bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of Plasma-Nitrided Barrier Layers Against Hydrogen Absorption and Diffusion in Pure Iron
Authors: Sugawara Yu , Kudo Tomohiro
Published: February 2024

Hydrogen embrittlement is a serious problem for steels such as high strength steels. Reducing hydrogen absorption into steels is required for the prevention of hydrogen embrittlement. In order to improve the hydrogen absorption resistance into steels, a nitriding treatment is one of the effective ways among surface modifications because nitriding may increase the overpotential for the hydrogen evolution reaction on the surface and decrease hydrogen diffusivity in nitrided layers. In this study, the phase structure in the nitrogen compound layers for the pure iron specimens was controlled by plasma nitriding with different types of plasma gas and gas composition. The influence of ε-Fe2-3N and γ’-Fe4N phases on hydrogen absorption into the inside of the pure iron matrix through the nitrided layers was evaluated. During the hydrogen permeation tests, the plasma-nitrided specimens showed small permeation current values compared to the as-polished specimen when it reached the steady state. Especially, hydrogen absorption and permeation for the specimen with the compound layer containing ε-Fe2-3N were extremely inhibited. Hydrogen absorption and permeation behaviors in the nitrided pure iron specimens were discussed in terms of the catalytic activity and hydrogen diffusivity.
Core/Shell Cu-TiO2 Nanoparticles As Efficient Anode Material for Li-Ion Capacitors
Authors: Abbasi Rabail Badar , Magdziarz Agnieszka , Koposov Alexey
Published: February 2024

Lithium-ion capacitor (LIC) belongs to a specific category of energy storage materials [1]. It is a combination of an electrode from a lithium-ion battery (LIB) with an electrode from an electrical double layer capacitor (EDLC). A usage of these two electrodes in one system results in formation of a hybrid energy device which can exhibit desired properties, such as: charge/discharge rapid capability, long cycle life and high energy density. However, the widescale usage of LICs is still limited due to the inherent low concentration of Li-ions in this system [2]. Typically, to improve it, an electrode needs to be pre-lithiated. There are many pre-lithiation methods that have been developed and implemented, but with varying level of success [3]. Therefore, the most optimal solution is to remove completely the need of pre-lithiation. In this work, we propose an approach which eliminates the requirement of pre-lithiation by designing a core-shell structure for the anodic active material. Herein, the shell is the material responsible for electrochemical activity and the core facilitates electronic conductivity.

Titanium dioxide (α-TiO2), a well-researched anode material, was used as the shell, while copper (Cu), a highly conductive metal, was used as a core. Cu@TiO2 core-shell structures were synthesized by a wet-chemistry approach. The microscopic studies of chemical composition and morphology confirmed that the formation of TiO2 on the surface of copper was successful. Electrochemical measurements in the half cell of the electrode with Cu@TiO2 as the active material showed a specific capacity of around 156 mAh g-1. Next, the Cu@TiO2 anode was tested in a LIC against cathode with activated carbon as the active material. The resulting LIC showed showed high specific capacity and stable cycling behavior up to a 1000 cycles at 2.5 A g-1, with a coulombic efficiency of around 98%. Rate capability tests also showed relatively high stability of the anode material at low to high current rates.

The results of this work open up potential avenues for further research focused on designing anode structures for LICs. The core-shell structure with Cu as the core and α-TiO2 as the shell has been demonstrated to enhance the stability of the capacitor and remove the need for pre-lithiation. The combination of low-cost and environmentally friendly materials for anode, and ease of LIC assembly, makes this a promising material for LICs.

[1] Amatucci, G.G.; Badway, F.; du Pasquier, A.; Zheng, T. An Asymmetric Hybrid Nonaqueous Energy Storage Cell. J. Electrochem. Soc. 2001, 148, A930

[2] Wang, H.; Zhu, C.; Chao, D.; Yan, Q.; Fan, H.J. Nonaqueous hybrid lithium-ion and sodium-ion capacitors. Adv. Mater. 2017, 29, 1702093

[3] Holtstiege, F.; Bärmann, P.; Nölle, R.; Winter, M.; Placke, T. Pre-Lithiation Strategies for Rechargeable Energy Storage Technologies: Concepts, Promises and Challenges. Batteries 2018, 4, 4
Designing Bifunctional Oxygen Electrocatalysts Using Prussian Blue Analogue and Carbon Nanostructure Hybrids: Understanding the Role of Individual Components for Oxygen Reduction and Evolution Reactions
Authors: Jain Priya , Ingole Pravin P
Published: February 2024

The incorporation and identification of active sites for OER and ORR is required for designing an efficient bifunctional oxygen electrocatalyst for low cost and high activity of electrochemical devices such as metal air batteries and regenerative fuel cells. In this work, we synthesized CoHCF/GO/f-CNT nanocomposite which showed excellent bi-functional activity with a low overvoltage of 0.8 V between the oxygen evolution reaction (E10 mA/cm
2) and the oxygen reduction reaction (E1/2). The specific functions of CoHCF and GO/f-CNT were described using hydrodynamic voltammetry measurements. For comparison, the pristine CoHCF and the composites with multiwalled carbon nanotubes (CoHCF/f-CNT) and graphene oxide (CoHCF/GO) were also synthesized and thoroughly characterised for physico-chemical and electrochemical properties. It was observed that CoHCF itself had poor ORR activity which increased on addition of GO/f-CNT. Electrochemical analysis suggested that CoHCF is primarily responsible for the OER activity in nanocomposites. The carbon nanostructure, due to strong metal support interactions (SMSI) and electrical conductivity helped in maximising the utilization of PBA active sites on the surface along with acting like a co-catalyst for ORR. The nanoscale geometries of the PBA and GO/CNT further enhanced the metal support and charge transfer interactions, thereby enhancing the activity. The findings of this study provide an insight for developing more effective PBA based nanocomposites for bifunctional OER/ORR electrocatalysis.
Monitoring Atmospheric Corrosion of Carbon Steel Under Controlled Electrolyte Droplet Distributions
Authors: Zhang Keer , Rahimi Ehsan , Van Den Steen Nils , Terryn Herman , Mol J.M.C. , Gonzalez-Garcia Yaiza
Published: February 2024

