bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) sald: Versatility of the Deposition Process Combined with in-Situ Characterization Methods
Authors: Barr Maissa K. S. 
Published: December 2024

We have proposed and demonstrated a novel thin film deposition technique by transferring the principles of atomic layer deposition (ALD), known with gaseous precursors, towards precursors dissolved in a liquid. 'Solution ALD'(sALD) shares the fundamental properties of standard ‘gas ALD’ (gALD), specially the self-limiting growth and the ability to coat conformally deep pores. It has been already shown that it is possible to transfer standard reactions from gALD to sALD such as oxides and sulfides deposition. However, sALD also offers novel opportunities such as overcoming the need for volatile and thermally robust precursors, offering the possibility to grow materials that cannot be obtained by gALD and using mild conditions which allow the growth on sensitive substrates. Recently we extended the understanding of the nucleation of selected materials grown by sALD such as Cu-BDC, MAPI, CuSCN, TiO2 and SnSx. The study of the nucleation process relies on, first the identification of the absorbed chemical species at the surface by in-situ infra-red spectroscopy, second the ability to determine the type of interaction of the precursor with the surface by ex-situ solid state nuclear magnetic resonance (NMR) and third the evolution of nuclei formation with in-situ x-ray reflectometry (XRR) and atomic force microscopy. We developed the necessary instrumentation to obtain measurement compatible in liquid environment for each in-situ method. Form IR we can identify the phase preferential phase that is obtained as well as the defects formation for extremely thin films and NMR shows the chemical bonding of precursors at an early stage. Additionally, the AFM and XRR investigations are needed to follow the evolution of the nuclei size and their distribution of a surface as well as the nuclei density of each half cycle.
The extension of the knowledge on the reaction mechanism in sALD process appears to be crucial to design next reactions and to understand later on the properties of the layers obtained with sALD.

Wu, D. Döhler, M. Barr, E Oks,M. Wolf, L. Santinacci and J. Bachmann, Nano Lett. 2015, 15, 6379 Fichtner, Y. Wu, J. Hitzenberger, T. Drewello and J. Bachmann, ECS J. Solid State Sci. Technol. 2017,6, N171 M. K. S. Barr, S. Nadiri, D.-H. Chen, P. G. Weidler, S. Bochmann, H. Baumgart, et al, .Chemistry of Materials 2022, 34, 9836-9843
Fabrication and Performance of Transmissive Light-Emitting Electrochemical Cells Using Spray- Coated Silver Nanowires(AgNW) Cathode
Authors: Akamatsu Ayumu , Aoki Atsushi 
Published: December 2024

In recent years, transmissive light-emitting devices have been in demand for digital signage, smart glasses, and other applications. In this study, we aimed to achieve both transparency and luminescence performance of light-emitting electrochemical cells (LECs) by thinning the thickness of the silver cathode of LECs until being semitransparent and depositing silver nanowires (AgNW), which are transparent conductive films, on the semitransparent silver cathode.
Cationic ruthenium complex Ru(bpy)3(TFSI)2 was used as an electrochemical luminescent chromophore. The LECs were fabricated as follows. The luminescent layer was spin-coated onto a patterned ITO substrate (anode). The luminescent layer solution was made of Ru complex (40 mg/mL) and polymethyl methacrylate (PMMA) (3 mg/mL) dissolved in acetonitrile. LiF and Ag were vacuum deposited at the film thickness of 0.5 nm as an electron injection layer on the top of the luminescent layer and as a cathode at the film thickness from 0 nm to 75 nm, respectively.
The transmittance of the LECs with the different film thickness of Ag cathode was investigated from UV-vis spectra in the visible region. The luminescence performance was measured by applying a constant current to LECs and obtaining voltage and luminance responses. The average transmittance in the visible region was confirmed to decrease with increasing film thickness of the Ag cathode until 20 nm. There is almost no transmittance in LECs with the film thickness above 20 nm. The luminescence performance of the LECs with the different film thickness of Ag cathode was then investigated by applying a constant current to the LECs. The voltage responses indicate that the voltage decays with time and became the constant voltage of about 2.7 V because of the formation of the electric double layer in the LECs with more than 10 nm film thickness. From the luminance responses, the light emission was observed. Meanwhile, it kept the upper limit voltage of 5.0 V in the LECs with less than 5 nm film thickness and no emission took place. It means that the film thickness less than 5 nm is too thin to flow current due to the formation of the sea-island structure of silver. Furthermore, the light emission was observed from both sides of not only the transparent ITO anode but also the semitransparent Ag cathode in the range of the film thickness between15 and 30 nm. Therefore, we demonstrated the transmissive LECs using Ag cathode at the film thickness of 15 nm.
However, the average transmittance in the visible region is even 10 % using Ag cathode at the film thickness of 15 nm. Therefore, in order to increase the transmittance and to decrease cathode resistance, we attempted to deposit AgNW on the semitransparent Ag cathode by spray coating. Unfortunately, Ru complex layer was dissolved by ethanol which was the solvent dispersed AgNW. Thus, we are underway to change solvent from ethanol to non-polar solvent such as hexane.
Bidirectional Polarization-Integrated Van Der Waals Ferroelectric Field-Effect Transistor for Multi-State Storage and Dual-Logic-in-Memory Computing
Authors: Niu Jingjie , Jeon Sumin , Kim Donggyu , Baek Sungpyo , Yoo Hyun Ho , Li Jie , Park Jisang , Lee Yoonmyung , Lee Sungjoo 
Published: December 2024

The rapidly growing number of AI-enabled applications is driving the need for development of energy efficient computing hardware that can handle massive amount of computations required for neural network operation. As one of the promising approaches for processing data within memory, Logic-in-memory is parallel execution of reconfigurable logic operation within memory allows fast and efficient computations. For realizing the logic-in-memory hardware, implementing practical logic functions with high density is of critical concern.
Here, we demonstrate a multi-state dual-logic-in-memory device implemented via a single bidirectional polarization-integrated ferroelectric field-effect transistor (BPI-FeFET) by integrating the in-plane vdW ferroelectric semiconductor SnS and the out-of-plane vdW ferroelectric gate dielectric CuInP2S6 (CIPS). Four reliable resistance/conductance states (two-bit storage) with an on/off ratio between the highest and the lowest channel current of >105, high switching endurance (>104 cycles), and stable retention characteristics (>104 s). The mechanism of two-bit storage in a single BPI-FeFET is analyzed from two perspectives: carrier density and carrier injection controls, originating from the out-of-plane polarization of the gate dielectric and in-plane polarization of the semiconductor, respectively.
Unlike the conventional multilevel FeFET, direct conversions among the four-memory states of proposed BPI-FeFET without pre-examination or additional erasing step are demonstrated experimentally. The potential of the BPI-FeFET as a low-cost and high-density in-memory computing circuit was further explored. To utilize the fabricated BPI-FeFET as a dual-logic-in-memory device, two logical operations are selected (e.g. XOR and AND) by properly setting initial states, and their parallel execution is demonstrated. Additionally, these logical computations are reconfigurable when the initial state of the device is set to different states, making it flexible for implementing various types of functions that can be potentially required for different types of neural networks. We believe the flexibility and efficiency of dual-logic-in-memory devices provide a promising pathway for realizing next generation low power computing systems.
Spin-State Analysis for a Fourteen-Membered Macrocyclic Fe Complex for Oxygen Reduction
Authors: Nabae Yuta , Feng Zhiqing , Honda Sotaro , Machida Masato , Ohyama Junya , Moriya Makoto 
Published: December 2024

For the broad application of polymer electrolyte fuel cells (PEFCs), the development of non-precious-metal (NPM) catalysts for oxygen reduction is extremely important. To date, many NPM catalyst have been synthesized by pyrolyzing Fe-, N-, and C-containing precursors, but they suffer from the low density and uncertain chemical structure of their active sites. On the contrary, our research group has been studying a 14-membered macrocyclic Fe complex, which was inspired by the FeNx sites embed in graphene sheets.
In this study, a fourteen-membered macrocyclic Fe complex was loaded on a carbon support and then heat-treated, and found to be quite active as a non-precious metal oxygen reduction catalyst. The improvement is attributed to a high turnover frequency rather than the number of active sites. To fully understand the mechanism for the improved catalytic activity, the spin-state of the catalysts was evaluated by X-ray emission spectroscopy, and the results were discussed in comparison to a simulation study based on the density functional theory (DFT). The obtained results suggest that the Fe-based active sites are working in a middle-spin state.

Figure 1
Composition-Activity-Stability Relationship Investigation of Trimetallic Pt-Ni-Au Oxygen Reduction Reaction Catalyst
Authors: Xie Xianxian , Briega Martos Valentin , Vorochta Michael , Matolínová Iva , Cherevko Serhiy , Khalakhan Ivan 
Published: December 2024

Hydrogen-fuelled proton-exchange membrane fuel cells (PEMFCs) offer a promising path towards zero-emission energy, but their commercialization is hindered by challenges, particularly in the cathode catalysts responsible for the oxygen reduction reaction (ORR). Current catalysts rely heavily on expensive platinum, which degrades quickly in the harsh cathodic environment. Efforts are thus focused on developing cost-effective and stable catalysts. Recent research has shown that alloying platinum with earth-abundant transition metals can reduce costs and improve ORR activity. Bimetallic Pt-M (M=Ni, Cu, Co, Fe, etc.) alloy catalysts, particularly those incorporating gold, have demonstrated superior performance. However, achieving both high activity and long-term stability remains a challenge. Our recent work emphasizes the importance of precise catalyst engineering to optimize both activity and durability, highlighting the need for a balanced alloy structure and compositional profile in Pt–Au catalysts.
In this work, a magnetron co-sputtering technique was utilized to introduce a small amount of Au (5, 10, and 20 at%) into Pt50Ni50 alloy. The resulting ternary PtNiAu alloy demonstrated enhanced stability compared to PtNi, as evidenced by reduced platinum and nickel dissolution with increasing Au content, confirmed over a wide potential range up to 1.5 VRHE. On the other hand, at elevated concentrations, Au showed a detrimental effect on the ORR activity. Despite showing lower activity than PtNi, the ternary PtNiAu alloy still displayed superior activity compared to pure Pt. The investigation employed robust characterization methods, including synchrotron radiation photoelectron spectroscopy (SRPES), in-situ scanning flow cell coupled with inductively coupled plasma mass spectrometer (SFC-ICP-MS), and rotating disc electrode (RDE), to probe the composition-activity-stability relationship and identify the optimal Pt-Ni-Au composition meeting both high activity and stability requirements.
Analysis of Crystalline and Amorphous Iridium Oxide Catalyst Layers after Accelerated Durability Test
Authors: Ishida Takanobu , Takeda Yuko , Watanabe Yuta , Aoki Naoya 
Published: December 2024

PEM water electrolysis has advantages such as high current density operation and quick response to input power.From these advantages, PEM water electrolysis is adequate to the hydrogen mass production system adopted the renewable energy.Iridium oxide shows good oxygen evolution reaction(OER) activity and durability for PEM water electrolysis anode catalyst, but there are material supply and cost issues as it is precious metal.To solve these issues, several studies have been conducted to improve OER activity of Iridium oxide.
Last year, we reported on highly active crystalline iridium oxide catalysts.In this work, we performed accelerated durability tests in single cell on crystalline and amorphous iridium oxide.After the durability test, the CCM was analyzed to investigate degradation factors.The results will be discussed on the day of the meeting.
The Impact of Progressive Buildup of Trapped Gas Bubbles on the Performance of Oxygen Evolution Reaction Electrodes during Alkaline Water Electrolysis
Authors: Hoffmann Jeff Owen , Wang Lan , Yan Yushan 
Published: December 2024

Hydroxide exchange membrane electrolyzers (HEMELs) stand to be an effective means of achieving low-cost green hydrogen. However, HEMEL durability remains a substantial barrier to realizing this goal. The United States Department of Energy has set a durability target of a voltage increase of 2 µV/hr1. We have previously demonstrated constant current degradation rates of 1810 and 560 µV/hr with applied current densities of 500 and 200 mA/cm2, respectively, thus illustrating the substantial gap between our current achievable HEMEL durability and our target durability2.
Gaseous products are formed at both electrodes in a HEMEL; by manipulating the wettability of the electrodes, recent studies have shown that the failure of gas bubbles to detach from the electrode surface leads to overpotentials associated with the loss of accessible reaction sites and exacerbated mass transport to those sites that remain accessible3,4. While these studies have demonstrated the impact of gas bubbles on acute water electrolyzer performance, we have found little work to investigate the impact of trapped gas bubbles from a durability perspective.
Here we find that electrode wettability can change throughout the lifetime of a device. We investigate the durability of an FexNiyOOH – nF anode catalyst supported on nickel felt in a three-electrode setup with 1M KOH. We find that at a moderately low current density of 50 mA/cm2 the performance of this catalyst degrades by tens of mV over several hundred hours and that this performance loss is recoverable with the removal of oxygen bubbles adhered to the anode surface at open circuit. Moreover, when we resume the passage of current, the surface layer of oxygen (and associated performance loss) evolves more rapidly – suggesting that the wettability of the anode has decreased throughout the experiment. This is further supported by contact angle measurements of pre- and post-mortem anodes. Finally, we investigate whether the introduction of hydrophilic ion-conducting polymers can mitigate the emergent hydrophobicity of the anode catalyst layer.

