Article
Chemistry, Physical
Xiaohui Qu, Danhua Yan, Ruoshui Li, Jiajie Cen, Chenyu Zhou, Wenrui Zhang, Deyu Lu, Klaus Attenkofer, Dario J. Stacchiola, Mark S. Hybertsen, Eli Stavitski, Mingzhao Liu
Summary: In situ synchrotron X-ray absorption near-edge structure characterization of thin-film titania growth by atomic layer deposition (ALD) over ZnO nanowires reveals persistent low-coordinated Ti motifs leading to a new picture of ALD growth. Through the design of growth and measurement cycles, Ti K-edge spectral data are continuously recorded, with a unified set of analysis tools developed to interpret the time-series of spectral data. The study observes distinct growth stages and specific spectral components associated with time-dependent concentrations, shedding light on the growth process of thin-film titania.
CHEMISTRY OF MATERIALS
(2021)
Article
Chemistry, Inorganic & Nuclear
Yali Hu, Yanxia Zhang, Tingbin Li
Summary: A novel metal-organic complex with a two-dimensional supramolecular plane structure was synthesized and characterized by X-ray single crystal diffraction. The thin film of this complex exhibited nonlinear optical properties and its surface morphology was studied using atomic force microscopy on quartz substrates. The theoretical calculation of frontier molecular orbitals and second hyperpolarizability gamma value was performed using time-dependent density-functional theory with the basis set LanL2DZ.
INORGANIC CHEMISTRY COMMUNICATIONS
(2021)
Article
Physics, Fluids & Plasmas
S. Sander, T. Ebert, D. Hartnagel, M. Hesse, X. Pan, G. Schaumann, M. Smid, K. Falk, M. Roth
Summary: This study utilized two-layer targets with laser-illuminated front-side microstructures for x-ray backlighter applications, consisting of a silicon front layer and copper back side layer. It recorded the total emission and one-dimensional extent of the copper K alpha x-ray emission, and demonstrated the suitability of these targets for probing applications with copper K alpha photon yields in the range of 10(11) sr(-1).
Article
Chemistry, Physical
Arramel, Francesco Maddalena, Muhammad Haris Mahyuddin, Xinmao Yin, Chi Sin Tang, Mohammad Kemal Agusta, Muhammad Fauzi Sahdan, Caozheng Diao, Cuong Dang, Muhammad Danang Birowosuto, Andrew Thye Shen Wee, Andrivo Rusydi
Summary: This study reports the electronic and optical variation of lead-free all-inorganic perovskites, which hold promising potentials for optoelectronics and spintronics applications.
MATERIALS TODAY ENERGY
(2022)
Article
Chemistry, Multidisciplinary
David Buceta, Shahana Huseyinova, Miguel Cuerva, Hector Lozano, Lisandro J. J. Giovanetti, Jose M. Ramallo-Lopez, Patricia Lopez-Caballero, Alexandre Zanchet, Alexander O. O. Mitrushchenkov, Andreas W. W. Hauser, Giampaolo Barone, Cristian Huck-Iriart, Carlos Escudero, Juan Carlos Hernandez-Garrido, Jose Juan Calvino, Miguel Lopez-Haro, Maria Pilar de Lara-Castells, Felix G. Requejo, M. Arturo Lopez-Quintela
Summary: This study investigates the thermal stability and oxidation susceptibility of sub-nanometer metal clusters. The experimental results show that Cu-5 clusters supported on a substrate can resist irreversible oxidation up to at least 773 K, even in the presence of 0.15 mbar of oxygen. Theoretical calculations based on dispersion-corrected density functional theory and first principles thermochemistry explain the transformation of adsorbed O-2 molecules into superoxo and peroxo species through collective charge transfer and large amplitude breathing motions within the network of Cu atoms. A chemical phase diagram for Cu oxidation states in the Cu-5-oxygen system is presented, revealing distinct chemistry compared to bulk and nano-structured Cu.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Materials Science, Multidisciplinary
Na Gong, Hwee Leng Seng, Hongmei Jin, Jing Cao, Tzee Luai Meng, Siew Lang Teo, Rahul Karyappa, Xikui Zhang, Lei Zhang, Ming Lin, Chee Kiang Ivan Tan, Ady Suwardi, Qiang Zhu, Hongfei Liu
Summary: The deposition of thin films has various multidisciplinary applications, and residual adsorptions play a crucial role in low-vacuum depositions. The mechanisms of thin film blistering are complex and comprehensive.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Biochemistry & Molecular Biology
Sergey A. Legkov, Galina N. Bondarenko, Julia V. Kostina, Eduard G. Novitsky, Stepan D. Bazhenov, Alexey V. Volkov, Vladimir V. Volkov
Summary: This study focused on aqueous solutions of Monoethanolamine (MEA) which are commonly used for CO2 removal from flue and oil gases. By combining experimental and theoretical methods of vibrational spectroscopy, the research analyzed the structural and energy characteristics of MEA-water associates and their ability to interact and retain carbon dioxide. The influence of temperature and MEA concentration on the structural changes of the associates was also investigated. The analysis of theoretical and experimental vibrational spectra helped identify the bands responsible for the formation of CO2 sorbing associates.
