bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hybrid Molecular Layer Deposition of Molybdenum-Aminates as Hydrogen Evolution Reaction Electrocatalysts
Authors: Persson K. Alex , Mattinen Miika , D'Acunto Giulio , Bent Stacey F. 
Published: August 2024

The development of high-performance hydrogen evolution reaction (HER) electrocatalysts from noble metal-free materials is critical to achieving cost-effective water splitting and ultimately realizing affordable hydrogen based on renewable energy. Compounds based on earth-abundant transition metals have been the subject of great research interest for this purpose, with metal nitrides gaining recent attention due to their high conductivity and corrosion resistance. Molybdenum nitride-based electrocatalysts have shown particular promise, with many of the best reported activities occurring in composite systems wherein crystalline MoNx domains are embedded in an amorphous N-doped carbon matrix. The present work demonstrates the formation of such uniquely active morphologies in films deposited by organic-inorganic hybrid molecular layer deposition (MLD).
Hybrid MLD is a hybridization of other well-established layer-by-layer deposition techniques – namely atomic layer deposition (used to deposit inorganic films) and purely organic MLD. This family of techniques involves the cyclical exposure of a growth surface to alternating vapor-phase chemical precursors which react in a self-limiting fashion to saturate available surface sites, offering atomic- and molecular-level control over the resulting films. This presentation will introduce the successful development of hybrid MLD deposition procedures for new Mo-aminate materials using Mo(CO)6 as a Mo precursor and various amine precursors, including ethylenediamine, p-phenylenediamine, and tris(2-aminoethyl)amine.
We will describe how the molecular level of control offered by this technique enables tunable variations in film composition and structure, lending unique insights into how the local bonding environment of Mo active sites affects their catalytic properties towards HER. Increased nitrogen loading in the MLD films was shown to decrease the overpotentials required to drive HER in acidic media (0.5 M H2SO4) and improve film stability. Catalysts with N/Mo ratios above 2 demonstrated the best performance, with overpotentials lower than 400 mV at -10 mA/cm2. By incorporating organic components in the MLD films, it was possible to induce desirable morphological changes in the catalytic material – notably including the development of increased active site density – simply through initial exposure to HER testing conditions. The choice of organic precursor affected the rate and extent of these changes through structural effects like crosslinking and crystallinity, which led to more stable catalysts, slowed the rate of morphological changes, and impacted final film structure.
Elucidating Photoelectrochemical Corrosion at III-V Semiconductor/Electrolyte Interfaces Using Electrochemical Impedance Spectroscopy
Authors: Hansen Mitchell J. , Steiner Myles A. , Young James L. , Deutsch Todd G , O'Hayre Ryan 
Published: August 2024

As the energy transition matures and society looks to mitigate the negative impact of hard-to-decarbonize sectors, the production of green sustainable fuels becomes increasingly important. Photoelectrochemical (PEC) water splitting offers a path towards direct solar-to-hydrogen conversion through its integrated all-in-one design. However, practical device efficiency goals (>20%) necessitate the use of high efficiency III-V semiconductor materials that are unstable in aqueous electrolyte. The rapid degradation of these materials in aqueous media limits their utility to short-lifetime lab-scale devices. Some of the highest efficiency PEC devices to date employ GaInP in the photocathode to drive the hydrogen evolution reaction despite its limited stability. Protective coatings and catalyst layers improve the stability of GaInP photocathodes, but much remains unknown about the exact degradation mechanisms. Here, we use electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRT) analysis to gain insight into the processes underpinning the degradation of GaInP-based photocathodes in PEC devices.
The EIS technique can monitor charge transfer resistance investigation in PEC devices, but it has had suspect utility for III-V photocathode degradation studies due to rapid material corrosion and slow measurement times. However, the emerging technique of rapid, hybrid EIS measurements provides immense value as a non-destructive and frequency-dependent probe which distinguishes physical processes by their time constants with high resolution. The DRT analysis deconvolutes features of an impedance spectrum without requiring a priori knowledge of the physical processes that contribute to the observed response and ensures unbiased assessment of the data. In this work, we test the effects of Pt nanoparticulate catalyst loading and illumination level on the device impedance and correlate the results to semiconductor corrosion. By varying the cell operating conditions, we perform a robust assignment of the impedance response to physical phenomena. EIS corrosion studies can be complemented by chemical (ICP-MS) and microscopic (optical interferometry) techniques to enhance their correlation. The impedance and material dissolution data provide a better understanding of III-V semiconductor photocorrosion mechanisms.
(Invited) In Situ Photoelectron Spectroscopy Reveals the Chemical Nature of Semiconductor Surface States
Authors: Favaro Marco 
Published: August 2024

The accessible photovoltage of semiconducting photoabsorbers is typically 0.5-1 V below the theoretically achievable values predicted by the Shockley-Queisser limit [1]. Although the reason for this is still not well understood, surface and interface states within the photoabsorbers energy band gap may play a crucial role as they generally induce Fermi level pinning [2]. Within the PEC community, two key elements have been identified for the maximization of the photovoltage in photoelectrodes for water splitting: (i) the passivation of surface defects which is needed to avoid Fermi level pinning, and (ii) the increase of the minority carrier concentration at the interface to improve contact selectivity and optimize carrier extraction [3,4].
To understand the role of surface defects on Fermi level pinning, detailed information on the chemical nature and electronic properties of surface states is needed. Such information is usually obtained with UHV surface science techniques such as XPS, but the photoelectrode surface under UHV conditions has little, if any, relevance to the electrified surface when immersed in the electrolyte. Moreover, recent studies have shown that semiconductor surfaces are not static, but undergo extensive structural and chemical transformations during PEC device operation [5,6]. In this talk, we will show our recent development of state-of-the-art techniques to study the structure and dynamics of semiconductor/water interfaces under practically relevant conditions [7]. The chemical nature of the electronic states for selected semiconductors prepared at the Institute for Solar Fuels has been explored using synchrotron-based resonant, ambient pressure soft and hard X-ray photoelectron spectroscopy (AP-XPS and AP-HAXPES) [6,8-11], and with in situ/operando Raman and photoluminescence spectroscopy. In particular, we will show that it is possible to study photon-induced chemical changes at solid/liquid interfaces using AP-XPS and AP-HAXPES [6,8].
We will conclude this contribution by discussing about future perspectives and technical implementations for multimodal in situ/operando investigations of photoelectrocatalytic processes.
[1] M.T. Mayer. Curr. Opin. Electrochem. 2017, 2, 104.
[2] A. J. Bard et al. J. Am. Chem. Soc. 1980, 102, 3671.
[3] A.G. Scheuermann et al., Nat. Mater. 2016, 15, 99.
[4] M. Schleuning et al., Sustainable Energy Fuels, 2022, 6, 3701.
[5] F.M. Toma et al., Nat.
Commun. 2016, 7, 12012.
[6] M. Favaro et al., J. Phys. Chem. B 2018, 122, 801.
[7] M. Favaro et al., Surf. Sci. 2021, 713, 121903.
[8] M. Favaro et al., J. Phys. D: Appl. Phys. 2021, 54, 164001.
[9] M. Favaro et al., J. Phys. Chem.
C 2019, 123, 8347.
[10] W. Wang et al., J. Am. Chem. Soc. 2022, 144, 17173.
[11] P. Schnell et al., Sol. RRL 2023, 2201104.
Easy Scalable Solid-State Synthesis of Highly Efficient Synergetic 2D/1D Micro/Nanostructured g-C3N4/MeS (Me=Cd, Mo) Photocatalysts for Organic Dye Degradation and Hydrogen Evolution
Authors: Khan Natalya , Sultanov Fail , Bakenov Zhumabay , Mentbayeva Almagul , Tatykayev Batukhan 
Published: August 2024

