Review
Chemistry, Multidisciplinary
Nedjeljko Seselj, Silvia M. M. Alfaro, Eftychia Bompolaki, Lars N. N. Cleemann, Tomas Torres, Kobra Azizi
Summary: The constant increase in global emission standards has led to the importance of fuel cell (FC) technology. Research in the past two decades has focused on developing more active catalysts for high-temperature polymer electrolyte membrane fuel cells (HT-PEMFC) and improving their durability. Two main approaches have been suggested: alloying platinum (Pt) with low-cost transition metals to reduce Pt usage, and developing novel catalyst supports to enhance metal particle anchoring and inhibit corrosion phenomena. This comprehensive review details the recent development of platinum group metal (PGM) and platinum group metal free (PGM-free) catalysts, as well as alternative carbon (C) supports for HT-PEMFCs.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Daniel Ilk, Viktoria Frick, Christopher Haenel, Thomas Schiestel, Michael Schoemaker, Holger Kraus, Harry E. Hoster
Summary: Membrane humidifiers are commonly used to improve the performance and lifespan of polymer electrolyte membrane fuel cells. This study tested five industrial humidifier membranes against five pollutant gases to evaluate their water transfer capabilities before and after exposure. The results showed that certain materials, such as polyimides and fluopolymers, were degraded by ozone, leading to decreased mechanical stability, while polysulfone membranes exhibited a decline in water transfer over time. The decline in water transfer could be attributed to physical degradation of the polymer rather than the presence of harmful gases. PFSA membranes were found to be particularly sensitive to ammonia.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2023)
Article
Chemistry, Physical
Akihiko Kato, Satoru Kato, Satoshi Yamaguchi, Takahisa Suzuki, Yasutaka Nagai
Summary: Excessive liquid water in the gas diffusion layer (GDL) of polymer electrolyte fuel cells (PEFCs) degrades their performance. The study classifies the condensation and transport of water into four categories based on the transient behavior of liquid water distribution. The possibility of oversaturation in the GDL and inconsistent experimental results with continuous water distribution are also proposed.
JOURNAL OF POWER SOURCES
(2022)
Article
Chemistry, Physical
Muhammad Faisal Jamil, Emre Bicer, Begum Yarar Kaplan, Selmiye Alkan Gursel
Summary: High Pt loading with improved performance and operational longevity is important in PEMFC. A novel electrophoretic deposition (EPD) method was used to fabricate Pt nanoparticles on reduced graphene oxide (rGO) supported carbon paper for PEMFC electrodes, achieving high ECSA value and Pt utilization efficiency at optimized Pt loading. The EPD technique showed viability, ease in handling, and reproducibility, leading to enhanced fuel cell performance.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Isaac Martens, Raphael Chattot, Jakub Drnec
Summary: Simultaneous in situ X-ray diffraction (XRD) and small angle X-ray scattering (SAXS) can independently decouple nanoparticle degradation mechanisms of aggregation, coalescence, and ripening in hydrogen fuel cell electrocatalyst layers. The ratio of particle size to crystallite size is proposed as a direct measurement of catalyst particle-particle interactions, which is applied to track the aggregation of a practical industrial fuel cell catalyst during accelerated degradation. The dominant catalyst degradation mode changes over the device's life cycle, passing through distinct phases of aggregation, coalescence, and ripening, emphasizing the importance of understanding each degradation mode for engineering next-generation catalysts with commercially acceptable durability.
JOURNAL OF POWER SOURCES
(2022)
Article
Biochemistry & Molecular Biology
Maito Koga, Hidetoshi Matsumoto, Mitsunori Kunishima, Masatoshi Tokita, Hiroyasu Masunaga, Noboru Ohta, Akihisa Takeuchi, Junji Mizukado, Hidekazu Sugimori, Kazuhiko Shinohara, Suguru Uemura, Toshihiko Yoshida, Shuichiro Hirai
Summary: Perfluorosulfonated ionomers are successfully used as ion-exchange membranes in industrial applications, and are also utilized in polymer electrolyte fuel cells (PEFCs) as a component of the catalyst layer. Through synchrotron X-ray scattering and transmission electron microscopy analyses, it was found that the ionomers cover the Pt/CB surface and the Pt catalyst nanoparticles aggregate in the catalyst layer of PEFCs.
