bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Carbon Addition and Passivation on the Mechanical Behavior of Freestanding Al Thin Films
Authors: Oh Injong , Lee Zion , Kim Hojang , Sim Gi-Dong
Published: December 2024

Thin films are widely used as functional and structural elements in micro-electronic devices. Therefore, understanding the mechanical behavior of thin films at different length scales and environmental conditions is essential for the design of reliable devices. However, it is difficult to precisely measure the properties of small-scale materials with the methods that are employed for bulk materials; probing micro/nano scale samples is challenged by the inherent difficulties associated with fabricating and handling of extremely small specimens. For several decades, much work has been dedicated to characterizing the mechanical behavior of thin metal films and it has been observed that the mechanical properties of thin films can be very different to those of their bulk counterparts. In addition, passivated metal thin films showed interesting features such as higher strain hardening rate and enhanced failure strain. In this presentation, the effect of carbon addition and passivation on the microstructure and mechanical behavior of freestanding Al thin films will be discussed. Tensile specimens with sub-micron thickness were fabricated via sputter deposition followed by standard Si-based microfabrication techniques. Mechanical characterization was carried out by performing micro-tensile tests and membrane deflection tests. Supersaturated Al-C thin films containing 10.3at% C exhibit yield strength of about 400 MPa, over three times the yield strength of pure Al thin films. This strengthening can be explained by the role of interstitial C atoms which block dislocations movement inside the Al matrix. In addition, an upper yield followed by drop in stress was observed in Al-C thin films which implies the formation of the Cottrell atmosphere. For passivated films, a large increase in the failure strain was observed when an ultra-thin layer (< 10 nm) is deposited, which is attributed to delay in the strain localization due to constraint imposed by the passivation layer.
Carbon Nanomaterial Enabled Ultra High Conductivity Cu Composites for Advanced Conductors
Authors: Aytug Tolga , Li Kai , Yoon Mina , McQuire Michael , Jiang Huixin , Lupini Andrew , Fred List , Haynes J. Allen
Published: December 2024

Growing demand for electrical energy and increasing need for high power grid systems necessitates development of new conductors for enhanced electrical and thermal conductivity. The power losses associated with the electrical resistance of Cu adversely impact the efficiency and performance of all electric devices. Ballistic electrical transport in carbon nanotubes (CNTs) is expected to improve the conductivity of the Cu matrix with additional CNT-enabled benefits that can enable low-weight, flexibility, and better thermal management. By using scalable, cost-effective, and commercially viable processing methods, we demonstrate a novel technological platform to produce high-performance conductors that incorporates CNTs into the Cu matrix ― ultra-conductive metal composites (UCC), which promise significant technological and economic impact in all energy sectors, ranging from electrical vehicles to power grid. Our approach, which combines materials synthesis, characterization, and first-principles modeling, enables an efficient and systematic exploration of the multidimensional complex materials parameter space of Cu-CNT composites with dopants and identifies the key individual structural and interfacial components that govern the electronic transport properties of the UCC composites. Our experimental technology platform is concentrated on Cu tapes and involves processes from production of stable CNT dispersions, electrospinning techniques to deposit shear induced aligned CNT coatings along the direction of the current flow, post thermal treatment procedures, and homogeneous deposition of metal overlayers onto CNT coated tapes. Here, we demonstrate that the prototype UCC composites exhibit improved electrical conductivity (by > 5%), higher current carrying capacity (> 10%), and higher mechanical strength (> 10%) than the reference pure Cu counterparts.
Investigation on the Charge Transport Properties of Cumulenic Sp-Carbon Wires in Solution and in Thin Films
Authors: Sala Ruben Elda , Pecorario Stefano , Galli Valerio , V. Damasceno Joao Paulo , Caironi Mario
Published: December 2024

Carbon allotropic forms have gained the spotlight due to their remarkable versatility. Among all, sp-hybridised carbon has been predicted to display unmatched mechanical, thermal, and electronic properties. Cumulenes, a category of finite sp-carbon-based molecules, are model moieties that have attracted particular attention also in the form of thin films, as they present a tuneable semiconducting nature. Indeed, solution-processed films of tetraphenyl[3]cumulene ([3]Ph) and tetraphenyl[5]cumulene ([5]Ph) have been successfully employed as active layers in p-type organic field-effect transistors (OFETs). [3]Ph-based devices can even reach a field effect mobility exceeding 0.1 cm2/Vs, showing ideal behaviour and operational stability in air in dark conditions. However, cumulenic charge transport mechanisms remain largely unknown.

We here present an investigation on the electronic properties of [3]Ph, taken as the reference cumulene. Chemical and electrochemical oxidations in solution, supported by UV-Vis and Raman spectroscopy, were employed to probe the charged single molecule, revealing the formation of new transitions related to the localisation of the charge on the sp-backbone. Charge modulation spectroscopy was performed on OFETs based on thin films of [3]Ph to investigate the solid state electronic properties, leading to a good match with the results obtained from the single molecule.

