Article
Materials Science, Multidisciplinary
N. Sreelakshmi, S. Amirthapandian, G. R. Umapathy, C. David, S. K. Srivastava, S. Ojha, B. K. Panigrahi
Summary: The study found that damage caused by low energy ions can be effectively recovered by high energy Si+ ion irradiation, mainly due to ionization induced annealing of defects.
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2021)
Editorial Material
Physics, Condensed Matter
Helmut Werheit
Summary: In their paper, Sahu et al. use an outdated model of the boron carbide structure and ignore numerous studies on its complex structure and effects on properties. The Raman spectra used as reference are not suitable or reliable. The claimed agreement between calculated and real Raman spectra is not convincing.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Materials Science, Multidisciplinary
Antoine Jay, Olivier Hardouin Duparc, Jelena Sjakste, Nathalie Vast
Summary: The Raman spectrum of boron carbide under pressure is explained by the vibrations of (B11C) icosahedra and C-B-C chains, while the behavior of a broad Raman band at low frequency is attributed to the activation of the chain bending mode in flexured chains. The 270 cm-1 ambient-P mode is proposed as a fingerprint for identifying chain defects and deviations from rhombohedral symmetry in boron carbide.
Article
Nanoscience & Nanotechnology
Jun Du, Kent Christian, Qirong Yang, Chawon Hwang, Eoin McAleer, Richard A. Haber
Summary: The study found that the stability of boron and silicon in boron carbide varies, with boron showing higher stability while silicon is in a metastable state under certain conditions. Dedoping of silicon may result in amorphization and degrade the ballistic performance of boron carbide.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Ceramics
Tian Tian, Lanxin Hu, Aiyang Wang, Chun Liu, Wenchao Guo, Pengyu Xu, Qianglong He, Weimin Wang, Hao Wang, Zhengyi Fu
Summary: In this study, boron carbides with different stoichiometric ratios were prepared using a hot-pressing sintering method, and the influences of the B/C atomic ratio on the microstructures and properties were explored. Excessive B atoms caused lattice expansion, promoted densification, and gradually changed the densification mechanism of boron carbide. Dissolving excessive B into boron carbide affected the microstructure and mechanical properties.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Hiroyuki Fukuyama, Hideo Higashi, Hidemasa Yamano
Summary: The addition of B4C has a significant effect on the solidus and liquidus temperatures of type 316 austenitic stainless steel. The density and surface tension of molten stainless steel are affected by the presence of B4C. Although B4C addition does not have a clear impact on surface tension, sulfur dissolved in the stainless steel causes a significant decrease in surface tension.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Chemistry, Analytical
Di Liu, Huimin Gao, Wenji Jiang, Su Yan, Hao Liu, Junjie Chen, Sisi Wen, Wei Zhang, Xu Wang, Bing Zhao, Wei Song
Summary: In this study, three-dimensional Ag aerogel-supported Hg single-atom catalysts were used as an efficient SERS substrate for monitoring enhanced oxidase-like reactions. The effect of Hg2+ concentrations on the SERS properties of 3D Hg/Ag aerogel networks was investigated, and an optimized addition of Hg2+ resulted in specific enhancement. The formation of Ag-supported Hg SACs was confirmed using HAADF-STEM imaging and XPS measurement, and the oxidase-like catalytic mechanism of Hg/Ag SACs was revealed using DFT. This research provides a mild synthetic strategy for fabricating Ag aerogel-supported Hg single atoms with promising prospects in various catalytic fields.
ANALYTICAL CHEMISTRY
(2023)
Article
Materials Science, Ceramics
Timothy Holmquist, Sidney Chocron, Art Nicholls
Summary: This study investigated the effect of the third invariant on the strength and failure of boron carbide and silicon carbide using new test data. The results showed that the failure strength varies under different stress states, indicating the significant impact of the third invariant.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2021)
Article
Materials Science, Ceramics
Tian Tian, Qianglong He, Chun Liu, Aiyang Wang, Lanxin Hu, Wenchao Guo, Weimin Wang, Hao Wang, Ji Zou, Zhengyi Fu
Summary: The study focused on the microstructure and mechanical properties of hot-pressed B4C, B4C + 5 wt% TiAl, and B4C + B + 5 wt% TiAl. While the addition of Ti-Al alone did not result in Al doping or reduce amorphization in B4C, the co-addition of Ti-Al and B resulted in solid solutions and effectively mitigated amorphization. The combined addition promoted interdiffusion of lightweight elements and the formation of a dense body with uniformly distributed second phase, leading to improved mechanical properties, including high density and hardness with moderate fracture toughness in the B4C + B + 5 wt% TiAl sample.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Kelvin Y. Xie, Qirong Yang, Christopher J. Marvel, Mo-Rigen He, Jerry C. LaSalvia, Martin P. Harmer, Chawon Hwang, Richard A. Haber, Kevin J. Hemker
Summary: This paper reviews the progressive understanding of amorphization in three successive generations of boron carbide, comparing the susceptibility of amorphization in each generation and elucidating the fundamental mechanisms that explain the reduction in amorphization for B-rich and B/Si codoped boron carbides. Future research directions to further deepen the understanding of stress-induced amorphization of boron carbide are also discussed.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Chemistry, Physical
Elumalai Ashok Kumar, Tzyy-Jiann Wang, Yu-Hsu Chang
Summary: Integrating noble-metal and semiconductor nanomaterials to achieve Raman signal enhancement is highly significant in the field of Surface-Enhanced Raman Spectroscopy (SERS). In this study, a SERS-active substrate consisting of Au nanoparticles (NPs) on Cu2O microspheres was developed for effective detection of organic dye molecules. The proposed heterogeneous nanomaterials showed high SERS activity through the synergistic interaction among Au NPs, Cu2O microspheres, and organic dye molecules. The optimized photochemical parameters resulted in high SERS signal intensity, with measured analytical enhancement factors (AEFs) as high as 2.55x10(12) for RhB and 1.2x10(11) for MB. The reproducibility and uniformity of the SERS substrate were confirmed, and real-sample analysis demonstrated satisfactory recovery values. This reliable and facile production approach is applicable for various real-world applications.