Field exposure testing and accelerated corrosion testing are two common approaches applied in the industry to assess the atmospheric corrosion rate of a specific material, both relying on visual inspection and weight change of the specimen. Field exposure testing occurs under natural atmospheric conditions but requires exposure times spanning decades, whereas accelerated corrosion testing shortens the exposure time to weeks; however, the connection between the natural environment and accelerated corrosion chamber conditions remains unresolved. Efforts have been made to correlate accelerated corrosion results with those obtained in field exposure based on weight loss, both qualitatively and quantitatively, primarily empirically and limited to small datasets.

This work examines the link between modified field exposure testing and the environment from the electrolyte perspective, under controlled laboratory conditions. In-situ monitoring and analysis of corrosion rate, electrolyte condition, and environment are demonstrated to be feasible, and the effect of NaCl concentration and droplet distribution on the atmospheric corrosion rate of carbon steel has been addressed.

This work proposes a setup wherein multiple droplet-based conditions are created, and corrosion kinetics are actively monitored using the electrical resistance method. The sample surface is simultaneously monitored with an optical microscope, through which both droplet distribution evolution and corrosion product formation can be visualized.
Corrosion Electrochemistry at Micro/Nano-Scale
Authors: Choudhary Sanjay , Kelly Robert G
Published: February 2024

A fundamental understanding of corrosion mechanisms is the key to developing suitable corrosion protection approaches for metallic structures and new corrosion resistant alloys for emerging technologies. However, corrosion testing methods such as mass loss and conventional electrochemical testing average over large areas and thus often mask the underlying mechanisms, due to either low sensitivity, low resolution, and/or a lack of element-resolved information. Recent advances in electron microscopy have led to development of liquid-cell transmission electron microscopy (LC-TEM) that allows in-situ monitoring of morphological and even compositional evolution in materials at high spatial resolution during interactions of surfaces with aqueous environments. However, electrochemical testing in such restricted volume with a very thin (~ 500 nm) electrolyte layer places stringent demands not only for a reference electrode, but also for a comprehensive understanding of the factors affecting electrochemical kinetics at the nano-scale1.

In order to solve the need for a micro-reference electrode, we recently proposed the concept of metallic Luggin-Haber probe2. The metallic Luggin-Haber probe is a metal wire that serves as a bridge between the test solution and the reference electrode that was in a physically-distinct container. In standard-scale electrochemical cells, it was found that the metal bridge (MB) provides a means of making potential measurements that are identical to those made using a direct reference electrode or using a salt bridge.

The MB is shown to be compatible with a wide range of electrochemical techniques including cyclic potentiodynamic polarization and electrochemical impedance spectroscopy. The present work explores the compatibility of the MB for electrochemistry in LC-TEM using Pt as working electrode. The work includes the effect of radiolysis of electrolyte, electrolyte flow rate, pH and potential scan rate on electrochemical kinetics when using LC-TEM, in a detailed comparison with results obtained using a standard-scale electrochemical cell. Present work is a discrete effort towards developing advanced methodologies for electrochemical measurement in situations involving restricted electrolyte volume including thin electrolyte layers, droplets, localized corrosion sites, batteries and fuel cells.

References

A. Kosari, H. Zandbergen, F. Tichelaar, P. Visser, H. Terryn, and A. Mol, Corrosion, 76, 4–17 (2020).

S. Choudhary, K. Marusak, T. Eldred, and R. G. Kelly, J. Electrochem. Soc., 169, 111505 (2022).
(Best Poster Award - 3rd Place) Development of Bipolar All-Solid-State Lithium-Ion Cell
Authors: Murat Yolande , Salomon Jérémie , Reynier Yvan , Brändel Timo , Giffin Guinevere A. , Mailley Sophie , Chavillon Benoit , Yildirim Gunay
Published: February 2024

For large-scale electricity storage applications such as automotive and stationary energy storage, the battery system requires a high voltage and energy density, which can be achieved by bipolar architectures. In conventional batteries, the cells are assembled in series. The amount of current collector and packaging substances (case, wires) increases the battery weight, reducing its energy density, and complicates the manufacturing. The switch to bipolar technology simplifies the cell architecture. The cathode and anode material layers are separately coated on both sides on a same current collector. This gives to the creation of electrolyte-separated units. External connectors are no longer necessary as the electron transfer between the two electrodes is through the current collector. As a result, the ohmic resistance is reduced and less heat is generated. The bipolar architecture leads to a simple and compact design for a high specific energy and a high-voltage and current output for a high specific power.

