bluuebunny/crossref_metadata_2025 huggingface dataset:
What If Electrochemical Energy Systems Were Made 40% More Efficient?
Authors: Leddy Johna
Published: November 2022

Electrochemical systems related to energy storage and generation have inherent thermodynamic advantages over thermal energy systems because electrochemical systems have do not require moving parts. Thermodynamic Carnot limitations restrict internal combustion engines (ICEs) to about 40% theoretical energy conversion efficiencies. Thermodynamically, electrochemical energy systems can be 100 % efficient. The high thermodynamic efficiency is however challenged by dynamics of kinetics and transport. Because electrochemical energy systems generally operate at lower temperatures and pressures than ICEs, greater finesse in design of catalysis is needed.

Electrochemical energy systems made 40% more efficient would substantially advance the economic and environmental advantages of electrochemical electrochemical energy. Consider mechanisms of physical catalysis where a physical gradient rather than a chemical composition drives chemical change. Magnetoelectrocatalysis is an example of physical catalysis that may provide means to enhance the efficiency of electrochemical energy systems.

Magnetoelectrocatalysis exploits magnetic gradients imposed at electrode surfaces to facilitate electron transfer and so electrocatalysis.

Here, magnetoelectrocatalysis is shown to increase energy, power, and conversion efficiency of several electrochemical energy systems by 40%. Examples include:

Proton exchange membrane (PEM) fuel cells

Alkaline batteries (MnO2|Zn)

Hydrogen evolution reaction (HER) at glassy carbon

MnO2 supercapacitors

Magnetic gradient effects on electrochemical efficiency are also observed for several environmentally relevant electrode reactions.

CO oxidation on Pt

HER on various metal electrodes and photocathodes

C1 reactions at rare earth electrocatalysts

From these outcomes, it is suggested that magnetoelectrochemical catalysis may provide a path to substantially more efficient electrochemical energy systems, perhaps approaching 40%.

Work is undertaken at the University of Iowa. The National Science Foundation (NSF CHE-1309366 and NSF CHE-0809745) and the Army Research Office (W911NF-19-1-0208 (74912-CH-II)) supported these projects.
(Digital Presentation) Engineering of Ni-Based Electrocatalysts for Direct Urea Oxidation
Authors: Kim Jiseon , Cho Kangwoo
Published: November 2022

In the water-energy nexus framework, the alternate renewable energy sources can be stored into molecular hydrogen or electricity with simultaneous water purification through wastewater electrolysis cell or wastewater fuel cell. Urea oxidation reaction (UOR) has been interrogated to enhance the energy efficiency and to recover energy from urea-rich wastewater. Nickel-based catalysts are up-to-date the most widely investigated materials as the UOR electrocatalyst. This presentation introduces our recent approaches for preparation of the UOR electrocatalysts by i) galvanostatic electro-deposition of mixed metal (oxy)hydroxide (NiFeOx or NiCoOx) with variable mixing ratios, ii) potentiostatic dealloying of commercial alloys (e.g. Ni-Fe, Fe-Ni, and Ni-Cr-Co) under variable pH, and iii) one-pot thermochemical treatment of NiFe alloy foam (NFF), both as substrate and catalyst source to create a self-supporting UOR electrocatalyst. The secondary elements (Fe and Co) were found to accelerate the formation of NiOOH (the active site for UOR), by partial charge transfer among the mixed metals. On the other hand, oxalic acid treatment of NFF generated prismatic NiFe-oxalate (O-NFF) which marked surprisingly small overpotential and Tafel slope for UOR. The coexistence of Fe and oxalate ligand simultaneously shift the surface electronic structure which in-turn affected the adsorption of reactants and desorption of products. The UOR on the engineed electrocatalysts could be further utilized for urea electrolysis (for molecular hydrogen production) or urea fuel cell.
Metal Oxide Inclusion in Polycrystalline Pt-Based Electrocatalyst for an Ammonia Oxidation Reaction
Authors: Huertas Namir Andrea , Cunci Lisandro
Published: November 2022

In April 2021, an average daily amount of 421 ppm of carbon dioxide (CO2) was recorded in the atmosphere, CO2
has increased more than 100 ppm in the last 66 years. Fuel cells are a suitable option for addressing the major issues of meeting current and future energy demand while also reducing CO2
pollution. If the fuel source originates from renewable sources, this makes the overall process CO2-neutral. In the quest for sustainable fuels with high energy density, focus is currently on nitrogen-containing fuels, such as ammonia (NH3) since their oxidation will yield predominantly dinitrogen (N2). Different platinum precursors (K2PtCl6 and H2Pt(OH)6) were used to study the effect on the electrocatalytic activity of Pt for an ammonia oxidation reaction when different metal oxides are added to Pt particles. The metal oxides chosen are CeO2, Fe2O3, and Ag2O. The morphology and element distribution of the Pt catalyst was determined by SEM equipped with an EDS detector. The crystalline phase present in the samples was determined by X-ray diffraction. Cyclic voltammetry was used to characterize the particles and to study the catalytic activity of Pt electrocatalyst for ammonia oxidation. No significant difference was found (by student t-test) between the onset potential for ammonia electrooxidation of Pt particles and Pt precursor. Average onset potential for ammonia electrooxidation was -0.464 V vs Ag|AgCl. The highest average current peak densities were reported by catalyst from non-chlorinated precursor with addition of Fe2O3. Current densities of nanoparticles synthesized from the H2Pt(OH)6 precursor decreased to 24.9 x 10-2 mA/cm-2 with CeO2 addition, but increased to 28.2 x 10-2 mA/cm-2 when Fe2O3 was added. We are currently working on the electrochemical characterization and oxidation of ammonia with catalyst from Ag2O addition
Multiplexed Electrochemical Device for the Detection of Biomarkers of Parkinson’s Disease Using 3D Printing
Authors: Ho Nguyen H. B. , Glasco Dalton Lee , Sopp Rhys N. , Bell Jeffrey Gordon
Published: November 2022