Article
Chemistry, Applied
Bo Hyung Kim, Evgeny Danilov, Seog Joon Yoon, Ahmed El-Shafei, Harold Freeman
Summary: Studies have shown that mixed dye systems with multiple components dissipate excited-state energy faster than single main dyes, emphasizing the benefits of having multiple components in commercial dyes for improving photostability.
Article
Biochemistry & Molecular Biology
Tereza Capkova, Barbora Hanulikova, Jakub Sevcik, Pavel Urbanek, Jan Antos, Michal Urbanek, Ivo Kuritka
Summary: This study investigates the application of new anti-octadecaborane(22) laser dyes in solid thin films. The results show that borane clusters are not firmly fixed within polymer matrices and can easily diffuse out of the film at higher temperatures. Spectroscopic analysis reveals that the structure and molecular weight of the polymer, as well as the concentration and type of clusters, significantly affect the mobility of borane clusters within the polymer matrix.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Physical
Jiaxin Jiang, Yu-Feng You, Dhanapal Vasu, Sheng-Chi Chen, Te-Wei Chiu, Gopi Prashanth, Po Chou Chen
Summary: In this research, the functional properties of CuCrO2, the most promising p-type transparent conductive oxide (TCO), were studied. Thin films were fabricated using a spin coating technique. X-ray diffraction and UV-visible absorption were used to analyze the film's diffraction patterns and absorption characteristics. FESEM analysis was used to analyze the physical properties of film formation and surface morphology. Aging properties were analyzed with different precursors and aging times. The CuCrO2 thin films exhibited better transmittance, resistance, figure of merit, and electrical conductivity.
Article
Chemistry, Physical
Noboru Watanabe, Masahiko Takahashi
Summary: This paper presents a theoretical study on valence shell excitation in CCl4 by high-energy electron impact. Generalized oscillator strengths are calculated for the molecule at the equation-of-motion coupled-cluster singles and doubles level, considering the effects of molecular vibration. Based on comparison with recent experimental data, spectral features are reassigned, finding that excitations from the Cl 3p nonbonding orbitals to sigma* antibonding orbitals play dominant roles below the excitation energy of around 9 eV. It is also revealed that molecular structure distortion due to asymmetric stretching vibration significantly affects valence excitations at small momentum transfers.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Monica Bernal-Salamanca, Javier Herrero-Martin, Zorica Konstantinovic, Lluis Balcells, Alberto Pomar, Benjamin Martinez, Carlos Frontera
Summary: This study systematically investigates the influence of film thickness on the structural and magnetic properties of PNMO double perovskite thin films. The results show a strong correlation between the film thickness and the structural and magnetic properties. The thinnest films exhibit a loss of ferromagnetism. Furthermore, through XAS and XMCD measurements and theoretical simulations, significant variations in the spin and orbital contributions to the magnetic moment are observed as the film thickness decreases.