Over the 15 past years, CEA developed an expertise on bipolar lithium-ion batteries1. However, the development of bipolar cells with liquid electrolyte has been rather limited in industrial applications due to electrolyte leakage: it is imperative to avoid liquid junction and to prevent the ion flow between each adjacent unit. The use of solid- electrolyte appears as the optimal solution and simplifies the manufacturing process and reduces cost2.

Astrabat project focused on all-solid-state lithium-ion batteries and the development of two tailored polymer electrolytes. These results are transferred and adapted to a bipolar architecture, composed of two units. The silicon anode and Ni-rich NMC cathodes are coated on an Al/Cu clad, serving as a current collector. This work will report the fabrication process and the electrochemical performances of the two-units bipolar architecture.

1M. Chami, S. Mailley, Y. Reynier, F. Masse, S. Martinet and F. Fusalba, World Electric Vehicle Journal Vol. 3 - ISSN 2032-6653

2 H.-S. Shin, W.-G. Ryu, M.-S. Park, K.-N. Jung, H. Kim and J.-W. Lee, ChemSusChem 2018, 11, 3184 – 3190

Figure 1
(Invited) Plasma-Synthesized Coupled Nanoplasmonic Gold for DNA Sersing
Authors: Shvalya Vasyl , Modic Martina , Zavašnik Janez , Rozman Damjana , Abdulhalim Ibrahim , Cvelbar Uros
Published: February 2024

The facilitated electrochemical properties of plasma play a critical role in enhancing the synthesis and design of functional nanomaterials for the development of novel sensors. The targeted challenge is to customize and tailor functionality at multiple scales to improve detection device performance. In the realm of optoelectronics, plasmonic sensing is considered an efficient tool for investigating molecular properties, often accompanied by Raman, FTIR or Fluorescent spectroscopy. Specifically, Raman scattering, also known as SERS (surface-enhanced Raman scattering), is commonly used to probe analytes at a reduced scale using plasmonic enhancers. This technique is especially useful for rapidly and accurately investigating biologically relevant samples, such as DNA and RNA. DNA/RNA-related investigations are crucial in modern nanomedicine due to the progress made in bionanotechnology, DNA vaccines, and functional gene engineering. DNA, in particular, is highly valued by microbiologists because it contains information about the nature of bio-species. Currently, PCR-related methods dominate the field for molecular-sensitive DNA-level studies, but it is challenging to investigate using optical techniques like SERS. Despite its promise, SERS still requires technological and analytical improvements. A sophisticated plasmonic nanomaterial provides considerably improved photon scattering due to the strongly localized field confinement effect, resulting in better performance. In this report, a nanoplasmonic sensor was designed using a plasma-driven electrochemical reduction mechanism, achieved through an atmospheric pressure He-plasma jet setup operating at kHz frequency. The reactive oxidative species donated electrons via liquid-gas electrochemistry towards the Ar-delivered Au(3+)-containing microdroplets, resulting in microscaled aggregates composed of AuNPs obtained from the nebulized ionic gold liquid precursor. Due to the strong coupling between nanoparticles, a high analytical enhancement factor of about 107 was achieved, and the substrate enabled obtaining Raman fingerprints of bacterial DNA fragments (M. luteus and S. aureus, E. coli, J. lividum) at nanovolume sample quantities. Additionally, the main DNA molecular vibrational signatures associated with nucleobase motions were extracted from the collected spectra and used to reliably classify bacterial strains using statistical principal component analysis.[1]

References

[1] Shvalya, V., Vasudevan, A., Modic, M., Abutoama, M., Skubic, C., Nadižar, N., ... & Cvelbar, U. (2022). Bacterial DNA Recognition by SERS Active Plasma-Coupled Nanogold. Nano Letters.
Phase Controlled Synthesis and Characterization of Large Area 2D Tin Sulfides
Authors: Glauber Jean-Pierre , Zanders David , Wree Jan-Lucas , Devi Anjana
Published: February 2024

Motivated by the increasing need to shift the energy sector from fossil fuels towards renewables, two-dimensional (2D) layered material systems have been explored as potential candidates for energy harvesting and storage applications.[1] In particular, 2D tin sulfides (SnS and SnS2) have emerged as promising candidate materials for photovoltaic and battery applications due to their high earth abundance and non-toxic nature.[2,3] The dual valency of tin and the numerous oxidation states of sulfur can result in three thermodynamically stable polymorphic phases namely SnS, SnS2 and Sn2S3. Thus, phase-controlled synthesis of SnSx materials can be challenging. A detailed investigation of material properties of SnSx is essential to correlate the structure property relationship. Gas phase synthesis such as chemical vapor deposition (CVD) enables the tuning of material phase by choosing suitable precursor chemistries, substrates as well as varying the process parameters such as temperature and pressure. In this study we have developed a new CVD process for the synthesis of SnSx thin films on Si and mica substrates using a combination of a metalorganic precursor for tin and elemental sulfur under mild process conditions. Complementary thin film analysis using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), Rutherford backscattering spectrometry (RBS), nuclear reaction analysis (NRA) and X-ray photoelectron spectroscopy (XPS) were performed. While XRD and Raman revealed the fabrication of phase pure crystalline SnS2 on both Si(100) and mica, XPS indicated inclusion of SnS species that couldn’t be identified unambiguously via XRD (Figure 1). A band gap of 2.2 eV estimated via UV-Vis spectroscopy further confirms the deposition of phase pure crystalline SnS2 layers. These new findings are very promising and pave a way to grow large area and phase controlled SnSx layers that can be suitable for potential functional applications such as batteries, photovoltaics, sensors etc.