Neurotransmitters are chemical messengers that carry signals between cells. Imbalances in neurotransmitter levels have been linked to physical, psychotic, and neurodegenerative diseases such as Alzheimer's, Parkinson's, dementia, addiction, depression, and schizophrenia. Therefore, the rapid detection of neurotransmitters such as dopamine, acetylcholine, glutamate, serotine, and norepinephrine are essential for early diagnosis of various neurological disorders. This talk will focus on the development of a multiplexed electrochemical device using 3D printing for the simultaneous detection of biomarkers related to Parkinson’s disease. By combining the capabilities of stereolithographic (SLA) and fused-deposition modelling (FDM) 3D printing, we demonstrate the ability to fabricate and integrate potentiometric and voltametric sensors into the device. Importantly, we show that this approach is highly modifiable and scalable, providing a pathway towards the development of a full-panel diagnostic test for neurological disorders.
Non-Enzymatic Electrochemical Sensor Based on ZIF-67 and Mwcnts-ZIF-67 Nanocomposites for Detection of Uric Acid in Human Urea
Authors: Sundeep Dola , K Varadharaj Eswaramoorthy
Published: November 2022

Metal-Organic Frameworks (MOFs) have much interest in the catalytic research community but are less attracted by the sensor society for their poor conductivity. In the present work, we report a novel Zeolitic Imidazolate Framework-67 (ZIF-67) and MWCNT’s-ZIF-67 nanocomposites based on non-enzymatic electrochemical sensors for sensing uric acid in human urea. The conductivity and binding affinity of ZIF-67 are improved by the addition of MWCNTs. Initially, ZIF-67 powders were prepared by facile in-situ synthesis method and then the MWCNTs were introduced into ZIF-67 powders. To achieve better bonding between the carbon and the ZIF-67, MWCNT’s functionalized to attach hydroxyl, carboxyl, and carbonyl groups on the surface of the carbon tubes. The obtained nanopowders were spectroscopically analyzed by using X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) spectroscopy, FESEM, and Raman analysis. The MWCNTs-ZIF-67 modified electrode offered the detection limit of uric acid with 1.18 µM and a sensitivity of 97.9 nA µM-1. The sensitivity was performed within two seconds with a linear response (R2=0.99). Fifteen repeated cyclic voltammetric responses were recorded to 0.1M of uric acid to analyze the stability and reproducibility of the electrode. All the sensor responses were determined in comparison with ZIF-67 with MWCNT-ZIF-67 modified electrode performance. In the present work, the catalytic MOFs with low conductivity was modified with MWCNTs and used for ultra-fast and highly-sensitive sensing of uric acid.

Keywords: ZIF-67, MWCNTs, Modified Electrode, Uric Acid, and Functionalization
(Invited) Fluorescence and Sensing Applications of Graphene Oxides
Authors: Wu Nianqiang
Published: November 2022

First, the florescence emission mechanism of graphene oxide will be discussed. Second, fluorescence of graphene oxide can be tuned by tailoring functional groups. Third, graphene oxide-based sensors can be designed with graphene oxide either as an energy donor or as an energy acceptor. Fourth, graphene oxide-based sensors have been sued to detect heavy metal and biomarkers.
Dense BaCe0.6Zr0.3Y0.1O3-Α Solid-State Electrolyte for Application in Hydrogen Sensors
Authors: Hinojo Antonio , Lujan Enric Lujan , Colominas Sergi , Abella Jordi
Published: November 2022

Fusion energy is a promising solution for the expected energy problems in the mid-term future. This technology is expected to use deuterium and tritium, two hydrogen isotopes, as fuel. Deuterium can be obtained from natural sources, but tritium, which is a non-stable hydrogen isotope, must be in situ generated. To assure the correct monitoring of both isotopes, it will be required the design and qualification of high-temperature sensors. The construction of H2 sensors based on solid-state electrolytes can be the first step towards the development of new analytical tools able to monitor hydrogen isotopes in that aggressive environment.

In previous work [1], amperometric sensors based on BaCe0.6Zr0.3Y0.1O3-α (BCZY) solid-state electrolyte have shown good analytical parameters for hydrogen monitoring. However, these materials need high temperatures during sintering to obtain full density due to their refractory nature. This lack of densification can affect their electrochemical response due to their low ionic conductivity. The use of sintering aids, like ZnO, can improve the densification of these ceramics at lower temperatures.

In the present work, hydrogen sensors based on BCZY were constructed and evaluated in potentiometric mode. Different sintering conditions for this electrolyte were tested and their potentiometric response was compared. The following disk-shaped electrolytes were prepared for that purpose: 1400 ºC – 30 h, 1650 ºC – 6h. Simultaneously, BCZY was sintered at 1400 ºC -12 h with 5 mol% of ZnO as a sintering aid. Samples were characterized using XRD (to determine the crystallographic phases) and SEM (for microstructural defects and sintering). Then, disks were platinized and sealed with a glass binder to alumina tubes for sensor construction. Measurements were performed at 400 and 500 ºC. The hydrogen concentration in the RE was 1000 ppm H2 in Ar. The response obtained with the three sensors was compared with the theoretical Nernst potential.

