bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective Aqueous Ammonia Sensors Using Electrochemical Stripping and Capacitive-Based Detection
Authors: Lalwani Anand Vikas , Mu Linchao , Woo Kelly , Guo Jinyu , Dong Hang , Holiday Maximillian A , Senesky Debbie G , Tarpeh William Abraham 
Published: December 2020

Harmful algal blooms (HABs) and eutrophication cause billions of dollars in damages and kill a large percentage of our aquatic ecosystem. According to Bernard et al. (2014), the costs of monitoring is on the order of 1 billion USD annually and Kim (2006) reported that due to HABs, Japan lost over 1 billion dollars in aquaculture.
To monitor and predict such blooms, we need to cost-effectively and remotely monitor pollutants in our water bodies. One prominent pollutant that is a factor in causing harmful algal bloom is dissolved ammonia from agriculture and sewage treatment plants. To that end, we propose a novel and cost-effective sensing solution that can detect ammonia in water. Using selective membrane separation and electrochemical stripping, we are able to selectively isolate ammonium ions from dissolved river water and wastewater in our small-scale 3-chamber system. Through capacitive sensing, we can then measure with high sensitivity (28-bit resolution) and precision the concentration of ammonium ions present in our final chamber.
Between the first and second chamber, there is a cation exchange membrane that allows only cations to pass through. Amongst the cations, only ammonium and hydrogen ions form gases and diffuse through the gas-permeable membrane between the second and third chamber. The ammonia gas is then dissolved into the sulfuric acid present in the third chamber. The dissolved ammonium ions change the permittivity of the overall solution and this change can be measured using highly sensitive capacitive-based sensors.
Presently, we have higher than 99% selectivity in isolating ammonium ions from wastewater and river water. Our capacitive sensor has a noise floor of 0.3 femtofarad. The capacitive measurements show a linear response under 0.4 mg N/L. The combination of high selectivity and high sensitivity unlocks the ability to detect small traces of dissolved ammonia at low power draw and low costs (under $29) thus enabling the use of such methods for remote immersible ammonia sensors for environmental sensing applications along with IoT nodes.
References:
Bernard S, Kudela RM, Velo-Suárez L. Developing global capabilities for the observation and prediction of harmful algal blooms. In: Djavidnia S, Cheung V, Ott M, Seeyave S, editors. Oceans and society: blue planet. Cambridge Scholars Publishing; 2014. Chapter 6
Kim HG. Mitigation and controls of HABs. In: Granéli E, Turner JT, editors. Ecology of harmful algae. Ecological Studies. Vol. 189. Springer-Verlag; Berlin: 2006. pp. 327–338
Flow Injection Electrochemical Quartz Microbalance with ICP-OES Detection
Authors: Molina Daniel , Beyenal Haluk , Ivory Cornelius F. 
Published: December 2020

The electrochemical quartz crystal microbalance (EQCM) has been previously reported in flow injection (FI) mode as a microgravimetric sensor for analytes that can be deposited onto an electrode surface through various mechanisms such as adsorption, covalent bond, or electrodeposition. Since this methodology does not provide the composition of the deposited species, it must be coupled with other analytical techniques.
In this work, a new hyphenated technique, flow injection – electrochemical quartz crystal microbalance – inductively coupled plasma optical emission spectroscopy (FI-EQCM-ICP-OES), is used to study the deposition and stripping of metallic ions under hydrodynamic conditions in a modified commercially-available EQCM flow cell with a reaction volume of 50 uL. An automatic flow injection valve (FIV) delivers a fixed volume of analyte from a sample loop to the EQCM flow cell, where the electrodeposition reaction occurs, and the current and frequency change corresponding to the mass deposited on the electrode is measured in real time. After a film of the analyte has formed it can be rapidly stripped by changing the potential of the electrode. An ICP-OES connected downstream of the EQCM provides continuous elemental analysis throughout the deposition and stripping processes. One of the advantages is the possibility of sequential deposition-stripping experiments without having to disturb the working electrode in the flow cell.
This platform was tested via flow injection of cupric sulfate samples in a sulfuric acid matrix at 200 uL/min, with cathodic electrodeposition and anodic stripping performed at different potentials. We also developed a finite element 3D model of the electrochemical flow cell in COMSOL Multiphysics®, with the simulated results in reasonable agreement to the measured current and mass deposition in the copper experiments. The image below shows the simulated [Cu+2] profile in COMSOL Multiphysics® during cathodic electrodeposition, 62 seconds after the sample enters the reaction chamber of the flow cell.

