bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unravelling the Influence of Oxygen on the Degradation Mechanisms of Fe-N-C Oxygen Reduction Reaction Catalysts
Authors: Kumar Kavita , Asset Tristan , Atanassov Plamen , Jaouen Frederic , Dubau Laetitia , Maillard Frederic 
Published: July 2022

Pyrolyzed iron-nitrogen-carbon materials (Fe-N-C) comprising mostly atomic Fe-Nx moieties are the most mature class of noble metal free catalysts for the oxygen reduction reaction (ORR) in acidic media. Such catalysts show excellent performance in proton exchange membrane fuel cell (PEMFC), approaching that of platinum-based catalysts. [1] However, an important performance loss is observed during operation, in conditions mimicking those of a PEMFC. [2] To shed fundamental light onto the degradation mechanisms at stake, two different Fe-N-C materials were prepared, one using a metal organic framework (MOF) and the other a sacrificial support method (SSM), and are labelled Fe-N-C_MOF and Fe-N-C_SSM, respectively. These materials were characterized before and after two different accelerated stress tests (ASTs: 10 k cycles, 0.6-1.0 V vs. RHE, 3s-3s, 0.1 M H2SO4, 80°C) under Ar or O2 atmosphere. Stronger degradation and higher ORR mass activity loss were observed when the AST is performed in O2
vs. Ar-saturated acidic electrolyte. For AST under Ar condition, physicochemical characterisations revealed a demetallation process and the eventual occurrence of a clustering mechanism whereas for AST performed in O2 atmosphere, a decrease of the Fe content and the formation of Fe oxide particles was observed (Figure 1).
Keywords: Electrocatalysis, Fe-N-C, Oxygen Reduction Reaction, Durability, PEMFC

Acknowledgements

These studies were financed by the French National Research Agency in the frame of the CAT2CAT (grant number n°ANR-16-CE05-0007) and the ANIMA (grant number n°ANR-19-CE05-0039) projects. References
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2011, 2, 416.
[2] Y. Shao, J. P. Dodelet, G. Wu, P. Zelenay, Adv.
Mater.
2019, 21, 1807615.
[3] K. Kumar, T. Asset, X. Li, Y. Liu, X. Yan, Y. Chen, M. Mermoux, X. Pan, P. Atanassov, F. Maillard, L. Dubau, ACS Catal.
2021, 11, 484-494.
[4] K. Kumar, P. Gairola, M. Lions, N. Ranjbar-Sahraie, M. Mermoux, L. Dubau, A. Zitolo, F. Jaouen, F. Maillard, ACS Catal.
2018, 8, 11264-11276.
[5] K. Kumar, L. Dubau, M. Mermoux, J. Li, A. Zitolo, J. Nelayah, F. Jaouen, F. Maillard, Angew.
Chem.
2020, 132, 3261-3269.

Figure 1
Nanometric Amorphous TiO2 As an Extrinsic Pseudo-Capacitive Electrode for All-Solid-State Asymmetric Hybrid Micro-Supercapacitors: Effects on the Electrochemical Performance
Authors: Sallaz Valentin , Poulet Sylvain , Rouchou Jouhaiz , Boissel Jean-Marc , Chevalier Isabelle , Secouard Christophe , Bedjaoui Messaoud , Voiron Frederic , Lamy Yann , Oukassi Sami 
Published: July 2022

