Article
Chemistry, Multidisciplinary
Meng Li, Matthew T. Curnan, Wissam A. Saidi, Judith C. Yang
Summary: Understanding the influence of defects on oxidation is crucial for the applications of nano-oxides in catalysis, electronics, and corrosion. This study investigates the uneven surface oxidation induced by surface steps on copper materials using atomic-scale in situ environmental transmission electron microscopy experiments. The results provide mechanistic explanations for the observed formation site preferences, which vary with surface orientation and oxygen concentration, based on Ehrlich-Schwobel barrier differences for oxygen diffusion on stepped surfaces.
Article
Physics, Applied
Milan Kubicki, Susi Lindner-Franz, Mario Daehne, Martin Franz
Summary: The growth of Co phthalocyanine films on one-dimensional Si(111)(4 x 1)-In surface was studied using scanning tunneling microscopy. It was found that at low coverages, the molecules were mobile, but they stabilized and formed a highly ordered two-dimensional monolayer as the coverage approached saturation. A structure model for this film was developed based on STM images, showing molecules selectively adsorbing on In chains with a periodicity of (4 x 4).
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Chenfan Yang, Wenda Zhong, Ke Shen, Qin Zhang, Rong Zhao, Hui Xiang, Jing Wu, Xuanke Li, Nianjun Yang
Summary: The surface of a Cu-Fe3O4 catalyst is reconstructed through an electrochemical activation method, leading to the formation of abundant defective FeOOH. This Cu-FeOOH/Fe3O4 catalyst exhibits excellent stability and activity for alkaline HER, surpassing the performance of the Pt/C catalyst. The incorporation of defective FeOOH on the catalyst surface decreases the energy barrier for H2O dissociation and H-2 generation, providing a new avenue for the production of efficient non-noble metal catalysts.
ADVANCED ENERGY MATERIALS
(2022)
Article
Computer Science, Artificial Intelligence
Steve Kench, Samuel J. Cooper
Summary: SliceGAN is a generative approach that constructs complex 3D images from 2D image examples, making it particularly useful for studying microstructured materials. It leverages high-quality 2D imaging techniques to create 3D datasets, eliminating the need for challenging 3D training data. This approach demonstrates promising potential for design optimization, with the ability to generate high-fidelity 3D datasets using a single representative 2D image.
NATURE MACHINE INTELLIGENCE
(2021)
Article
Chemistry, Physical
Lei Yang, Tengyang Gao, Saisai Yuan, Ying Dong, Yiming Chen, Xijuan Wang, Chuanxiang Chen, Liang Tang, Teruhisa Ohno
Summary: This study developed a heterojunction photocatalyst by in-situ growth of 2D cadmium sulfide on the surface of copper-doped In2S3 to suppress charge recombination. The experiment showed that the efficient interface contact formed between In2S3 and CdS promoted charge transfer and exhibited a high spatial charge separation rate.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Materials Science, Coatings & Films
Florian Brix, Emilie Gaudry
Summary: We have combined density functional theory calculations with an evolutionary algorithm to investigate the possible structural models for two-dimensional Pb films on the Al13Co4(100) quasicrystal surface. Our findings show that the stable structure contains 16 Pb atoms per surface cell, in line with the measured coverage. Alternatively, a metastable structure made of 15 Pb atoms also fits with the experimental observations.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Chemistry, Multidisciplinary
Zisheng Zhang, Ziyang Wei, Philippe Sautet, Anastassia N. Alexandrova
Summary: Atomistic insight into the restructuring of the electrochemical interface under different potentials and adsorbate coverages is gained from first principles. The study reveals the formation of a shifted-row reconstruction on Cu(100) under electroreduction conditions induced by hydrogen adsorption. The findings provide valuable understanding for the design of Cu-based materials in electrocatalysis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
Jose A. S. Laranjeira, Nicolas F. Martins, Sergio A. Azevedo, Guilherme S. L. Fabris, Julio R. Sambrano
Summary: The discovery of graphene has led to the investigation of various 2D carbon allotropes, including penta-graphene (PG), through computational simulations. This study focused on examining the electronic, structural, dielectric, piezoelectric, and catalytic properties of one- and two-dimensional PG-like structures (P-XC2 where X = C, Si, or Ge). The results showed that P-XC2 systems have an indirect band gap energy ranging from 2.65 to 3.55 eV. P-GeC2 exhibited the highest dielectric and piezoelectric constants, while penta-graphene had higher elastic constants compared to P-SiC2 and P-GeC2. Additionally, the band alignment suggested that PXC2 and their respective nanotubes could be favorable for hydrogen production through water splitting.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Scott Stonemeyer, Mehmet Dogan, Jeffrey D. Cain, Amin Azizi, Derek C. Popple, Austin Culp, Chengyu Song, Peter Ercius, Marvin L. Cohen, Alex Zettl
Summary: Fine control over material synthesis on the nanoscale has allowed for the selective creation of one-dimensional TaTe3 chains or two-dimensional TaTe2 nanoribbons using carbon nanotube reaction vessels. This control extends to the number of chains or the thickness and width of nanoribbons. Transmission electron microscopy and scanning transmission electron microscopy provide detailed atomic structure of the encapsulated materials, revealing complex superstructures such as multichain spiraling and multilayer moire patterns.
Article
Chemistry, Physical
Pablo Salcedo-Abraira, Ruben Serrano-Nieto, Catalina Biglione, Maria Cabrero-Antonino, Sergio M. F. Vilela, Artem A. Babaryk, David Tilve-Martinez, Antonio Rodriguez-Dieguez, Sergio Navalon, Hermenegildo Garcia, Patricia Horcajada
Summary: Two three-dimensional metal-organic frameworks (MOFs) called IEF-8 and IEF-9, based on the pyrene tetraphosphonate ligand and copper, have been successfully synthesized and characterized. These MOFs exhibit good thermal and chemical stability, as well as photoresponse suitable for photocatalysis. Specifically, IEF-8 showed higher catalytic efficiency than the benchmarked Ti carboxylate photocatalyst MIL-125-(Ti)-NH2, producing 1800 mu mol center dot g(-1) of hydrogen after 22 hours of UV-vis irradiation without any co-catalyst.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Sebastian Kunze, Liviu C. Tanase, Mauricio J. Prieto, Philipp Grosse, Fabian Scholten, Lucas de Souza Caldas, Dennis van Voerden, Thomas Schmidt, Beatriz Roldan Cuenya
Summary: The oxidation of Cu(100) and Cu(111) surfaces through exposure to oxygen plasma was studied, revealing differences in the oxide species and morphology formed on substrates with different orientations. These findings illustrate the potential for tailoring the oxidation state, structure, and morphology of metallic surfaces through oxygen plasma treatments.
Article
Metallurgy & Metallurgical Engineering
Haiguang Gao, Rui Shi, Yana Liu, Yunfeng Zhu, Jiguang Zhang, Liquan Li, Xiaohui Hu
Summary: The catalytic effects of two-dimensional Ti3C2Tx MXenes with different exposed facets on MgH2 were systematically investigated through experimental and theoretical approaches. The exposed facets were found to be the dominant factor for the catalytic activity of Ti3C2Tx towards MgH2. