Article
Geochemistry & Geophysics
Elizabeth C. Thompson, Andrew J. Campbell, Jun Tsuchiya
Summary: Using density functional theory calculations, the stability, structure, and elastic properties of pyrite-type FeO2H were determined and compared with other polymorphs, suggesting composition-driven behavior at mantle pressures. The coexistence of pyrite-type (Al,Fe)OOH with CaCl2-type delta-(Al,Fe)OOH in the deep Earth is possible.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
Juan Chen, Heping Li, Yi Yuan, Mengxue Zhang, Shuhang Shuai, Jingjing Wan
Summary: Variations in the Raman spectra of pyrite were studied under different temperatures and pressures. The results showed that temperature increase led to a decrease in frequencies and the transformation from pyrite to hematite. The interaction of pressure and temperature also affected the Raman modes.
Article
Chemistry, Physical
Patrick Gono, Alfredo Pasquarello
Summary: The outstanding performance of NiOOH/FeOOH-based oxygen evolution reaction (OER) catalysts is rationalized by a bifunctional mechanism involving two distinct active sites, which can effectively overcome the limitations imposed by the linear scaling relationships and improve overall activity.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Physics, Multidisciplinary
Yao Wang, Dan Xu, Shan Gao, Qi Chen, Dayi Zhou, Xin Fan, Xin-Jian Li, Lijie Chang, Yuewen Zhang, Hongan Ma, Xiao-Peng Jia
Summary: In this study, we modified pyrite by exploiting the reducibility of aluminum under high-pressure and high-temperature conditions, which effectively improved its conductivity. We also found that high pressure enhances the thermal stability of pyrite. In addition, we explored the influence of aluminum addition on the hardness and toughness of pyrite samples through hardness and density tests.
Article
Chemistry, Multidisciplinary
Stefan Markulik, Marek Solc, Jozef Petrik, Michaela Balazikova, Peter Blasko, Juraj Kliment, Martin Bezak
Summary: This article focuses on risk evaluation in pressure leaching at elevated temperatures and found a disproportionately high probability of process failure, indicating the need for corrective actions. The Monte Carlo method was used to simulate the effect of basic events’ probability on the top event – failure of the leaching process.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Inorganic & Nuclear
Egor Koemets, Timofey Fedotenko, Saiana Khandarkhaeva, Maxim Bykov, Elena Bykova, Marcel Thielmann, Stella Chariton, Georgios Aprilis, Iuliia Koemets, Konstantin Glazyrin, Hanns-Peter Liermann, Michael Hanfland, Eiji Ohtani, Natalia Dubrovinskaia, Catherine McCammon, Leonid Dubrovinsky
Summary: The study found that goethite decomposes into oxygen-rich fluid and different iron oxides under high-pressure and high-temperature conditions. Goethite, formed from about 3.8 billion years ago until 2.2 billion years ago, was transported into the mantle through plate tectonics.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Metallurgy & Metallurgical Engineering
Richard Li Jie Lee, Yongjun Peng
Summary: This study evaluated the use of 30 wt% Cr steel in high-pyrite-content copper flotation, comparing it with traditional forged steel. The results showed that the 30 wt% Cr steel effectively produced a high Cu concentrate grade when treating low-concentration pyrite ores, while forged steel poorly depressed pyrite due to strong galvanic interaction between the steel and pyrite. The study provides direction for depressing high-concentration pyrite in copper flotation.
MINERAL PROCESSING AND EXTRACTIVE METALLURGY REVIEW
(2023)
Article
Chemistry, Physical
Evgenii V. Beletskii, Mikhail A. Kamenskii, Elena V. Alekseeva, Alexey I. Volkov, Daniil A. Lukyanov, Dmitrii V. Anishchenko, Anton O. Radomtseu, Anastasiya A. Reveguk, Oleg V. Glumov, Oleg V. Levin
Summary: Amorphous urchin-like FeOOH nanoparticles and their graphite composite (FeOOH/Gr) synthesized in a one-step atmospheric plasma-assisted procedure show excellent electrochemical performance as anode materials for Li-ion batteries.