On-chip solid-state micro-supercapacitors (MSCs) have gained widespread attention owing to their versatile benefits, including high power density and long cycle life1,2. Recently asymmetric hybrid microsupercapacitors (AsHMSCs) introducing a charge storage mechanism based on both faradaic reaction and electric double-layer phenomena have been considered to increase the energy density. Within this context, the selection of electrode materials and their interaction at the interface with the electrolyte is a key issue to optimize the AsHMSC electrochemical performance.
In this work, nanometric (5-20 nm thick) amorphous TiO2 films have been elaborated and characterized in liquid and solid-state electrolyte (LiPON) half-cell configurations. Interestingly, TiO2 films after LiPON deposition exhibited a constant initial amount of intercalated lithium ions for all considered thicknesses and did not require a first activation process, in comparison to the liquid electrolyte configuration. For all considered configurations, the specific capacity extracted from cyclic voltammetry and galvanostatic cycling within [0.5-3V] potential range correspond to the theoretical value expected for the Lix=1TiO2 phase at low current density. Furthermore, the cooperative effects of high Li ion intercalation kinetics and Low interfacial charge transfer resistance for 5nm TiO2 electrode (extracted from electrochemical impedance spectroscopy analysis) exhibit an outstanding specific capacity of 2mC.cm-2 at 1µA.cm-2, and high rate performance with 60% capacity holding ratio at 100µA.cm-2, thus highlighting the extrinsic pseudo-capacitive behavior of the sub 10nm electrodes.
A TiO2 5nm/LiPON 100nm/Pt AsHMSC is successfully fabricated, which achieves an operating voltage window of 3V and a specific capacity of 0.3mC.cm-2 at 1mA.cm-2.In addition, the device also exhibited a 100% coulombic efficiency even after cycling for 6000 continuous charge-discharge cycles. This work offers an approach to tune the Li ion storage properties of TiO2 by nano-engineering and gives insights into the enhancement of pseudocapacitance-assisted lithium-storage capacity.
References

Kyeremateng et al., Nature Nanotech 12, 7–15 (2017). https://doi.org/10.1038/nnano.2016.196

Sallaz et al., J. Power Sources 451, 227786 (2020), doi: 10.1016/j.jpowsour.2020.227786.

Figure 1
Impact of Flushing Agents in Broadband Dielectric Spectroscopy (BDS) Study of Ethanol Detection By HKUST-1 Metal-Organic Frameworks
Authors: Amoah Papa K. , Redel Engelbert , Baumgart Helmut , Obeng Yaw 
Published: July 2022

Traditional volatile organic compounds (VOC) detection with metal semiconductor oxide (MOS) sensing elements depends on chemical resistivity measurements which require electrical contact to the sensing materials [1]. These measurement contacts / probes are inadequate because they tend to introduce parasitic electrical errors which result in misleading reported resistivity values [2]. On the other hand, contactless broadband dielectric spectroscopy (BDS) is a potential alternative metrology [3]. In this paper, we will demonstrate that by using contactless broadband dielectric spectroscopy (BDS)-based metrology, in combination with a metal-organic framework (HKUST-1 SMOF) sensing element, we can avoid distortions in the reported resistivity values in gas monitoring, as well as develop new and unique mechanistic insights into the VOC detection. Specifically, we show that the experimental ambient influences the detection mechanism. The microwave insertion loss data (S21) shows that we lose resolution when N2 was used as the flushing agent, as compared to air, during the measurements. This suggests a possible competition between the ethanol and the N2 for the unsaturated copper centers inside the MOF. Therefore, we opted to use air as a flushing agent in the subsequent experiments. Additionally, the use of BDS enables stable VOC sensing in air at temperatures below 100 °C, which are well below the 200-300C normally used for VOC detection [1, 2].
1) Huaping Wang et al 2021 J. Phys.: Condens. Matter 33 303001
2) Chem. Soc. Rev., 2020,49, 6364-6401, https://doi.org/10.1039/C9CS00778D
3) Papa K Amoah et al 2021 J. Phys. D: Appl. Phys. 54 135104
(Invited) Flock -Flare Clock: Passive Sweat-Based Eczematous Flare Detection System
Authors: Prasad Shalini 
Published: July 2022