[1] A. Hinojo, I. Soriano, J. Abellà, S. Colominas, Evaluation of High-Temperature Hydrogen Sensors Based on BaCe0.6Zr0.3Y0.1O3-α and Sr(Ce0.9Zr0.1)0.95Yb0.05O3-α Perovskites for Industrial Applications, Sensors. 20 (2020) 7258. https://doi.org/10.3390/s20247258.
Real-Time Continuous Monitoring of Fuel Cell Ionomer Degradation with Electrochemical Inline Micro Sensor Arrays
Authors: Benhaddouch Tinsley Elizabeth , Marcial John , Metler Christopher , Bhansali Shekhar , Dong Dongmei
Published: November 2022

Proton Exchange Membrane Fuel Cells (PEMFCs) are the preferred energy source for green transportation over CO2 emitting engines. In Nafion®-based PEMFCs, the radical attack causes polymer chain scission and irreversible reaction. It results in the global and local thinning of the ionomer, followed by producing fluorinated and sulfated degradation materials into reactant outlet streams. Synchronous fluorinated and sulfated degradation products will accumulate into reactant outlet streams. Radical attack diminishes the performance and stability of membrane electrode assembly (MEA). Chemical degradation will increase the flow rate of the relevant fluorinated degradation products. The concentrations are enhanced at elevated temperatures and lower humidity conditions. The byproduct fluoride and sulfate anion emission rates can be drawn as the signature of the PEMFC degradations. Electrochemical micro-sensors have been promising diagnostics tools due to low cost, small size, robustness, and their applications for continuous real-time monitoring. We have used fluoride emission as a sensing model. Highly fluoride-sensitive membranes (LaF3/CaF2) for inline microsensor arrays have been introduced as the sensing active layer. The functionalization of the working electrode varies the selectivity/sensitivity. High sensitivity sub 1 ppm has been achieved after optimizing the sensing layer deposited by spin-coating. In addition, advanced deep learning (DL) and long-short term memory (LSTM) algorithms will be used for the sensor-based predictive maintenance (PM) of PEMFCs. Even higher sensitivities sub 100 ppt and prediction accuracy for the end of life (EOL) can be achieved based on LSTM algorithms. The development of inline microsensor arrays gives a complementary approach to existing PEMFC characterization and diagnostics techniques.

Figure 1
(Invited) Challenges with Electronic Biosensors
Authors: Vogel Eric M. , Brightbill Eleanor L. , Gezahagne Hilena , Jin Decarle S.
Published: November 2022

The detection of chemical and biological species is critical for applications in healthcare, environmental monitoring, food safety and drug screening. Potentiometric biochemical sensors rely on the specific adsorption of charged analytes that changes the potential of the functionalized sensor surface. The change in surface potential can be measured using a field-effect-transistor (FET) enabling low-cost fabrication, and easy integration with portable readout electronics. The FET concept has previously been applied to numerous (nano-) materials including conventional silicon, nanowires and 2D materials such as graphene. Although many biosensing experiments have been reported, many of the results are not well understood and several key challenges are still limiting their widespread application. In this work, the experimental response from a variety of sensor surfaces and transducers and will be presented.

The results show that the choice of the active interface in contact with the electrolyte determines the sensor response and selectivity (the signal) is relatively independent of the transducer. Ideally, protein recognition mechanisms are leveraged to allow only target proteins to attach to the surface, imparting signal selectivity. However, unwanted protein interactions with sensor surfaces cause signal instability and increase false-positive rates. Although commonly used to functionalize the sensing surface, carboxyl-terminated thiol self-assembled monolayers (COOH-SAMs) can have large defect densities, which in turn leads to large non-selective adsorption of proteins to hydrophobic surfaces exposed by these defects. A procedure is developed where the surface of COOH-SAMs is treated before functionalization to improve the reliability and quality of receptor attachment to the sensor surface. Beyond SAM-based sensors, there has been significant interest in biomedical applications of two-dimensional materials such as graphene, including potentiometric sensing. There is conflicting literature on to what extent interaction from the substrate are transmitted through a monolayer, and the subsequent effect on biomolecule interactions are unknown. Therefore, the degree to which the substrate influences graphene-protein interactions is explored. Finally, the choice of the readout transducer (e.g. a graphene transistor) is shown to influence the noise limit, and, hence, the signal-to-noise ratio. Models for diffusion, attachment, and electrical response of these sensors will be described that demonstrates good agreement to experimental data. Despite the current challenges facing label-free, portable biosensors, the work presented here provides a step towards reliable biosensing.
Evaluation of the Response of High-Temperature Hydrogen Sensors for Fusion Applications
Authors: Lujan Enric Lujan , Hinojo Antonio , Colominas Sergi , Abella Jordi
Published: November 2022

The use of hydrogen gas in different chemical processes and industries is common. Hydrogen gas has to be monitored in order to provide control of reactions, detect leakages or avoid accumulations in confined spaces, among many other applications. In this frame, and depending on its final application there is a need to develop hydrogen sensors capable to operate in all kinds of conditions in terms of concentration range and temperature. Moreover, these sensors should provide measurements with high sensitivity, selectivity and fast response time. Furthermore, logistical properties such as low cost, long-term stability and easy operation should also be considered in all applications.