Figure 1
The Effect of Junction Composition of Polarization Behaviour of Bipolar Membranes
Authors: Kao Yi-Lin , Aili David
Published: February 2024

Bipolar membranes (BPMs), i.e, laminates cationic and anionic polymer membranes, have a wide range of applications. Starting from an early application in electrodialysis systems, the application scope has more recently broaden to electrochemical energy conversion systems such as water electrolyzer and CO2 reduction reaction, fuel cells and flow batteries.1 In connection to CO2 reduction reaction, the implementation of BPM effectively mitigates CO2 crossover driven by (bi)carbonate migrations, but the rate capability is limited by the large overpotential across current state-of-the-art BPMs.2 The large overpotential primarily originates from the slow water dissociation (WD) kinetics at the interface between the cation exchange layer (CEL) and anion exchange layer (AEL), and largely depends on junction morphology. The detailed structure-properties relationships remain poorly understood, but physical properties of individual polymeric membranes and the composition and morphology of the WD catalyst are important parameters and the optimal combination of materials may be different for different systems. Furthermore, the WD performance of BPM in MEA water electrolyzer not only depends on BPM’s junction contact, but also the interface contact between electrodes and CEL/AEL.

In this work, a series of BPM system featuring different compositions of membrane layers and WD catalysts are explored and characterized by polarization behaviour (J-V curve) via H-cell and MEA water electrolyzer. We attempt to link the junction composition created by different BPM systems to its WD performance and provide a systematic choice of CEL/AEL and WD catalyst in the BPM system.

(1) Blommaert, M. A.; Aili, D.; Tufa, R. A.; Li, Q.; Smith, W. A.; Vermaas, D. A. Insights and Challenges for Applying Bipolar Membranes in Advanced Electrochemical Energy Systems. ACS Energy Lett.
2021, 2539–2548. https://doi.org/10.1021/acsenergylett.1c00618.

(2) Garg, S.; Giron Rodriguez, C. A.; Rufford, T. E.; Varcoe, J. R.; Seger, B. How Membrane Characteristics Influence the Performance of CO 2 and CO Electrolysis. Energy Environ. Sci.
2022. https://doi.org/10.1039/D2EE01818G.
(Invited, Digital Presentation) Overview of Current and Future 3D Heterogeneous Integration Architectures
Authors: Elsherbini Adel
Published: February 2024

High performance computing architectures such as high core count servers and AI accelerators have increasing demands on performance and energy efficiency. This requires power efficient and high bandwidth integration of multiple functions such as processing, memory and high speed circuits in a single package. Current trend is to separate these functions into chiplets with optimized technology then integrating them using advanced packaging technologies that target ease of integration, low overhead and maximum flexibility. In this talk, we will provide an overview of current and future 3D packaging technologies. We will start with solder silicon interposers which enable die stacking to support improved logic density/mm2 of package area and cover their design considerations and applications. Next, we will cover local silicon interconnect architectures which bridge the flexibility gap between 2.5D architectures and 3D interposer architectures. Afterwards, we will discuss the next generation architectures which are based on hybrid bonding. These architectures offer much higher interconnect density up to >100,000 connections/mm2 and enable new types of integration. Finally, we will discuss some future directions to continue to support performance and bandwidth scaling.
Investigation of CMP Process of Silica Substrate by Ceria Abrasive: Insights from Molecular Dynamics Simulation with Neural Network Potential
Authors: Ota Fukiko , Hirakawa Teruo , Antoku Nanami , Iikura Daisuke , Orita Akihiro , Okuno Yoshishige , Nomura Satoyuki
Published: February 2024

Chemical mechanical polishing (CMP) is a process of surface planarization by chemical and mechanical driving forces. CMP is expected to solve various problems, including the surface roughness on semiconductor devices. An aqueous slurry, including abrasive grains and chemical components, is used in the CMP process. Development of slurries with high polishing rate, excellent planarity, and superior processability is not only a key challenge, but also a significant opportunity for the future of our industry. In order to achieve the development, it is necessary to understand the detailed mechanism of CMP, which involves complex phenomena accompanied by interfacial chemical reactions and mechanical friction.

Computational scientific approaches, such as density functional theory (DFT) and molecular dynamics (MD) simulations, are powerful tools for understanding complex tribochemical phenomena at the atomic scale. However, these methods require much computation time and present difficulties for large-scale simulations. To overcome this limitation, a computational method called Neural Network Potential (NNP) is a powerful tool because it achieves a good balance between accuracy and computational efficiency by constructing potential energy surfaces based on a neural network-based method.

We performed NNP-MD simulations of the ceria/silica interface with the development of CMP slurry including ceria abrasive grains, which is typically used on the surfaces of silicon layered devices. As a result, we succeeded in observing polishing phenomena at the interface at the atomic scale, namely Ce-O-Si bond formation between ceria abrasive grains and silica substrate, hydrolysis reaction of Si-O bond, and associated mono-silica dissociation from the substrate. We also performed simulations of systems containing chemical compounds added to the slurry for the purpose of controlling the polishing rate and observed the role of additives on the CMP process. In this presentation, we will show simulation results and discuss the mechanism of CMP of silica substrates with ceria abrasive grains in terms of dependence on surface morphology at the atomic scale and the role of additives.