Point-of-need platforms that work with sweat offer the advantage of self-monitoring for chronic diseases. Sweat based platform offer benefits in areas like comfort, functionality, and provide real time analysis of biomarker fluctuations in the body. For chronic conditions like Atopic Dermatitis, evaluating the severity of the disease on a case-by-case basis can help with providing an effective treatment plan. Sweat contains biomarkers like interleukin-31 and cortisol, which are biomarkers for atopic dermatitis (AD) and circadian disruption that is associated with the itching symptom of the disease. This portable detection technology is aimed at bridging the gap between assessing the severity of the disease and providing a patient-centric treatment plan. The research is envisioned to work as a wearable that can predict flares based on the biomarker levels and help with management of severe cases of AD, especially in pediatric populations.
FLOCK (flare clock) system is a novel platform that comprises of a nanoporous membrane based multilayer stack that works with passively secreted sweat. It is designed to capture eczema severity and circadian disruption caused due to its symptoms. This is aimed to be a wearable designed for efficient management of the flaring associated with Atopic Dermatitis (AD). The work presents the development of an eczematous flare tracker that detects IL-31 and cortisol levels to create an AD management platform. The platform uses electrochemical detection for tracking these biomarkers in sweat. It is sensitive to IL-31 levels in various flare-based formulations tested through simulated sweating with a detection limit of 50 pg/mL and range 50-1000 pg/mL. On-body study highlights the ability of the wearable platform to track the rise and fall in the biomarkers’ levels. These levels are well correlated to salivary levels and commercial gold standard techniques (r>0.8, R2 >0.95).
(Invited) Development of New Strategies for Bringing Photoelectrochemical Biosensing to the Point-of-Need
Authors: Soleymani Leyla , Saha Sudip , Victorious Amanda , Sakib Sadman , Zhitomirsky Igor 
Published: July 2022

Photoelectrochemistry combines light excitation with electrochemical readout for lowering the bias voltage needed for performing electrochemical reactions. As a result, when used in biosensing, photoelectrochemical signal readout reduces the background signals, lowering the limit-of-detection of such biosensors. To enable photoelectrochemical (PEC) signal readout to be applied to point-of-need biosensing, we have taken a three tiered approach focused on improving the understanding of signal transduction in PEC Biosensing, developing label-free assays, and creating handheld readout platforms.
In this work, we developed a system using DNA as a nano-ruler to control the distance between plasmonic nanoparticles and PEC electrodes. This system was used to rationally-design PEC material systems for signal-on biosensing. Using this materials architecture, we developed a signal-on biosensor without target labeling for detecting DNA hybridization. This assay uses sequential DNA hybridization to generate a PEC signal. First, the DNA target is captured on probe-modified photoelectrodes. This is followed by hybridization of the unbound probes with DNA strands modified with plasmonic labels. The plasmonic label modulates the PEC signal, increasing the measured PEC current at low target concentrations. To enable biosensing at the point-of-need, we also developed a handheld PEC reader. The integration of plasmonic nanoparticles with PEC electrodes, label-free DNA assays, and handheld PEC readout paves the way toward bringing point-of-need PEC Biosensing.
Robust Cycling of Ultrathin Li-Metal Enabled By Nitrate-Preplanted Li Powder Electrode
Authors: Jin Dahee , Roh Youngjoon , Ryou Myung-Hyun , Lee Hongkyung , Lee Yong Min 
Published: July 2022

The Li metal anode has been spotlighted for large-scale battery systems such as electric vehicles (EVs) and energy storage systems (ESSs) because of its high theoretical energy density and lowest potential. However, the Li metal anode still has the several challenging issues like Li dendrite growth and many side reactions. Our strategy to this problem is to utilize Li metal powder (LMP), which has superior advantages in reducing local current and utilizing slurry-based coating process for wide-width electrodes. Nevertheless, the spherical shape of LMP with the imperfect protection layer can be lost during the long-term cycling, which leads to dead particles formation and ununiform Li distribution.
In this work, we present a LMP electrode having pre-planted nitrates (LN-LMP). The LiNO3 additive in the LMP electrode can chemically replace the native layer with the uniform Li3N-rich passivation layer on the surface during the simple slurry mixing process. Furthermore, residual LiNO3 was continuously released toward electrolyte, thereby repairing the SEI during cycling. As a result, the 20 µm‐thick LN‐LMP electrodes exhibited the robust cycling performances compared to control cells with conventional LMPs and LiNO3‐containing electrolytes.
3D Modeling on Diffusion-Dependent Graphite-Silicon Electrode for All-Solid-State Batteries
Authors: Jung Seungwon , Kim Ju Young , Park Joonam , Song Jihun , Lee Yong Min 
Published: July 2022