The global reserves of oil, gas, and coal are acknowledged finite, and their consumption rates are increasing each year [1]. Following Fujishima’s groundbreaking discovery of photocatalytic water splitting using TiO2 electrodes in 1972 [2], photocatalysis technology gained recognition as a promising approach for renewable energy and environmental conservation [3]. Since that pivotal moment, significant advancements have been made in developing preparation methods for highly efficient photocatalysts, predominantly centered on semiconductors like metal oxides and sulfides [4].
In this study, we introduce effective synergistic photocatalysts, that utilize g-C3N4 and MeS (Me=Cd, Mo) semiconductors featuring a 2D/1D micro/nanostructure. Photocatalysts were successfully produced through solid-state method using planetary ball mill, where reaction of MeS formation occurs on the surface of g-C3N4. A comprehensive analysis of the binding energy of electrons of semiconductors was conducted to understand its impact on the photocatalytic activity of the prepared g-C3N4/MeS. The fabricated materials were used in the photodegradation of organic dyes and demonstrated remarkable efficacy. Regarding photocatalytic hydrogen evolution, the g-C3N4/CdS in conjunction with Pt co-catalyst, achieved a hydrogen evolution rate of up to 2254.54 μmol*h⁻¹ *g⁻¹, accompanied by apparent quantum efficiency of 2.0%.

Acknowledgments

This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. АР13068426).

References

[1] E. V. Kondratenko, G. Mul, J. Baltrusaitis, G. O. Larrazábal, J. Pérez-Ramírez, Status and perspectives of CO2 conversion into fuels and chemicals by catalytic, photocatalytic and electrocatalytic processes, Energy & Environmental Science. 6 (2013) 3112–3135. https://doi.org/10.1039/C3EE41272E.
[2] A. Fujishima, K. Honda, Electrochemical Photolysis of Water at a Semiconductor Electrode, Nature. 238 (1972) 37–38. https://doi.org/10.1038/238037a0.
[3] M. Ni, M.K.H. Leung, D.Y.C. Leung, K. Sumathy, A review and recent developments in photocatalytic water-splitting using TiO2 for hydrogen production, Renewable and Sustainable Energy Reviews. 11 (2007) 401–425. https://doi.org/10.1016/j.rser.2005.01.009.
[4] C. Acar, I. Dincer, G.F. Naterer, Review of photocatalytic water-splitting methods for sustainable hydrogen production, International Journal of Energy Research. 40 (2016) 1449–1473. https://doi.org/10.1002/er.3549.
Multifunctional Nanocomposites Synthesized By Solid-Phase Method with High Photocatalytic, Antibacterial, and Fungicidal Activity
Authors: Tugelbay Saparbek , Tatykayev Batukhan , Mucsi Gabor , Shevelkov Andrei , Shalabayev Zhandos , Khan Natalya , Burkitbayev Mukhambetkali 
Published: August 2024

An easily scalable technology was developed for the solid-state synthesis of multifunctional hybrid Ag3PO4/AgCl nanocomposites. This innovative approach relies on solution-free (dry) mechanical activation, implemented through successive ion-exchange reactions in a planetary ball mill. The nanosized hybrid structure of the synthesized Ag3PO4/AgCl nanocomposites was substantiated through the utilization of XRD, SEM, TEM, DSC, and UV-visible spectroscopy methods. The investigation also unveiled a synergistic effect between Ag3PO4 and AgCl.
The Ag3PO4/AgCl nanocomposites with a ratio of 75:25 mas. % exhibited the highest and most stable photocatalytic activity under visible light irradiation (λ≥400 nm). The rate constant for the photocatalytic degradation of Methylene Blue (10 mg/L) was found to be two times greater than that observed with Ag3PO4 nanoparticles and four times faster than for AgCl nanoparticles, as illustrated in Figure 1. "In addition, the synthesized nanocomposites remained stable after five cycles of the photocatalytic process, with their activity remaining almost unchanged.
Furthermore, the antimicrobial and fungicidal efficacy of these nanocomposites was assessed using Staphylococcus aureus, Candida albicans, Escherichia coli, Pseudomonas aeruginosa, and Erwinia amylovora test strains. The results of the microbiological tests revealed, that almost all prepared materials were able to suppress pathogenic microorganisms. The conducted study identified these nanocomposites as promising candidates for further detailed and targeted studies concerning their interaction with specific microorganisms.

Figure - 1. (a) Visible spectrum changes of MB during its photodegradation by the Ag3PO4/AgCl -75/25 composite. (b) Photocatalytic degradation profiles of MB over AgCl, Ag3PO4 and Ag3PO4/AgCl catalysts under visible light irradiation. (c) Graphs for determining the kinetics of decomposition of MS under the influence of different catalysts. (d) Photodegradation stability of MB using the Ag3PO4/AgCl – 75/25 catalyst.
Acknowledgments
This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan, grant number АР13068426.

Figure 1
Atomic Layer Deposition of Noble Metal Nanoparticles for Electrocatalytic Applications
Authors: Bawab Bilal , Zazpe Raul , Rodriguez Pereira Jhonatan , Sopha Hanna , Macak Jan M. 
Published: August 2024

Noble metals such as Pt, Ru, Pd, Ir, etc., have superior performance for various catalytic applications [1]. Due to their scarcity, efforts were being made to reduce the mass/loading or replace these noble metals. Atomic Layer Deposition (ALD) is one among the best technique to facilitate lowering of loading mass on a support of interest [2,3]. Due to the governing surface energy variations between noble metals and support surfaces, the growth initiates as nanoparticles (NP) and with a further increase in ALD cycles the agglomeration among NP’s dominates over the individual NP size increase, thus developing thin films of relatively higher thickness.
For electrocatalytic applications, it is important to choose the right substrates. Among available substrates, carbon papers and titania nanotube layers are best choices considering their physio-chemical properties, availability and low costs incurred.
The uniform decoration of these substrates by NPs of catalysts proved to be highly efficient in electrocatalysis, as shown in our recent papers [3-5].
The presentation will introduce and describe the synthesis of different noble metal NPs by ALD on important substrates. It will also include the corresponding physical and electrochemical characterization and encouraging results obtained in electrocatalysis. References
[1] Huang, Z. F. et al. Advanced Energy Materials vol. 7 (2017) 1700544.
[2] Yoo, J. E. et al. Electrochem. commun. 86, (2018) 6
[3] Anitha, V. C. et al. J. Catal. 365, (2018) 86.
[4] Sitaramanjaneya M. Thalluri & Macak, J. M. Small 19 (2023) 2300974.
[5] B. Bawab et al., Electrochim. Acta 429 (2022) 141044
The Range of Influence across Commercial Glass Fiber Separators on the Cycling of the Zinc Metal Anode
Authors: Hansen Evan J. , Wu Zhenrui , Olfatbakhsh Tina , Milani Abbas , Liu Jian 
Published: August 2024

Aqueous zinc-ion batteries (AZIBs) have attracted significant research attention due to their promising potential for large-scale energy storage applications in support of the rapid global growth of renewable wind and solar energy generation. However, challenges associated with the limited cycling life and low energy density of AZIBs persist as the critical limiting factors preventing their practical use in utility-scale energy storage applications [1]. Throughout zinc-ion research working to address these challenges, commercial glass fiber (GF) membranes are often used as the separator in studies investigating cathode, electrolyte, and anode designs [2]. Nevertheless, commercial GF membranes are available with a range of physicochemical properties, and the specific details of the selected membrane are often missing in published studies. In our work, we systematically compare Whatman™ GF separators (GF/A, GF/B, GF/C, GF/D, and GF/F) to assess the influence of the separator’s physicochemical properties (i.e., pore size and thickness) on the cycling life and cell-to-cell variability across multiple trials of Zn|Zn cells. Under constant current cycling, significant differences were observed in the cycling life and cell-to-cell consistency depending on the pore size and thickness of the GF separator [3]. In addition, our use of micro-computed X-ray tomography explores the associations between the separator’s pore size and zinc deposition morphology and provides visual identification of the failure mechanism corresponding with an overpotential collapse. The results of this work clarify the importance of GF separator selection and the separator’s influence to support the improvement of other cell components.

References

[1] L. Ma, M. A. Schroeder, O. Borodin, T. P. Pollard, M. S. Ding, C. Wang, K. Xu, Realizing high zinc reversibility in rechargeable batteries, Nature Energy 5(10) (2020) 743-749.
[2] Y. Zhang, G. Yang, M.L. Lehmann, C. Wu, L. Zhao, T. Saito, Y. Liang, J. Nanda, Y. Yao, Separator Effect on Zinc Electrodeposition Behavior and Its Implication for Zinc Battery Lifetime, Nano Letters (2021).
[3] E. J. Hansen, Z. Wu, T. Olfatbakhsh, A. Milani, J. Liu, The role of glass fiber separators on the cycling of zinc metal anodes, Journal of Membrane Science 688 (2023) 122130.
Sodium-Metal Battery Based on Reversible Oxide Chemistry at the Cathode
Authors: Azaribeni Adel , mosen Harzandi Ahmad , Asadi Mohammad 
Published: August 2024