Reference

[1] Tran*, R., Lan*, J., Shuaibi*, M., Wood*, B., Goyal*, S., Das, A., Heras-Domingo, J., Kolluru, A., Rizvi, A., Shoghi, N., Sriram, A., Ulissi, Z., & Zitnick, C. (2022). The Open Catalyst 2022 (OC22) Dataset and Challenges for Oxide Electrocatalysis. arXiv preprint arXiv:2206.08917.
(Invited) Developing High-Energy All-Solid-State Batteries with Long Cycle Life
Authors: Yang Shuhao , Kim Se Young , Chen Guoying
Published: February 2024

While conventional lithium-ion batteries (LIBs) continue to gain progress through incremental improvements, the presence of organic liquid electrolytes brings about fundamental safety issues as their reactivity and flammability subject LIBs to thermal runaway. [1-4] With higher energy densities and better safety performances, all-solid-state batteries (ASSBs) consisting of a 4 V-class cathode active material (CAM), an inorganic solid-state electrolyte (SE) and a lithium-metal anode are considered the future of energy storage technologies. [5-6] The development of practical ASSBs, however, has met a number of challenges. SEs simultaneously meeting the criteria in conductivity, stability and mechanical properties are yet to be discovered. At the anode, reductive degradation of SE, high interfacial impedance and dendrite formation are the most pressing issues. At the cathode, instabilities due to oxidative degradation of SE, reactivities between SE and CAM as well as the loss of mechanical integrity significantly limit ASSB performance.

In this presentation, we discuss our recent effort in addressing these challenges, including the development of novel halide SEs, design of composite cathode structure that enables direct use of uncoated-LiNi0.8Co0.1Mn0.1O2 CAM, and implement of Li-metal based anodes that enable better interface with the SE. We demonstrate the excellent long-term cycling performance achieved on such cells and illustrate the underlying working mechanism. [7] The importance in proper matching of cathode, SE and anode properties as well as our views on future development of better-performing ASSB cells will be presented.

References

Arbizzani, G. Gabrielli and M. Mastragostino, Journal of Power Sources, 2011, 196, 4801-4805.

Murmann, R. Schmitz, S. Nowak, N. Ignatiev, P. Sartori, I. Cekic-Laskovic and M. Winter, Journal of The Electrochemical Society, 2015, 162, A1738.

Cao, X. Ren, L. Zou, M. H. Engelhard, W. Huang, H. Wang, B. E. Matthews, H. Lee, C. Niu and B. W. Arey, Nature Energy, 2019, 4, 796-805.

Fan, L. Chen, O. Borodin, X. Ji, J. Chen, S. Hou, T. Deng, J. Zheng, C. Yang, S.-C. Liou, K. Amine, K. Xu and C. Wang, Nature Nanotechnology, 2018, 13, 715-722.

Janek and W. G. J. N. E. Zeier, Nature Energy, 2016, 1, 1-4.

Famprikis, P. Canepa, J. A. Dawson, M. S. Islam and C. Masquelier, Nature Materials, 2019, 18, 1278-1291.

Y. Kim, H. Cha, R. Kostecki and G. Chen, ACS Energy Letters 2023, 8, 521.
PFAS Degradation from Water by Using Metal Oxide as Photocatalyst
Authors: Niu Junjie
Published: February 2024

The recalcitrant nature of perfluoroalkyl substances (PFAS) urge scientists to discover solutions to permanently remove PFAS contaminations from water with less energy in contrast to incineration. In this presentation, we will introduce a duo-functional tri-metallic-oxide (f-TMO) hybrid photocatalyst that was synthesized via a facile process, which displayed both high adsorption capacity and high defluorination rate of a series of PFAS including PFOA, PFOS, PFHpA, PFHxA and PFBA due to the generated holes/electrons (h+/e-) and multi-radicals such as O2
•- and SO4
•- (Samuel, Shang, Niu.
Chemosphere
, 293 (2022) 133568). The Langmuir adsorption capacities up to 827.84 and 714.46 mg g-1 along with the adsorption efficiency of 99.8% and 99.4% for PFOS and PFOA were respectively achieved. A defluorination ratio of as high as 74.8% with PFOA and a ratio up to 67.6% with PFOS were respectively received. Over 98% PFOA molecules were degraded within as fast as 15 min under initial concentrations ranging from 1 ppb to 1000 ppb, which demonstrates an excellent degradation kinetics. After degradation, the PFOA residuals were as low as 10 ng L-1 in industrial wastewater with an initial concentration of 1 ppb. Moreover, as high as 95.5% degradation efficiency of PFOS was obtained within 300 min. The high physical adsorption capacity and high defluorination rate make this f-TMO catalyst promising applications in removing PFAS from a broad range of water sources.

Keywords: Perfluoroalkyl substances (PFAS); Photocatalytic degradation; Water Remediation
Non-Equilibrium Plasma Oxidation of Elemental Hg
Authors: Jurov Andrea , Gačnik Jan , Živković Igor , Ribeiro Guevara Sergio , Kotnik Jože , Berisha Sabina , Vijayakumaran Nair Sreekanth , Cvelbar Uros , Horvat Milena
Published: February 2024

Atmospheric mercury, specifically oxidized mercury (HgII), is the largest anthropogenic pool of mercury in the atmosphere. This type of mercury can accumulate in the food chain after undergoing methylation and entering ecosystems through wet and dry deposition. It is important to evaluate the level of wet and dry deposition, but measurements of atmospheric mercury have been biased due to insufficient consideration of measurement uncertainty and metrological traceability, especially for low ambient concentrations of gaseous HgII species.

