Article
Multidisciplinary Sciences
Sayma Khanom, Nobuya Hayashi
Summary: In this study, zinc ions dissolved in water were attempted to be removed by generating zinc oxides using oxygen gas in a dielectric barrier discharge (DBD) plasma system. The removal rate of zinc oxides production was measured at different treatment periods, showing an initial increase followed by a decrease with treatment time. The optimal removal rate of zinc ions from water (29%) was achieved at a treatment period of 10 minutes, with a lower pH (7.4). The study indicates that controlling the penetration amount of active oxygens to keep the pH below 7.5 is crucial for effectively removing zinc ions and preventing a decrease in removal rate of zinc oxides' deposit.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Analytical
Alex I. Oje, A. A. Ogwu, A. M. Oje
Summary: The study investigates the effect of temperature change on the electrochemical performance of silver oxide thin films supercapacitor. Results show improved electrochemical performance with increasing temperature, attributed to higher ionic conductivity, reduced resistance, and faster ion adsorption/desorption.
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Physical
Yi Wang, Guichan Chen, Jiao Xie, Dengjie Chen
Summary: This study demonstrates a simple non-metal/metalloid modification method to create efficient electrocatalysts for the oxygen evolution reaction (OER). The developed SrCo0.95M0.05O3_$ catalysts show lower overpotential and improved stability compared to the traditional SrCoO3_ $. The findings provide a simple and viable strategy for creating highly efficient perovskite electrocatalysts for OER.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Douha Harbaoui, Moustafa M. S. Sanad, Cecile Rossignol, El Kebir Hlil, Noureddine Amdouni, Kader Zaidat, Said Obbade
Summary: The limited resources of lithium have led to research on new polyanionic cathode materials for sodium-ion batteries. Three compounds, Na2M22+Fe3+(PO4)(3) (M = Mn, Ni, and Co), were synthesized and their properties were investigated.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Mengshi Zeng, Jingsong Liu, Huiqin Li, Shuren Zhang
Summary: Lead-free energy storage ceramics, specifically (Sr0.7Ca0.3)(1-1.5x)BixTiO3 relaxor ferroelectric ceramics, are studied for their potential in pulsed power technology. Introducing Bi2O3 enhances polarization, resulting in increased dielectric constant. The ceramics exhibit low dielectric loss at a given measurement frequency. Specifically, the Sr0.49Ca0.21Bi0.2TiO3 ceramic demonstrates high energy storage density and efficiency under an electric field. Moreover, these ceramics display desirable temperature stability within a certain temperature range.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Engineering, Chemical
Bin Wu, Xiao-Dan Weng, Naixin Wang, Ming-Jie Yin, Lin Zhang, Quan-Fu An
Summary: This study fabricated novel positively charged polyamide NF membranes with exceptional water permeability and chlorine resistance through surface-initiated ATRP, showing high retentions to heavy metal ions and stability during long-term operation.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Environmental Sciences
Qingfeng Ma, Yongbao Chu, Xiaoyu Ni, Jingyi Zhang, Haoze Chen, Fei Xu, Yan Wang
Summary: In this study, a CeO2 modified carbon nanotube electrified membrane (CeO2@CNT membrane) was prepared for the degradation of antibiotics using NaClO. The CeO2@CNT membrane showed a higher reaction rate constant compared to the traditional carbon nanotube electrified membrane and exhibited good stability.
Article
Engineering, Environmental
Yuqin Wei, Long Zhao, Yongdi Liang, Mingcai Yuan, Qijie Wu, Zhaoli Xue, Xinping Qiu, Jianming Zhang
Summary: Three novel triphenylamine cobalt porphyrins were designed and tested for their efficacy in electrocatalytic oxygen reduction reactions. The benzoyloxy substitute showed the best performance among the catalysts and may provide an applicable protocol for engineering efficient metalloporphyrins as electrocatalysts.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Taito Murakami, Toshiya Shibata, Yuta Yasui, Kotaro Fujii, James R. Hester, Masatomo Yashima
Summary: Investigation on solid solutions Ba7Ta4-xMo1+xO20+x/2 (x = 0.2-0.7) reveals high oxide-ion conductivity and stability under reducing conditions in Ba7Ta3.7Mo1.3O20.15, which indicates a strategy for the development of solid electrolytes based on hexagonal perovskite-related oxides.