Figure 1
Novel Design of Multiple Nested Coaxial ZnO Nanotube Gas Sensors Synthesized in Porous Templates By Atomic Layer Deposition
Authors: Lin Pengtao , Zhang Kai , Baumgart Helmut - 
Published: December 2020

Among the various Metal Oxide Semiconductor (MOS) gas sensor types, solid-state gas sensors based on ZnO nanostructures have been widely used due to their properties of large exciton binding energy, wide band gape of 3.37 eV, good electrical conductivity, low cost, and high mechanical stability. In this work, ZnO nanotube nanostructures were employed for gas sensing of ethanol vapor concentrations, which is aided by their high electrochemical stability, nontoxicity, and, especially, high surface-to-volume ratio. Multiple coaxial nested ZnO nanotubes were synthesized inside porous membranes and porous templates to further enhance the sensing response to ethanol vapors with vastly increased reaction surfaces.
In this study, ZnO nanotubes were synthesized by Atomic Layer Deposition (ALD) on porous Anodic Aluminum Oxide (AAO) templates with sacrificial Al2O3 layers and on porous Si membranes. The Al2O3 sacrificial layers were synthesized on porous AAO and porous Si by ALD with TMA (Al2(CH3)6) and DI water as ALD precursors. Then ZnO thin films were deposited on the surface of the sacrificial layer with precisely controlled thickness by ALD. The entire ALD procedure is considered as one ALD super cycle. More super cycles were applied to synthesize additional coaxial ZnO nanotubes. For the final removal of the sacrificial layer, Precision Ion Polishing System (PIPS) was used to first remove the top ALD surface cover. In this way, the Al2O3 sacrificial layers were exposed for Sodium Hydroxide (NaOH) etching. The objective of the Al2O3 sacrificial layers was to expose additional reactive sensing surfaces to react with the target gas by subsequent removal of these sacrificial layers. Finally, after the sacrificial layers were completely removed by wet chemical NaOH dissolution, the nested coaxial ZnO nanotube gas sensor design was fabricated with multiple sensing surfaces.
To investigate the sensing performance of ZnO nanotube gas sensors to ethanol vapor, a gas sensor testing system was developed with a sealed reaction chamber and control system with stable temperature control and accurate concentration control. The sensing performance of single ZnO nanotubes, two nested coaxial ZnO nanotubes, and three nested coaxial ZnO nanotubes to ethanol vapor were measured and analyzed under various ethanol vapor concentrations and at different operating temperatures. The ZnO nanostructures sensing results on ethanol vapor demonstrated the sensing performance was considerably enhanced due to the increased surface to volume ratio in the ZnO tube structures.
Development of Miniaturized Interdigitated Electrode Sensors and Their Application in Taste Sensing
Authors: Dudala Sohan , Srikanth Sangam , Dubey Satish Kumar , Javed Arshad , Goel Sanket 
Published: December 2020

Interdigitated Electrodes (IDEs) or Interdigitated Arrays (IDAs) are frequently used in a variety of sensing mechanisms including electrochemical detection and have been subjected to extensive miniaturization in recent times. Multiple methods involving the fabrication of IDEs have been reported. However, these fabrication methods are often time consuming, multistep, skill intensive, expensive and require clean room conditions. This work reports on the fabrication and comparison of miniaturized IDEs fabricated using two inexpensive and clean room free approaches - inkjet-printing and direct laser writing (DLW) based photolithography. For inkjet-printing approach, a commercially available printed-circuit board (PCB) printer was used with a carbon ink to print the IDEs on a glass slide. For photolithography-based fabrication, a DLW system was used for the fabrication of IDEs on a copper-clad FR4 PCB board. Previously established, validated and reported models were employed for the design of IDEs. The design parameters were selected to optimize sensitivity while striking a balance with the overall size of the sensor. The application of the developed IDE sensors was demonstrated for its taste sensing capability. Sensing of five fundamental tastes, namely salty, sweet, sour, bitter, and umami, was established with electrochemical impedance spectroscopy (EIS). The chemicals which can simulate these fundamental tastes for experimental purposes were identified as sucrose (sweet), sodium chloride (salty), citric acid (sour), L-tryptophan (bitter) and guanosine monophosphate (GMP) (umami). EIS was performed on a benchtop electrochemical workstation with two electrode configurations and data was analysed in the frequency range of 1 Hz to 1 MHz. The obtained data was analyzed for different chemicals at varying concentrations and compared for changes in the response. DLW photolithography-based approach produces IDEs with excellent geometric dimensional repeatability. The IDEs produced on glass slides using Carbon ink-based printing were fabricated in under 2 minutes and cost less than US$ 0.3. Both approaches demonstrate the applications of IDEs with fairly reasonable and benchmarked taste sensing capabilities.
Figure: a) Optimised Design b) Carbon ink-based printing c) IDE printed on glass slide d) Photlithography based DLW IDE fabrication e) IDE on a copper cladded FR4 PCR board.