Article
Nanoscience & Nanotechnology
Hyoung Jun Lim, Geonwoo Kim, Gun Jin Yun
Summary: In this study, the chemo-mechanically coupled behavior of Nafion212 is investigated using multiphysics modeling and experimental validation. The degradation of perfluorosulfonic acid (PFSA) membrane, which plays a critical role in fuel cell performance and durability, is quantitatively estimated by measuring fluoride release. The nonlinear behavior of the PFSA membrane in tensile testing is modeled using J(2) plasticity-based material modeling, and the material parameters are characterized based on fluoride release levels. A pinhole growth model is adopted to investigate the life prediction of the membrane, and the validation is conducted by comparing it with the accelerated stress test (AST).
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Energy & Fuels
Qian Zhang, Mathias Schulze, Pawel Gazdzicki, K. Andreas Friedrich
Summary: This study analyzed the impact of three recovery procedures on the performance of polymer electrolyte membrane fuel cells. The research found that these procedures can effectively recover performance losses at high current densities, but show significant differences at lower current densities. The JRC protocol recovers kinetic losses by reducing the cathode potential and fuel cell temperature, while the DOE protocol has relatively poorer recovery effects.
Article
Chemistry, Physical
Dan Wu, Samindi Madhubha Jayawickrama, Tsuyohiko Fujigaya
Summary: This study investigates the effect of polymer-coating on the durability of Pt nanoparticles in polymer electrolyte membrane fuel cells (PEMFC). The results show that using a polymer-coated catalyst leads to a smaller decrease in maximum power density after accelerated durability tests, indicating the potential of the polymer-coating method to improve PEMFC durability.
JOURNAL OF POWER SOURCES
(2022)
Article
Chemistry, Physical
Qian Zhang, Mathias Schulze, Pawel Gazdzicki, K. Andreas Friedrich
Summary: This study presents a methodology for quantifying the recovery of reversible voltage losses in polymer electrolyte membrane fuel cells, and evaluates the influence of different recovery procedures on fuel cell performance. Results show that using polarization curves and voltage data logged during load cycling lead to the same recovery outcomes, indicating that in-depth electrochemical characterization may not be necessary for assessing recovery efficiency. EIS data are used to determine the main mechanisms leading to recovery, identifying weaknesses in specific recovery procedures for proposing improvements.
JOURNAL OF POWER SOURCES
(2021)
Article
Chemistry, Physical
Elena Colombo, Andrea Baricci, Daniele Mora, Laure Guetaz, Andrea Casalegno
Summary: Automotive Polymer Electrolyte Membrane Fuel Cells (PEMFC) need to improve durability for better competitiveness. Single cell accelerated stress tests (ASTs) have been standardized to accelerate the development of durable materials. However, current ASTs are not easily correlated with real-world aging. To address this issue, a new hydrogen/air AST was developed to comprehensively mimic the driving functioning. The aging results of state-of-the-art PEMFC were successfully correlated with realistic load cycling, showing a 10-fold acceleration in time.
JOURNAL OF POWER SOURCES
(2023)
Review
Chemistry, Physical
Qianwen Tang, Bing Li, Daijun Yang, Pingwen Ming, Cunman Zhang, Yanbo Wang
Summary: The article reviews the literature on hydrogen crossover in PEMFC, covering consequences, causes, mitigation measures, and detection methods. It discusses the influences of hydrogen crossover on the components and performance, analyzes the causes, and summarizes methods to alleviate membrane degradation. Various monitoring methods are described, providing a foundation for further research and improvement in fuel cell durability.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Nanoscience & Nanotechnology
Junmo Koo, Heon Jun Jeong, Wonjoon Choi, Joon Hyung Shim
Summary: Platinum-carbon nanotube (CNT) catalysts were evaluated as cathode catalysts for polymer electrolyte membrane fuel cells. Pt catalysts were fabricated using atomic layer deposition on bare or O2 plasma treated CNTs. The morphology of the Pt particles differed on the two types of CNT supports, leading to differences in electrochemical and fuel cell performance. Factors other than geometric features also influenced fuel cell performance.
SCRIPTA MATERIALIA
(2023)
Article
Energy & Fuels
Yun Sik Kang, Segeun Jang, Eunho Choi, Sunhee Jo, Sang Moon Kim, Sung Jong Yoo
Summary: Improving the durability of PEMFCs by incorporating radical scavengers such as ceria into the MEA, especially the membrane, is crucial for further commercializing polymer electrolyte membrane fuel cells. A novel method of constructing a robust membrane by adding ultrathin ceria barriers to the outermost sides of a commercial Nafion membrane has been developed, leading to enhanced durability and proper areal density of CeO2 barriers. The decreased amount of fluoride ion emission and loss of proton conductivity with increasing CeO2 density suggest improved performance and durability of the modified membrane.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Chemistry, Physical
Amir Peyman Soleymani, Leonard Bonville, Chunmei Wang, Stephanie Schaefer, James Waldecker, Jasna Jankovic
Summary: Despite progress in improving the performance of PEMFCs, catalyst degradation still remains a challenge. Startup/shutdowns of FCEVs can cause degradation and failure of PEMFCs. In this study, the correlation between microstructural changes and performance data of SUSD samples was quantified. Severe carbon corrosion and Pt degradation were observed during unprotected SUSD operation at 35 degrees C. However, after implementing a protective protocol, carbon corrosion and Pt degradation were significantly reduced, preserving the microstructure of the PEMFC and improving its lifetime.
JOURNAL OF POWER SOURCES
(2023)
Article
Chemistry, Physical
A. E. Kozhukhova, S. P. du Preez, D. G. Bessarabov
Summary: The performance and durability of Pt/CZY/AAO catalyst in hydrogen combustion were studied, showing stable average combustion temperature for prolonged periods. Limited or no catalyst deactivation was observed, indicating good potential for practical applications.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Jamey Davies, Stephanus P. du Preez, Dmitri G. Bessarabov
Summary: In this investigation, ternary Al-Bi-Zn composites were prepared using mechanochemical activation to study the effects of low-cost Bi and Zn on the morphology change and reactivity of Al during hydrolysis reaction. The results showed that Bi and Zn were distributed uniformly in Al particles without forming intermetallic phases. The composite with 7.5 wt% Bi and 2.5 wt% Zn exhibited a high hydrogen yield.
Article
Energy & Fuels
Jamey Davies, Stephanus P. Du Preez, Dmitri G. Bessarabov
Summary: In this study, Al-Bi-Ni composites were successfully prepared and hydrolyzed. Scanning electron microscopy showed that Bi and Ni were uniformly distributed in the Al particles, resulting in micro-galvanic interactions during the hydrolysis reaction. The successfully prepared composites exhibited good hydrogen production, and the mass ratio and water quality affected the hydrolysis activity.
Article
Chemistry, Physical
Phillimon Modisha, Rudaviro Garidzirai, Hande Gunes, Selmi Erim Bozbag, Sarshad Rommel, Erdal Uzunlar, Mark Aindow, Can Erkey, Dmitri Bessarabov
Summary: Pt/Al2O3 catalysts prepared using the SCD method showed the best catalytic performance for the dehydrogenation of H18-DBT, attributed to the higher dispersion of Pt particles and smaller particle size. The deactivation was mainly caused by adsorbed H0-DBT blocking the active sites. The study revealed that improved catalyst performance led to increased production of liquid by-products and carbon materials.
Article
Geochemistry & Geophysics
Jamey Davies, Dogan Paktunc, Jose Juan Ramos-Hernandez, Merete Tangstad, Eli Ringdalen, Johan P. Beukes, Dmitri G. Bessarabov, Stephanus P. Du Preez
Summary: This study explores the potential use of hydrogen as a reductant in stainless steel production, investigating the reduction of chromite ore by hydrogen through experiments and thermodynamic modeling. The results show that under the explored reduction parameters, iron oxides in chromite can be reduced and removed, while the chromium oxide in chromite does not undergo significant metallization.
Article
Nanoscience & Nanotechnology
Alina E. Kozhukhova, Stephanus Petrus du Preez, Dmitri Bessarabov
Summary: The catalytic performance of Pt/CZY/AAO washcoat catalyst was investigated under different gas flow velocities and hydrogen concentrations, and the effects of Pt sintering on catalyst activity were explored through aging tests and characterization methods.