Technical Targets for Proton Exchange Membrane Electrolysis, Hydrogen and Fuel Cell Technologies Office. https://www.energy.gov/eere/fuelcells/technical-targets-proton-exchange-membrane-electrolysis.

J. Xiao et al., ACS Catal., 11, 264-270 (2021).

R. Iwata et al., Joule, 5(4), 887-900 (2021).

Z. Kang et al., Electrochimica Acta, 354 (2020).
Performance and Durability of Metallic Aerogel Anode Catalyst in Pure-Water-Fed Hydroxide Exchange Membrane Electrolyzers
Authors: Zeng Yachao , Qi Manman , Yan Yushan 
Published: December 2024

Hydrogen holds significance as a versatile energy carrier that can be used in various sectors. Recently, hydroxide exchange membrane electrolyzers (HEMELs) towards clean hydrogen production have gained intensive attention, due to the possibility to use low-cost platinum group metal (PGM)-free electrocatalysts and cheaper membranes, ionomers.1 Although a variety of PGM-free catalysts have shown promising activities towards the alkaline oxygen evolution reaction (OER), few of them delivered sufficient stability in the pure-water-fed HEMELs.2 In this work, metallic aerogel, featured with high porosity and amorphous metal oxide shells, was deployed as platform to study the structural-performance relationship in HEMELs. A poly(aryl piperidinium) membrane and ionomer with high hydroxide conductivity were integrated to study the evolution in the composition and structure of PGM-free anode catalysts.3 Owing to unique properties of the 3D metallic aerogel, the optimal aerogel anode outperformed the Ir-based anode in the KOH-fed HEMELs. A transition in the HEMEL performance with different anode catalyst was observed when shifting from alkaline electrolyte to pure water, implying a steering in the rate limiting steps in the different anode feedings. The limiting factor of pure-water-fed HEMEL was probed by deconvoluting the contributions from ohmic resistance, electrode kinetic, and mass transport. The optimal metallic aerogel anode showed no performance loss during the 580-hour stability test at an industrial electrolyzer-relevant current density of 1 A cm−2 in pure water feeding. The HEMEL performance was monitored, revealing the degradations of critical components in the membrane-electrode-assembly. The structural performance relationship in HEMEL was probed by linking the physical properties of the catalysts with HEMEL performance. The gained insight will shed light on the development of highly efficient PGM-free anode catalysts for viable pure-fed HEMELs.
References

R. Abbasi, B. P. Setzler, S. Lin, J. Wang, Y. Zhao, H. Xu, B. Pivovar, B. Tian, X. Chen, G. Wu and Y. Yan, Advanced Materials, 31, 1805876 (2019).

M. Chatenet, B. G. Pollet, D. R. Dekel, F. Dionigi, J. Deseure, P. Millet, R. D. Braatz, M. Z. Bazant, M. Eikerling, I. Staffell, P. Balcombe, Y. Shao-Horn and H. Schäfer, Chemical Society Reviews, 51, 4583 (2022).

J. Wang, Y. Zhao, B. P. Setzler, S. Rojas-Carbonell, C. Ben Yehuda, A. Amel, M. Page, L. Wang, K. Hu, L. Shi, S. Gottesfeld, B. Xu and Y. Yan, Nature Energy, 4, 392 (2019).
Industrial Scale Anodes and Cathodes for Conventional Alkaline Electrolysis and Anion Exchange Membrane Water Electrolysis
Authors: Abellán Gonzalo , Abellán Gonzalo , Lloret Segura Vicent , Seijas Da Silva Alvaro 
Published: December 2024

The merging of conventional Alkaline Electrolysis (AEL) and Proton Exchange Membrane Water Electrolysis (PEMWE) has led to the development of Anion Exchange Membrane Water Electrolysis (AEMWE). At this juncture, both AEL and AEMWE technologies offer an advantage over PEMWE as they do not require critical raw components and/or materials (CRM and PFAS).[1] While AEMWE has demonstrated higher efficiencies than AEL with thin membranes and low concentrations of KOH, AEL technology addresses the significant stability challenge posed by anionic membranes by employing KOH electrolyte in a zero-gap configuration, relying on stable diaphragms. Consequently, AEL technology offers a more cost-effective and scalable solution for current large-scale hydrogen production, while AEMWE remains a promising solution that will most probably be implemented on larger scales in the following decade.
New and scalable synthetic routes for more efficient catalysts and electrodes that lower the overall cell voltage of electrolyzers are required on a large scale to reach the readiness level of alkaline technologies. Matteco’s patented processes stand at the forefront of manufacturing highly active and stable catalysts and electrodes crafted from Layered Double Hydroxides (LDHs), which have gained increasing attention due to their low overpotentials and promising stabilities.[2] Beyond the intrinsic properties of the catalysts, a myriad of factors—electrolyte concentration, substrate type, loading, and the catalyst/substrate interface—play pivotal roles in determining electrolyzer activity and stability, forming a complex multiparameter matrix.
This work presents the electrochemical performance and stability of novel and scalable anode and cathode catalyst coated substrates for both AEL and AMWE technologies.