APPLIED SURFACE SCIENCE
(2022)
Article
Materials Science, Coatings & Films
Chung-Chuan Lai, Robert Boyd, Per-Olof Svensson, Carina Hoglund, Linda Robinson, Jens Birch, Richard Hall-Wilton
Summary: Amorphous boron carbide (B4C) thin films are commonly used as neutron converting layers in 10B-based neutron detectors. The microstructure of these films is closely related to important properties such as density and adhesion, which affect detection efficiency and long-term stability. A study was conducted to examine the influence of substrate roughness and material on B4C films. It was found that high skewness substrates resulted in a decrease in mass density, but films deposited on different roughness Al, Ti, and Cu substrates showed similar microstructures and mass density, with good adhesion.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
K. Bera, Anushree Roy, D. Chugh, J. Wong-Leung, H. Hoe Tan, C. Jagadish
Summary: This study on the thermal response of wafer-scale hexagonal boron nitride (hBN) layers reveals that strain evolution plays a dominant role in governing the characteristics of thinner films during heat treatment. Both defects and strain determine the spectral line-width of these large-scale films, indicating a potential reduction in thermal transport compared to their bulk counterparts.
Article
Chemistry, Multidisciplinary
Nguyen Thuy Ngoc Thuy, Huynh Nguyen Thanh Luan, Van Vo Kim Hieu, Mai Thi Thanh Ngan, Nguyen Tri Trung, Le Vu Tuan Hung, Tran T. T. Van
Summary: This work presents a simple and inexpensive method to prepare SERS substrates by creating pyramid structures through anisotropic wet etching of a silicon wafer and depositing a silver thin film on these arrays, followed by annealing to form silver nanoparticles. The optimized sizes and densities of pyramids and AgNPs allow for the detection of abamectin concentrations as low as 5.7 x 10(-9) M, with a strong SERS signal observed at a pyramid base-edge size of 7-10 µm, showing high potential for applications in medicine, biotechnology, and food security sensing.
Article
Materials Science, Multidisciplinary
S. Vignesh, J. T. Winowlin Jappes, S. Nagaveena, Krishna Sharma, M. Adam Khan
Summary: This study focuses on the preparation of B4C dispersed epoxy composites for irradiation shielding applications. Samples of different compositions were made and subjected to thermal characterization and irradiation attenuation studies. The results show that the thermal stability of the samples increased due to the intrinsic conductivity of the filler particles, while the shielding performance of the samples increased with an increased addition of B4C at lower energies due to photoelectric absorption.
Article
Chemistry, Multidisciplinary
Max Hofmann, Leonard Rossner, Marc Armbruster, Michael Mehring
Editorial Material
Materials Science, Multidisciplinary
Marc Armbruester, Yuri Grin
SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS
(2020)
Article
Chemistry, Multidisciplinary
Kevin Ament, Nicolas Koewitsch, Dianwei Hou, Thomas Goetsch, Jutta Kroehnert, Christopher J. Heard, Annette Trunschke, Thomas Lunkenbein, Marc Armbruester, Josef Breu
Summary: This study demonstrates the fabrication of a new catalyst structure using liquid crystalline phases of fluorohectorite nanosheets, which performed better in oxidation reactions compared to traditional catalysts. By effectively trapping Pd nanoparticles in the gaps between nanosheets, the structure improved catalytic performance by preventing CO poisoning.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Nicolas Koewitsch, Lukas Thoni, Benjamin Klemmed, Albrecht Benad, Paul Paciok, Marc Heggen, Isabel Koewitsch, Michael Mehring, Alexander Eychmueller, Marc Armbruester
Summary: Methanol steam reforming produces clean hydrogen for fuel cell applications, with high CO2 selectivity enabled by the dynamic equilibrium between intermetallic and oxidic species. The active participation of chemically bound oxygen in the catalyst leads to excellent selectivity towards CO2. This is achieved through a Mars-van Krevelen mechanism involving selectivity-decisive redox centers.