The understanding of the fundamental charge transport mechanism is pivotal to exploiting the full potential of sp-hybridized molecules for large-area organic electronics, and it could also contribute to new insights regarding the infinitely long sp-carbon allotrope known as carbyne.
Preparation and Properties of Activated Carbon for Capacitive Deionization to Obtain Clean Water
Authors: Lee Song Mi , Lee Seon Ho , Jung Doo-Hwan
Published: December 2024

Efforts to obtain clean water continue around the world due to population growth and industrial growth. However, many countries still have difficulty obtaining water. Seawater desalination is attracting attention as one of the alternatives to solve water shortage. Among various methods for seawater desalination, capacitive deionization (CDI) using a separation membrane does not pollute the environment and is inexpensive. Among methods to improve desalination performance, activated carbon is used as a CDI electrode material. However, the price of activated carbon is increasing every year, and in order to find a way to prepare for the depletion of activated carbon raw materials, new raw materials were used as a CDI electrode material.
High Performance Self-Powered UV Photodetector Based on Nitrogen-Doped Graphene Quantum Dot Schottky Diode
Authors: Sultan Muhammad Shehzad , Nazario Ernesto Espada , Ramos Bianca S Umpierre , Negron Daniele D. , Ramos Alers Luis O. , Jadwisienczak Wojciech , Weiner Brad R , Morell Gerardo
Published: December 2024

We report a straightforward bottom-up approach for the synthesis of high-quality nitrogen-doped graphene quantum dots (NGQDs). This approach is cost-effective, environmentally friendly, and suitable for the production of high-quality NGQDs on a large scale. The as-synthesized NGQDs have high crystalline quality with an average size of 3.26 nm, are water soluble, and show strong fluorescence. The UV-vis spectra indicate that N-doping introduces new energy levels into the electronic structure of graphene, which tune the optical properties, resulting in a photoluminescence quantum yield (PLQY) of 73%. The NGQDs show excitation wavelength-dependent fluorescence with a maximum excitation and emission at 340 and 431 nm, respectively. Using the as-synthesized NGQDs, we fabricated a high-efficiency and fast-response self-powered UV photodetector. Under the illumination of 365 nm UV light with a power density of 25 mW/cm, the NGQD photodetector shows a high photoresponsivity of 37 A/W, detectivity of 1 * 10 Jones, and external quantum efficiency (EQE) of 12.6 * 10%. This UV photoresponse is fast, with rise time of 0.29 s and fall time of 0.33 s. This work paves the way for the development of graphene-based high-performance optoelectronic devices.
Study on Enhanced Electron Field Emission Properties of Graphene Quantum Dots Synthesized By Pulsed Laser Ablation
Authors: Sultan Muhammad Shehzad , Nazario Ernesto Espada , Ramos Bianca S Umpierre , Negron Daniele D. , Ramos Alers Luis O. , Jadwisienczak Wojciech , Weiner Brad R , Morell Gerardo
Published: December 2024

Graphene quantum dots (GQDs) and nitrogen-doped graphene quantum dots (N-GQDs) were synthesized by the Pulsed LASER Ablation method. The nanostructure and chemical composition of the GQDs were analyzed by means of TEM, HRTEM, Raman, XPS, and FT-IR spectra. Field emission is a quantum mechanical phenomenon where electrons tunnel from the cathode to the anode through vacuum under an applied electric field. So far, the field emission properties of two-dimensional (graphene) and one-dimensional (CNT) carbon nanostructures have been extensively studied. For the first time, to the best of our knowledge, the field emission behavior of GQDs and N-GQDs, deposited on n-Si (100) substrates, is studied. As a candidate of cold cathode, the GQDs display good field emission performance. The field emission properties of GQDs and N-GQDs were studied by measuring turn-on field (E) and field enhancement factor β.The results show that nitrogen doping improved the field emission properties of GQDs by reducing the turn-on field from 13.1V/μm (GQDs) to 7.9V/μm (N-GQDs) and enhancing the field enhancement factor β from 1427 (GQDs) to 2511 (N-GQDs). The field emission behavior of pristine GQDs and N-GQDs is explained in terms of change in the effective microstructure as well as a reduction in the work function, as probed by measured characterizations. The enhanced emission properties of N-GQDs are mainly attributed to the upshifting of fermi energy level and defects produced as a result of nitrogen doping. The good emission performance of the GQDs field emitters suggests promising applications in next-generation vacuum micro and nano-electronic devices.
Controllable Synthesis of Work Function Tailored Zeolite Derived Hierarchically Porous and Active Site Enrich Carbon Framework for ORR in Acidic and Alkaline Medium and Its Application Towards Zinc Ion Hybrid Supercapacitor Device
Authors: Mane Rupali , Jha Neetu
Published: December 2024

