bluuebunny/crossref_metadata_2025 huggingface dataset:
(Digital Presentation) Improved Properties of Polyurethane Coatings Using Mesoporous Silica Nanoparticles Loaded with Imidazole
Authors: AlJundi Ibrahim , Shakoor R. a. , Hasan MD Anwarul
Published: December 2024

Corrosion causes damage to the steel infrastructure, and polyurethane coatings were developed to overcome this issue. Three types of samples were evaluated in the study: the first consisted of pure polyurethane (PU), serving as the reference for comparison; the second incorporated Mesoporous Silica (MSN) within the polyurethane matrix; and the third involved polyurethane mixed with Imidazole-loaded MSN, which was then applied to the carbon steel substrate. Thermogravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR) affirmed the effective encapsulation of the corrosion inhibitor Imidazole in MSN, achieving a loading capacity of 37 wt.%. The electrochemical technique was employed to assess the corrosion resistance, where results obtained from Electrochemical Impedance Spectroscopy (EIS) over a period of 168 hours indicated that the Imidazole-loaded coatings provided more robust and consistent corrosion protection compared to both the MSN-enhanced and the pure PU samples by maintaining the impedance above 1 GΩ by the end of the test period while the other two sample types went below 1 MΩ. This enhanced protective performance is credited to the inhibitor's role in passivating the steel surfaces against saltwater exposure. Additionally, Potentiodynamic testing (Tafel) on scratched samples over 144 hours period showing a change in the corrosion current from 1.07 μA to 20.4 μA then back to 10.8 μA for the MSN, and from 1.39 μA to 7.54 μA and finally back to 2.07 μA for the Imidazole loaded MSN-PU coating demonstrating the corrosion protection benefits of both coating with better performance when using the Imidazole loaded MSNand better the an the steadily decreasing performance in the pure PU samples going from 3.43 μA to 40.2 μA over the same timeframe.
(Invited) In-Operando Vibrational Spectroscopy for Next Generation Lithium Batteries
Authors: Kalra Vibha
Published: December 2024

In this talk, I will present our group’s research on in-operando vibrational spectroscopy for next generation lithium batteries. In the first half of the presentation, I will discuss our work on in-operando ATR-FTIR spectroscopy to develop a molecular level understanding of the polysulfide speciation, product-cathode and product-electrolyte interactions in Lithium sulfur batteries. I will specifically focus on sulfurized polymers, sulfur-diisopropenylbenzene copolymer and sulfurized polyacrylonitrile, and the role of C-S bonds in defining their redox mechanism in Li-S batteries. In the second half of my presentation, I will discuss our research on in-operando Raman spectroscopy that allows us to probe Raman active species in the electrode, electrolyte and the SEI in Lithium batteries. Using this technique, we have monitored the evolution of the dynamic interface of an anode-free gel polymer electrolyte cell as it undergoes lithium plating and stripping. In doing so, we also observe initial SEI components that form on the copper electrode before lithium plating. The flexibility of this technique allows us to observe these types of interfacial products in-operando for any solid electrolyte
Dual Atmosphere Oxidation of Fe-9mass%Cr Alloy at 923 K Using Samples with Hydrogen Charged Palladium
Authors: Ueda Mitsutoshi , Norimatsu Shunsuke
Published: December 2024

Hydrogen have an effect on initial steam oxidation behavior of heat resistant steels and alloys. This effect can be observed clearly in dual atmosphere oxidation. Initial oxidation test in the dual atmosphere gives useful knowledge to clarify the hydrogen effect in steam oxidation. However, dual atmosphere oxidation tests are inapplicable to initial oxidation and include some technical difficulties in assembling and sealing. In contrast, in-situ observation using microscopes is one of the useful techniques to clarify particularly initial oxidation, whereas this technique is used only for small samples. This study aims to fabricate a small sample with hydrogen charged palladium and simulate dual atmosphere oxidation using this sample. A disk-shaped sample of Fe-9mass%Cr alloy with blind holes was prepared. Several pieces of hydrogen charged palladium were placed in the blind holes, then the blind holes were sealed with cupper bars. After preparing the sample, oxidation test was conducted at 923 K for 1.8 ks in ambient air. A sample without hydrogen charged palladium was also oxidized as a reference sample. For the sample with hydrogen charged palladium, magnetite mainly formed on the sample after oxidation. This acceleration in oxidation is caused by hydrogen permeation from inside the sample during oxidation. Overall, this method is useful for in-situ observation during dual atmosphere oxidation.
Electrochemical Study of the Hot Corrosion Behavior of TP347H in Coal Ash
Authors: Hu Shanshan , Zhang Youyuan , Liu Xingbo
Published: December 2024

To maximize the effectiveness and efficiency of regular maintenances, it is crucial to predict the lifetime of critical components in coal-fired power plant by understanding the corrosion behavior of alloys in coal ash with varying thickness due to the continuous deposition and under different temperatures. This study explores the hot corrosion behavior of TP347H, which is a material commonly used as superheaters, in coal ash of varying thickness and at different temperatures. Through the use of electrochemical techniques such as open circuit potential (OCP), electrochemical noise, and potentiodynamic polarization (PDP), this study demonstrates a bell-shaped variation in the corrosion rate of TP347H between 650°C and 750°C. Furthermore, it was found that an increase in the thickness of coal ash significantly accelerates the kinetic processes involved in corrosion.
Investigation of Metal Oxides as Potential Anodes for Oxide Reduction in Molten LiCl-Li2O
Authors: Moore Craig , Selmi Thomas , Chidambaram Dev
Published: December 2024

During the electroreduction step of pyroprocessing, UO2 is reduced to metal while oxygen is evolved at an anode in a molten LiCl-Li2O electrolyte. Replacement of currently used high cost noble metal anode materials, such as platinum, that corrode during operation with transition metal oxides will improve the economic feasibility of pyroprocessing. Conductive transition metal oxides were tested to investigate their durability as anodes in molten LiCl-Li2O. Electrochemical and post testing surface characterization results including X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy will be presented to provide insight into the durability of the tested materials.