Article
Chemistry, Multidisciplinary
Jing Shi, Chang Han, Haibo Niu, Youzhang Zhu, Sining Yun
Summary: Perovskite oxide RbBiNb2O7 exhibits good proton-transport behavior in the a-b plane due to its unique layered crystal structure, making it a promising candidate for electrolyte membrane applications in solid oxide fuel cells. The proton diffusion in RbBiNb2O7 is two-dimensional layered in nature and isolated by a higher energy barrier in the Rb-O and Nb-O layers, showing potential for efficient proton conductivity. This study provides theoretical evidence for the potential application of RbBiNb2O7 as an electrolyte in SOFCs by revealing its microscopic mechanisms of proton conductivity.
Article
Chemistry, Physical
Sourav Chowdhury, Ram J. Choudhary, Deodatta M. Phase
Summary: The research investigates the origin of magnetic interaction in SrCoO2.75 and SrCoO3 thin films by analyzing their experimental valence band (VB) and conduction band (CB). It is found that negative charge transfer energy contributes to the lowest energy charge fluctuations, with a larger effect in SrCoO2.75 film. Magnetic exchange interactions are realized from a model derived from combined VB-CB spectra and Co L-edge absorption spectra, offering valuable insight into the correlation between microscopic electronic structure and macroscopic magnetization in negative double-exchange ferromagnetic oxides.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Astronomy & Astrophysics
Keri Heuer, Adam R. Foster, Randall Smith
Summary: The new high-resolution X-ray spectroscopy missions, XRISM and Athena, will observe deeper and with higher X-ray resolution than ever before. Understanding the impact of uncertainties on fundamental atomic quantities such as collisional cross sections, transition rates, and wavelengths on spectral models is crucial for interpreting these new X-ray spectra. Methods have been developed to estimate uncertainty in final spectral calculations based on experimental data and plausible approximations to uncertainties in underlying atomic data.
ASTROPHYSICAL JOURNAL
(2021)
Article
Chemistry, Physical
Chen Liu, Tomoki Uchiyama, Noriyuki Nagata, Masazumi Arao, Kentaro Yamamoto, Toshiki Watanabe, Xiao Gao, Hideto Imai, Syota Katayama, Seiho Sugawara, Kazuhiko Shinohara, Koichiro Oshima, Shigeki Sakurai, Yoshiharu Uchimoto
Summary: The influence of specific adsorption of the sulfo group in the perfluorosulfonic acid ionomer, Nafion, on the oxygen reduction reaction (ORR) of a carbon-supported Pt/C catalyst was investigated through electro-chemical measurements, operando X-ray absorption spectroscopy (XAS), and CO stripping voltammetry. Activity of the Pt/C catalyst decreased with increasing ionomer-to-carbon weight ratios. Additionally, quantitative evaluation of specific adsorption at the ORR potential was performed by measuring the 5d orbital vacancy of the Pt/C catalyst using operando XAS.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Chemistry, Physical
Chen Liu, Tomoki Uchiyama, Kentaro Yamamoto, Toshiki Watanabe, Xiao Gao, Hideto Imai, Masashi Matsumoto, Seiho Sugawara, Kazuhiko Shinohara, Koichiro Oshima, Shigeki Sakurai, Yoshiharu Uchimoto
Summary: The study revealed that the size of Pd core in Pt/Pd/C catalyst significantly influences the ORR activity and oxide species coverage, with the activity of Pt/Pd/C diminishing with increasing temperature due to the compressive surface strain from the Pd core.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Chemistry, Physical
Yao Xiao, Kentaro Yamamoto, Yukiko Matsui, Toshiki Watanabe, Atsushi Sakuda, Koji Nakanishi, Tomoki Uchiyama, Akitoshi Hayashi, Shoso Shingubara, Masahiro Tatsumisago, Masashi Ishikawa, Masayoshi Watanabe, Yoshiharu Uchimoto
Summary: By studying the reaction mechanism of sulfide cathodes in different electrolyte systems, it was found that the reduction products of sulfur cathodes vary in different electrolytes, thereby affecting electrochemical properties such as discharge voltage.
ACS APPLIED ENERGY MATERIALS
(2021)
Review
Chemistry, Multidisciplinary
Kazuhiko Maeda, Fumitaka Takeiri, Genki Kobayashi, Satoru Matsuishi, Hiraku Ogino, Shintaro Ida, Takao Mori, Yoshiharu Uchimoto, Setsuhisa Tanabe, Tetsuya Hasegawa, Nobuhito Imanaka, Hiroshi Kageyama
Summary: This Account describes the recent progress in the development of new mixed-anion compounds by the MEXT mixed-anion project, focusing on the results related to the development of materials used as photocatalysts/photoelectrodes, phosphors, secondary battery components, conductors, and thermoelectric materials.
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN
(2022)
Article
Chemistry, Physical
Yanchang Wang, Kentaro Yamamoto, Yoshihiro Tsujimoto, Toshiyuki Matsunaga, Datong Zhang, Zulai Cao, Koji Nakanishi, Tomoki Uchiyama, Toshiki Watanabe, Tsuyoshi Takami, Hidenori Miki, Hideki Iba, Kazuhiko Maeda, Hiroshi Kageyama, Yoshiharu Uchimoto
Summary: All-solid-state fluoride-ion batteries offer high specific capacities, and Ruddlesden-Popper-type perovskite-related compounds serve as promising cathode materials due to reversible fluoride-ion (de)intercalations with low volume expansion. In this study, chemically fluorinated Ruddlesden-Popper compounds were synthesized and compared, revealing that oxygen substitution with fluorine in the apical sites can suppress phase transitions and improve power density.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Physical
Kentaro Yamamoto, Takahiro Yoshinari, Akihide Kuwabara, Eri Kato, Yuki Orikasa, Koji Nakanishi, Tomoki Uchiyama, Kazuhiko Maeda, Hiroshi Kageyama, Toshiaki Ohta, Yoshiharu Uchimoto
Summary: The study focused on the electrochemical properties of surface-nitrided LiFePO4 thin film and found that nitrogen doping led to the formation of new energy levels and an increase in the Fe-O bond distance at the surface. These changes accelerated lithium ion diffusion at the interface between surface-nitrided LiFePO4 and the electrolyte, thereby improving the battery's rate performance.
SOLID STATE IONICS
(2021)
Article
Chemistry, Physical
Datong Zhang, Kentaro Yamamoto, Yanchang Wang, Shenghan Gao, Tomoki Uchiyama, Toshiki Watanabe, Tsuyoshi Takami, Toshiyuki Matsunaga, Koji Nakanishi, Hidenori Miki, Hideki Iba, Koji Amezawa, Kazuhiko Maeda, Hiroshi Kageyama, Yoshiharu Uchimoto
Summary: This study reports the first use of stable and low-cost cuprous oxide as a cathode material for all-solid-state fluoride-ion batteries, showing reversible and fast defluorination behavior. The phase-transition reaction mechanism involving Cu+/Cu2+ redox for charge compensation is confirmed using electrochemical methods and X-ray absorption spectroscopy. Despite fast capacity fading observed in the initial cycles, the material exhibits superior rate capability compared to simple metal/metal fluoride systems.