Rational design of a non-precious and efficient electrocatalyst for oxygen reduction reaction (ORR) is of utmost importance for sustainable energy exploitation, to solve the energy crisis and environmental jeopardy. In this regard herein, we report work function tailored zeolite derived hierarchically porous and active site enrich electrocatalyst to study ORR in acidic and alkaline medium and its application towards Zinc ion hybrid supercapacitor (ZIHSC). The electrochemical analysis proposes that the optimized electrocatalyst with high surface area, porosity, and high active site density facilitate the electronic transfer from atomic Co to Nitrogen-doped graphitic carbon framework (NGC) and, further to the antibonding state of oxygen. The optimized catalyst AL-Co/NGC-800 shows better ORR performance, with remarkable onset potential (E onset acid- 0.89 V, E onset alkaline – 0.951 V) and a large number of active site density (ASD acid -7.84×1022 /g, ASD alkaline - 1.51×1022 /g) along with excellent stability and durability. It is proposed that the high performance of the catalyst is attributed to the reduction in work function (WF ZIF 67- 5.2 to WF optimized- 4.6) as an effect of temperature followed by post ‘acid leaching’ (AL) treatment which alters the surface area of the catalyst. In account with its promising ORR activity, the catalyst was further tested for proton exchange membrane fuel cell (PEMFC) as a cathode catalyst which displays a maximum power density of 18 mW/cm2 at the current density of 63 mA/cm2. Owing to the high surface area and microporosity of the catalyst which improves the kinetics of the cathode, ZIHSC delivers a high capacitance of 190 F/g and a maximum energy density of 67.39 Wh kg-1 with a power density of 242.64 Wh kg-1. Herein, we represent a favorable strategy for the fabrication of a highly efficient and durable ORR catalyst with promising energy density in ZIHSC. This hybrid structure provides a new perspective to catalyst architectures.

Figure 1
Microwave Approach to Multi-Functional Graphene Nanocomposites for Energy Applications
Authors: Zhang Xinyu , Sarwar Shatila
Published: December 2024

Nanocomposites are composed of a large selection of nanomaterials, such as nanocarbons, metal oxides/chalcogenides, carbides, phosphides, polymers, etc., which possess superior mechanical, thermal, and electrical properties, leading to broad applications in smart structures, chemical sensors, energy storage and nano-electronic devices. However, the high cost and difficulty in getting large-scale, high-quality nanocomposites remain challenges. Zhang Research Group has been dedicated to developing facile, reliable, sustainable manufacturing technologies towards functional nanocomposites for energy-related applications. For example, the manufacturing of transition metal chalcogenides (MCs) on graphene support (MC-Gr) was developed based on a one-step microwave approach. In this regard, a series of suitable combinations of metals and chalcogens have been selected, such as molybdenum disulfide (MoS2), molybdenum ditelluride (MoTe2), molybdenum sulftotelluride (MoSTe), cobalt doped MoS2 (Co-MoS2) and other hybrids. Electrochemical characterizations i.e., cyclic voltammogram (CV), galvanostatic charge-discharge (GCD), electrochemical impedance spectroscopy (EIS) and so on, reveal that the as-produced nanocomposites can be used as high mileage catalyst materials for hydrogen evolution reaction (HER) and electrical energy storage (EES) such as hybrid-capacitor applications. This work will focus on hydrogen evolution reaction catalyzed by Graphene/Molybdenum chalcogenides nanocomposites, manufactured by microwave approach.
Structured Carbon Nanofibrous Electrode for Mass Transport Enhanced MEA for PEMFCs
Authors: Ji Yunseong , Shul Yong Gun
Published: December 2024

Polymer electrolyte membrane fuel cell (PEMFC) technology is advancing towards commercialization, with efforts focusing on the mass production of various materials to reduce development costs. Despite these efforts, the use of platinum-based catalysts—a key component in fuel cells—presents a challenge for cost reduction. As a result, the proportion of catalyst costs in the final price of fuel cells has been increasing, currently accounting for approximately 40%. Enhancing the activity and durability of the electrode layer, along with efficient catalyst utilization, could significantly lower these costs and facilitate broader market adoption of fuel cell technology.

Traditional fuel cell electrodes are fabricated by applying a mixture of platinum, carbon, and ionomers onto a polymer electrolyte membrane. The performance of these electrodes, however, is heavily influenced by the interactions among the components, making the technology less universally applicable due to its sensitivity to even minor changes in componentry.

This research introduces a novel approach by employing carbon nanofibers, created through electrospinning and subsequent graphitization, as a structural basis for the electrode layer. This carbon nanofiber layer offers structural and chemical stability, enabling a secure physical and chemical anchorage for the catalyst and ionomer. It also features well-connected macro-pores, which enhance internal reactant supply and improve gas transport within the fuel cell. Utilizing this method, an electrode layer demonstrating superior performance—approximately 800 mW/cm2 at 0.1 mgPt/cm2 and 0.65 V, with a peak performance of 1080 mW/cm2—was developed. Moreover, this electrode exhibited minimal performance degradation over 20,000 cycles under a carbon corrosion protocol, indicating significant advancements in fuel cell durability and efficiency.
(Invited) Nanosheet Antibody Mimics for Diagnosis and Therapy of Bacterial Infections
Authors: Lee Sin , Choi Yujin , Kim Jong-Ho
Published: December 2024

Antibodies are widely employed as recognition elements in diagnosis and therapy of various diseases [1], however, they have some limitations such as poor stability, long discovery time, and high cost. Herein, we present a facile approach to create nanosheet antibody mimics with multivalent peptide recognition phases and luminescent rigid transition metal dichalcogenide (TMD) nanosheets for the selective recognition, detection, and eradication of pathogenic bacteria. Tripeptides with a nitriloacetate-Cu group were spontaneously assembled on TMD nanosheets via coordinate bonding, providing a variety of TMD-tripeptide assembly (TPA) antibody mimics [2]. TMD-TPA antibody mimics selectively recognized various pathogenic bacteria, including E. coli O157:H7, S. aureus, and S. typhimurium, with high binding affinities. The bacterial binding sites for TMD-TPA were identified by experiments and molecular dynamics simulations, revealing that the dynamic and multivalent interactions of TMD-TPA antibody mimics played an important role for their selective recognition and high affinity. The TMD-TPA antibody mimics allowed the rapid, selective, and sensitive detection of pathogenic bacteria from human serum and urine. In addition, the TMD-TPA antibody mimics selectively killed the pathogenic bacteria infecting the wounds of mice under near-infrared irradiation, leading to effective healing. This work demonstrates the potential of TMD-TPA antibody mimics as an alternative to protein antibodies for diagnosis and therapy.