Article
Energy & Fuels
Yaxiong Tian, Ningning Liu, Tunmise Ayode Otitoju, Yun Wang, Zhongmin Feng, Ting Sun
Summary: An ultra-thin VOx nanosheet with abundant lattice defects and large interlayer distance was obtained via an electrodeposition method, showing excellent electrochemical performance as a binder-free anode for Mg2+ storage. It exhibited a high specific capacity of 402 mAh g-1 and excellent cycling stability with 89.5% capacity retention after 500 cycles. The charge storage mechanism of VOx in an AMIB system was revealed and it was highlighted as a high-performance electrode material for AMIBs.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Chemistry, Multidisciplinary
Li Wang, Rui Peng, Xue Liu, Chendi Heng, Yanni Miao, Wei Wang, Andrew Carrier, Ken Oakes, Xu Zhang
Summary: An innovative biofilm removal technology was developed based on nitrite-accelerated Fenton chemistry, utilizing dissolved Cu ions and nano-CuO surfaces to efficiently generate reactive nitrogen species as disinfectants. This simple, efficient, and cost-effective approach provides important insights into Fenton chemistry, considering the ubiquity of copper, hydrogen peroxide, and nitrite in the environment, biological systems, and various industrial processes.
CHEMICAL COMMUNICATIONS
(2021)
Article
Engineering, Chemical
Qingbo Huang, Song Liu, Yanan Guo, Gongping Liu, Wanqin Jin
Summary: In this study, a graphene oxide (GO) membrane with charged interlayer channels was developed for the separation of mono-/di-valent ions. The membrane achieved selective transport of monovalent ions by utilizing size-sieving and electrostatic repulsion. The introduction of polyethyleneimine (PEI) into the interlayer channels not only controlled the charge property but also increased the hydrophilicity of the membrane surface. The optimal GO-PEI membrane exhibited high permeation rates and selectivity for monovalent ions.
JOURNAL OF MEMBRANE SCIENCE
(2022)
Article
Electrochemistry
Dapynhunlang Shylla, R. Harikrishnan, Radhika Swarnkar
Summary: Series connected batteries require cell balancing during charging and discharging to prolong battery lifespans, ensure safe operation, and increase the capacity of the battery pack. However, charge imbalance issues can lead to battery cell damage and reduced battery life. This study analyzes, designs, and implements cell balancing using dc-to-dc buck-boost converter and interleaved flyback converter topologies operating in discontinuous current mode. The efficiency of these converters is evaluated for state of charge (SOC) balancing and voltage balancing.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Mohammad H. BinSabt, Ahmed Galal, Ahmed Abdel Nazeer
Summary: Beta-Ni(OH)(2) and beta-Ni(OH)(2)/graphene oxide (GO) were prepared on an Ni foil electrode using the electrochemical cyclic voltammetry in 0.5 M KOH solution. Surface analyses such as XPS, XRD, and Raman spectroscopies confirmed the chemical structure and SEM and AFM determined the morphologies. The addition of GO layer significantly increased the specific capacitance of the hybrid. The supercapacitor exhibited high stability even after 500 cycles without reduction in capacitance values.