This work was performed under ARPA-e grant DE-AR0001697. XPS was purchased under NSF MRI award 2117820. C.M. is supported by DOE Fellowship under award DE-NE0009105.
Hot Corrosion Behavior of Nickel-Based Superalloys in Molten Na2so4-MgSO4 Salts
Authors: Zhang Youyuan , Hu Shanshan , Teka Michael , Liu Xingbo
Published: December 2024

Due to their excellent mechanical properties and corrosion resistance, nickel-based superalloys are extensively used in the hot components of turbine blades and aero engines. However, the molten sulfate salts induced hot corrosion might significantly undermine the performance. To reveal the underlying mechanism, herein, various electrochemical methods including open circuit potential (OCP), electrochemical noise (EN), electrochemistry impedance spectroscopy (EIS) and potentiodynamic polarization (PDP), have been utilized to systematically investigate the hot corrosion behavior of three Ni-based alloys, i.e, Waspaloy, IN718 and IN100, in Na2SO4/MgSO4 eutectic molten sulfate salts at 700°C. With the aid of electrochemical study and post-mortem analysis, the mechanism, corrosion rate and type of corrosion are elucidated in detail.
Effects of Cr on Microstructure and Pitting Corrosion Resistance of Femnalc Lightweight Steels
Authors: Ha Heon-Young , Park Seong-Jun , Kim Kyong-Won , Lee Chang-Hoon , Lee Tae-Ho , Moon Joonoh , Lee Ho Sik
Published: December 2024

Lightweight steels, characterized by a significant addition of Al, have lower density compared to conventional steels. These steels are attracting attention due to their excellent mechanical properties and the anticipated weight reduction effect that would result from replacing conventional steels with low-density alternatives. FeMnAlC lightweight steel was initially developed in the 1950s to create inexpensive corrosion-resistant steel, but it exhibits significantly lower corrosion resistance compared to FeCrNi stainless steel. In this study, the effects of Cr content on the microstructure and pitting corrosion resistance of Fe-19Mn-12Al-1.5C-xCr (wt%) lightweight steel were investigated. Microstructural analysis indicated that the optimal Cr content for a homogeneous austenitic microstructure was 5 wt%. Cr content higher than 5 wt% resulted in a multi-phase microstructure composed of austenite, ferrite, and Cr7C3. Passive film analysis showed that alloying Cr up to 5 wt% in the matrix increased both the Cr and Al content in the passive film. Thus, Fe-19Mn-12Al-1.5C-5Cr exhibited the highest resistance to pitting corrosion among the investigated alloys due to the homogeneous microstructure and a (Cr,Al)-enriched passive film.
Effect of Sn on Dissolution Behavior of Al Prepared By Spark Plasma Sintering
Authors: Nishimoto Masashi , Shinagawa Fuki , Muto Izumi
Published: December 2024

Aluminum-air batteries are promising power source alternatives owing to the high specific capacity, abundant reserves, and light weight of the Al anode. Alkaline and neutral solutions have been considered as electrolytes for aqueous Al-air batteries. A uniform dissolution is required for the anode of Al-air batteries. However, localized corrosion generally occurs on Al in a neutral solution. In this study, the effect of Sn addition on the dissolution behavior of Al was investigated.

Sn-free and Sn-added specimens were fabricated by ball milling and spark plasma sintering. The dissolution behavior of the specimens was analyzed by potentiostatic polarization in 2 M NaCl. An optical microscope and a scanning electron microscope equipped with an energy-dispersive X-ray spectroscopy system were used to capture images of the specimen surfaces.
60 Years' Marine Corrosion of Aluminium Alloy 24S (A2024) - Conservation and Treatment of Very Corroded Aluminium Alloys with 100% Carbon Vegetal Corrosion Inhibitors
Authors: Rocca Emmanuel , Paris-Mirambet Agnès , Mirambet Francois
Published: December 2024

Aluminium alloys forming the remnants of Lockheed P38 of Antoine de Saint-Exupéry was identified as the 24S aluminium alloy developed in 1930’s. After 60 years in seawater, thick corrosion layers composed of aluminium hydroxide, copper salts and nanometre pure copper particles. In addition, the ancient aluminium alloy has undergone a very important intergranular corrosion. After the synthesis of Al2Cu, Al7Cu2Fe and Al2CuMg intermetallic phases, the study of their electrochemical behaviour in NaCl medium explains the significant presence of pure copper, because all the phases undergo a dealloying process. Electrochemical impedance spectroscopy measurements show that the kinetic of dealloying is constant versus immersion time, and is not limited by diffusion which explains the complete formation of copper sponge in NaCl medium in the conditions of long-term corrosion on aluminium artefacts.

Specific corrosion inhibitors (non-toxic and based on vegetal compounds) were developed to treat the artefacts in very corroded 24S alloys from Lockheed P38 to respect the specifications of conservation of cultural heritage.
Transmission Electron Microscope Characterizations of the Localized Corrosion Behavior of Biodegradable ZX21 Mg Alloy in Hanks’ Balanced Salt Solution
Authors: Sung Chih-Wei , Fan Chien-Wei , Chen Chun , Chu Peng-Wei
Published: December 2024

Magnesium (Mg) alloys attract a lot of attention as next-generation biodegradable implant materials due to their excellent biocompatibility and unique biodegradability. By utilizing Mg alloys as implants, Mg alloys can be degraded naturally in the human body, avoiding the second removal surgery. In addition, Mg alloys are promising for orthopedic applications because of their similar density and mechanical properties to bones, which mitigate the stress shielding effect. Among various Mg alloy systems, the ZX-series Mg alloys, which contain zinc (Zn) and calcium (Ca), show great potential for orthopedic applications since Zn and Ca are essential for metabolism and bone regeneration and improve the mechanical strength of the alloys. However, localized corrosion of a ZX-series Mg alloy was reported in our previous study [1], leading to a faster degradation rate and possible premature failure of the implant.

To further study the origin and detailed mechanism of the localized corrosion behavior of ZX-series Mg alloys in simulated physiological environments, transmission electron microscope (TEM) characterizations were performed on a ZX21 (Mg-2.15 wt%Zn-0.97 wt%Ca) Mg alloy before and after corrosion in a Hanks’ balanced salt solution (HBSS) at 37°C. Two second phases, Ca2Mg6Zn3 and Mg2Ca, were found adjacent to each other in the cast ZX21 alloy. The potential difference between the two second phases leads to microgalvanic corrosion and the preferential dissolution of the lower-potential Mg2Ca, initiating localized corrosion on the alloy surface. The localized corrosion propagates a few micrometers deep in the alloy and underneath the surface corrosion film. By selected area electron diffraction (SAED) and energy dispersive X-ray spectroscopy (EDS) analysis in TEM, the corrosion products in the propagating localized corrosion regions are primarily composed of Mg(OH)2, which is different from the surface corrosion film (Mg(OH)2 + CaHPO4·2H2O) formed on the alloy surface [1]. Furthermore, the presence of Cl signal in the localized corrosion regions indicates that the Cl- ions in HBSS promote the propagation of localized corrosion.

[1] P.W. Chu et al., Corrosion Behavior and Microstructure of the Surface Corrosion Film of Biodegradable WE43 and ZX21 Mg Alloys in Hanks’ Balanced Salt Solution, Materials Chemistry and Physics, vol. 312, pp. 128609-128620, 2024.
Corrosion Behavior of Additively Manufactured AZ91 Mg Alloy
Authors: Reyes Raul , Garcia-Galvan Federico R. , Jiménez José Antonio , Feliu Sebastian , Barranco Violeta , Galvan Juan Carlos , Fajardo Santiago
Published: December 2024

Additive manufacturing, heralded for its ability to produce intricate geometries with unparalleled precision while potentially minimizing material and energy consumption compared to traditional methods, has garnered significant attention in recent years. Magnesium, with its density of around 1.74 g/cm³ and appropriate mechanical strength, is an appealing lightweight structural material widely employed in industries such as automotive and aerospace. Despite these advantages, the corrosion behavior of additively manufactured magnesium alloys remains relatively unexplored, posing challenges for their widespread adoption. In this work, the corrosion behavior of AZ91 Mg alloy obtained through additive manufacturing was investigated.

Cylindrical AZ91 Mg alloy samples were fabricated using the Powder Bed Laser Fusion (PBLF) technique. Analysis was conducted in both the transverse and longitudinal planes, where the transverse plane represents the top plane of the cylinder and the longitudinal plane represents a section through the center of the cylinder. This comparative approach, allowed a comprehensive examination of corrosion kinetics and behavior across different orientations. Furthermore, cast AZ91 Mg alloy was also studied for comparative purposes.

Potenciodynamic polarization (PDP) tests, including both cathodic and anodic polarization, revealed similar kinetics for both the longitudinal and transverse planes studied, indicating consistent corrosion behavior across different orientations.

Simultaneous gravimetric hydrogen collection and electrochemical impedance spectroscopy measurements (EIS) were performed to elucidate the underlying mechanisms governing corrosion processes. Furthermore, galvanodynamic polarization tests were employed to investigate the anomalous hydrogen evolution (AHE) intrinsic to Mg alloys. These tests were conducted in both planes, with concurrent hydrogen collection. Additionally, the role of the beta-Mg17Al12 phase on the electrochemical response of the additively manufactured AZ91 Mg alloy was investigated.

The results of this study have significant implications for various industries, particularly automotive and aerospace applications, where Mg corrosion resistance is crucial for ensuring structural integrity and component longevity. Understanding the corrosion behavior of additively manufactured Mg alloys is paramount for optimizing their performance and facilitating widespread adoption in critical applications.
Nanoscopic Strain-Associated Lithium Diffusion in Single-Crystalline NMC Battery Particles
Authors: Lee Danwon , Nam Chihyun , Kim Juwon , Koo Bonho , Hyun Hyejeong , Chung Jinkyu , Seo Sungjae , Song Munsoo , Song Jaejung , Alsem Daan Hein , Salmon Norman , Lee Suyong , Kim Namdong , Shapiro David , Lim Jongwoo
Published: December 2024