Reference

[1] a) H. K. Binz, P. Amstutz, A. Pluckthun, Nat. Biotechnol.
2005, 23, 1257; b) M. Gebauer, A. Skerra, Curr. Opin. Chem. Biol. 2009, 13, 245

[2] T. W. Kang, I. J. Hwang, S. Lee, S. J. Jeon, C. Choi, J. Han, Y. So, W. Son, H. Kim, C. S. Yang, J. H. Park, H. Lee, and J. H. Kim, Advanced Materials, 2021, 2101376
Sustainable Binder Materials and Their Benefits for Li-Ion Batteries
Authors: Kandula Maja , Yarangünü Ayse , Rajic Anja , Hartwig Sven
Published: December 2024

Binder materials play an increasingly important role in battery technology; they have a substantial influence on the batteries performance and lifetime behavior. However, it is widely noticed that deficiencies in binder performance, as well as aging-related issues, significantly affected the resultant shortened life cycle of batteries.

Established systems utilizing carboxymethyl cellulose (CMC) and polyvinylidene fluoride (PVDF) have fallen short of meeting the increasing requirements regarding poor elasticity and polarity, which are of importance for accommodating volume expansion and ensure adhesion. The adhesion plays a crucial role for the connection and conductivity not only within the electrode materials but also towards the current collectors and therefore is significant for battery performance. Different influencing factors on the polymer structure like mechanical shear stress during the dispersion process or the crosslinking behavior of the binder with the active material depending on the functional groups have an impact on the binder-material-interaction and therefore on adhesion and performance of the battery cell.

The mechanical and electro physical tasks of the binder are very diverse and grow with the increase of new materials, as active materials e.g., and processing methods. However, the property profile of the binder is rarely adapted, ever through it contributes significantly to the performance of the binder cell. This research deals with sustainable battery processing by using e.g. biodegradable polymeric binder materials and the application in energy storage systems. The investigation of adhesion and cohesion characteristics of new binder systems were characterized with a combination of electrochemical impedance spectroscopy (EIS) to study the binder influence on the battery cell. Especially the aging of a battery connected to the binder is evaluated by EIS. The results lead to further interpretations on the adhesion ability and the failure patterns.

Consequently, a comprehensive knowledge about binder behavior within a battery system and associated optimization of binder properties, which is imperative for achieving sustainable battery materials, is the goal for sustainable energy materials.
The Passive Flow Zinc Bromine System
Authors: Steingart Daniel A. , Irvin Lynne Elizabeth , Mohr Robert , Ju Dongrun , Williams Mateo Sebastian
Published: December 2024

This work demonstrates a minimal overhead storage technology exploiting, rather than compensating for, the innate physical properties of the zinc-bromide system. Using two symmetric planar electrodes and a homogenous electrolyte, we present a ZnBr2 cell with over 50 Wh/L energy density, over 70% roundtrip efficiency, and a lifetime limited by cell sealing quality. The scaled cell cost is estimated to be $40/kWh.

The zinc-bromide system is known for its theoretically low cost, long lifetime, and high energy density. However, resolving this theory to practice has been difficult in active flow systems. Classic design goals work to “correct” the physical chemistry of the ZnBr systems, including rigorous separation of the charged Zn and Br2 phases, active phase control of the Br2/water mixture, and forced convection to maximize power density. But balance-of-plant support of concentrated halide electrolytes, complexing required to create reliable Br2 miscibility, and secondary safety systems required when running bromine through forced convection through manifolds conspire to increase the CAPEX and OPEX of the ZnBr2 system while decreasing its reliability.

We have previously demonstrated a “static” ZnBr2 system that follows a traditional unit cell design, where zinc plates upon a carbon current collector and Br2 reside in a carbon foam's porosity. Here we present our new designs, where we remove the complexity of the “cathode carbon foam,” replacing it with a simple carbon surface and augmenting it with a better understanding of the native stratification and mixing behaviors of the ZnBr2 electrolyte at different concentrations/state of charge. We will also present learnings of the mixing/settling behavior of the electrolyte as a function of concentration (effective SoC) and orientation, as well as the kinetics of bromine oxidation and consumption on simple carbon electrodes.

Figure 1
Pickering Emulsion-Mediated Two-Step Interfacial Assembly of Carbon Film with Catalysts
Authors: Ku Kang Hee
Published: December 2024

Freestanding functional carbon films are essential for high-performance applications. However, traditional powdered catalytic systems suffer from brittleness and particle aggregation, which compromises both their structural integrity and efficiency. In this study, we present a scalable method for the Pickering emulsion-mediated interfacial assembly of carbon-supported catalyst films by leveraging the catalytic decomposition of hydrogen peroxide at the fluid interface. This strategy enables the formation of ultrathin, densely packed nanoparticle films with precise control over their size and thickness, while significantly reducing waste through recyclability. In addition, we demonstrate the versatility of this method by extending the scope of multi-component metal catalyst films and customized substrate-free gold electrodes. These films, which are transferable onto diverse substrates including a leaf and flexible templates, address key challenges in Pt/C catalysts, such as aggregation and inconsistent structural arrangements, and can significantly advance catalytic film technologies.
Enhancing Corrosion Resistance of Type 316L Stainless Steel in Marine Environments: Role of Surface Roughness and Organic Acid Passivation
Authors: Jung Rockhoon , LIM Hana , Kim Hyun-Jong
Published: December 2024

Stainless steel is widely used in marine environments due to its excellent corrosion resistance properties. However, recent occurrences of corrosion issues related to Type 316L stainless steel in marine atmospheric environments have led to concerns regarding the suitability of Type 316L stainless steel material selection according to international standards. Factors such as surface roughness and passivation treatments can significantly affect the corrosion behavior of stainless steel in marine atmospheres. In particular, the surface roughness of conventional stainless steel piping can lead to corrosion in marine atmospheric environments when exposed for extended periods. Either option requires improving the surface roughness or applying passivation treatments to enhance corrosion resistance.

This study examines the effect of surface roughness on the corrosion resistance of Type 316L stainless steel in a marine environment using potentiodynamic polarization and accelerated corrosion tests. In addition, the impact of organic acid passivation on the corrosion behavior of stainless steel in a marine atmosphere is investigated. Surface roughness was controlled by mechanical polishing, while organic acid passivation was achieved using a solution containing citric acid, phosphoric acid, and hydrogen peroxide. Electrochemical measurements and surface characterization techniques were employed to assess the corrosion resistance of the specimens. The results demonstrate that surface roughness and organic acid passivation significantly impact the corrosion resistance of stainless steel in a marine atmosphere. Understanding the synergistic effects of these factors is crucial for enhancing the durability and performance of stainless steel components in marine applications.
Optimum Conditions for the Fabrication of Ordered Porous Alumina Via Anodizing in Etidronic Acid at Higher Voltages
Authors: Koguchi Takumi , Kikuchi Tatsuya
Published: December 2024

Anodizing aluminum in an etidronic acid solution leads to the higher applied voltages of up to approximately 260 V without oxide burning and subsequent formation of porous alumina with a larger interpore distance measuring 650 nm. Typically, the interpore distance increases linearly with the applied voltage during anodizing. However, excess voltage more than 270 V during anodizing in etidronic acid causes oxide burning and the formation of non-uniform porous alumina film. In the present investigation, we describe the optimum operating conditions for the fabrication of ordered porous alumina with larger interpore distance via anodizing in etidronic acid at higher voltages more than 270 V.

Commercially available 4N aluminum plates were ultrasonically degreased and electrochemically polished. The pretreated aluminum specimen was placed parallel to a platinum plate as the cathode in a 0.3 M etidronic acid solution (volume: 150-555 mL) at 293 K using an electrochemical cell (inner diameter: 55-105 mm), then anodized under a linear voltage sweep at 0.1 Vs-1and constant voltage of 260-280 V for up to 6 h. The effect of a) the surface area of the platinum cathode (6.28-624 mm2), b) distance between two electrodes (50-90 mm), and c) stirring rate (300-900 rpm) on the anodizing behavior was investigated. The anodized specimens were examined by scanning electron microscopy (SEM).

The oxide burning voltages were measured by anodizing in etidronic acid under various operating conditions by the linear voltage sweep method. The burning voltage was unchanged with the surface area of the platinum cathode increased, whereas increased with the stirring rate of the etidronic acid solution due to the efficient Joule heat removal. In addition, the burning voltage increased with decreasing distance between two electrodes at the same stirring rate, because of the higher flow velocity of the solution. As a result, steady-state anodizing can be achieved in etidronic acid at the higher voltage of 270-280 V. Figure 1 shows SEM images of the dimple array formed on the aluminum surface via anodizing at 270 V and 280 V for 6 h. A larger porous alumina measuring 665-726 nm in interpore distance was successfully fabricated via anodizing under the optimum operating condition.

Figure 1
Advancing Chemical Synthesis through Integrated High Temperature Electrochemical and Thermochemical Processes for Enhanced Efficiency, Yield, and Sustainability
Authors: Duan Chuancheng
Published: December 2024

This presentation delves into the integration of high-temperature electrochemical and thermochemical processes, aimed at revolutionizing chemical synthesis for enhanced efficiency, yield, and sustainability. Traditional chemical manufacturing methods often face challenges like high energy consumption and significant emissions. By synergizing electrochemical techniques such as electrolysis with thermochemical methods like gasification, we effectively harness the thermal energy from one process to enhance the efficiency of the other. This talk will particularly highlight the latest developments in catalysts, materials, and devices that are engineered to endure the severe conditions of these integrated processes. We will discuss the design of robust catalysts that improve reaction kinetics and selectivity, along with the development of materials and devices designed for high durability in high-temperature environments. The presentation will also showcase case studies demonstrating significant improvements in the production of essential chemicals like hydrogen and ammonia, with a strong emphasis on the substantial environmental benefits, including reduced emissions.
Effect of Trace Moisture on the Corrosion of Commercial Alloys in Molten LiCl-KCl
Authors: Selmi Thomas , Moore Craig , Chidambaram Dev
Published: December 2024