ACS APPLIED NANO MATERIALS
(2022)
Review
Energy & Fuels
Artem S. Pushkarev, Irina Pushkareva, Dmitri G. Bessarabov
Summary: Polymer electrolyte membrane (PEM) water electrolysis is a practical way to produce green hydrogen using renewable energy, and Ir-based supported oxygen evolution catalysts have the potential to reduce costs and enhance catalytic activity.
Article
Geochemistry & Geophysics
Jamey Davies, Merete Tangstad, Eli Ringdalen, Johan Paul Beukes, Dmitri Bessarabov, Stephanus Petrus du Preez
Summary: The use of hydrogen as a reductant for chromite ore can reduce carbon emissions, although the reduction of chromium oxide is more challenging than that of iron oxide. However, pre-oxidation can enhance the reducibility of iron oxide and increase the metallization of iron.
Article
Chemistry, Physical
Kingsley Onyebuchi Obodo, Cecil Naphtaly Moro Ouma, Dmitri Bessarabov
Summary: Spin-polarized van der Waals corrected density functional theory calculations were used to evaluate the catalytic activity of Sn-Pt alloys towards the dehydrogenation of methylcyclohexane (MCH). The study suggested that Sn-Pt alloys have superior catalytic performance compared to pristine Pt catalysts.
Article
Chemistry, Physical
Artem S. Pushkarev, Irina V. Pushkareva, Stephanus P. du Preez, Dmitri G. Bessarabov
Summary: Low-cost anion exchange membrane (AEM) water electrolysis is a promising technology for producing green high-purity hydrogen using platinum group metal (PGM)-free catalysts. The performance of AEM electrolysis depends on different processes in the water electrolyzer and can be unraveled using electrochemical impedance spectroscopy. This study focuses on solving and quantifying the contributions to the total polarization resistance of the AEM water electrolyzer, including non-faradaic charge transfer resistance and ohmic resistance.
Review
Geochemistry & Geophysics
Stephanus P. du Preez, Tristan P. M. van Kaam, Eli Ringdalen, Merete Tangstad, Kazuki Morita, Dmitri G. Bessarabov, Pieter G. van Zyl, Johan P. Beukes
Summary: Ferrochrome is the main source of chromium used in modern-day chromium-containing alloys, particularly in the production of stainless steel. The production process of ferrochrome generates various by-products, which are often classified as waste materials. The current waste management practices in the South African ferrochrome industry are limited, and alternative approaches such as low-carbon, low-temperature processes and hydrogen reduction have not been considered.
Article
Biochemistry & Molecular Biology
Torsten Berning, Dmitri Bessarabov
Summary: We propose a MEA for a proton exchange membrane water electrolyzer with a graphene oxide (GO) layer at the cathode side. This GO layer strengthens the MEA, allowing for operation at a higher pressure difference and preventing water and hydrogen crossover. It also eliminates the need for hydrogen clean-up steps and allows for a thinner polymer electrolyte membrane, saving cost. The effect of electro-osmotic drag on water content in the MEA is discussed, suggesting an oversaturated membrane is desirable.
Article
Engineering, Chemical
Kyatsinge Cedric Musavuli, Nicolaas Engelbrecht, Raymond Cecil Everson, Phillimon Modisha, Gunther Kolb, Ralf Zapf, Christian Hofmann, Dmitri Bessarabov
Summary: The study investigates the synthesis of methanol using a fixed-bed reactor with CO2 as the carbon feedstock. The results show promising performance under high pressure and specific conditions, providing insights for finding new ways to utilize CO2.
Article
Chemistry, Multidisciplinary
Phillimon Modisha, Dmitri Bessarabov
Summary: Hydrogen production from renewable energy sources can reduce the carbon footprint of sectors relying on fossil fuels. Liquid organic hydrogen carrier (LOHC) technology can overcome the limitations of conventional hydrogen storage. Dibenzyltoluene and benzyltoluene are currently the benchmark LOHC molecules, but improvements in catalysts and reactive distillation methods are needed to increase hydrogen release efficiency and lower dehydrogenation temperature.