Article
Chemistry, Physical
Mengxia Ji, Yifan Shao, Emmanuel Nkudede, Zihan Liu, Xing Sun, Junze Zhao, Ziran Chen, Sheng Yin, Huaming Li, Jiexiang Xia
Summary: In this study, a high-efficient broad-spectrum photocatalyst with surface oxygen vacancy was successfully fabricated, extending its absorption region and improving the degradation efficiency of ciprofloxacin. The research demonstrated the significant influence of oxygen vacancy on the catalytic efficiency.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Kazuma Ito, Hideaki Sawada, Shingo Tanaka, Shigenobu Ogata, Masanori Kohyama
Summary: In this study, the high segregation energies of P and S in steel causing grain boundary embrittlement were investigated using ab initio local energy analysis and COHP analysis. It was found that the local energy changes of Fe atoms adjacent to a solute atom is the main cause of GB segregation of P and S, with unique functional forms for each solute species. The distance dependency of Fe-atom local energy change is influenced by solute-Fe bonding interactions, which is governed by the valence atomic-orbital characters of each solute species.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2021)
Article
Electrochemistry
Ryota Yuge, Sadanori Kuroshima, Mitsuharu Tabuchi, Kyosuke Doumae, Hideka Shibuya
Summary: The study found that Li-rich layered manganese oxides undergo changes in valence and structure during charging and discharging, including reconstruction of transition metal and oxide ions in the lattice as well as the formation and recovery of oxygen deficiency.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2021)
Article
Materials Science, Multidisciplinary
Zhuo Xu, Shingo Tanaka, Masanori Kohyama
Summary: This study investigated the atomic configurations and energies of tilt grain boundaries in hexagonal Mg using density-functional theory. Special grain boundaries showed clear changes in energy and volume curves with rotation angles, while stable grain boundaries exhibited moderate variations in energy and charge homogeneity. These findings provide insights into interface stability and deformation mechanisms of Mg and other simple metals.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2021)
Article
Physics, Applied
Takanori Asano, Manabu Tezura, Masumi Saitoh, Hiroki Tanaka, Jun Kikkawa, Koji Kimoto
Summary: We observed the nanoscale distribution of subgap excitations induced by Ga-ion beam processing in beta-Si3N4 using electron energy-loss spectroscopy. By combining crystallinity, composition, and bandgap measurements, we found that defects excited at different energy levels exhibit different dependence trends with respect to crystallinity. This proposed technique can effectively distinguish between various amorphous materials.
APPLIED PHYSICS EXPRESS
(2022)
Article
Materials Science, Multidisciplinary
Mitsuharu Tabuchi, Yoshikazu Sasaki, Hideka Shibuya, Kyousuke Doumae, Misaki Katayama, Keisuke Yamanaka, Yasuhiro Inada, Ryota Yuge, Kei Kubota
Summary: Samples calcined in different environments showed variations in initial capacities and crystal phase structures. The sample calcined in N-2 atmosphere exhibited higher initial capacities and suppressed the formation of cubic spinel. Fe3+ ions were effectively utilized as redox centers. The sample underwent partial reduction to the trivalent state during discharging.
MATERIALS RESEARCH BULLETIN
(2022)
Article
Materials Science, Multidisciplinary
Yoyo Hinuma, Masanori Kohyama, Shingo Tanaka
Summary: This study proposes algorithms for constructing tilt grain boundary models without relying on the coincidence site lattice (CSL). By computationally searching, candidate grain boundary planes for a selected rotation axis are obtained, allowing for systematic treatment of diverse grain boundary systems. Surface-slab supercells with shared two-dimensional lattice are used for feasible computational analysis, and a procedure to obtain a GB-model supercell with alternately stacking these slabs is given. The proposed algorithms enable streamlined generation of both symmetric and asymmetric GB models.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Shingo Hasegawa, Shinya Masuda, Shinjiro Takano, Koji Harano, Jun Kikkawa, Tatsuya Tsukuda
Summary: The study investigated the geometric structure and catalytic performance of single Pd atom doped Au23Pd1 clusters stabilized by polyvinylpyrroli-done (Au23Pd1:PVP), showing significantly higher catalytic activity than undoped Au24:PVP. The kinetic studies revealed that the doped Pd atom acts as the active center, lowering the activation energy for hydride abstraction compared to undoped Au24:PVP.
Article
Microscopy
Mitsutaka Haruta, Jun Kikkawa, Koji Kimoto, Hiroki Kurata
Summary: The noise performance and detection limits of a direct-counting CMOS K2 camera and a CCD camera were evaluated in EELS experiments. The K2 camera has a lower detection limit in counting mode, but its spectral noise increases with longer dwell times. The CCD camera remains effective for long acquisition times. Therefore, choosing the appropriate camera according to experimental needs is crucial.