The corrosivity of molten halide salts is increased by the presence of moisture in the salts. Moisture impurities can form hydroxides, oxides, oxyhalides, and hydrogen halide acids which can affect the corrosion rate of alloys in the salt. Corrosion tests using commercial alloys were performed in salts containing differing amounts of moisture to quantify this effect. In addition to corrosion data, surface characterization using X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, infrared spectroscopy and scanning electron microscopy was performed to fully characterize the corrosion products and the deleterious effects of the moisture impurity in the molten salt. Results from these studies will be presented.

This work was funded by DOE under grant DE-NE0009370 and DE-EE0009822 and ARPA-e under DE-AR0001697.
Localized Corrosion Behavior of Type 304 Stainless Steel Electrolytically Charged with Hydrogen
Authors: Tada Eiji , Cheng Hongming , Ooi Azusa
Published: December 2024

The authors have been studying the relationship between hydrogen-induced crack initiation and propagation mechanisms in type 304 stainless steels in chloride solution environments. As part of this study, plastic strain was applied to hydrogen-charged austenitic stainless steels to investigate crack initiation and propagation behavior. Interestingly, the induction time of localized corrosion and crack initiation almost disappeared in the case of hydrogen charging. Furthermore, it was observed that localized corrosion initiation also occurred quickly in the case of hydrogen-charged, however not plastically strained, specimens. Such localized corrosion behavior was attributed to the decrease in corrosion resistance of the passive film due to hydrogen charging. However, a detailed evaluation of the corrosion resistance of hydrogen-charged stainless steel has not been conducted. In this study, the effect of hydrogen charging on localized corrosion behavior was investigated by measuring anodic polarization curves of type 304 stainless steel electrochemically charged with hydrogen. The specimen used in the experiments was type 304 stainless steel. Hydrogen charging was performed by cathodic polarization at constant current in 1 M NaCl solution. The anodic polarization curves of hydrogen-charged 304 stainless steel were measured by a three-electrode method, using a Pt wire as the counter electrode and an Ag/AgCl electrode (saturated KCl) as the working electrode. Anodic polarization behavior of type 304 stainless steel after electrolytic hydrogen charging was the same as that of the specimens without hydrogen charging, and current changes in passivity and localized corrosion were observed, however pitting potential became lower due to cathodic polarization. The localized corrosion behavior due to hydrogen charging is discussed in this study.
Cathodic Corrosion of Copper: A DFT and Kmc Simulation Study
Authors: Sarker Hori Pada , Goswami Anshuman , Tang Michael , Ablid-Pedersen Frank
Published: December 2024

The electrochemical CO2 reduction reaction (eCO2RR) is one of the promising pathways which primarily leverages electrocatalysts such as copper (Cu) to facilitate the conversion of CO2 into higher value carbon products; C1 (e.g., CO, methane, formic acid, and methanol etc.) and C2 (e.g., ethylene, ethane, and ethanol etc.) using renewable electricity. Cu is the only monometallic electrocatalyst able to electrochemically transform CO2 into higher hydrocarbons with appreciable activity and selectivity. However, Cu and oxide-derived Cu surfaces (OD-Cu) fall short in stability or durability during eCO2RR. One significant challenge is the cathodic corrosion of Cu. Cathodic corrosion leads to degradation of Cu surfaces, reducing their catalytic activity, selectivity, and long-term operability. In this study, using a combination of density functional theory (DFT) and kinetic Monte Carlo (KMC) simulations, we delve into the intricate mechanisms driving this phenomenon. Our hypothesis posits the pivotal role of alkaline hydrogen evolution reaction (HER) in facilitating cathodic corrosion. Through comprehensive analysis, we establish correlations between various microenvironments, including subsurface oxygen (Osub) diffusion, pH-dependent OH adsorption on the Cu surface, and Cu dissolution as a (Cu-OH) complex into the electrolyte solution. We rigorously calculated the pH-dependent OH adsorption on the surface, as well as the stability and diffusion behavior of Osub. Furthermore, our investigation explores the significance of under-coordinated sites in Cu corrosion. By integrating DFT-derived thermodynamic data into our KMC model, we successfully predict the formation of experimentally observed corrosion pits on Cu surfaces. This combined approach not only advances our fundamental understanding of Cu cathodic corrosion but also offers insights crucial for developing effective corrosion mitigation strategies. The data obtained from theoretical calculations were also corroborated with available experimental observations. Finally, the details of this study will be presented during the conference.