References:

[1] N. Du, C. Roy, R. Peach, M. Turnbull, S. Thiele and C. Bock, Chemical Reviews, 122, 11830 (2022).
[2] L. Hager, M. Hegelheimer, J. Stonawski, A. T. S. Freiberg, C. Jaramillo-Hernández, G. Abellán, A. Hutzler, T. Böhm, S. Thiele and J. Kerres, Journal of Materials Chemistry A, 11, 22347 (2023).
Activity and Stability of Iridium-Based Alloy Catalysts for PEM Electrolyzer
Authors: Mariappan Sakthivel , Drillet Jean-Francois 
Published: December 2024

For large-scale production of green hydrogen via renewable energies, large capacities of highly performing, cost-effective water electrolyzers are needed. Polymer electrolyte electrolysis (PEMEL) operates at high current and pressure and is very compact compared to alkaline technology. However, it relies on very expensive noble catalysts such as Pt and Ir for H2 and O2 electrode, respectively. Meanwhile, unsupported Iridium black is considered as state-of-the-art in terms of corrosion stability and activity, whereas a lot of efforts aim at reducing loading by alloying or/and developing supported materials [1,2].
In this work, Ir black and bi-metal Ir-M (M = Pt, Pd, Cr, Co) black catalysts were synthesized by co-reduction of iridium chloride and M-ion containing precursor in 0.1 M sodium borohydride at 180°C for 3 h under hydrothermal condition. The nominal mass ratio of Ir:M was fixed to 3:1. The structural characterization of the as-prepared catalysts was performed by means of XRD, TEM, Raman, and BET. Electrochemical activity of Ir-M black catalyst for OER was studied in deaerated 0.5 M H2SO4 electrolyte at room temperature by using a rotating disk electrode (RDE) cell. The total catalyst loading was about 200 μgIr cm-2. Additional cyclic voltammetry measurements over the potential range of -0.1–1.4 V vs. RHE at 40 mV s-1 were performed to identify redox behavior of the catalysts (fig. 1a). The accelerated degradation tests (ADT) were performed between 1.1 and 1.6 V at dE/dt=0.5 V s-1 with RDE at 1600 rpm for 1000 cycles. A commercial Ir-black catalyst purchased from Alfa Aesar was used as reference. Based on half-wave potential value at 30 mA cm-2 (fig. 1b), the following trend in lower overpotential for OER was obtained: Ir-Cr > Ir-Pt > Ir-Pd >> Ir-Co > Ir-black.
PEMEL full cell experiments were performed in single cell with 5 cm² geometrical area in a balticFuelCells fixture at 60°C. The catalyst coated membrane (CCM) consists of 2 mgIr cm-2 anode and 1 mgIr cm-2 cathode coated on Nafion 117. Titanium felt and carbon paper were used as porous transport layers in the anode and cathode side, respectively. Accelerated stress tests (AST) were performed by using rectangular polarization signal to reflect dynamic electrolyzer operation. Thereby, the current density was varied between 0.05 and 3 A cm-2 in 10 s for at least 1000 h. After test, the cell components were post analyzed by SEM/EDX, XRD and XPS technique and anolyte/catholyte were analyzed by ICP-OES in order to evaluate the dissolved species. The electrochemical degradation performance of bi-metal alloy anode catalysts in PEMEL test will be presented as well.
References
[1] H. P. Tran, H. N. Nong, H.-S. Oh, M. Klingenhof, M. Kroschel, B. Paul, J. Hübner, D. Teschner, and P. Strasser, Chem. Mater. 2022, 34, 9350
[2] A. Hartig-Weiss, M. Miller, H. Beyer, A. Schmitt, A. Siebel, A. T. S. Freiberg, H. A. Gasteiger, and H. A. El-Sayed, ACS Appl. Nano Mater. 2020, 3, 2185

Figure 1