In the present work, solid-state electrolyte based amperometric sensors were constructed to measure hydrogen gas under high-temperature conditions. BaCe0.6Zr0.3Y0.1O3-α electrolyte (BCZY) was obtained by the solid-state method and characterized using SEM and XRD. Then, BCZY powder was sintered as a pellet and sealed to an alumina tube to construct the sensors. Finally, operational conditions were optimized and the analytical parameters of these sensors were evaluated at 500 °C and 600 °C. All measurements were performed in an argon atmosphere containing different hydrogen concentrations.
An Electrochemical Proximity Assay (ECPA) Based Sensor for Antibody Detection
Authors: Kurian Amanda Siyanka Nellimale , Mazumder A Z M Mainul Islam , Gurukandure Asanka , Easley Christopher John
Published: November 2022

Biomarker detection is vitally important for disease diagnosis. Critical biomarkers which are present in ultra-low concentrations in body fluids have been detected with immunoassays such as ELISA and improved versions such as Alpha-LISA and digital ELISA. Although these techniques have fM-pM range detection limits, the requirement of special instruments, reagents, and labor-intensive workflows have directed researchers to develop simpler assay techniques. The ideal alternative assay will be cost effective, with simple mix-and-read workflows, yet will not compromise its specificity and sensitivity. Analyte-driven hybridization of short complementary DNA strands have gained substantial attention for these reasons. Molecular pincer assays and proximity ligation assays (PLA) have successfully demonstrated sensitivities comparable to ELISA, using antibody-DNA conjugates. These techniques rely on fluorescence detection, which is sensitive and specific, but is challenging in terms of miniaturization and point-of-care (POC) use. Electrochemical (EC) detection, on the contrary, can be easily miniaturized and employs simple instrumentation with high sensitivity. We have previously introduced the electrochemical proximity assay (ECPA), where insulin and thrombin have been detected at fM or pM concentrations, respectively. ECPA leverages target driven hybridization of a methylene blue (redox reporter) tagged DNA to a thiolated DNA attached to a gold surface. In this work, we have developed a novel assay for antibody detection, leveraging the ECPA concept. Here, simultaneous binding of recognition elements to paratopes of the antibody results in hybridization of methylene blue (MB) tagged DNA to thiolated-DNA (see schematic), and generated current is proportional to the antibody concentration. Using free-solution, thermoflourimetric analysis (TFA) of similar strands, we showed that probe flexibility is very important for sensor response, where ssDNA with polyethylene glycol (PEG) linkers improved sensitivities significantly. Using information from TFA, we used the same modification and demonstrated that analyte-dependent EC current was increased after ssDNA attachments to the electrode were substituted with more flexible PEG linkers (see data). This modification was introduced to both the MB-DNA and thiolated-DNA, allowing direct antibody sensing of 45 nM. With optimization in the near future, this new ECPA-based antibody sensor should be useful for clinical monitoring of the immune response.

Figure 1
Poly(5-Amino-1,4-naphthoquinone) – Lasered Graphene Sensor for the Detection of Cysteine
Authors: Barber Robert , McCrory Elisha , Brennan Sarah L. , Cameron Sarah , Smith Robert B. , Papakonstantinou Pagona , Davis James
Published: November 2022

The electrosynthesis of a novel polyquinone film onto laser induced graphene (LIG) substrates is presented as a sensitive and scalable route to the production of thiol sensors. The one pot electroreduction of 5-nitro-1,4-naphthoquinone and subsequent electro-oxidation of the resulting amine was found to yield polymeric films consisting of repeating 1,4-naphthoquinone units. The resulting film exhibited electrochemically reversible behaviour (Eo = -0.1V at pH 7 (vs 3M NaCl Ag/AgCl) and found to exhibit a pH sensitivity of 61 mV / pH unit. The quinone groups within the film were found to react with cysteine (as a model thiol biomarker) through conventional 1,4-Michael addition resulting in the covalent modification of the film and the generation of new discrete redox entities. The voltammetric signature of the latter enabled interference free measurement of cysteine concentration at -0.42V with a detection limit of 5.2 mM. This contrasts the response to cysteine at unmodified LIG substrates where a detection potential of +0.55V was required and suffered inevitable interference from other species common to biofluids (i.e. tyrosine). The electrode mechanisms have been elucidated and the nature of the reaction with cysteine investigated using electrochemical and surface characterization techniques. The sensing performance of the polyquinone film towards cysteine is place in context with alternative electrode modifications.

Figure 1
An Interfacial Label-Free Electrochemical Approach to in-Situ Soil pH Monitoring
Authors: Eldeeb Mohammed , Dhamu Vikram Narayanan , Paul Anirban , Muthukumar Sriram , Prasad Shalini
Published: November 2022