Figure 1
Real-Time Glucose Monitoring System Containing Enzymatic Sensor and Reference Electrodes for Application In Vivo
Authors: Ramašauskas Lukas , Ratautas Dalius 
Published: December 2020

Nearly every electrochemical biosensor uses two or three electrode setup which involves sensing electrode (usually containing oxidoreductase) for a specific reaction, metal/salt reference electrode (i.e., Ag/AgCl or Hg/Hg2Cl2) for the control of the potential and, is some cases, counter electrode for the compensation of the current. This setup did not change significantly since 1962,1 when the idea of biosensors was proposed, despite having significant flaws related to metal/salt reference electrodes: they are bulky and difficult to miniaturize, leak electrolyte to the medium, lose the ability to define the electrochemical potential precisely in time, consequently, have to be updated or replaced.2 This causes significant problems then the biosensor cannot be easily replaced (e.g., implanted electronics). It is worth noting, that significant potential drifts for an in vivo tested metal/salt reference electrodes (Ag/AgCl or Hg/Hg2Cl2) were noticed as early as in 1986,3 yet little efforts were reported to solve the above-mentioned issues, despite significant advances in the development of sensor electrodes. The majority of the reported works focused on improvement and miniaturization of current technology – metal/salt electrodes.
Here we present a real-time glucose monitoring system capable of referencing its own electrochemical potential (Figure). By using sensing electrode composed of wired glucose dehydrogenase and enzymatic reference electrode composed of wired laccase we have managed to create stable and accurate electrode system which measured fluxes in concentration of glucose in a physiological range (3–8 mM). To the best of our knowledge, this is the first fully enzymatic electrode system capable to reference its own potential and avoid usage of metal/salt reference electrodes. Our designed enzymatic reference electrode is universal and we envision that it may be applied for other biosensors, thus open possibilities for the new generation of implantable devices for healthcare monitoring in vivo.

References

(1) Clark, L. C.; Lyons, C. Electrode Systems for Continuous Monitoring in Cardiovascular Surgery. Annals of the New York Academy of Sciences
1962, 102 (1), 29–45.
(2) Hashemi, P.; Walsh, P. L.; Guillot, T. S.; Gras-Najjar, J.; Takmakov, P.; Crews, F. T.; Wightman, R. M. Chronically Implanted, Nafion-Coated Ag/AgCl Reference Electrodes for Neurochemical Applications. ACS Chemical Neuroscience
2011, 2 (11), 658–666.
(3) Thompson, M.; Vandenberg, E. T. In Vivo Probes: Problems and Perspectives. Clinical Biochemistry
1986, 19 (5), 255–261.

Figure 1
The Effects of H3PO4 Treatment on Li/Mn-Rich Layered Li1.2-X[Mn0.55Ni0.15Fe0.10]O2(1-x)F2x Cathode Materials for Li-Ion Batteries
Authors: Acuna Sinjin , Kucuk Kamil , Segre Carlo U. , Timofeeva Elena V. 
Published: December 2020