ADVANCED ENERGY MATERIALS
(2021)
Article
Chemistry, Physical
Seunghoon Yang, Kentaro Yamamoto, Xiaohan Mei, Atsushi Sakuda, Tomoki Uchiyama, Toshiki Watanabe, Tsuyoshi Takami, Akitoshi Hayashi, Masahiro Tatsumisago, Yoshiharu Uchimoto
Summary: All-solid-state batteries (ASSBs) are considered as a potential future battery paradigm due to their safety and stability compared to lithium-ion batteries (LIBs). The use of graphite as an anode material in ASSBs offers superior power density compared to LIBs, but the overall power density is still lower. Coating LiI directly onto the graphite surface can improve discharge capacity and stabilize interface behavior.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Physics, Condensed Matter
Kosuke Suzuki, Yuji Otsuka, Kazushi Hoshi, Hiroshi Sakurai, Naruki Tsuji, Kentaro Yamamoto, Naoaki Yabuuchi, Hasnain Hafiz, Yuki Orikasa, Yoshiharu Uchimoto, Yoshiharu Sakurai, Venkatasubramanian Viswanathan, Arun Bansil, Bernardo Barbiellini
Summary: Understanding the nature of orbitals involved in the redox reactions of lithium-ion batteries is crucial for improving their capacity and energy density. The study of the magnetic Compton profiles of the LTMO compound provides insights into the role of Mn 3d magnetic electrons and 0 2p holes in the magnetic redox properties of LTMO.
Article
Physics, Applied
Aierxiding Abulikemu, Shenghan Gao, Toshiyuki Matsunaga, Hiroshi Takatsu, Cedric Tassel, Hiroshi Kageyama, Takashi Saito, Toshiki Watanabe, Tomoki Uchiyama, Kentaro Yamamoto, Yoshiharu Uchimoto, Tsuyoshi Takami
Summary: Researchers have discovered partial cation disorder in Li2MnO3 crystals synthesized under high pressure. Magnetization and specific heat measurements indicate the formation of long-range antiferromagnetic order below 35 K, with observed irreversibility and a peak suggesting coexistence of antiferromagnetic order and partial magnetic disorder.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Seunghoon Yang, Masakuni Takahashi, Kentaro Yamamoto, Koji Ohara, Toshiki Watanabe, Tomoki Uchiyama, Tsuyoshi Takami, Atsushi Sakuda, Akitoshi Hayashi, Masahiro Tatsumisago, Yoshiharu Uchimoto
Summary: To increase the energy density of all-solid-state batteries, researchers have proposed using Li metal as the anode. However, safety issues associated with lithium dendrites have been a concern. One proposed solution is to use lithium-halide doped Li3PS4 to suppress the formation of lithium dendrites. This study compared LiBr-doped Li3PS4 with LiI-doped Li3PS4 to investigate the reason for the excellent suppression of lithium dendrites by LiI. The results revealed that the suppression is due to the improvement of ionic conductivity and the formation of a stable interfacial layer.
SOLID STATE IONICS
(2022)
Article
Multidisciplinary Sciences
Kota Motohashi, Yosuke Matsukawa, Takashi Nakamura, Yuta Kimura, Naoaki Kuwata, Yoshiharu Uchimoto, Koji Amezawa
Summary: This study proposes a new material design for fast anion conductors, using flexible molecular cation as a host cation. It demonstrates successful fluoride ion conduction in NH4MgF3 and (NH4)2MgF4 based materials. The findings suggest the potential of molecular cation-containing compounds as attractive material groups for fast anion conductors.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
Chunxiao Zhang, Bo Wei, Meiyu Wang, Datong Zhang, Tomoki Uchiyama, Chaoping Liang, Libao Chen, Yoshiharu Uchimoto, Ruifeng Zhang, Peng Wang, Weifeng Wei
Summary: This study proposes a La/Al co-doping strategy to address the irreversibility of anionic redox reactions by tuning the electronic structure. The co-doped LMNLAO cathode exhibits outstanding cycling stability with a capacity retention of 93.6% after 200 cycles.