Article
Nanoscience & Nanotechnology
Leonard Roessner, Holger Schwarz, Igor Veremchuk, Ridha Zerdoumi, Thomas Seyller, Marc Armbruester
Summary: Molybdenum-nickel materials show instability in accelerated durability tests, leading to nickel-enriched surfaces and formation of Ni(OH)(2) layers, causing deactivation. The crystal structure of the intermetallic compounds does not affect activity, which is mainly attributed to increased specific surface areas in unsupported bulk Mo-Ni electrodes.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Nicolas Koewitsch, Lukas Thoni, Benjamin Klemmed, Albrecht Benad, Paul Paciok, Marc Heggen, Alexander Eychmueller, Marc Armbruester
Summary: This study reveals that redox activity in the In-Pt system can be guided by gas-phase changes, resulting in highly active catalytic materials with excellent CO2 selectivity. The reactive transformations between different phases plays a crucial role in achieving high selectivity.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Kevin Ploner, Parastoo Delir Kheyrollahi Nezhad, Maximilian Watschinger, Lukas Schlicker, Maged F. Bekheet, Aleksander Gurlo, Albert Gili, Andrew Doran, Sabine Schwarz, Michael Stoeger-Pollach, Johannes Bernardi, Marc Armbruester, Bernhard Kloetzer, Simon Penner
Summary: This study investigated the influence of the Cu-ZrO2 interface on the methanol steam reforming performance by varying the Cu loading. The results showed that Cu (80 wt%)/ZrO2 emerged as the best MSR catalyst, avoiding adverse support effects and providing a high number of support-wetting bulk-like Cu sites.
APPLIED CATALYSIS A-GENERAL
(2021)
Article
Chemistry, Inorganic & Nuclear
Ridha Zerdoumi, Marc Armbruester
Summary: The study established and characterized three isostructural series, providing a platform to investigate the effects of electronic, structural and their combination on chemical and physical properties in heterogeneous catalysis. The results showed that the volume of the unit cell increases linearly with the substitution degree x in both series.
ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
(2021)
Editorial Material
Materials Science, Multidisciplinary
Helmut Werheit
Summary: The Raman spectra of boron carbide provided by Roma et al. are affected by surface excitations due to the inappropriate energy of the laser used in their spectrometer. As a result, the claimed correlation between point defects in the structure and the resonance peaks in their Raman spectra is highly questionable.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Chemistry, Physical
Ridha Zerdoumi, Marc Armbruester
Summary: The gradual substitution of one element by another from a different group in isostructural intermetallic compounds allows for a systematic variation of the total number of electrons per unit cell with only minor variation in geometric parameters, highlighting the correlation between electronic and electrocatalytic properties in the methanol oxidation reaction.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Chemistry, Inorganic & Nuclear
Helmut Werheit, Bernhard Herstell, Walter Winkelbauer, Gabriel Pristas, Slavomir Gabani, Karol Flachbart, Sulkhan Shalamberidze
Summary: This study investigates the electronic properties of B4.3C and finds that the electrical conductivity follows Mott's law of variable-range hopping at low temperatures and is thermally activated at high temperatures, with the activation energy providing information about the energy position of gap states related to the chemical composition.
SOLID STATE SCIENCES
(2022)
Editorial Material
Physics, Condensed Matter
Helmut Werheit
Summary: In their paper, Sahu et al. use an outdated model of the boron carbide structure and ignore numerous studies on its complex structure and effects on properties. The Raman spectra used as reference are not suitable or reliable. The claimed agreement between calculated and real Raman spectra is not convincing.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Physical
Kevin Ploner, Andrew Doran, Martin Kunz, Albert Gili, Aleksander Gurlo, Nicolas Koewitsch, Marc Armbruester, Johannes Bernardi, Maximilian Watschinger, Simon Penner
Summary: This study compared the performance of different intermetallic compounds in methanol steam reforming, finding that Cu2In exhibited the highest activity, while Cu7In3 and Cu11In9 showed stable performance with high CO2 selectivity. No significant self-activation of the intermetallic compounds was observed, but through redox activation, the catalytic performance was further enhanced. The formation of In2O3 patches under MSR conditions helped to explain the least deactivation of the interface with the highest indium content.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Kevin Ploner, Parastoo Delir Kheyrollahi Nezhad, Albert Gili, Franz Kamutzki, Aleksander Gurlo, Andrew Doran, Pengfei Cao, Marc Heggen, Nicolas Kowitsch, Marc Armbruster, Maximilian Watschinger, Bernhard Klotzer, Simon Penner
Summary: The study demonstrates that different morphologies of Cu/ZrO2 catalysts can be obtained by various calcination temperatures, and Cu/amorphous ZrO2 catalysts exhibit superior MSR activity and long-term stability compared to other morphologies.
MATERIALS CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Physical
Kevin Ploner, Maximilian Watschinger, Parastoo Delir Kheyrollahi Nezhad, Thomas Goetsch, Lukas Schlicker, Eva-Maria Koeck, Aleksander Gurlo, Albert Gili, Andrew Doran, Lei Zhang, Nicolas Koewitsch, Marc Armbruester, Stefan Vanicek, Wolfgang Wallisch, Christoph Thurner, Bernhard Kloetzer, Simon Penner
JOURNAL OF CATALYSIS
(2020)