Understanding the dynamics of lithium diffusion within solid-state electrodes is pivotal for advancing high-performance batteries. Conventionally, lithium diffusion within solid-solution battery particles has been assumed to be solely driven in the direction of minimizing the concentration gradient, resulting in a monotonous lithium distribution. However, employing operando scanning transmission X-ray microscopy, this study has revealed the presence of non-monotonous dense and dilute concentration domains of lithium within individual single-crystalline LiNi1/3Mn1/3Co1/3O2 particles at the nanoscale during charging and discharging processes. Our findings advocate that the formation of Li-dense and -dilute domains is associated with nanoscopic non-uniform strain fields, challenging conventional solid-solution lithium diffusion models that rely solely on the concentration gradient as the driving force. Bragg coherent X-ray diffraction imaging verified such non-uniform nanoscopic intraparticle strain fields, which may cause the direction of lithium diffusion to deviate from the direction of the concentration gradient. Moreover, we have identified that Li-dilute domains near the surface could be manipulated in situ to enhance rate-capability. This study paves a new avenue for understanding solid-state diffusion at the nanoscale, enabling the fabrication of high-performance batteries.

Figure 1
Effects of Composition and Texture of Ti Alloys on the Anodic Growth of Nanotubular Oxide Layers
Authors: Tsuchiya Hiroaki , Fujimoto Shinji
Published: December 2024

Anodization has been used to fabricate nanoporous and nanotubular oxide layers on many metals and alloys. Solution chemistry is one of the important factors that affect the growth of the layers. On the other hand, metallurgical aspects have been also examined. In the present work, effects of composition and texture on the growth of anodic nanotubular oxide layers are examined, in particular Ti alloys are focused.
Radical Surface Chemistry: The Surprising Reactivity of Silica and Partially Oxidized Porous Silicon Surfaces
Authors: Li Yangie , Narasimhan Ramya , Monack Denise M. , Zare Richard N , Hetzel Juliana T , Kolasinski Kurt W
Published: December 2024

Silica and amorphous silicon oxides are generally considered to be inert substrates but have recently been shown to exhibit surprising catalytic activity as a base.1,2 While their weakly acidic nature has long been recognized, recent work has shown that during the formation of microdroplets contact electrification at the water/SiO2 interface is related to formation of radical species such as •OH and H•.3,4 Nano- and micro-structuring, asperities, and anisotropic charge distributions within the double layer may all play roles in the generation of electric fields that facilitate electrochemical processes such as the stripping of an electron from OH– generated by water autoionization that leads to •OH radical formation.5,6 Such radicals may participate in aqueous phase chemistry or produce surface bound radicals such as SiO• that act as active sites. We present evidence for such radical-mediated chemistry at amorphous silica and partially oxidized porous silicon surfaces. Examples include the formation of disulfide linkages from amino acids including cysteine, penicillamine, and glutathione that are mediated by a surface radical site on amorphous silica surfaces.7 Partially oxidized porous silicon is found to be a prodigious producer of H2O2 formed by the reactions of •OH radicals (or other reactive oxygen species) in solution. The reactive oxygen species formed couple synergistically with reduced pH to effectively kill salmonella. Experimental studies are supported by density functional theory (DFT) calculations, which are used to screen possible reactions based on their thermodynamics as well as to explore reaction pathways.

1Y. Li, T. F. Mehari, Z. Wei, Y. Liu, and R. G. Cooks, Angew. Chem., Int. Ed. Engl. 60, 2929 (2021).

2Y. Li, K.-H. Huang, N. Morato, and R. G. Cooks, Chem. Sci. 12, 9816 (2021).

3X. Chen, Y. Xia, Z. Zhang, L. Hua, X. Jia, F. Wang, and R. N. Zare, J. Am. Chem. Soc. 145, 21538 (2023).

4M. A. Mehrgardi, M. Mofidfar, and R. N. Zare, J. Am. Chem. Soc. 144, 7606 (2022).

5C. F. Chamberlayne and R. N. Zare, J. Chem. Phys. 152, 184702 (2020).

6H. Hao, I. Leven, and T. Head-Gordon, Nature Communications 13, 280 (2022).

7Y. Li, K. W. Kolasinski, and R. N. Zare, Proc. Natl. Acad. Sci. U. S. A. 120, e2304735120 (2023).
(Invited)Titania Nanostructures in Single-Atom-Mediated Photocatalytic Processes
Authors: Schmuki Patrik
Published: December 2024

In1972 Fujishima und Honda (1972) reported on the use of TiO2 as a solar-illuminated semiconductor for the splitting of water into H2 and O2. Meanwhile, a large body of literature exists on photocatalytic H2 generation using a wide variation of semiconductors, morphologies, and strategies to split water using the semiconductors suspended in an aqueous solution (with or without sacrificial agents). Many semiconductors have in common that for an efficient transfer of photogenerated charge carriers, a co-catalyst is required. For electron transfer and H2 generation mostly Pt nanoparticles are used that are deposited onto the semiconductor surface by various techniques. Due to the precious nature of Pt, over the years, numerous efforts have been devoted to the shrinkage of the particle size and thus to enhance the utilization of the noble metal – in the most extreme case down to an insulated single atom of Pt.

In the presentation we discuss the use of Pt dispersed and anchored as single atoms (SAs) on TiO2 surfaces and the activation to a most efficient use for photocatalytic H2 generation. We discuss various trapping and stabilization approaches of SAs on photocatalysts that prevent agglomeration (and according deactivation of SA Pt). Moreover, we show that only a small amount of Pt (loading density of SAs) is needed to achieve a maximum activity of a semiconductor surface.