In this study, sol-gel synthesized Li/Mn-rich layered Li1.2-x[Mn0.55Ni0.15Fe0.10]O2(1-x)F2x was studied as an alternative to commercial NMC and LiCoO2 batteries due to greater theoretical capacity ~250 mAh g-1, increased safety, and lower-cost. Despite these advantages, MNF cathodes show experimentally lower capacity and decay, voltage fading, and poor rate capability [1]. To address these problems, the creation of a Li3PO4-coating with a H3PO4 solution treatment was investigated. Treatment has resulted in increased initial discharge capacity for the first 3 cycles at 0.1C and increased cell retention for the following 97 cycles at 0.33C compared to untreated MNF551510. As alternatives to the classic NMC and LiCoO2 arise, H3PO4 treatment can be a useful technique to enhance electrochemical performance of novel cathode materials.
Powder X-ray diffraction was used to determine the phase of the material as well as the amount of lithium carbonate contamination before and after Li3PO4-coating. Furthermore, scanning electron microscopy (SEM) was performed to analyze the effects of Li3PO4-coating on the morphology of the particle. For electrochemical analysis, galvanostatic charge-discharge cycling and cyclic voltammetry (CV) were completed.
Covalent Triazine Frameworks Incorporating Charged Polypyrrole Channels for High-Performance Lithium-Sulfur Batteries
Authors: Elabd Ahmed , Kim Jiheon , Chung Sung-Yoon , Coskun Ali , Choi Jang Wook 
Published: December 2020

Covalent triazine frameworks (CTFs) have emerged as promising electrode materials for lithium-sulfur (Li-S) batteries owing to their pristine pyrdinic sites, conjugated backbone and ability to stabilize remarkable sulfur contents. Following the first synthesis of sulfur-CTFs under catalyst and solvent-free reaction conditions[1], new synthetic strategies have been extensively investigated to improve CTFs properties for Li-S batteries applications. Further upgrading for CTFs was introduced to achieve extremely high sulfur contents CTFs via employing nucleophilic aromatic substitution reaction (SNAr) between perfluoroaryl units and elemental sulfur.[2] However, the previous (SNAr) approach possessed immense sulfur conent up to 82%, it is challenging to endure high ionic and electronic conductivity with mitigation of Li-polysulfide (Li-PS) shuttling. These fatal problems limit their cycling performance at high active mass loadings. In an effort to tackle the previously mentioned problems, a new approach incorporates the integration of one-dimensional charged conducting polymers with a two-dimensional covalent triazine framework in the presence of elemental sulfur.[3] Noticeably, the addition of charged conducting polymers triggers a 3D nanochannel formation in the CTF framework with high-affinity anchoring sites towards Li-PS while achieving decent ionic and electronic conductivity. The resulting polymers showed significantly improved ionic , electronic conductivities and high sulfur loadings. Because of these remarkable properties, we are able to obtain exceptional electrochemical performance at high mass loading of 3 mg sulfur per cm2 with a specific capacity of 1275.2 mAh g−1 at 0.05C.

References:

[1] S. N. Talapaneni, T. H. Hwang, S. H. Je, O. Buyukcakir, J. W. Choi, A. Coskun, Angew. Chemie - Int. Ed.
2016, 55, 3106–3111.
[2] S. H. Je, H. J. Kim, J. Kim, J. W. Choi, A. Coskun, Adv. Funct. Mater.
2017, 27, 1–9.
[3] J. Kim, A. Elabd, S-Y. Chung, A. Coskun, J. W. Choi. Chem. Mater.
2020, under revision.
Analysis of the Effect of Particle Shape on Pore Structure
Authors: Oh Hyeseong , Kim Youngmin , Jeong Kyeong-Min 
Published: December 2020

Market requirements for lithium-ion batteries are gradually increasing as they expand their applications from small electronic devices to large EVs and ESSs. Various active materials, binders, and conductive materials could be used to make batteries. In manufacturing electrodes, the microstructure of each porous electrode will vary depending on the size and shape of the particles used.1 Many studies show that the microstructure of lithium-ion battery electrodes affects cell resistance, cycle life, and rate capabilities.
In this study, electrodes with various mass loading levels and composite densities were fabricated using single crystal and secondary particle NCM cathode active materials. Two major parameters of the porous electrode, porosity and tortuosity, were obtained. Mercury intrusion porosimetry was used to measure porosity. Tortuosity was obtained from Bruggeman’s relationship,2,3 using electrochemical impedance spectroscopy (EIS). We compared porosity and tortuosity values with the SEM image of each electrode. It was confirmed that the pore structure can be well maintained in the single crystal NCM based electrode due to the high stiffness of the active material.
References

Harris, Stephen J., and Peng Lu. The Journal of Physical Chemistry C 13 (2013): 6481-6492.

Landesfeind, Johannes, et al. Journal of The Electrochemical Society 7 (2016): A1373-A1387.