CURRENT OPINION IN GREEN AND SUSTAINABLE CHEMISTRY
(2023)
Article
Physics, Condensed Matter
Louise Magdalene Botha, Cecil Naphtaly Moro Ouma, Kingsley Onyebuchi Obodo, Dmitri Georgievich Bessarabov, Denis Lvovich Sharypin, Pyotr Sergeevich Varyushin, Elizaveta Ivanovna Plastinina, Amir-Abbas Haghighirad
Summary: This study investigated the properties of Pt/Pd alloys using density functional theory (DFT) calculations. The results showed that these alloy structures are energetically and elastically stable, with a metallic character and non-magnetic properties. This research contributes to a better understanding of Pt/Pd alloy structures and their applications in materials science and catalysis.
Article
Chemistry, Physical
Sergey Yu. Ketkov, Sheng-Yuan Tzeng, Elena A. Rychagova, Anton N. Lukoyanov, Wen-Bih Tzeng
Summary: Metallocenes, including methylcobaltocene, play important roles in various fields of chemistry. The ionization energy and vibrational structure of (Cp ')(Cp)Co can be influenced by introducing methyl substituents. The mass-analyzed threshold ionization spectrum and DFT calculations provide accurate information about the properties and transformations of (Cp ')(Cp)Co.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Review
Chemistry, Physical
Qifeng Mu, Jian Hu
Summary: Polymer mechanochemistry has experienced a renaissance due to the rapid development of mechanophores and principles governing mechanochemical transduction or material strengthening. It has not only provided fundamental guidelines for converting mechanical energy into chemical output, but also found applications in engineering and smart devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Da Hye Yang, Francesco Ricci, Fredrik L. Nordstrom, Na Li
Summary: Through systematic evaluation of the oiling-out behavior of procaine, we identified both stable and metastable liquid-liquid phase separation, and established phase diagrams to assist in rational selection of crystallization strategies.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Vikki Anand Varma, Simmie Jaglan, Mohd Yasir Khan, Sujin B. Babu
Summary: Designing engineering structures like nanocages, shells, and containers through self-assembly of colloids is a challenging problem. This work proposes a simple model for the subunit, which leads to the formation of monodispersed spherical cages or containers. The model with only one control parameter can be used to design cages with the desired radius.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Hainan Jiang, Yaolong He, Xiaolin Li, Zhiyao Jin, Huijie Yu, Dawei Li
Summary: The cycling lifespan and coulombic efficiency of lithium-ion batteries are crucial for high C-rate applications. The Li-ion concentration plays a crucial role in determining the mechanical integrity and structural stability of electrodes. This study focuses on graphite as the working electrode and establishes an experimental system to investigate the mechanical properties of composite graphite electrode at different C-rates. Considering the effect of Li-ion concentration in stress analysis is found to be significant.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Zhiye Wang, Yunchuan Li, Mingjun Sun
Summary: This study investigates the influence of intramolecular pi-pi interactions on the electronic transport capabilities of molecules. By designing and analyzing three pi-conjugated molecules, the researchers observe that different pi-conjugated structures have varying effects on electron transport. The findings provide a theoretical foundation for designing single-molecule electronic devices with multiple electron channels based on intramolecular pi-pi interactions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Yuandong Xu, Haoyang Feng, Chaoyang Dong, Yuqing Yang, Meng Zhou, Yajun Wei, Hui Guo, Yaqing Wei, Jishan Su, Yingying Ben, Xia Zhang
Summary: Hollow MoS2 cubes and spheres were successfully synthesized using a one-step hydrothermal method with the hard template method. The hollow MoS2 cubes exhibited higher specific capacitance and energy density compared to the hollow MoS2 spheres. The symmetrical supercapacitors assembled with these hollow structures showed good performance and high capacity retention after multiple cycles. These findings suggest that controlling the pore structure and surface characteristics of MoS2 is crucial for enhancing its electrochemical properties.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Ainhoa Oliden-Sanchez, Rebeca Sola-Llano, Joaquin Perez-Pariente, Luis Gomez-Hortiguela, Virginia Martinez-Martinez
Summary: The combination of photoactive molecules and inorganic structures is important for the development of advanced materials in optics. In this study, bulky dyes were successfully encapsulated in a zeolitic framework, resulting in emission throughout the visible spectrum.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Miaomiao Zhang, Cunyuan Pei, Qiqi Xiang, Lintao Liu, Zhongxu Dai, Huijuan Ma, Shibing Ni