APPLIED SURFACE SCIENCE
(2022)
Article
Engineering, Environmental
Elham Aseman-Bashiz, Abbas Rezaee, Gholamreza Moussavi
Summary: By utilizing a conductive microbial cellulose (MC) cathode stabilized by polyaniline (PANI) in the presence of nano-pyrite (FeS2), this study introduced an efficient, sustainable, and economical integrated electrochemical system for the electrochemical removal of hexavalent chromium (Cr (VI)). The synergistic effect and cooperation between the MC/PANI cathode and the nano-pyrite catalyst improved the removal efficiency of Cr (VI) through the creation of different electron transfer pathways. The results showed a high Cr (VI) removal rate of 98.6% in the presence of both the MC/PANI cathode and nano-pyrite in the electrochemical process.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Article
Engineering, Environmental
Xinyu Lu, Kai-hang Ye, Siqi Zhang, Jingnan Zhang, Jindong Yang, Yongchao Huang, Hongbing Ji
Summary: A new method was designed to induce oxygen vacancies in BiVO4/FeOOH nanostructures, leading to improved performance in photoelectrochemical water oxidation. The strategy involved integrating Bi2S3 quantum dots into BiVO4/FeOOH to create defect-rich high-performance photoanode Vo-BiVO4/FeOOH.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Tong Liu, Yutian Hu, Nan Chen, Qiaochong He, Chuanping Feng
Summary: This study investigated the performance of pyrite autotrophic denitrification (PAD) in the presence of EDTA and uncovered the mechanism of anaerobic pyrite oxidation and microbial mineral transformation. The electrochemical threshold for converting pyrite into bioavailable forms in PAD conditions was found to be around 200 mV, and the presence of Fe3+-EDTA complexes accelerated pyrite oxidation. Higher abundances of sulfur- and nitrogen-cycling genera were observed in cultures containing EDTA, indicating increased functional diversity and redundancy in the microbial community. These findings contribute to a better understanding of pyrite oxidation under anaerobic neutral conditions and suggest practical applications for PAD.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Chemistry, Physical
Zhe Lin, Xiaohua Jia, Jin Yang, Yong Li, Sizhe Wang, Haojie Song
Summary: This study successfully fabricated multicolored carbon fiber cloths using an eco-friendly one-step hydrothermal method, with bright colors easily controlled by adjusting the hydrothermal temperature. The cloths demonstrated excellent structural stability and durability, and were found to be a new candidate for photothermal deicing, showing a significant increase in temperature.
APPLIED SURFACE SCIENCE
(2021)
Article
Physics, Multidisciplinary
Osamu Ikeda, Tatsuya Sakamaki, Takaya Mitsui, Kosuke Fujiwara, Catherine A. McCammon, Akio Suzuki
Summary: Mossbauer spectra of polycrystalline e-57FeOOH were measured up to 14.6 GPa at room temperature using the energy-domain synchrotron 57Fe Mossbauer source at BL11XU in SPring-8. Based on measurements with and without an external magnetic field, e-FeOOH exhibits antiferromagnetic behavior at ambient pressure and temperature. Compression-induced changes in the quadrupole shift 2e, observed at -8 GPa, suggest a magnetic spin rotation and indicate a third pressure-induced transition in addition to hydrogen-bond symmetrization and electronic spin transition, without significant structural changes as observed by previous XRD studies.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Article
Chemistry, Multidisciplinary
Lingling Feng, Junshuang Zhou, Mingxin Liu, Zikang Zhao, Nan Zhang, Xuezheng Ma, Shengwei Sun, Faming Gao
Summary: This study demonstrates the successful preparation of dendritic structured catalysts using a one-step cathodic deposition method, which enables efficient hydrogen production from seawater at low overpotentials in industrial environments. The catalyst exhibits excellent stability, attributed to its dendritic structure that resists corrosion and exposes a large number of catalytically active sites.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Anna Olejnicza, Anna Katrusiak, Marcin Podsiadlo, Andrzej Katrusiak
Summary: Under ambient conditions, high nitrogen content compound C6H5N7 forms two concomitant monohydrate polymorphs (alpha-C6H5N7.H2O and beta-C6H5N7.H2O) and anhydrate C6H5N7 from acetone solution. High-pressure recrystallizations produce new forms. The alpha-hydrate can be reversibly compressed to 0.6 GPa, while the beta-hydrate can be compressed to and from 1 GPa. Isochoric recrystallizations above 0.3 GPa preferentially form the alpha-hydrate. Compound C7H7N7 can only be recrystallized from aqueous solution as sesquihydrate C7H7N7 & BULL;1.5H2O. Hydrogen bonds and tandem contacts between azide groups govern the molecular packing in all hydrates.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Physics, Condensed Matter