Soil is a critical entity of Earth’s ecosystem. Healthy soil supports a landscape that is more resilient to the impacts of drought, flood, or fire. It also helps regulate the Earth’s climate. Real time assessment of soil health is imperative to improving crop yield as well to sustain an ever growing human population. Soil health encompasses moisture content, phosphorus, pH, nitrate, and other parameters. One of the most important parameters is soil pH which affects nutrients availability to plants and nutrients leaching in the soil. Current soil pH assessment techniques require destructive sampling of the soil where a core of soil is collected then treated at a lab before measuring the pH. This method measures pH at time points and doesn’t provide a continuous real time monitoring of pH. This work utilizes commercial screen printed electrodes with a pH sensitive coating for low cost continuous in-situ soil pH measurement. The coating is made up from alizarin an anthraquinone compound that undergoes a redox reaction in the presence of hydrogen ions and nafion an ion permeable membrane. Square wave voltammetry (SWV) is utilized since the output current signal shows the redox of alizarin while rejecting the capacitive current that’s inherent in soil. This redox peak current potential is dependent on the concentration of hydrogen ions which is gives a direct measure of pH. Due to the sensitivity of SWV, it is possible to measure unbuffered soil ph (without CaCl2 and KCl to improve the electrolyte ionic strength) accurately. The nafion layer protects the alizarin from dissolving in water present in soil as well as promoting the diffusion of hydrogen ions into the coating thus improving sensitivity. The alizarin has been used previously in screen printed electrodes however, this is the first work to our knowledge to utilize it to measure soil pH in-situ over a period of time. The sensor output was first calibrated in different unbuffered soil textures against the gold standard glass electrode. The calibrated response of the sensor in unbuffered sandy loam soil slurry is shown in Fig. 1. Then the sensor accuracy was validated by testing different soil samples using the sensor and later mixing it with deionized water and measuring the pH using the glass electrode. The sensor’s stability was evaluated by taking a measurement every hour for 48 hours without removing it from the soil sample. The temporal study showed a coefficient of variation less than 1% and an average reading of within 0.3 pH of the actual pH of the soil sample.

Fig. 1 Calibrated response of proposed sensor in sandy loam soil slurries with 40% water

Figure 1
Portable Mixed Potential Sensors for Natural Gas Emissions Monitoring
Authors: Halley Sleight , Tsui Lok-kun , Ramaiyan Kannan , Agi Kamil , Garzon Fernando H.
Published: November 2022

The US Environmental Protection Agency has estimated that emissions from natural gas and petroleum systems account for 32% of methane emissions in the US.[1] Natural gas (NG) is transported along hundreds of thousands of miles of pipeline in the US, and any plan to perform continuous monitoring of NG systems for leak detection will require the development of low-cost, field-deployable systems. Mixed potential systems based on ceramic electrolytes and metal or metal-oxide electrodes are expected to be capable of resolving CH4, C2H6 and other sub-components of natural gas mixtures and interferent mixes at the resolution required for buried pipeline monitoring. We have developed additively manufactured mixed potential electrochemical devices which are paired with artificial neural networks to perform mixture identification and discrimination.[2] Deployment of these devices outside of the laboratory setting requires the integration of the sensors into a portable sensor package (Figure 1(a)). We have produced a small form-factor housing for the four-electrode mixed potential device with an integrated heater. This is coupled with an Internet-of-Things data acquisition and networked transmission system to enable recording of the sensor response and transmission to the cloud for processing. The sensor system has demonstrated the capability to resolve simulated natural gas mixtures at the 40 ppm CH4 level (Figure 1(b)). Initial results of testing the sensing system outside the laboratory will also be presented. This work is supported by US Department of Energy, Office of Fossil Energy and Carbon Management award DE-FE0031864.

References:

[1] US Environmental Protection Agency, National GHG Emissions and Sinks 1990-2000, April 2022.

https://www.epa.gov/ghgemissions

[2] Halley, S.; Tsui, L.K.; and Garzon, F.H. “Combined Mixed Potential Electrochemical Sensors and

Artificial Neural Networks for the Quantification and Identification of Methane in Natural Gas

Emissions Monitoring.” J. Electrochem. Soc. 168, 097506. DOI: 10.1149/1945-7111/ac2465.

Figure
1. (a) A photograph of a portable sensor package with integrated heater is shown being tested.

(b) Sensor response data showing resolution of 40 ppm CH4 in a simulated natural gas mixture in air.

Figure 1
(Digital Presentation) Development of a Novel pH Sensor Based Polyaniline Supported on Nickel Modified Nickel Foam Electrode
Authors: Islam Mirazul , Rasel Md. , Jamal Mamun
Published: November 2022

pH is an essential parameter that has to be regularly monitored in biological and environmental applications [1]. Typically, handling fragile electrodes and a number of calibration steps make the measuring process time-consuming. Polyaniline-modified electrodes have several advantages in terms of dependability, miniaturization, and cost-effectiveness, all of which are important features for in vivo applications.

In this work, a hybrid material made of polyaniline, nickel, and nickel foam (PANI/Ni/NF) was combined together to detect H+ ions. First, using cathodic electrodeposition, nickel (Ni) was electrodeposited onto the surface of nickel foam (NF) [2]. Then, the surface of Ni/NF was modified by a self-assembled polyaniline (PANI) membrane to improve the ability of Ni to transform charges. SEM, EDX, Raman spectroscopy and XPS were used to characterize the morphology of PANI/Ni/NF. Fig. 1 shows SEM image of PANI on the surface of nickel oxide modified nickel foam electrode. Cyclic voltammetry (CV) and Open circuit potential (OCP) were used to monitor the potential shift based on different pH in the buffer solutions. The pH sensor displays the sensitivity of −46.00 mV/pH (R2=0.99) with stable performance in the physiological pH range from 3–11. This prototype has been tested along with a commercial pH meter on real samples (orange, baking powder solution). The durability and repeatability tests also show promising results. This porous and tiny pH sensor opens up new horizons for monitoring H+ in biological, environmental or wet laboratory based samples.

Acknowledgments

University of Grants Commission of Bangladesh (2021-22) for funding this research.

References

F. Song et al., ACS Appl. Energy Mater., 2018, 1, 1, 3–8.

M. Jamal et al., J. Electrochem. Soc., 2022, 169, 057517

M. Jamal et al., Microsys
t.
Technol
.
, 2018, 24, 4217–4223.

Fig. 1. SEM image of PANI modified Ni/NF

Figure 1
Safety-Enhanced Polyethylene Separator with Thermally Conductive Ultra-Thin Ceramic Coating Layer for Advanced Libs
Authors: Kim Ucheol , Roh Youngjoon , Lee Yong Min
Published: November 2022

Lithium-ion batteries (LIBs) are widely used from small electronic devices to large-format electric vehicles and energy storage systems. However, as the energy density of LIBs increases, ensuring safety becomes more important to battery manufacturer. [1] As a result, battery engineers are reluctant to use bare polyethylene separators without the ceramic coating layer, which is generally fabricated from the slurry containing ceramic particles, binder, and solvent. Thus, the ceramic-coated separator (CCS) becomes a must-have item for state-of-the-art LIBs. However, since an additional ceramic layer not only reduces the energy density of LIBs, but also increases the cell resistance, there are previous works to reduce those resistive ceramic layers without compromising the thermal or mechanical properties of CCSs. [2] The key process they utilized was the deposition, which can coat the SiO2, Al2O3, or TiO2 ceramic layers of tens of nanometer on the surface of separators. [3,4,5,6] Thus, without ceramic coating layer of a few micrometers, they could show both improved electrolyte affinity and thermal stability comparable to the conventional slurry-based CCSs. However, except for oxide-based ceramics, other ceramics like nitride, which has a good thermal conductivity, have not been tried for this ultra-thin ceramic coating layers.

Thus, herein, we attempt to deposit nitride on polyethylene separators using RF sputtering method. After the CCS was prepared, its physical properties such as thickness, mass per area, permeability, and morphological change were evaluated with a control CCS with Al2O3 layer. Also, not only thermal stability but also thermal conductivity was compared between nitride- and oxide-based CCSs. Furthermore, their electrochemical properties such as cyclability and rate capability were also investigated with large-area pouch-type full cells. Through these comparative study, pros and cons of ultra-thin nitride layer would be reported for advanced LIBs.

[1] John B. Goodenough et al., J. Am. Chem. Soc. 2013, 135, 1167−1176.

[2] Karun Kumar Jana et al., ChemBioEng Reviews, 2018, 5, 346-371

[3] Taejoo Lee et al., Macromolecular Research, 2014, 22, 1190–1195

[4] Min Kim et al., Journal of Power Sources, 212, 2012, 22-27

[5] Yoon Seok Jung et al., Adv. Energy Mater. 2012, 2, 1022–1027

[6] Kun Peng et al., RSC Adv., 2015, 5, 81468
Suppressing Li-Dendrite By the Structural Design of Li-Si Alloy-Anode in Sulfide Based All-Solid-State Batteries
Authors: Kim Minhyung , Lim Hyung-Tae
Published: November 2022

All-solid-state batteries (ASSBs) were fabricated with alloy-anode composite (Li3.25-Si + Li2S-P2S5), sulfide-based glass electrolyte (Li2S-P2S5), and sulfur-based composite cathode (S + Li2S-P2S5 + C). When the anode was made of only lithium silicide, voltage noise occurred under 0.5-3.7 V cut-off condition, which is out of the electrochemical stability window of the solid electrolyte (SE). This result indicates that Li-dendrites were generated by irreversible Li-ion deposition at the limited interface between the anode and the SE due to oxidative decomposition of SE. We modified the anode to the composite structure consisting of lithium silicide + sulfide SE to increase the number of the alloying reaction site. The pyrolytic graphite sheet (PGS) was placed between the anode and the current collector to facilitate electron transport. As a result, the voltage noise did not occur under the 0.5-3.7 V cut-off condition. This study indicates that increasing the number of alloying reaction sites improves the structural stability of the full cell, thereby increasing the cycle life.
Applications of Soft Dendritic Colloids in Li-Ion Batteries with Advanced Structure-Derived Performance
Authors: Petrecca Michael J. , Christopher Jerush , Velev Orlin D. , Fedkiw Peter S.
Published: November 2022

Adoption of electric vehicles and increasing demands of consumer electronics require electrochemical energy storage devices with high capacity and rate capabilities. Supply-chain and material-cost concerns as well as charge-rate limitations associated with irreversible lattice changes motivates the replacement of mixed-metal oxide cathodes in lithium-ion batteries (LIBs). Electrochemically active polymeric materials have emerged as promising candidates to replace metal oxides due to their high tunability and increased capacity. However, many of these materials suffer from poor intrinsic electronic conductivity and may be soluble into the electrolyte, causing irreversible capacity fade. Nanostructuring and composite formation are two polymer processing methods that can be leveraged to combat these drawbacks. The introduction of new nanostructured and nanocomposite cell components can decrease diffusion length scales, increase mechanical stability, and allow for higher electronic conductivity in polymer electrodes. Herein, we utilize a new class of polymeric materials called soft dendritic colloids (SDCs) as a platform for creating such nanocomposites. These fibrillar polymeric particles, formed via turbulent solvent-nonsovent induced phase separation, have hierarchical morphology, large aspect ratios and demonstrate pronounced adhesion and network-forming behavior. SDC-based materials have shown impressive results as nonwoven polyvinylidene difluoride separators in Li-ion batteries. Herein, we propose and present their use as Li-ion battery electrodes with advanced structural properties, derived from electroactive polymeric materials.
Design Studies Using Corrosive and Non-Corrosive Materials to Improve on Reliability and Efficiency of an Impeller of a Centrifugal Pump
Authors: Idris Muhammad Nuru
Published: November 2022

Design Studies using Corrosive and Non-corrosive Materials to Improve on Reliability and Efficiency of an Impeller of a Centrifugal Pump

N. Idris*1, 3and I. U. Umaru2

1Department of Chemical Engineering

University of Maiduguri

Borno State, Nigeria

Email: idrismn@unimaid.edu.ng

ABSTRACT

The quest to improve on the reliability, operability, sustainability of centrifugal pumps in all facets of process operations, oil and gas industries across the globe have a pivoted role to play in the development of world energy technology and sustainability in numerous ways. This is because several operability challenges and malfunctioning of centrifugal pumps can usually results to unexpected shutdown of process operations and mostly in cases with faulty standbys.