Figure 1
Origin of Copper Dissolution in Electrocatalytic Reduction Conditions Involving Amines
Authors: Guan Yani , Sautet Philippe
Published: December 2024

Cu dissolution has been identified as the dominant process that causes cathode degradation and losses even under cathodic conditions involving . Despite extensive experimental research, our fundamental and theoretical understanding of the atomic-scale mechanism for Cu dissolution in electrochemical conditions, eventually coupled with surface restructuring processes, is limited. Here, driven by the observation that the working Cu electrode is corroded using mixtures of acetone and methylamine even under reductive potential conditions (-0.75V vs RHE), we employed Grand Canonical density functional theory to understand this dynamic process under potential from a microscopic perspective. We show that amine ligands in solution directly adsorb on the electrode, coordinate with the metal center, drive the rearrangement of the copper surface by extracting Cu atoms in low coordination positions, where other ligands can coordinate and stabilize a surface copper-ligands complex, finally forming a detached Cu-tetramine di-cation complex in solution, even at negative potential conditions. Calculations predict that dissolution would occur for a potential of -0.7 V vs RHE or above. Our work provides a fundamental understanding of Cu dissolution facilitated by surface restructuring in amine solutions under electroreduction conditions, which is required for the rational design of durable Cu-based cathodes for electrochemical amination or other amine involving reduction processes.
(Invited) Influence of Environmental Variables on Localized Corrosion
Authors: Schaller Rebecca Filardo , Katona Ryan
Published: December 2024

Localized corrosion and stress corrosion cracking (SCC) are potential degradation mechanisms for engineering alloys during exposure to corrosive environments. However, a variety of environmental factors can govern the localized corrosion environment that forms, and thus the subsequent corrosion susceptibility. One example variable, in atmospheric environments, is the relative humidity, which plays a role in establishing the equilibrium concentration and composition of a brine that forms. However, kinetically driven chemical and electrochemical reactions can also alter brine compositions, thus convoluting the role of RH plays in governing localized corrosion. Additionally, dynamic conditions, such as diurnal cycles, can further modify the influences of RH. This presentation will explore a range of environmental variables and their implications on corrosive environment formation, how they drive corrosion susceptibility, and potential variances in mechanism.

Acknowledgements

SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. This document is SAND 2024-04323A.
Kelvin Probe Techniques in Corrosion Science: Probing Reactivity with Spatial Resolution
Authors: Rohwerder Michael
Published: December 2024

More than 30 years after the introduction of the Kelvin Probe technique into corrosion research by Stratmann et al. [1, 2], Kelvin Probe techniques such as Scanning Kelvin Probe Microscopy (SKP) or Scanning Kelvin Probe Force Microscopy (SKPFM) are now quite routinely applied in the corrosion community. If the Kelvin probe is suitably calibrated, it allows to measure localized electrode/corrosion potentials [3]. Some main applications are for studying delamination of organic coatings and ion migration [2, 4, 5], mapping of hydrogen distribution [6], or characterizing potential differences on the surface of materials for assessing the risk of formation of Galvanic elements on the surface [7]. Besides such experiments where maps of the electrode potential are obtained, it is also possible to obtain meaningful information about the localized electrochemical activity, such as reaction kinetics of ORR, for instance [8]. There are different variants of how to use Kelvin Probe-based techniques to assess the activity of localized Galvanic coupling and also to monitor for instance the degree of inhibition of ORR by released inhibitors, such as Zn2+ [9]. In this presentation further and more recent examples will be presented.

[1] S.G. Yee, R.A. Oriani, M. Stratmann, J. Electrochem. Soc. 138 (1991) 55-62

[2] R. Feser, M. Stratmann. Materials and Corrosion 42 (1991) 187-195

[3] R. Hausbrand, M. Sratmann, M. Rohwerder, J. Electrochem. Soc. 155 (2008) C369-C379

[4] C. Senoz, M. Rohwerder, Electrochim. Acta 56 (2011) 9588-9595

[5] J. M. Prabhakar, A. de Vooys, M. Rohwerde, Npj Materials Degradation 6 (2022) 76

[6] S. Evers, C. Senoz, M. Rohwerder, Science and Technology of Advanced Materials 14 (2013) 014201

[7] P. Schmutz, G.S. Frankel, J. Electrochem. Soc. 145 (1998) 2295-2306

[8] X. K. Zhong, et al., Chemelectrochem 8 (2021) 712-718

[9] R. Krieg et al., Corros. Sci. 65 (2012) 119-127
Understanding the Effect of Microstructure and Composition on Localized Corrosion Susceptibility of 6xxx Aluminum Alloys
Authors: Frankel Gerald S. , Adapala Priyanka , Avey Thomas , Yuan Yudie , Lim Mary Lyn , Bhaskaran Ganesh , Das Sazol , Luo Alan
Published: December 2024

The corrosion performance of 6xxx series Al alloys has been found to depend on small changes in composition and microstructure. The corrosion behaviors of three aluminum alloys, AA6111, AA6451 and AA6016, were investigated. AA6111, containing primarily α (Al15 (Fe,Mn)3Si2) intermetallic particles (IMPs), and AA6016, containing primarily β (Al8Fe2Si) IMPs, exhibited the best and the worst overall corrosion performances, respectively, as indicated by the extent of corrosion in exposure tests. However, this ranking was not predicted by standard interpretation of potentiodynamic polarization curves measured on the alloys. The corrosion susceptibilities of the three alloys were further investigated by evaluating the electrochemical behavior of the component phases separately. Bulk analogs of the component phases were fabricated using standard alloy casting techniques. The fabricated bulk analogs of α and β IMPs as well as the three alloy matrix phases were tested using either macrocell or microcell testing. An explanation for the alloy performances was developed by combining the behavior of the component phases.
In-Situ Non-Destructive Corrosion Monitoring
Authors: Seisdedos Gonzalo , Prisbrey Milo Guy , Vakhlamov Pavel , Pantea Cristian , Davis Eric Sean , Rockward Tommy
Published: December 2024