Satoshi Ohmura, Taku Tsuchiya, Fuyuki Shimojo
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2020)
Article
Geosciences, Multidisciplinary
Zhihua Xiong, Taku Tsuchiya, James A. Van Orman
Summary: The Earth's core may be a reservoir for He-3, but is unlikely to be a significant source for Ar-36. The partitioning behaviors of He and Ar between liquid metal and silicate melt during core formation are influenced by pressure.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Elizabeth C. Thompson, Andrew J. Campbell, Jun Tsuchiya
Summary: Using density functional theory calculations, the stability, structure, and elastic properties of pyrite-type FeO2H were determined and compared with other polymorphs, suggesting composition-driven behavior at mantle pressures. The coexistence of pyrite-type (Al,Fe)OOH with CaCl2-type delta-(Al,Fe)OOH in the deep Earth is possible.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2021)
Article
Geochemistry & Geophysics
K. Ozawa, K. Hirose, Y. Kuwayama, Y. Takahashi
Summary: Tungsten plays a key role in planetary core formation, with its coordination structure and metal-silicate partitioning being influenced by pressure and silicate melt composition. Research suggests that at high pressures, the coordination of tungsten is controlled by Si-O coordination, potentially affecting metal-silicate partitioning.
GEOCHEMICAL PERSPECTIVES LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Yasuhiro Kuwayama, Kei Hirose, Laura Cobden, Mayu Kusakabe, Shigehiko Tateno, Yasuo Ohishi
Summary: Through high-pressure and high-temperature X-ray diffraction measurements, we discovered that a phase transition occurs in pyrolite even at high temperatures and pressures, indicating the presence of post-perovskite above the core-mantle boundary. This has significant implications for seismology, geodynamics, and heat transfer.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
T. Matsumura, Y. Kuwayama, K. Ueki, T. Kuwatani, Y. Ando, K. Nagata, S. Ito, H. Nagao
Summary: The study uses Bayesian modeling of the equation of state to estimate the density and P wave velocity of liquid iron in Earth's outer core, providing credible intervals for the deviations from the preliminary reference Earth model. The Bayesian modeling allows integration of small data sets including unobserved data and evaluation of uncertainty ranges of physical properties essential for comparison with seismological properties of the core.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Physics, Condensed Matter
Taku Tsuchiya, Saito Nakagawa
Summary: The high-pressure behavior of SiO2 is a key subject in various research areas. Researchers have shown a new structure directly converted from alpha-quartz under uniaxial compression and elucidated a simple transition pathway to the Fe2P-type phase. An intermediate state with the Li2ZrF6-type structure has been discovered, with some interesting properties. The Li2ZrF6-type phase is found to be metastable at lower pressures but becomes energetically stable than alpha-quartz at around 12 GPa, suggesting potential applications in ambient conditions.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Geosciences, Multidisciplinary
Satoshi Ohmura, Fuyuki Shimojo, Taku Tsuchiya
Summary: The structural and bonding properties of liquid iron-light-element-oxygen ternary systems are studied using ab initio molecular dynamics simulations. H, C, O, Si, and S are investigated as light elements in the Earth's outer core. The simulations reveal that H, C, and O exhibit interstitial behavior while Si and S show substitutional behavior. Covalent-like interactions are observed between C-C, Si-Si, and Si-O, even under high-pressure conditions. The covalent bond between Si and O leads to a positive shift in Si's ionic charge, which may relate to the immiscibility of liquid Fe-Si-O.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geochemistry & Geophysics
Saori Kawaguchi, Guillaume Morard, Yasuhiro Kuwayama, Kei Hirose, Naohisa Hirao, Yasuo Ohishi
Summary: The density and equation of state parameters of liquid iron-nickel-sulfur alloy were determined, and the sulfur content in Earth's outer core was estimated based on these results.