To address this issue, a calibration method for HgII species has been presented based on atmospheric pressure non-equilibrium plasma oxidation of Hg0 to HgII. Hg0 is generated by reducing HgII in aqueous solution by SnCl2 and aeration, then oxidized to different HgII species using He plasma with traces of different reactive gases. The non-equilibrium plasma oxidation efficiencies, with corresponding expanded standard uncertainty values, were evaluated using a highly sensitive radiotracer. The efficiencies were found to be 100.5 ± 4.7% (k = 2) for 100 pg of HgO, 96.8 ± 7.3% (k = 2) for 250 pg of HgCl2, and 77.3 ± 9.4% (k = 2) for 250 pg of HgBr2. The presence of HgO, HgCl2, and HgBr2 was confirmed by temperature-programmed desorption quadrupole mass spectrometry (TPD-QMS).

The results demonstrate the potential of non-equilibrium plasma oxidation for reliable calibration of ambient air measurement instrumentation, leading to a better understanding of the sources, transport, and fate of this toxic pollutant in the environment. Knowing the chemistry and composition of atmospheric HgII species is crucial for assessing the extent of dry and wet deposition and mitigating the negative impacts of mercury pollution on human health and the environment.
Preventing Pt Catalysts in PEM Fuel Cells from CO Poisoning by Getting COPROX to Work
Authors: Rolison Debra R. , Novak Travis G. , DeSario Paul A. , Herzog Austin E. , Brintlinger Todd H. , DeBlock Ryan H. , Long Jeffrey W.
Published: February 2024

Proton-exchange membrane fuel cells still require CO-scrubbed H2 feedstreams to sustain long-duration performance. Sufficiently CO-free H2 costs an order of magnitude more than steam refining fossil fuels to generate H2—and until green processes produce the bulk of H2, preferential oxidation of CO from H2-rich feedstreams, also known as COPROX, is a necessity. We design architected catalytic platforms as ultraporous metal nanoparticle–modified oxide aerogels in which a covalently bonded oxide nanoparticulate network (NPs) supports comparably sized catalytic nanoparticles (NPs). The degree of physical and chemical interfacial intimacy stabilizes the more catalytically active low valent state of Cu and the ultraporous catalytic platform demonstrates high activity and on-stream durability for thermal catalysis of CO [1]. We then evaluate the selectivity and activity of this architected catalyst and a related aerogel, Cu/GdxCe1–xO2, for preferential oxidation of CO (COPROX) in H2 feedstreams. The catalysts convert >95% of CO at temperatures that prevent oxidation (consumption) of the H2 fuel (a purification reaction necessary to prevent poisoning of the anode catalysts in H2 fuel cells). The architected Cu/ceria catalysts achieve >95% selectivity vs. H2 and maintain this unprecedented activity for >16 h at 100°C in dry or humidified feedstreams [2,3]. The ability to purify H2 from steam-reformed fuels for use in proton-exchange membrane fuel cells increases power source flexibility as the world transitions to more sustainable, carbon-neutral routes to highly purified H2.

[1] Stabilization of reduced copper on ceria aerogels for CO oxidation. C. L. Pitman, A. M. Pennington, T. H. Brintlinger, D. E. Barlow, L. F. Esparraguera, R. M. Stroud, J. J. Pietron, P. A. DeSario, D. R. Rolison, Nanoscale Adv. 2020, 2, 4547–4556 (10.1039/D0NA00594K).

[2] Preferential oxidation of CO in H2-containing gas. T.G. Novak, D.R. Rolison, P.A. DeSario, US Patent Application, filed Jan 27, 2023 [Navy Case #210,945].

[3] Cu/CeO2 and Cu/Gd-substituted CeO2 aerogels for active, selective, and stable COPROX catalysis. T.G. Novak, P.A. DeSario, T.H. Brintlinger, R.H. DeBlock, J.W. Long, and D.R. Rolison, ACS Sus. Chem. Eng.
2023, 11, 2853–2860 (10.1021/acssuschemeng.2c06158).
Batteries Worth Their Salt: Targeting Next Generation Stationary Storage with Molten Salt Electrolytes
Authors: Spoerke Erik D. , Maraschky Adam M. , Meyerson Melissa L , Percival Stephen J. , Peretti Amanda S. , Gross Martha S. , Small Leo J.
Published: February 2024

There is an imminent need for batteries capable of meeting the evolving demands of a growing stationary storage landscape, one rich in renewable energy sources and challenged with unprecedented global electrification. Key to our future electrical grid, desirable large-scale, long-duration batteries must not only meet demands for high power and energy density, but they must be safe, cost-effective, and should be sustainably sourced from earth-abundant materials. Here, we will highlight our research and development of low temperature molten salt batteries that employ active materials such as sodium, aluminum, iron, chloride, and iodide. We will demonstrate the promise of our approach through a low-temperature (100°C) molten sodium battery that comprises a molten sodium anode, a solid-state NaSICON ceramic separator, and a low-cost molten metal-halide salt catholyte. These batteries, with remarkable voltages greater than 3.1V, are capable of months of cycling as well as high current charge and discharge behavior, greater than 50mA/cm2. Here, we will not only highlight these performance metrics, but we will describe how we used specialized electrochemical and chemical characterization technique to understand the impacts of molten salt electrolyte composition, electrochemistry, and interfacial interactions on battery performance. By understanding the connections between specific electrochemical phenomena and battery chemistry, we have learned to improve battery performance through tuning of properties, such as molten salt Lewis acidity and current collector composition. This scientifically-motivated battery design approach continues to enable agile innovation and advances to realize the potential of molten salt batteries as a new, impactful stationary storage technology.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
Mechanical Properties of Vcrmn and Vcrmnti High Entropy Alloys
Authors: Sultana Najmin Ara , Mohammed Yousuf S , Baumgart Helmut , Elmustafa Abdelmageed
Published: February 2024