Bruggeman, Von DAG. Annalen der physic 7 (1935): 636-664.
Application of Spinel MgMn2-X
Al
x
O4 As Cathode for Mg Rechargeable Battery
Authors: Yokozaki Rika , Kobayashi Hiroaki , Mandai Toshihiko , Honma Itaru 
Published: December 2020

【Introduction】
Lithium-ion battery (LIB) has mainly used in our life, but its high price due to Li and Co metals are crucial problem. Magnesium rechargeable battery (MRB) has been recently studied as a post LIB due to elemental abundant supply and superior theoretical volumetric energy density of magnesium. For cathode materials, spinel oxides is one of a candidate of MRB due to its high redox potential and three-dimensional diffusion paths.[1] Especially, MgMn2O4 is expected to perform high theoretical capacity because utilization of both Mn3+/Mn4+ and Mn2+/ Mn3+ redox is possible in the potential window of the common electrolyte.[2] But structural change from tetragonal to cubic occurs due to Jahn-Teller effect of Mn3+ ion during charge/discharge, which decreases reversibility. In this study, we tried to enhance reversibility of MgMn2O4 spinel by substituting Al for Mn to release its Jahn-Teller distortion, and the optimal substitution ratio and their electrochemical property were evaluated.
【Experimental】
MgMn2-xAlxO4 (x = 0, 0.1, 0.2, 0.5) were synthesized by Pechini method[3] with an annealing process of 400 ºC, 10 hour. Cathodes were prepared by mixing the obtained samples with acetylene black and polytetrafuluoroethylene at a weight ratio of 60/30/10 . Mg alloy (AZ31) was used for an anode. Galvanostatic charge/discharge profiles were obtained by using a coin cell with a 0.3 M Mg[B(HFIP)4]2/triglyme electrolyte at 25 ºC, 10 mA/g.
【Results and discussion】
According to X-ray diffraction(XRD) patterns, MgMn2-xAlxO4 (x = 0, 0.1, 0.2, 0.5) spinel were obtained and their crystallinity become lower by Al substitution. In MgMn1.5Al0.5O4, the crystal structure changed from tetragonal to cubic phase, suggesting that the Jahn-Teller effect is suppressed by the formation of the solid solution of tetragonal MgMn2O4 and cubic MgAl2O4. The Al-substituted MgMn2O4 exhibited higher discharge capacities compared with MgMn2O4 (64.0 mAh/g), and especially MgMn1.9Al0.1O4 showed the highest discharge capacity of 92.3 mAh/g. In the poster session, X-ray absorption spectroscopy (XAS) and cycle characteristics will be reported.
【Acknowledgment】
This work was supported by JST ALCA-SPRING Grant Number JPMJAL1301, Japan.
【References】
[1] S. Okamoto, T. Ichitsubo, T. Kawaguchi, Y. Kumagai, F. Oba, S. Yagi, K. Shimokawa, N. Goto, T. Doi and E. Matsubara, Adv.
Sci., 2015, 2, 1500072
[2] H. Kobayashi, K. Yamaguchi and I. Honma, RSC Adv., 2019, 9, 36434-36439.
[3] J. Yin, A. B. Brady, E. S. Takeuchi, A. C. Marschilok and K. J. Takeuchi, Chem. Commun., 2017, 53, 3665-3668.
Enhancement of Electrochemical Redox Reaction By Transition Metal Oxalates for High-Performance Lithium-Sulfur Battery
Authors: Seo Gyuwon , Kim Jin Won , Lee Jaeyoung 
Published: December 2020

As the size and usage of electronics are diversified, demand for secondary batteries with higher capacity and performance is increasing. Lithium-sulfur(Li-S) battery is one of the promising next generation battery due to high theoretical capacity(1,672 mAh/g), natural abundance and environmental nontoxic compare to conventional active materials of lithium-ion batteries. However, lithium polysulfide(PS) dissolution issue which causes capacity fade inevitably must be overcome for commercialization.
In this study, we introduced first transition metal oxalates as cathode additives which have a high polar surface area to enlarge the electrocatalytic interfacial boundary enabling LiPS redox reactions to occur, by controlling the carbon and metal oxalates ratio. Furthermore, physicochemical interactions between LiPS and metal oxalates were verified by UV-vis, X-ray Photoelectron Spectroscopy and Electrochemical Analysis(Cyclic Voltammetry, Galvanostatic Intermittent Titration Technique, Electrochemical Impedance Spectroscopy). As a result, the modified cathode by the best candidate effectively decreased cell overpotential and improved the cycle stability by maximized electrochemical utilization

Figure 1