Article
Nanoscience & Nanotechnology
Koji Kimoto, Motoki Shiga, Shinji Kohara, Jun Kikkawa, Ovidiu Cretu, Yohei Onodera, Kazuo Ishizuka
Summary: This study demonstrates a novel technique to analyze the local structure of disordered materials using scanning transmission electron microscopy (STEM) under a contrast variation scheme. By utilizing the contrast of annular dark-field (ADF) and annular bright-field (ABF) imaging, the method provides consistent results with traditional diffractometry techniques and reveals the short-range ordering of amorphous materials.
Article
Chemistry, Multidisciplinary
Meijia Yang, Hiroki Hanayama, Long Fang, Matthew A. Addicoat, Yunyu Guo, Robert Graf, Koji Harano, Jun Kikkawa, Enquan Jin, Akimitsu Narita, Klaus Mu''llen
Summary: To overcome the photoluminescence quenching of COFs, a strategy involving interrupting intralayer conjugation and interlayer interactions using cyclohexane as the linker unit is proposed. By altering the building block structures, imine-bonded COFs with different topologies and porosities are obtained, showing enhanced emission with record-high photoluminescence quantum yields in the solid state. Furthermore, the resulting cyclohexane-linked COF exhibits excellent sensing performance for the trace recognition of various molecules.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Norihiko Sasaki, Jun Kikkawa, Yoshiki Ishii, Takayuki Uchihashi, Hitomi Imamura, Masayuki Takeuchi, Kazunori Sugiyasu
Summary: Although the principles of noncovalent bonding are well understood, supramolecular noncovalent synthesis still cannot match the precision and complexity of organic and/or macromolecular covalent synthesis. In this study, we demonstrate the stepwise synthesis of block supramolecular polymers with precise control over their compositions and sequences using fluorinated alkyl chains on metal-porphyrin derivatives. This site selectivity enables the formation of toroidal structures through one-dimensional supramolecular polymerization and cyclization, followed by the formation of two-dimensional assemblies with concentric toroidal morphologies through secondary nucleation, elongation, and cyclization steps.
Article
Chemistry, Physical
Kosuke Kawai, Takaaki Sudayama, Daisuke Asakura, Jun Kikkawa, Eriko Watanabe, Masashi Okubo, Atsuo Yamada
Summary: Conventional cathode materials of lithium-ion batteries have moderate specific capacity. Investigating alternative oxygen redox host frameworks is necessary to develop high-capacity and durable cathode materials. This study examined the oxygen redox activity of lithium-rich spinel oxides and found that it can undergo oxidation through delithiation, but the high-voltage capacity fades rapidly upon cycling.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Min-Wen Yu, Yu-Tang Lin, Chia-Hung Wu, Tung-Jung Wang, Jhuang-Hao Cyue, Jun Kikkawa, Satoshi Ishii, Tien-Chang Lu, Kuo-Ping Chen
Summary: This work successfully controlled the number of sulfur vacancies in monolayer WS2 flakes synthesized by chemical vapor deposition (CVD), resulting in a difference in photoluminescence (PL) intensity. The sulfur vacancies introduce defect trap states that cause carrier recombination and reduce carrier drift to graphene, thus decreasing the photocurrent. Furthermore, the gate-tunable Fermi level of graphene allows tunable responsivity of the WS2-graphene photodetector.
APPLIED SURFACE SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Jun Kikkawa, Koji Kimoto
Summary: In this study, a method for temperature measurement using monochromated electron probes is reported. Based on the principle of balancing between the annihilation and creation of phonons, this method enables the investigation of local static and dynamic thermal properties in various materials and devices. The use of acoustic phonons improves the accuracy of low-temperature measurements.
Article
Chemistry, Multidisciplinary
Kosuke Kawai, Xiang-Mei Shi, Norio Takenaka, Jeonguk Jang, Benoit Mortemard de Boisse, Akihisa Tsuchimoto, Daisuke Asakura, Jun Kikkawa, Masanobu Nakayama, Masashi Okubo, Atsuo Yamada
Summary: Integrating anionic-redox with cationic-redox is a promising strategy, but hysteresis is a challenge in oxygen-redox cathodes. In this study, nonpolarizing and polarizing oxygen-redox reactions are found to coexist and compete in a specific material. Preventing the polarizing reaction is crucial for achieving nonpolarizing and energy-efficient oxygen-redox reactions.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