References

Fujishima A, Honda K., Nature, 238 (1972) 37–38Denisov N., Qin S., Will J., Vasiljevic B.N., Skorodumova N.V., Pašti I.A., Sarma B.B., Osuagwu B., Yokosawa T., Voss J., Wirth J., Spiecker E., Schmuki P., Advanced Materials 35 (2023) art. no. 2206569Wang Y., Qin S., Denisov N., Kim H., Bad'ura Z., Sarma B.B., Schmuki P., Advanced Materials 35 (2023) art. no. 2211814Qin S., Will J., Kim H., Denisov N., Carl S., Spiecker E., Schmuki P., ACS Energy Letters, 8 (2023) 1209 – 1214Qin S., Denisov N., Kim H., Schmuki P., Angewandte Chemie Int. (in press)
(Invited) A New Perspective on Pore Growth in Anodic Alumina Films
Authors: Ono Sachiko
Published: December 2024

Pores in the porous-type anodic oxide film of aluminum have conventionally been thought to grow vertically in a straight tube-like manner. However, branching and nano-branching pores (referred to as feather-like) typically observed in films generated in chromic acid solutions are considered non-steady-state morphologies. However, are these formed only under specific conditions? These have also been observed in neutral borate electrolytes, highlighting the need to clarify the dominant factors governing pore morphology. In this study, we report the results of observations and discussions on the fine structure of pore morphology, including typical films grown in oxalic acid or sulfuric acid, using state-of-the-art analytical techniques to elucidate the dominant factors influencing pore formation [1].

Observation of the initial pore formation in the three types of electrolytes, sulfuric acid, oxalic acid, and phosphoric acid, reveals that the initial pores are considerably smaller in diameter and more numerous than the main pores. This is presumed to be due to pore formation through dissolution under low electric field strength caused by the presence of a thick barrier layer. Observation of the growth process of pores generated in sulfuric acid and oxalic acid electrolytes using high-resolution TEM revealed that neither film grows in a tubular manner but rather undergoes repeated branching at a fine scale. The cause of nano-branching in the main pores is similarly attributed to thickening of the barrier layer for some reason in the electrolyte, resulting in a decrease in the electric field. Thus, it is considered that pores do not grow in a straight tube-like manner but rather universally involve branching, and the grown pores are subsequently smoothed out by chemical dissolution.

These results thus indicate that the formation of radial nano-branched pores is not unique to chromic acid films. Instead, this is a universal phenomenon of anodic films that frequently occurs when the electric field strength decreases during anodizing for the same reason. When Thompson et al. first reported horizontal cross-section observations of various porous anodic films in 1978, they stated that “steady-state anodizing is not as regular as previously assumed”. This remains true, and elucidation of the actual structure of the porous film is important for more effective application of the film.

[1] S. Ono, H. Asoh, Electrochem. Comm. (2021).

Figure 1
Highly Efficient Blue Energy Harvesting By Nanoarchitectured Tri-Continuous Porous Structures with Ultrathin Light-Responsive Covalent-Organic Framework Membrane
Authors: Peng Yu-Hsiang , Yeh Li-Hsien
Published: December 2024

Designing ion-selective membranes for directly energy harvesting from a salinity gradient between seawater and river water has attracted significant interest. Despite increasing efforts have been made, achieving simultaneously smart ion transport as well as high-performance blue energy output remains largely unexplored. Herein, we report a novel light-responsive ionic diode membrane (TpOMe-Azo/BANM), composed of a branched alumina nanochannel membrane (BANM) and an ultrathin light-responsive TpOMe-Azo covalent-organic framework (COF) layer. The design endows the heterogeneous membrane with tri-continuous porous structures of large-geometry gradient from submicro-scale to sub-3 nm-scale, amplifying diode-like directional ion transport property. The orderly and negatively charged sub-3 nm-scale ion channels in TpOMe-Azo COF makes it highly cation-selective. We demonstrate that the incorporation of the TpOMe-Azo COF endows the membrane with high light-regulated ion transport behavior up to 50% under the UV light irradiation. Benefiting from the merits of high cation-selectivity and ionic diode property, the exploited membrane can produce a high power density of 5.46 W/m2 under the concentration gradient condition of mixing seawater and river water, and even achieves an unprecedented value of up to 7.16 W/m2 under the UV light irradiation. This groundbreaking design of the ionic diode membrane not only marks a substantial advancement in materials science but also delves into novel avenues for light-amplified ion transport utilizing heterogeneous ionic diode membranes.

Figure 1
Chloride-Induced Stress Corrosion Cracking Behavior of Duplex Stainless Steels for Dry Storage Canister Application Via Atmospheric Corrosion Tests and Scanning Electrochemical Microscopy
Authors: Kim Seunghyun , Park Suhyun , Gu Minsu , Jang Changheui , Kim Gidong , Song Sang-Woo
Published: December 2024

This study presents an analysis of Chloride-induced Stress Corrosion Cracking (CISCC) behavior in Duplex Stainless Steels (DSS), which are among the candidate materials for dry storage containers for spent nuclear fuel. Dry storage containers, designed to securely store spent nuclear fuel under reduced temperatures and radiation levels, are typically constructed from stainless steel due to its high corrosion resistance and excellent mechanical properties. These containers are expected to be installed in various environments, including coastal areas, taking into consideration cooling efficiency. However, austenitic stainless steels like 304L and 316L are known to be susceptible to CISCC in environments characterized by cyclic changes in humidity and temperature, leading to the deliquescence of salts. In this context, the present study involves an evaluation of CISCC and a Scanning Electrochemical Microscope (SECM) analysis of localized corrosion in two types of DSSs: commercial 2205 and a newly developed improved DSSs. Previous research has shown that delta ferrite formed in 304L-ER308L welds is susceptible to CISCC, serving as preferential sites for crack initiation and propagation. However, the experimental results obtained thus far indicate that CISCC did not occur in the two types of DSSs tested. Nevertheless, it has been observed that there are significant electrochemical differences between the two phases in DSS. Therefore, further investigations are planned to analyze the CISCC behavior of DSSs in more detail.
Accuracy and Limitations of Measuring Corrosion Rates and Depth of Penetration on Corroded Steel Plates Using Dual-Element Ultrasonic Sensors
Authors: Yamamoto Blake , Hihara Lloyd H.
Published: December 2024