AMERICAN MINERALOGIST
(2022)
Article
Geochemistry & Geophysics
Kenta Oka, Shigehiko Tateno, Yasuhiro Kuwayama, Kei Hirose, Yoichi Nakajima, Koihiro Umemoto, Noriyoshi Tsujino, Saori Kawaguchi
Summary: In this study, pressure-induced phase transitions in Fe2S were examined using high-pressure and high-temperature X-ray diffraction measurements. A novel cotunnite-type Fe2S phase was discovered, which has important implications for understanding the composition of iron cores in planets.
AMERICAN MINERALOGIST
(2022)
Article
Geochemistry & Geophysics
Elizabeth C. Thompson, Andrew J. Campbell, Jun Tsuchiya
Summary: This study uses first-principles calculations to evaluate the structure, equation of state, and elasticity of phase D with different compositions. The results show that both the magnesium endmember and the aluminum endmember undergo hydrogen-bond symmetrization, but the increase in bulk modulus is different. The aluminum endmember phase D has higher density, lower compressibility, and faster compressional and shear velocities compared to the magnesium endmember. Additionally, the properties of phase D with 50% Al-substitution cannot be accurately modeled by interpolating the properties of the magnesium and aluminum endmembers.
Article
Geochemistry & Geophysics
Wen-Pin Hsieh, Enrico Marzotto, Takayuki Ishii, Leonid Dubrovinsky, Alena A. Aslandukova, Giacomo Criniti, Yi-Chi Tsao, Chun-Hung Lin, Jun Tsuchiya, Eiji Ohtani
Summary: The deep water cycle of the Earth has a significant impact on its physical and chemical properties, as well as its geodynamics. This study focuses on the influence of dense hydrous magnesium silicates (DHMSs) on the thermal evolution and dynamics of sinking slabs. The research shows that the thermal conductivity of DHMSs is lower than that of other components along slab subduction, which contributes to the formation of a cold hydrous layer within sinking slabs, stabilizes hydrous minerals, and promotes water transportation to the deeper mantle.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Review
Geosciences, Multidisciplinary
Jun Tsuchiya, Elizabeth C. Thompson
Summary: Hydrous minerals are thermodynamically stable at lower mantle pressures, with symmetric hydrogen bonds playing a key role. Ab initio calculations are crucial for identifying novel phases and determining geophysical properties.
PROGRESS IN EARTH AND PLANETARY SCIENCE
(2022)
Article
Physics, Condensed Matter
Haruhiko Dekura, Taku Tsuchiya
Summary: The effects of iron incorporation on the lattice thermal conductivity of MgO under high pressure and temperature conditions were investigated using density-functional theory and anharmonic lattice dynamics theory. The lattice thermal conductivity of ferropericlase was determined using the LDA + U method and phonon Boltzmann transport equation. The results showed that the incorporation of iron significantly decreased the lattice thermal conductivity of MgO.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Physics, Multidisciplinary
Masamichi Noda, Toru Inoue, Taku Tsuchiya, Yuji Higo
Summary: A new method for precisely measuring elastic wave velocity is developed by combining in situ synchrotron X-ray technique and ultrasonic interferometry with a Kawai type multi-anvil apparatus. The validation using literature data and new elastic constant data of gold shows that the corrected elastic wave velocities are in good agreement with experimental measurements and calculations. The correction for the bond effect is highly important, particularly when the sample length is less than 1 mm.
HIGH PRESSURE RESEARCH
(2022)