The novel electrode design, which is a diffusion-dependent electrode structure composed only of active materials, can theoretically realize high energy density. The diffusion-dependent electrode structure can transport lithium ions in the entire electrode through lithium-ion diffusion between the active material particles unless the connectivity between the active material particles is cut off. However, since the electrode structure transfers ions through diffusion, if the thickness of the electrode is too thick, there is a possibility that the performance may have deteriorated. For this purpose, by using not only graphite but also silicon particles, it is possible to have a thin electrode structure compared to the same capacity.
In this study, graphite-silicon diffusion-dependent electrode according to the silicon particle size is formed into a digital three-dimensional electrode structure and based on this, electrochemical simulation and analysis of an all-solid-state battery having a diffusion-dependent electrode are performed. The importance and cause of the size of silicon particles in the graphite-silicon diffusion-dependent electrode will be investigated.
Reference

Diffusion-dependent graphite electrode for all-solid-state batteries with extremely high energy density,
ACS Energy Letters
, 5(9) (2020) 2995-3004

Revisiting TiS2 as a diffusion-dependent cathode with promising energy density for all-solid-state lithium secondary batteries,
Energy Storage Materials
, 41 (2021) 289-296
A Low-Cost and Green Si-Based Anode Material for Lithium-Ion Batteries
Authors: Heitz Alexandre , Vanpeene Victor , Herkendaal Natalie , Soucy Patrick , Douillard Thierry , Roué Lionel 
Published: July 2022

The conception of cheaper and greener electrode materials is critical for Li-ion battery manufacturers. In this study, it is shown that a by-product of the carbothermic reduction of SiO2 to Si, containing Si, SiC and C materials, can be valorized as a low-cost and high-capacity anode material for Li-ion batteries after an appropriate high-energy ball milling treatment. The latter results in the production of a micrometric powder (D50 ~1 mm) in which submicrometric SiC inclusions are embedded in a nanocrystalline/amorphous Si matrix. Such a microstructure prevents the deleterious formation of c-Li15Si4 phase, which is well known to accentuate particle cracking. As a result, the electrode is able to maintain a capacity >1000 mAh g-1 (>3 mAh cm-2) over 100 cycles. Moreover, calendering has no negative impact on the electrode performance. However, a significant and irreversible increase of the electrode mass and thickness was observed over cycling, which is mainly attributed to the accumulation of SEI products.
In order to have deeper insights into the microstructural evolution of the electrode during cycling, a focused ion beam (FIB) milled microcavity (45×20×50 µm3) was created in the center of the pristine electrode. This cavity was observed by SEM at different cycling periods of a single electrode (Fig. 1a). This investigation method allows following the same electrode along different steps of its cycling, nearly as for an in-situ method. Additionally, backscattered-electron (BSE) imaging was performed on broad ion beam (BIB) polished cross-section of the electrode after different periods of cycling (Fig. 1b). The morphological change is characterized at the electrode and particle scales by monitoring the thickness, mass, porosity and macrocracking of the electrode, SEI layer thickness and particle morphology. On the basis of these investigations, a more comprehensive view of the degradation phenomena of the electrode is established.

Figure 1
A Novel Electrochemical Method to Extract Lithium from Aqueous Solutions
Authors: Brabson Logan , Huang Po-Wei , Filippas Alexandros , Liu Nian 
Published: July 2022

Increasing demand for lithium has been largely spurred by the rapid growth of lithium-ion batteries, most notably in electric vehicles. The need for lithium will continue to increase as demand for safe, reliable, and sustainable energy grows. Global lithium production more than tripled between 1995 and 2008 to nearly 140,000 tons, and lithium demand is projected to reach as high as 1.6 million tons by 2030 with the rise of electric vehicles. Unfortunately, the global land-based lithium supply is maldistributed. A scalable electrochemical route to lithium extraction from brines and seawater is investigated. The oceans represent a nearly infinite lithium supply, containing approximately 230 billion tons of lithium compared to just 14 million tons on land, albeit at very low concentrations of approximately 0.17 ppm.
A four-step electrochemical lithium extraction method is presented. The working lithium iron phosphate (LFP) electrode is first inserted into the lithium-containing brine or seawater, and a negative current is applied to the system. During discharge, lithium ions intercalate into the working electrode. Next, the electrode is placed in a recovery solution, and the system is charged to release the lithium on the electrode surface. The lithium-free working electrode is then reused in another cycle. Once a substantial lithium concentration is achieved in the recovery solution following several cycles, soda ash is added to precipitate the lithium ions as lithium carbonate, the working form of lithium in many battery applications. The working electrode is surface treated with a lithium-selective polymer (LSP) coating to exclude larger, more concentrated metal ions such as sodium from intercalating to the electrode surface. This work explores the effectiveness of crown ethers such as Dibenzyl-14-crown-4 as LSPs.
The combination of our electrochemical extraction process and a focus on enhancing selectivity shortens the lithium production time from years to days and presents a promising image for the future of lithium mining. The ability to extract lithium from the oceans with nominal energy requirements and environmental impacts could revolutionize the lithium mining and battery industries.
Single Crystal Copper and Gold Alloys for the Plasmonically Enhanced CO2 Reduction Reaction
Authors: Adserias Albert , Leach Gary W. 
Published: July 2022