In this research, magnetron sputtering is employed to fabricate thin films of high entropy alloys. The target materials are derived from VCrMn and VCrMnTi systems. The focus is to pinpoint suitable candidates for robust and long-lasting beam exit windows in e-beam accelerators. The selection process considers their inherent characteristics, their capacity to dissipate power, and how they respond to irradiation in terms of mechanical traits like hardness, ductility, defect density, and strength.

For the bulk alloy samples of VCrMn and VCrMnTi, a sequence of nanoindentation tests has been executed to evaluate hardness and elastic modulus. The outcomes reveal that both the hardness and modulus are notably greater than those of any individual metal samples. It is anticipated that fabricated alloy films with same compositions will exhibit robust qualities in terms of mechanical properties, including ductility, defect density, and strength. The incorporation of additional titanium (Ti) alloying elements into the high entropy alloys (HEAs) of VCrMn is projected to enhance electron transmission.

The fabricated films have undergone thorough analysis and testing to comprehend their microstructural attributes and chemical composition which involves the utilization of SEM with EDS, FESEM, AFM to investigate microstructural and surface properties of the films. Subsequently, X-ray diffraction has been employed to acquire insights into the morphology and lattice orientation of the films.
Projection Micro Stereolithography of Skin Layered Microporous Polymer Membranes As a Separator for Li-Ion Batteries
Authors: Ma Meghann , Wan Jiandi , Ye Jianchao
Published: February 2024

Commercial liquid electrolyte lithium-ion batteries (LIBs) traditionally incorporate microporous polymer membranes, or separators, to isolate electrode contact and enable ionic transport. Although they do not actively participate in cell chemistry, well-designed separators can influence cell performance and safety, and thus, are essential components of a cell. Current separator manufacturing processes include "wet" or "dry" mechanical stretching , phase inversion, and evaporation-induced phase separation. However, these processes have limited morphological control of geometry and layered structures. Additive manufacturing techniques have been used to rapidly prototype materials that have both high customizability and fine microstructural control. We investigate hexanediol diacrylate (HDDA) as a polymer system using projection micro-stereolithography, a layer-by-layer photopolymerization technique, to develop separators with controlled microstructures for Li-ion batteries. We successfully fabricate a unique polymer architecture of alternating nanometer thin skin layers and microporous network. The fine control of printing parameters (i.e., printing platform, skin layers, and exposure time), results in tunable porosity and morphology. This unique approach to manufacturing LIB separators provides hierarchical homogeneity for more uniform Li-ion transport. It’s potential as a LIB separator is explored by characterizing its electrolyte wettability, thermal tolerance, electrochemical properties, and mechanical stability. Finally, lithium symmetric cells using the HDDA microporous membranes are evaluated against Celgard 2325 separators. This work provides a promising new route for developing separators using additive manufacturing techniques to enable high performance Li-ion batteries.
Thermal Efficiency Evaluation after Thermocompression of Copper Layer Obtained By Dynamic Hydrogen Bubble
Authors: Schoenleber Jonathan , Janod Goulven , Chachay Lucas , Gigandet Marie-Pierre , Avenas Yvan , Daudin Remi , Missiaen jean-Michel , Bouvard Didier , Khazaka Rabih , Hihn Jean-Yves
Published: February 2024

With the increase in engines electrification, especially in aircraft future developments, there is a need of extremely high-power converters in the power electric chain, interfacing the electrical network and the electric motors. The COPPERPACK project (COPPER based PACKaging for direct cooled power module ANR-19-CE05-0011) aims to module assembling by thermocompression, which requests the elaboration of thin nanoporous copper films to be placed between chips and metallized ceramic substrates. Different possibilities exist and have been tested all along the project, such as copper-zinc or copper-manganese electrodeposition followed by an anodic dissolution, but the faster and simpler way resides in electroforming deposition made by Dynamic Hydrogen Bubble Template (DHBT) [1]. This process works in unusual potentials and current densities where the competition between hydrogen discharge (commonly avoided) and copper reduction is very high. In this case, this method achieves thick deposits in very short time (few seconds) with high currents allowing a very fast growth of copper around hydrogen bubbles. Pores and ligaments sizes can be controlled by several operating parameters i.e. current densities, temperature, deposit time, chemical additives [2] as well by pulsed currents. Films were tested for chips assembling by thermocompression, and present excellent behavior’s. Several conditions have been tested, in different configurations, varying the size and the height of the chips.

Eventually, this system has been extended to cooling systems, favoring the assembling of copper foams and complex copper shapes, designed for cooling fluid circulation. Once again, the copper layers obtained by DHBT allow to build compact and efficient systems.