Monitoring corrosion is a vital step to prevent catastrophic structural failure. With accurate corrosion rate data, the risk of failure can be mitigated by performing routine maintenance on components that have become compromised. When corrosion occurs in an inaccessible area such as the inside of a pipe or back side of an underground storage tank, however, conventional monitoring techniques such as visual inspection are inadequate or impossible. Non-destructive evaluation (NDE) techniques must be used to determine the condition of the structure to maintain its integrity. Ultrasonic (UT) Thickness Sensors were investigated for corrosion monitoring use. The chosen sensors had a resolution of a limit of 25.4μm. A system was designed to utilize Electrochemical Machining (ECM) to simulate a corrosion at various rates in a localized region (approximately 1 cm in diameter) while its thickness was monitored by a permanently attached UT sensor. Multiple techniques such as a 3D profilometer, and depth-gauge were used to validate the measurement of the permanently attached UT sensor. Multiple ECM experiments were conducted using NaCl electrolyte solution at 1, 10, and 100 g/L concentrations. Occasionally, variations in pit formation were observed and likely caused by the orientation of the counter electrode to the steel surface. The smallest and most consistent surface roughness was obtained using the 10 g/L concentration. Larger variations in surface roughness were observed at 1 and 100 g/L NaCl concentrations leading to the selection of 10 g/L solution for experiments. The ECM system rendered reproducible machining rates showing that the UT sensors were capable of monitoring very low corrosion rates averaged to 3μm per day. Discrepancies up to a few mm were sometimes measured between the UT sensor, 3D profilometer and depth-gage values. The discrepancies were attributed to non-uniform corrosion in the vicinity of the permanently attached UT sensor. The sensor therefore provided readings of a specific localized spot of the corroded region, or the profile of the corroded region interfered with the UT signals. The accuracy of UT sensor readings was also studied for various geometrical pit profiles. Certain defect geometries made it impossible for the UT sensor to record accurate measurements. This was also observed on naturally corroded steel plates. Therefore, UT sensors may sometimes provide inaccurate or no reading over certain corrosion profiles and should therefore be used with prudence.
Performance and Degradation of Li-Ion Battery Cells for Stationary Applications
Authors: Choi Daiwon , Shamim Nimat , Thomsen Edwin , Huang Qian , Crawford Alasdair , Viswanathan Vilayanur , Reed David M , Sprenkle Vincent
Published: December 2024

Electrochemical energy storages (EES) are being actively deployed as more renewable energy generation are integrated into the grid infrastructure. Among various EES, Li-ion batteries share more than 80% of EES utilized but reliability and performance have not been clearly evaluated and compared. In this presentation, performance of nine different commercial Li-ion battery cell chemistries under standardized grid duty cycle testing protocols developed by DOE-OE will be presented. The lifecycle derived from capacity, round trip efficiency (RTE), resistance, charge/discharge energy and total utilized energy of the battery chemistries will be compared. Furthermore, effect of aging, frequency regulation (FR), peak shaving (PS) and electric vehicle (EV) drive cycles on degradation mechanisms of different battery chemistries will be discussed.
Regulating Molybdenum Dissolution through Controlled Oxide Phase Formation in CMP with Catalytic Oxidation
Authors: Lee Bobae
Published: December 2024

Molybdenum (Mo) is a promising candidate for replacing tungsten in next-generation semiconductor processes due to its lower electrical resistivity and superior gap-filling capabilities. Despite its properties, the high dissolution of Mo during chemical mechanical planarization (CMP) leads to surface deterioration and device failure, limiting its practical application.

Mo CMP, like other metal CMP, uses hydrogen peroxide (H2O2) to form and then remove metal oxide layers. However, H2O2 is a strong oxidant at a commonly used pH, and thus soluble Mo (Ⅵ) oxide (i.e., MoO3) formation cannot be avoided. One of Mo's oxides, MoO3, has a solubility of 4.9-70 g/L at room temperature, and Mo film reacts with H2O2 to form it in a chain. Excessive oxidation of Mo results in defects such as Mo dissolution and local corrosion during the CMP process, affecting the performance and reliability of the device.

We control the formation of Mo oxide phases, affecting the dissolution properties of Mo, by modulating the activity of the oxidant and catalyst. Catalytic oxidation with Fe ion catalyst and H2O2 oxidant promotes the formation of the insoluble MoO2 and Mo2O5 phases while reducing the formation of the soluble MoO3 phase. With catalytic oxidation facilitated by Fe ions, during CMP, the removal rate of Mo increased from 780 to 1500 Å/min, and the dissolution rate decreased from 636 to 57 Å/min. In addition, surface roughness (Rq) also decreased from 3.38 to 0.35 nm. These results indicate that the improvement in Mo CMP performances could be achieved by employing Fe ions in catalytic oxidation.
An Orthogonal Approach of Corrosion Resistance Performance Evaluation for Passive Layer on Aluminium Alloy Deploying Electrochemistry and GDOES Analysis
Authors: Daniilidis Ioannis Lazaros
Published: December 2024

The integrity and quality of the passive layer is key to the overall performance for corrosion resistance of a coated surface.