Chemical fixation of carbon dioxide (CO2) into chemical fuels has raised a lot of interest due to its role in removing greenhouse gasses from the atmosphere to store them as a potential source of energy. CO2 removal techniques have been widely studied and are of great interest because they can be used synergistically as a low-cost source of carbon to supplement and support the existing chemical synthesis of feedstocks and hydrocarbon fuels. One of the most common approaches to the remediation of atmospheric CO2 is the electrochemical reduction of CO2. We have been studying the formation of copper (Cu) films and its alloys with gold (Au). Metal alloys have been shown to exhibit interesting properties to enhance chemical processes beyond those of their individual components, improving the applications in the plasmonic and catalysis fields.
Cu and Au are both excellent plasmonic and catalytic materials that show tunable optical properties, strong absorptions in the visible and near infrared, and catalytic activity. However, the applications of Cu materials alone are limited due to Cu’s chemical instability and tendency to oxidation, which inhibits their plasmonic properties and reduces their catalytic performance. By alloying Cu with Au, we have overcome copper’s chemical instability and improved the catalytic properties due to synergistic effects.
As a result of our studies, we have also developed a method to deposit Cu2O single crystal film, a material that exhibits semiconductor properties and opens a new line of opportunities for plasmonic applications. In this poster, we will show an overview of our results and discuss the potential applications to plasmonic electrocatalysis and sensors.
Electrokinetic Preconcentration and Label-Free Electrical Detection of Sars-Cov-2 RNA at a Packed Bed of Bioconjugated Microspheres
Authors: Claus Echo LeeAnn , Strait Madison , Anand Robbyn Kimberly 
Published: July 2022

In diagnostics, point-of-care (POC) devices, such as lateral flow assays, play an important role due to their ease of use, practical application, and fast response. However, one of the major limitations of POC devices is low sensitivity. To address this limitation, electrokinetic techniques have been utilized to enrich the target analyte prior to detection. In one such technique, ion concentration polarization (ICP), an ion depleted zone (IDZ) is formed near an ion permselective membrane or electrode following the application of an external electric field. The low conductivity of the IDZ supports the formation of an extended electric field gradient. Enrichment arises from focusing of a charged analyte along this electric field gradient in the presence of opposing fluid flow. ICP focusing is a reliable technique for the enrichment and mobility-based separation of charged species, such as DNA, RNA, or proteins. However, ICP focusing is negatively impacted by electroconvective vortices that drive unwanted mixing.
We utilize an out-of-plane faradaic ion concentration polarization (fICP) technique that employs a 3D porous electrode and an adjacent packed bed of insulating microbeads to improve the stability of the enriched plug. In this work, we exhibit the detection of SARS-CoV-2 RNA, extracted from lysed virus, at subpicomolar concentrations in this microfluidic device. Here, the insulating beads are bioconjugated with an uncharged peptide nucleic acid (PNA) oligoprobe that hybridizes with the target RNA. The resulting increase in negative charge on the bead surface leads to a shift in a current-voltage curve between the 3D electrode and a driving electrode at the microchannel inlet. This shift in conductivity serves as a non-optical sensing mechanism for detection of the hybridized SARS-CoV-2 RNA. Most notably, this enrichment and sensing scheme utilizes off-the-shelf streptavidin-modified beads, making it highly versatile, while the reagent-free approach and low driving voltage render it amenable to POC implementation.
This work is supported by a grant from the Roy J. Carver Charitable Trust.