Centrifugal pump is a type of a turbo machine in which mechanical energy is converted into pressure energy by means of centrifugal force acting on the fluid. The impeller is the revolving component of the centrifugal pump that transmits energy from the electric motor that drives the pump to the fluid being pumped by acceleration of the fluid outwards from the centre of rotation.

Several researches have been conducted using experiment and numerical simulations to design the centrifugal pump impellers. As a result of recent research, the performance of contemporary centrifugal pump impellers yielded positive results. However, for sustainability there is a need to design the impellers using corrosive and non-corrosive materials to improve on its reliability and efficiency of the pump.

The aim and objective of the studies are: to analyze the pressure, head and efficiency of the designed centrifugal pump impeller, to improve on the efficiency and reliability of a centrifugal pump impeller by changing the blade angle and the use of corrosive and non-corrosive fluids, experimental measurements to analyze the pressure fluctuation performance of a centrifugal pump impeller using CFD.

Keywords: Oil and gas, centrifugal pump, reliability, sustainability

Correspondence about this article: Please for all correspondence on this article, kindly contact the principal author as stated above. Thank you.
(Digital Presentation) Evaluation of Two Methods of Bias Correction of Precipitations on Improvement of Hydrological Simulation:Case of Chiffa Basin-Northern Algeria-
Authors: Zoubida Madani Amina
Published: November 2022

This work aim to assess the “basic-quantile”and“gamma-mapping” bias correction methods in order to improve hydrological simulations of the Chiffa watershed. The results are provided by the conceptual rainfall-runoff GR2M model in the R environment, coupled with the outputs of rainfall data simulations from the RCA4 model of CORDEX-AFRICA forced by two global circulation models (MPI-ESM-LR and CRNM-CM5) under two Representative Concentration Pathways (RCP) RCP4.5 and RCP 8.5 .The validation of GR2M hydrological model on the Chiffa basin using Nash criteria made it possible to simulate future flows over the period 2074-2099. The results showed that the future flows simulated from raw rainfall data are not in adequacy with the evolution of future rainfall simulations whereas the flows simulated from the corrected rainfall data shown better results, which highlights the importance of bias correction for hydrological impact studies. Finally, the regional climate models simulate a 9% decrease in winter, and a 6% increase in spring under RCP4.5 by the end of the 21st century

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Development of Responsive Polymeric Nanocomposites for Enhanced CeO2 Removal in Post-Chemical Mechanical Planarization (p-CMP)
Authors: Wu Kun , Caridi Adam T. , Gentile Ryan J. , Powell Joseph L. , Keleher Jason J.
Published: November 2022

As integrated circuits (ICs) and logic devices continue to shrink according to Moore’s Law, the demand for enhanced Chemical Mechanical Planarization (CMP) processes has increased dramatically. More specifically, an area that has gained tremendous attention is Shallow Trench Isolation (STI) CMP. The process of STI involves the electrical isolation of active components that require exposure by removing the bulk oxide (i.e., TEOS) overburden from the deposition process. Traditional STI slurry formulations are comprised of a CeO2 nanoparticle dispersion, rate enhancers, selectivity and rheology modifiers, and pH adjusters. Due to the presence of defect states (i.e., oxygen vacancies (Ovacs)) on the surface of CeO2 nanoparticles, their photocatalytic properties can be exploited to induce redox reactions. Specifically, the reduction of Ce4+ to Ce3+ leads to the formation of additional Ovacs on the surface of CeO2, which causes hard adsorption of CeO2 nanoparticles to TEOS surfaces. Significant work has been conducted on optimizing the post-CMP (p-CMP) cleaning process by creating low shear force environments via charge transfer chemistries to remove CeO2 adsorbed to TEOS. As a result, this work presents the design of responsive polymeric composites that may be employed in the brush scrubbing of TEOS to enhance particle removal while minimizing shear and compressive forces. This will ultimately limit secondary defectivity and induce more efficient cleaning of nanoparticles from the dielectric material. To monitor the cleaning process, coefficient of friction (CoF), shear force (SF), defect measurements via profilometry, particle removal efficiency (PRE), and Ce4+/Ce3+ ratio measurements will be utilized. Using a UV/Vis spectroscopic technique to monitor the Ce4+/Ce3+ ratio, initial results show a correlation between the oxidation state of CeO2 and PRE. Additionally, using a non-traditional polymeric brush during cleaning has shown higher PRE while maintaining lower shear force environments.
Transition Metal Doped-Chalcogenide Based Electrocatalysts for Oxygen Evolution Reaction
Authors: An Wonyoung , Choi Sung Ryul , Park Jun-Young
Published: November 2022