The evaluation of a Cr-based chemical conversion coating applied on an aluminium alloy has been conducted deploying an electrochemical method (EIS - Electrochemical Impedance Spectroscopy) and a spectroscopical method (GDOES - Glow Discharge Optical Emission Specstropscopy) for the depth profile and distribution of elements on the surface.

The complementarity of the two techniques confirm and justify the obtained performance.
Binder-Free CuO Nanowires Assisted Electrochemical Carbon-Dioxide Reduction Reaction
Authors: Hyo Bin Kwak
Published: December 2024

ECO2RR (Electrochemical carbon-dioxide reduction reaction) is a widespread and most promising strategy for controlling CO2 emission, global warming, etc. We have developed binder-free copper oxide nanowires (CuO NWs) to address this issue using a conventional synthesis process. The prepared electrocatalyst was confirmed through powder-XRD, high-resolution XPS, and FE-SEM analysis. The EDAX elemental mapping confirmed the presence of Cu and O elements. The CuO NWs showed exceptional activity in the CO2(g) purged electrolyte system. Moreover, the CuO NWs achieved the maximum current density of in the CO2(g) medium (56.5 mA cm-2), whereas in the N2(g) medium, it was 33.8 mA cm-2. In addition, predominant catalytic activity, selectivity, and stability properties are observed; further post-mortem analysis demonstrates the choice of material importance. The present work describes an impressive approach to develop highly active electrocatalysts for selective ECO2RR applications.
Modified Split Hopkinson Pressure Bar Experiments of Grooved Al-Sheet Stacks As Energy Absorption Materials for Thermal Battery
Authors: Kang Hyungu , Ahn Tae-Young , Roh Heesook , Kang Seung-Ho , Choi Yu Song
Published: December 2024

As a highly reliable energy storage, lithium thermal batteries have been used in variety of military applications including missiles and rockets. There have been several attempts to use thermal batteries in artillery platforms, however absorbing the shock emitted by artillery fire to protect the embedded electronic equipment has been a major challenge. In this study, we suggest that thin aluminum sheet stacks with fine grooves are effective materials for energy absorption. The materials’ energy-absorbing performance was assessed using a modified split Hopkinson pressure bar (SHPB). Impact momentum (I) and maximum impact acceleration (a
max
), which are the two important energy-absorbing parameters, were measured from stress-time (σ-t) curves. These parameters were found to vary with groove shape, groove cavity fraction, and specimen thickness. By carefully examining appropriate groove designs, cavity fractions, and stack thicknesses, this work offers a viable method for creating a variety of aluminum sheet stacks that show decreased a
max
and I, particularly in dynamically pressurized artillery settings.

Figure 1
(Keynote) Toward High Performance Perovskite Solar Cells and Modules: Current Situation and Future Prospects
Authors: Segawa Hiroshi
Published: December 2024

Organometal halide perovskite is one of the promising materials for the light-weight and high-efficiency solar cells. In this lecture, current situation and future prospects of the high performance perovskite solar cells and modules with high performance are summarized.

The crystal structure of the organometal halide perovskite is important for both of the absorption and the photophysics, whereas the structural aspects within the simple organometal halide perovskite are still controversial issue. In our study, direct observation of the nanostructure of the thin film organometal halide perovskite using transmission electron microscopy was investigated. Unlike previous reports, it is identified that the tetragonal and cubic phases coexist at room temperature, and it is confirmed that superlattices composed of a mixture of tetragonal and cubic phases are self-organized without a compositional change. The organometal halide perovskite self-adjusts the configuration of phases and automatically organizes a buffer layer at boundaries by introducing a superlattice. These results show the fundamental crystallographic information for the organometal halide perovskite and demonstrates new possibilities toward high performance perovskite solar cells.

Through the many studies related to the organometal halide perovskite solar cells, the composition of the organometal halide perovskite is recognised as one of the key factors in the improvement of the stability and efficiency. Many groups investigated mixed cation and mixed halogen perovskite absorber toward the high efficiency, whereas unexpected ion migration and/or phase segregation were observed. For the improvement of the stability, several approaches have been investigated. In our study, K+-doped perovskite is good for the stabilization with keeping relatively high performance. The small amount of K+ into the FA-MA double organic cation perovskite absorber improved the photovoltaic performance of the perovskite solar cells significantly, and the K+-doping diminished I-V hysteresis. The crystal lattice of the organometal halide perovskite was expanded with increasing of the K+ ratio, where both absorption and photoluminescence spectra shifted to the longer wavelength, suggesting that the optical band gap decreased. It is concluded that stagnation-less carrier transportation could minimise the I-V hysteresis of perovskite solar cells. The K+-doped perovskite can be stabilized to such an extent that they do not decompose after 10000 h of heating at 85 °C.
(Invited) Progress in Materials and Process Engineering for Sustainable Perovskite Solar Cells
Authors: Jung Hyun Suk
Published: December 2024

All solid-state solar cells based on organometal trihalide perovskite absorbers have already achieved distinguished power conversion efficiency (PCE) to 26.1% and further improvements are expected up to 27%. Now, the research on perovskite solar cells (PSCs) has been moving toward commercialization. To facilitate commercialization of these great solar cells, some technical issues such as long-term stability, large scale fabrication process, Pb-related hazardous materials, and environmentally-burdened toxic solvent-based process need to be solved.

