δ: Investigation and Use of Multicationic Pseudocapacitive Oxides
Authors: Brousse Thierry , Lannelongue Pierre , Le Vot Steven , Fontaine Olivier , Bodin Charlotte , Douard Camille , Crosnier Olivier , Iadecola Antonella , Favier Frederic 
Published: February 2020

BSCFs oxides have been prepared by sol-gel process followed by high temperature treatment. The resulting powders show the same perovskite structural arrangement as well as identical morphology characteristics. BSCFs electrodes were tested in 5M LiNO3 aqueous electrolyte, and have demonstrated promising pseudocapacitive behavior while performances depend on the Co/Fe ratio. A maximum capacitance of 87 F.g-1 was obtained for the electrode based on the BSCF material with x = 0.80. Charge storage mechanism was investigated by in situ X-Ray Absorption Spectroscopy carried out on the ROCK beamline at SOLEIL Synchrotron (France) at both Fe and Co K-edges. Both Co and Fe were found being electrochemically involved in the charge storage mechanism. XAS in situ measurements allow to propose an advanced description of the charge storage mechanism. It shows the involvement of electrolytic cations but also of oxygenated moieties.
BSCFs oxides were also investigated in asymmetric devices using FeWO4 or activated carbon as negative electrode. These two devices were operated between 0 and 1.6 V and have demonstrated a remarkable cycling ability with a high capacitance retention over 45,000 cycles. The advantages and limits of high density oxides with pseudocapacitive behavior operated in devices will also be highlighted in this study.