Summary: The design of a solid electrolyte interphase (SEI) plays a crucial role in improving the electrochemical performance of anode materials. In this study, lithium difluoro(oxalate)borate (LiDFOB) is used as an electrolyte additive to form a protective SEI film on Li3VO4 (LVO) anodes. The addition of LiDFOB results in a dense, uniform, stable, and LiF-richer SEI, which enhances the Li-ion storage kinetics. The generated SEI also prevents further decomposition of the electrolyte and maintains the morphology of LVO anodes during charge/discharge processes. This work demonstrates the effectiveness of LiDFOB as a multi-functional additive for LiPF6 electrolytes and provides insights into SEI construction for high-performance LVO anodes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
B. V. Andryushechkin, T. V. Pavlova, V. M. Shevlyuga
Summary: The atomic structure of the Ag(111)-p(4 x 4)-O phase was reexamined and two phases with the same periodicity were discovered. It was demonstrated that the accepted Ag6 model is incompatible with high-resolution oxygen-sensitive STM images.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
S. L. Romo-Avila, D. Marquez-Ruiz, R. A. Guirado-Lopez
Summary: In this study, we used density functional theory (DFT) calculations to investigate the interaction between model graphene oxide (GO) nanostructures and chlorine monoxide ClO. We aimed to understand the role of this highly oxidizing species in breaking C-C bonds and forming significant holes on GO sheets. Our results showed that C-C bonds in a single graphene oxide sheet can be broken through a simple mechanism involving the dissociation of two chemically attached ClO molecules. The formation of carbonyl groups and holes on the GO surface was also observed. This study provides important insights into the degradation of carbon nanotubes and the stability of GO during the myeloperoxidase (MPO) catalytic cycle.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Alberto Garcia-Fernandez, Birgit Kammlander, Stefania Riva, Hakan Rensmo, Ute B. Cappel
Summary: In this study, the X-ray stability of five different lead halide perovskite compositions (MAPbI3, MAPbCl3, MAPbBr3, FAPbBr3, CsPbBr3) was investigated using photoelectron spectroscopy. Different degradation mechanisms and resistance to X-ray were observed depending on the crystal composition. Overall, perovskite compositions based on the MA+ cation were found to be less stable than those based on FA+ or Cs+. Metallic lead formation was most easily observed in the chloride perovskite, followed by bromide, and very little in MAPbI3. Multiple degradation processes were identified for the bromide compositions, including ion migration, formation of volatile and solid products, as well as metallic lead. CsBr was formed as a solid degradation product on the surface of CsPbBr3.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Timofei Rostilov, Vadim Ziborov, Alexander Dolgoborodov, Mikhail Kuskov
Summary: The shock-loading behavior of nanomaterials is investigated in this study. It is found that shock compaction waves exhibit a distinct two-step structure, with the formation of faster precursor waves that travel ahead of the main compaction waves. The complexity of the shock Hugoniot curve of the tested nanomaterial is described, and the effect of initial porosity on the compressed states is demonstrated.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Sergey S. Nikitin, Alexander D. Koryakov, Elizaveta A. Antipinskaya, Alexey A. Markov, Mikhail V. Patrakeev
Summary: The stability of La1/3Sr2/3Fe1-xMnxO3-delta, a perovskite-type oxide, under reducing conditions is dependent on the manganese content. Increasing the manganese content leads to a decrease in stability. The behavior of iron and manganese in the oxide shows distinct differences, which can be attributed to the difference in the enthalpy of oxidation reactions. Additionally, the change in the La/Sr ratio affects the concentration of iron and manganese ions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Mosayeb Naseri, Shirin Amirian, Mehrdad Faraji, Mohammad Abdur Rashid, Maicon Pierre Lourenco, Venkataraman Thangadurai, D. R. Salahub
Summary: Inspired by the successful transfer of freestanding ultrathin films of SrTiO3 and BiFeO3, this study assessed the structural stability and investigated the electronic, optical, and thermoelectric properties of a group of two-dimensional perovskite-type materials called perovskenes. The findings revealed that these materials are wide bandgap semiconductors with potential application in UV shielding. Moreover, they exhibit better electrical and thermal conductivity at high temperatures, enabling efficient power generation in thermoelectric devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)