This talk is dealing with our recent efforts to facilitate commercialization of perovskite solar cells. For examples, we introduce a recycling technology of perovskite solar cells, which covers the regeneration process of Pb contained perovskite layer as well as recycling process of Au electrodes and transparent conducting oxide glass. Also, novel strategies for recycling toxic solvents such as DFM, used in fabricating PSCs are introduced, which is critical to realize close loop recycling process of PSCs. Finally, recent studies for achieving high efficiency PSC using ecofriendly solvent are demonstrated.
Fabrication of Cost-Effective Carbon-Based Multiporous-Layered-Electrode Perovskite Solar Cells
Authors: Ito Seigo
Published: December 2024

To be commercialized photovoltaic panels, one of the most important issue is the stability. Normally, thin-film perovskite solar cells have been suffered from it. Contrary, carbon-based multi-porous-layered-electrodes perovskite solar cells (MPLE-PSCs) have enough stability for it. Specially, the porous carbon electrodes have five merits for the stability as below,

[1] high stability against halogen in perovskite crystal (Au and Ag can be damaged by the halogen)

[2] high conductivity to be the back contact electrodes (the sheet resistance can be around 5 ohm/square)

[3] strong hole-extraction ability (in place of organic hole-transporting material)

[4] water absorption ability as activated carbon after annealing procedure at 400 °C

[5] water blocking ability after making photovoltaic device with perovskite crystal

Hence, such porous carbon electrodes enhance the stability of MPLE-PSCs. Moreover, the merits for the commercialization of MPLE-PSCs can be listed as,

[1] high stability against high temperature and strong radiation against sun illumination

1-1 Thermal stability at 100 ֩C over 4500 h in dark (by Univ. of Hyogo, Japan).

1-2 Damp-heat stability at 85 ֩C-85%RH over 3,000 h in dark (by Univ. of Hyogo and Kishu Giken Kogyo, Japan).

1-3 Light stability at 55 ֩C over 10,000 h (by EPFL, Switzerland ).

[2] relatively photoenergy conversion efficiency for the utilization (11.5% as module)

[3] cost-effective fabrication process by fully-printing method under ambient air (without glove box and dry room)

[4] Recyclable device

In the conference, the fabrication technology and the challenging works of high thermal stability at 140 ֩C will be presented.
Investigating the Influence of Alkali Metal Carbonates on Oxygen Vacancies for Efficient and Stable Perovskite Solar Cells
Authors: Jang Won Jin , Kim Soo Young
Published: December 2024

Effectively suppressing non-radiative recombination at the SnO2/perovskite interface is imperative for perovskite solar cells. Although the capabilities of alkali salts at the SnO2/perovskite interface have been acknowledged, the effects and optimal selection of alkali metal cations remain poorly understood. Herein, a novel approach for obtaining the optimal alkali metal cation (A-cation) at the interface is investigated by comparatively analyzing different alkali carbonates (A2CO3; Li2CO3, Na2CO3, K2CO3, Rb2CO3, and Cs2CO3). Theoretical calculations demonstrate that A2CO3 coordinates with under-coordinated Sn and O on the surface, effectively mitigating oxygen vacancy (VO) defects with increasing A-cation size, whereas Cs2CO3 exhibits diminished preferability owing to enhanced steric hindrance. The experimental results highlight the crucial role of Rb2CO3 in actively passivating VO defects, forming a robust bond with SnO2, and facilitating Rb+ diffusion into the perovskite layer, thereby enhancing charge extraction, alleviating deep-level trap states and structural distortion in the perovskite film, and significantly suppressing non-radiative recombination. X-ray absorption spectroscopy analyses further reveal the effect of Rb2CO3 on the local structure of the perovskite film. Consequently, a Rb2CO3-treated device with aperture area of 0.14 cm2 achieves a notable efficiency of 22.10%, showing improved stability compared to the 20.11% achieved for the control device.
(Invited) Breaking Centro-Symmetry in Formamidinium Lead Triiodide (FAPbI3) Films with Preferred Oriented Grains
Authors: Shin Hyunjung
Published: December 2024

Formamidinium lead triiodide (FAPbI3) is gaining much interest with an optimal band gap of ~ 1.5 eV. Although α-FAPbI3 is the most thermodynamically stable photoactive phase, it can kinetically stabilize δ-FAPbI3 in ambient. Many attempts were studied to stabilize the black α-phase, for example, pseudo-halide anion engineering, ionic liquid engineering, and incorporation of additives. Incorporating with methylammonium chloride (MACl) as an additive not only induces the stabilized α-FAPbI3, but also affects the crystallization kinetics of α-FAPbI3. Along with the role of methylammonium chloride (MACl) as a ‘stabilizer’ in the formation ofα-FAPbI3, we pointed out the additional role as a ‘controller’ in the crystallization kinetics. Herein, we examined the crystallization process of MACl, as higher concentration of MACl induces slower crystallization kinetics. Microscopic observations, such as electron back-scattered diffraction (EBSD), confocal photoluminescence (PL), time-resolved photoluminescence (TRPL) mapping, and conductive atomic force microscopy (C-AFM), were conducted to examine the optoelectronic properties of [001] preferentially oriented grains. Reduction in the non-radiative recombination, a longer lifetime of charge carriers and less photocurrent deviation between each grain induce higher short-circuit current density (Jsc
) and fill factor (FF) in α-FAPbI3 based perovskite solar cells (PSCs) with MACl40%.It highlights the importance of crystallization kinetics resulting in desirable microstructures for device engineering.