[1] Abdel-Karim, R.; El-Raghy, S. Chap 4 in Advanced materials and their applications - micro to nano scale. One Central Press, United Kingdom, pp 69–91, 2017

[2] Shin, H.-C.; Liu, M. Chem. Mater. 2004, 16, 25, 5460–5464 doi.org/10.1021/cm048887b
Light-Induced Platinum Deposition on Silicon-Based Semiconductor Devices
Authors: Fritz Mathias , Hoess Christian Elieser , Deckert Finn-Merlin , Bund Andreas
Published: February 2024

Metal-semiconductor compounds are used in large numbers in microelectronics and need to be constantly improved. Platinum-silicon semiconductor contacts are often used in sensors and detectors, especially infrared detectors and cameras. Recent developments enable applications in medical technology, such as implanted pressure sensors in the human body.

Currently, platinum coatings on silicon-based semiconductor devices are mostly realized by sputtering techniques or platinum-containing printing pastes with subsequent heat treatment.

This paper will discuss recent results from the authors' lab on light-induced platinum electrodeposition. Special focus will be given to the pre-treatment of the substrates for the subsequent platinum deposition under illumination. In a systematic approach, all influencing parameters were identified and the most influential ones (pre-treatment, current density, electrolyte type, additives, etc.) were incorporated into an experimental plan. The challenges include a homogeneous platinum coating with low contact resistance and good adhesion. Last but not least, the characterization of the layers (with SEM, EDX, laser scanning microscope, etc.) will be discussed.
Electrochemical Nucleation and Growth: A Multimicroscopy Approach at the Same Scale
Authors: Torres Daniel , Bernal Lopez Miguel , Ustarroz Jon
Published: February 2024

Electrodeposition is a critical electrochemical reaction with broad applications in technology. This demands a comprehensive understanding of the electrochemical nucleation and growth process (EN&G), and the different factors driving the formation of a new phase on a given substrate. Our understanding of the role of the substrate and the real nature of active sites still remains elusive due to the challenge of probing specific sites and bringing a statistical interpretation of the nucleation process. Moreover, conventional macroscopic approaches often record electrochemical magnitudes over large areas (cm2) which are then correlated with surface characterizations obtained from a vastly different scale (~μm2), correlations, which are not necessarily representative of the macroscopic surface. In order to establish meaningful and unambiguous correlations, it becomes necessary to employ techniques capable of surveying the surface with a high spatial-temporal resolution, such as scanning probe techniques, capable of recovering information in a scale closer to the growth of the new phase, i.e., local scale1. To address these challenges, we employed Scanning Electrochemical Cell Microscopy (SECCM), to study the EN&G of Cu on a glassy carbon substrate at a scale closer to the initial stages of the electrodeposition2. SECCM can be combined with other imaging methods such as scanning electron microscopy (SEM) to recover information from the deposited nanostructures at the same scale as the electrochemical response3. This so-called multimicroscopy approach allows us establishing direct correlations between the EN&G and the morphological, structural, and compositional features of the substrate and deposit. As a result, new insights that are not available with conventional macro-electrochemical analysis can be gained, such as the time-, potential-, and site-dependent nature of the EN&G process with a statistical perspective. This approach provides a new avenue for developing novel analysis strategies to understand the real nature of active sites for nucleation.

References

M. Bernal, D. Torres, S. S. Parapari, M. Čeh, K. Ž. Rožman, S. Šturm, and J. Ustarroz, Electrochim. Acta, 445, 142023 (2023).

D. Torres, M. Bernal, A. Demaude, S. Hussain, L. Bar, P. Losada-Pérez, F. Reniers, and J. Ustarroz, J. Electrochem. Soc., 169, 102513 (2022).

D. Torres, M. Bernal Lopez, and J. Ustarroz, Electrochemical nucleation and growth: A multimicroscopy Approach at the same scale, In preparation. (2023).

Figure 1
Electrodeposited Ni-Based Catalysts for the Oxygen Evolution Reaction
Authors: Deo Yashwardhan , Thissen Niklas , Mechler Anna K.
Published: February 2024

Alkaline water electrolysis is one of the most mature technologies for producing green hydrogen. However, there still are possibilities to enhance this process by using better electrocatalysts for the kinetically limited oxygen evolution reaction (OER). While there are several existing methods for catalyst synthesis, such as spray coating, coprecipitation and hydrothermal synthesis, they face challenges of either versatility or scalability.[1,2] In this regard, electrodeposition is a promising catalyst synthesis method, due to its excellent process control and ease of scalability.

In this work, electrodeposition is used to prepare nickel-based catalysts as a benchmark system. These catalysts are deposited on expanded Ni-mesh supports. Initially, the deposition parameters are optimized to obtain uniform Ni deposits, which provide reproducible activity measurements. Herein, we observe that the deposited Ni catalysts exhibit better OER activities than the Ni mesh support, most likely due to the evolution of a pyramidal morphology with an increased surface area (Fig. 1). The optimized deposition parameters are further used to deposit different Ni-based alloys such as Ni-Fe and Ni-Co, by adding the respective ionized metal species to the Ni electrolyte. The microstructure and composition of these catalysts is analyzed using material characterization techniques like scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Finally, the OER activity and long-term stability of the deposited catalysts is evaluated in an in-house developed electrochemical beaker cell at elevated concentration, temperature, and current densities (30 wt.% KOH, 80 °C, up to 1 A/cm2). The results obtained for the different catalysts are compared to understand the correlation of the catalyst structure and composition with their electrochemical OER performance under industrial conditions.

Bibliography

[1] Lu Xunyu et al.; Nature Communications; DOI: 10.1038/ncomms7616

[2] Zuraya Angeles-Olvera et al.; Energies; DOI: 10.3390/en15051609

Figure 1