ENERGY STORAGE MATERIALS
(2022)
Article
Chemistry, Physical
Yadan Ren, Jun Oyama, Tomoki Uchiyama, Yuki Orikasa, Toshiki Watanabe, Kentaro Yamamoto, Tsuyoshi Takami, Yoshinori Nishiki, Shigenori Mitsushima, Yoshiharu Uchimoto
Summary: This study successfully observed the surface reconstruction of oxygen evolution reaction (OER) catalysts through the combination of ex situ and in situ techniques, confirming that surface reconstruction enhances the OER activity. This finding is of great significance for understanding the behavior of OER catalysts and can provide guidance for designing active catalysts.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Physical
Datong Zhang, Kentaro Yamamoto, Aika Ochi, Yanchang Wang, Takahiro Yoshinari, Koji Nakanishi, Hiroyuki Nakano, Hidenori Miki, Shinji Nakanishi, Hideki Iba, Tomoki Uchiyama, Toshiki Watanabe, Koji Amezawa, Yoshiharu Uchimoto
Summary: This study investigates the properties of 3d transition metals on LaF3 substrates using thin-film cells, discovering the highly reversible (de)fluorinations of Cu, Co, and Ni at different temperatures and achieving high capacity utilizations at 150 degrees C. By combining XAS and electrochemical characterization results, the electrochemical behaviors of Cu, Co, and Ni, as well as the two-phase transition mechanism during the M/MF2 reaction, are reported for the first time, providing new insights for future cathode designs for use in all-solid-state FIBs.
JOURNAL OF MATERIALS CHEMISTRY A
(2021)
Article
Chemistry, Physical
Erhao Gao, Wenjing Feng, Qi Jin, Li Han, Yi He
Summary: The influence of K-doping on the reactive oxygen species and elementary reactions of HCHO catalytic oxidation was investigated using density functional theory (DFT). The introduction of K-doping changed the electronic structures of Ce and O, facilitating the adsorption and activation of HCHO and O2 molecules, enhancing lattice oxygen mobility, and reducing the energy barrier for HCHO oxidation. K-doping also promoted the formation of hydroxyl groups, facilitating HCHO adsorption and oxidation.
Article
Chemistry, Physical
Hao Fu, Zhangliang Xu
Summary: In this study, the adsorption mechanisms and detection performance of formaldehyde, ammonia, and sulfur dioxide on undoped and metal-doped ZnO surfaces were investigated using density functional theory. The results showed that formaldehyde and ammonia were physically adsorbed on the undoped ZnO surface, while sulfur dioxide was weakly chemisorbed. The adsorption energy was enhanced when ZnO was doped with metals. These findings provide theoretical guidance for the application of ZnO substrate materials in gas sensitivity research.
Article
Chemistry, Physical
Atsushi Nomura, Tohru Kurosawa, Migaku Oda, Satoshi Demura, Shogo Kuwahara, Sora Kobayashi, Hideaki Sakata
Summary: The study investigates the tunneling spectra of 1T-TiSe2 in the CDW state and the dip structure below the Fermi level, aiming to determine whether this dip is a CDW gap. The answer to this question is crucial for understanding the driving mechanism of CDW.
Article
Chemistry, Physical
A. S. Petrov, D. I. Rogilo, A. I. Vergules, V. G. Mansurov, D. V. Sheglov, A. V. Latyshev
Summary: This study investigates Si mass transport and morphological transformations on the Si(111) surface during (root 3 x root 3)-Sn reconstruction formation and Si homoepitaxy. The research shows that the formation of different Sn phases at different temperatures affects the Si island nucleation and monatomic step shift, which in turn impact the morphology of the Sn/Si(111) interface. Electromigration-induced drift of disordered Sn domains leads to enhanced noncompensated Si mass transport and surface roughening.
Article
Chemistry, Physical
D. V. Gruznev, L. V. Bondarenko, A. Y. Tupchaya, A. A. Yakovlev, A. N. Mihalyuk, A. V. Zotov, A. A. Saranin
Summary: Deposition of thallium (Tl) onto the Au/Si(111)5 x 2 reconstruction followed by annealing results in the formation of a surface structure with 4 x 2 periodicity. The immiscibility of Au and Tl leads to the migration of Tl atoms over the Si chains. Thallium donates electrons to the surface, converting the metallic surface into an insulating state and altering the inter-chain distance within the array of Au atomic wires.