Sodium-metal batteries are considered as a promising energy storage alternative for currently available lithium-based batteries owing to their high gravimetric energy density and more specifically the natural abundance and the low price of Na metal that can lead to an inexpensive and low weight battery technology.
In this study, we employ a Na-metal cell design that works based on reversible phase/composition change of sodium oxides (superoxide and peroxide) using a highly active cathode catalyst and an ether-based ionic-liquid electrolyte. The process involves in-situ production of sodium oxides in the controlled oxygen environment at the cathode. Subsequently, the cathode composed of sodium oxide compositions is assembled into a Na-metal architecture to do performance study and analysis. Our results indicated that the designed Na-metal battery demonstrates stable performance over 50 cycles with an overpotential of less than 100 mV and a coulombic efficiency exceeding 99%. Various electrochemical and physicochemical characterization techniques, including Raman spectroscopy, X-Ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), and Transmission Electron Microscopy (TEM), were employed to gain insight into cell chemistry and mixed ion-electron conduction mechanism. The findings underscore the significance of well-designed cell components in Na-O2 battery technologies, positioning them as a promising avenue in energy conversion and storage systems.
Operando X-Ray Fluorescence Analysis of Dynamic Cerium Radical Quencher Motion Perpendicular to MEA
Authors: Orikasa Yuki , Takezawa Aika , Morita Kaoruko , Zhong Chengchao , Tsuji Yoichiro , Asaoka Takahiko , Ohki Maria , Sekizawa Oki , Nitta Kiyofumi 
Published: August 2024

Polymer electrolyte fuel cells (PEFCs) are required to have a durability of over 50,000 hours. One of the degradation factors is chemical degradation of perfluorosulfonic acid (PFSA) electrolyte membrane. The reaction of hydrogen peroxide with iron impurities produces hydroxyl radicals that break the chemical bonds in the PFSA membrane. Cerium ions are added to electrolyte membranes to absorb these radicals and act as a radical quencher, contributing to improved membrane durability.1 However, cerium ions have been shown to move in both the planar and through-plane directions under fuel cell operating conditions.2,3 The spatial scale of migration in the membrane planar direction is large, and therefore the time scale is also large, where analysis of end-of-life samples has been reported. On the other hand, the observation of the movement in the membrane direction is not easy because the thickness of the electrolyte membrane is 10 micrometers, and it is estimated to be significantly different between the post-disassembly condition and the operating condition. Therefore, it is necessary to establish operando measurement technique for cerium ion concentration with high spatial and temporal resolution in the direction perpendicular to the membrane. We developed an operando X-ray fluorescence spectroscopy technique using a combination of high-energy X-rays and a focused microbeam, and analyzed the behavior of cerium concentration change under current-applied conditions.4 The distribution behavior of cerium ions in the membrane is significantly different depending on the current and humidity. In a high-humidity environment, the ions move in the membrane in the vertical direction in about 1 second. Therefore, in this study, we developed a method to continuously measure the cerium ion concentration in the membrane on a sub-second scale and were able to estimate the effective cerium diffusion coefficient. It was also found that cerium ions migrate to the cathode layer under current-applied conditions. This behavior is accelerated in low humidity environments. This is because the diffusion coefficient of cerium ions is smaller at lower humidity and the back-diffusion flux is smaller.
This work is based on results obtained from the project commissioned by the New Energy and Industrial Technology Development Organization (NEDO) of Japan.
[1] E. Endoh, ECS Trans., 16, 1229–1240 (2008).
[2] Y. Lai, K. M. Rahmoeller, J. H. Hurst, R. S. Kukreja, M. Atwan, A. J. Maslyn,C. S. Gittleman, J. Electrochem. Soc., 165, F3217-F3229(2018).
[3] S.M. Stewart, D. Spernjak, R. Borup, A. Datye, F. Garzon, ECS Electrochem. Lett., 3, F19-F22 (2014).
[4] Y. Orikasa, A. Takezawa, K. Amemiya, Y. Tsuji, T. Asaoka, M. Ohki, O. Sekizawa, K. Nitta, ECS Trans.,
109 109 (2022).