Proton exchange membrane fuel cells (PEMFCs) frequently utilize metallic bipolar plates because they are easy to manufacture, possess excellent electrical and thermal conductivity, and have strong mechanical properties. However, the acidic environment within fuel cells can be corrosive to the metallic bipolar plate, which can gradually degrade its surface. This corrosion-induced degradation causes a reduction in performance over time due to decreased electrical conductivity, reduced mechanical integrity, and contamination of the electrolyte. Current corrosion characterization methods in bipolar plates involve lab-type equipment and cannot be performed while the fuel cell is in operation, decreasing their feasibility and practicality. Therefore, having the capability to characterize the corrosive state of the bipolar plate in real time is essential to reduce operational and maintenance costs while ensuring adequate performance of the fuel cell.

A customized in-situ characterization method using ultrasound was utilized to assess the quality of the surface of a titanium bipolar plate while being exposed to a minute amount of sulfuric acid solution. Potentiostatic and potentiodynamic conditions at various temperatures (30-80 ºC) were tested to simulate the PEMFC operating environment. Corrosion was detected and monitored as it was induced on the surface of the bipolar plate. This non-destructive method is not only useful for characterizing the degradation of bipolar plates, but it can also help understand the corrosion dynamics of different materials at varying operating conditions.
Fabrication of Alumina Membrane Filters with Framework
Authors: Yanagishita Takashi , Boushi Youta
Published: December 2024

Membrane filters are becoming increasingly important because of their wide range of applications. Precise control of the pore size is essential for precise separation using membrane filters. In addition, a high solution permeability is required for efficient filtration. We previously reported that a large alumina membrane filter with a high density of pores and uniform diameter can be obtained by detaching anodic porous alumina from Al substrates by two-layer anodization using concentrated sulfuric acid [1]. Using this method, the pore size and thickness of the resulting alumina membrane can be controlled by adjusting the preparation conditions, making it possible to produce alumina membrane filters suitable for various applications. However, the resulting alumina membrane filters have a nanohole array structure with cylindrical pores, which makes it difficult to achieve efficient filtration because the solution permeability deteriorates as the thickness of the membrane increases. On the other hand, reducing the membrane thickness to improve the solution permeability results in the deterioration of the mechanical durability. Therefore, alumina membrane filters have a problem in that they cannot achieve both solution permeability and mechanical durability.

In this report, we describe the preparation of membrane filters with a structure consisting of a thin filter layer formed at the openings of a thick framework that serves as the support layer. The structure of the membrane filter proposed in this study allows the mechanical strength of the membrane to be reinforced by a thick framework and the filter layer to be thin. This allows the membrane filter to achieve a high permeability and mechanical strength, which is a problem with conventional ordered alumina through-pore membranes.

Anodic porous alumina, consisting of a thick framework and a thin filter layer, was prepared by selective etching of anodic porous alumina with a resist mask and re-anodization [2]. Finally, an alumina membrane with a framework was fabricated by detaching porous alumina from the Al substrate via two-layer anodization using concentrated sulfuric acid. The framework structure can be controlled by changing the resist pattern formed on the anodic porous alumina. The thicknesses of the filter and framework layers can also be controlled by adjusting the anodization time. The results of the water permeation measurements using the obtained alumina membrane filter confirmed that it exhibited high permeation performance. The membrane filter with the framework obtained in this study is expected to efficiently separate and filter various substances, such as microplastics, viruses, and bacteria.

References

[1] T. Yanagisihta and H. Masuda, Electrochim. Acta, 184, 80 (2015).

[2] Y. Boushi and T. Yanagishita, Langmuir, 40, 5278 (2024).
Semiconducting/Ferromagnetic Nanocomposites Investigated By High Temperature FORC
Authors: Granitzer Petra , Rumpf Klemens , Gonzalez-Rodriguez Roberto , Nachtnebel Manfred , Coffer Jeffery
Published: December 2024

In the frame of this work magnetic interactions between magnetic nanostructures (Ni, Co, NiCo, and Fe3O4) deposited within porous silicon (PSi) and silicon nanotubes (SiNTS) are investigated by first order reversal curves (FORC). Magnetic cross-talk between metal deposits can be controlled by the morphology of the porous silicon (distance between the pores) or silicon nanotubes (wall thickness) and also by the distribution and size of the deposits within the pores. To get a clear knowledge about the magnetic interactions single hysteresis curves are not sufficient and thus first order reversal curves (FORC) are performed. The temperature-dependency of the magnetization of the various composite systems consisting of (PSi) and (SiNTs) with embedded Ni, Co, NiCo, and Fe3O4 structures is discussed. The temperature is varied between 80 and 1273 K which allows to determine the Curie Temperature of the composites which differs from the corresponding bulk materials. High temperatures result in an alteration of the chemical sample-composition. Depending on the temperature specific metal-silicide formation occurs usually beginning around 600 K. This leads to modified magnetic behavior of the composites which can be observed by repeated measurements.