Hydrogen, which possesses high gravimetric energy density, has recently received great attentions to respond to the seriousness of global climate change [1, 2]. In particular, the alkaline water electrolysis cells (AECs) that can produce hydrogen through electrochemical reactions without greenhouse gas emissions are substantially promising as renewable next-generation energy storage and conversion devices. In AECs, oxygen evolution reactions (OERs) occur at the anode, while hydrogen evolution reactions take place at the cathode [3, 4]. However, the sluggish kinetics of the multi-electron transfer process is a paramount challenge for efficient OER activity. Furthermore, precious metal catalysts such as iridium and ruthenium are still mainly used as an OER catalyst, and their low economic efficiency and durability are acting as major problems in the commercialization stage. Therefore, the reduction of reaction overpotential is crucial to boost catalytic efficiency for OER in AECs. In this study, the OER catalyst study is performed on sulfide-based chalcogenide materials. It has been reported that the sulfide-based chalcogenide materials have shown the excellent catalytic activity because the covalent characteristics between transition metal and chalcogenide is stronger than that of oxide-based catalysts [5]. In particular, among various sulfide-based chalcogenide materials, nickel sulfide-based catalysts have actively studied because they can simply synthesize using a hydrothermal method. Additionally, nickel sulfides have a structurally Ni-Ni metal bond that makes it easy to transfer charge species for OERs. Herein, various transition metals are doped into the nickel sulfide to improve the catalytic activity and electrical conductivity via generation of extra defects in the crystal structure. The crystal structure and catalytic activity of chalcogenide catalysts are analyzed through various physicochemical and electrochemical analysis methods.

References

[1] Hainan Sun, Xiaomin Xu, Zhiwei Hu, Liu Hao Tjeng, Jie Zhao, Qin Zhang, Hong-Ji Lin, Chien-Te Chen, Ting-Shan Chan, Wei Zhou, Zongping Shao, Journal of Materials Chemistry A 7 (2019) 9924.

[2] Thomas E. Mallouk, Nature Chemistry 5 (2013) 362–363.

[3] Muhammad Saqib, In-Gyu Choi, Hohan Bae, Kwangho Park, Ji-sup Shin, You-Dong Kim, John-In Lee, Minkyeong Jo, Yeong-Cehol Kim, Kug-Seung Lee, Sun-Ku Song, Eric D. Wachsman and Jun-Young Park, Energy & Environmental Science 14 (2021) 2472–2484.

[4] Sung Ryul Choi, John-In Lee, Hyunyoung Park, Sung Won Lee, Dong Yeong Kim, Won Young An, Jung Hyun Kim, Jongsoon Kim, Hyun-seok Cho, Jun-Young Park, Chemical Engineering Journal 409 (2021) 128226.

[5] Hatem M. A. Amin, UIf-Peter Apfel, European Journal of Inorganic Chemistry 2020 (2020) 2679–2690.

Keywords: Oxygen evolution reaction, Alkaline electrolysis cell, Water splitting, Transition metal, Post-transition metal, Chalcogenide.

* Corresponding author: jyoung@sejong.ac.kr (J. Y. Park)
Operando X-Ray Fluorescence Measurement Method of Cerium Radical Quencher Distribution in through-Plane MEA
Authors: Takezawa Aika , Orikasa Yuki , Tsuji Yoichiro , Asaoka Takahiko , Ohki Maria , Sekizawa Oki , Nitta Kiyofumi
Published: November 2022

Hydroxyl and hydroperoxyl radicals produced by reacting impurities with hydrogen peroxide is one of the degradation factors of polymer electrolyte [1]. A method to suppress this degradation is the addition of cerium into the polymer electrolyte membrane (PEM), which serves as radical quencher [2,3]. However, cerium ion in PEM migrates from the initial state by fuel cell operation [4]. The lack of cerium ion in PEM causes degradation from radical species. Information on cerium migration in PEM is necessary to design the membrane electrode assembly (MEA) for long-term operation. Although the observation of cerium ion diffusion with in-plane direction of PEM has been reported [5], it is difficult to detect the distribution in through-plane of MEA under fuel cell operating condition due to the quite narrow thickness of PEM. This study reports an operando X-ray fluorescence analysis technique to detect cerium distribution in through-plane direction of MEA using high-energy X-ray nanobeam.

MEAs were prepared by a conventional method using Pt/C catalyst and polymer electrolyte with the thickness of 12 mm. The active electrode area was 1 cm2. Single cells were assembled using custom-made end-plates that have an X-ray permeation window. Operando X-ray fluorescence spectroscopy measurements were performed at SPring-8, BL37XU (Japan). The monochromatized X-ray at an energy of 45 keV was focused to less than 200 nm by Kirkpatrick-Baez mirror. To detect the cerium distribution in MEA, Ce-Ka fluorescence intensity was counted using a Ge semiconductor detector with scanning the position of the cell. The cell temperature was 80 ℃. O2 and H2 gases with relative humidity of 100% were flew to cathode and anode, respectively.

Figure 1 shows line-scan profile of Ce-Kα fluorescence X-ray intensity from the as-prepared MEA. The x-axis represents the through-plain position, where the positive and negative sides corresponds to cathode and anode sides, respectively. The two peaks are observed at 678 and 685 mm and the peak width is approximately 13 mm. This peak shows PEM containing cerium ion. During the fuel cell operation, the line-scan is repeated and cerium ion distribution can be analyzed.

Acknowledgment

Part of this work is based on results obtained from the project commissioned by the New Energy and Industrial Technology Development Organization (NEDO) of Japan.

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Figure 1