Article
Chemistry, Physical
Simone Giusepponi, Francesco Buonocore, Barbara Ferrucci, Massimo Celino
Summary: Using ab-initio calculations, the interaction between lead adatom and both clean and doped iron (100) surfaces was investigated. It was found that the lead adatom prefers to adsorb in the hollow site, which is more stable compared to the top and bridge sites, and in this position, it is energetically favorable over the iron adatom. Moreover, lead adsorbed in the hollow site of the iron (100) surface doped with chromium was found to create a more stable system compared to nickel-doped surfaces with an iron adatom in the same position. The study also explored inter-layer distances, bonding mechanisms, magnetic behaviors, and charge density differences. The results provide insights into the role of doping in the interaction between lead adatom and iron surface, and have implications for the analysis of corrosion processes caused by liquid lead.
Article
Chemistry, Physical
Shuo Zhang, Jin-Ho Choi
Summary: The recent synthesis of two-dimensional layered WSi2N4 has attracted attention due to its potential applications. This study investigates the catalytic performance of WSi2N4 monolayers with nitrogen vacancies in the hydrogen evolution reaction using first-principles calculations. The results show that the defective WSi2N4 monolayers exhibit remarkably high catalytic activity comparable to platinum catalysts. Electronic structure calculations also reveal the emergence of spin-polarized states due to the introduction of nitrogen vacancies.
Article
Chemistry, Physical
Xiaoyan Yu, Xin Cao, Wei Kang, Shanhua Chen, Ao Jiang, Yuhao Luo, Wenwei Deng
Summary: First-principles calculations were used to investigate the electronic properties of a TiO2 heterostructure modified with Bi2Te3 co-catalyst. The study revealed that the Bi2Te3/TiO2 interface introduced optimal band offsets, effectively suppressing electron-hole recombination and enhancing the utilization efficiency of photo-generated carriers. Additionally, the Bi2Te3 co-catalyst introduced extra catalytic active sites, further boosting the photo-catalytic hydrogen evolution efficiency.
Article
Chemistry, Physical
Filippo Longo, Emanuel Billeter, Selim Kazaz, Alessia Cesarini, Marin Nikolic, Aarati Chacko, Patrik Schmutz, Zbynek Novotny, Andreas Borgschulte
Summary: Alkaline water electrolysis is a simple and efficient method for renewable hydrogen production, utilizing cheap and abundant transition metals. The catalytic properties of Ni materials are enhanced by the formation of oxidized compounds on the surface. The high electrocatalytic activity of Ni (oxy)-hydroxides is directly related to water intercalation in the passivation layer, supporting the hypothesis of a water mediated OH- diffusion mechanism. The self-organization of the surface structure during passivation layer formation enables high electrode performance.
Article
Chemistry, Physical
Mohan Kumar Kuntumalla, Miriam Fischer, Alon Hoffman
Summary: By investigating the bonding, retention, and thermal stability of nitrogen in H-Diamond (100), it was found that nitrogen can partially recover its bonding with carbon atoms after high-temperature annealing, indicating a high thermal stability of nitrogen in diamond.
Article
Chemistry, Physical
Dong Yue, Liangying Wen, Rong Chen, Jianxin Wang, Zhongqing Yang
Summary: The adsorption behavior of Cl2 molecules on the TiC surface and the formation and transfer of reaction products were studied using first-principles ab initio calculations. The results show that the Cl atoms bonded to the surface Ti atoms are more stable, and the TiCl3 intermediate is easier to form than the TiCl2 intermediate.
Article
Chemistry, Physical
Yatao Wang, Peng Zhang, Hongjuan Li, Qiuju Xu, Shujun Liu, Xiaopeng Liu, Xuehua Guo, Yitao Li, Jinzhang Liu, Sen Dong, Zhi Wei Seh, Qianfan Zhang
Summary: In this study, the adsorption performance of two types of metal-organic frameworks (MOFs) for thiophene and benzene was experimentally investigated. The results showed that IZE-1 exhibited high selectivity and superior adsorption capacity for thiophene, especially at low concentrations. First-principles calculations and molecular dynamics simulations provided insights into the mechanism of thiophene adsorption and the high selectivity observed. This research demonstrates the potential of MOFs for thiophene adsorption, particularly at high concentrations.
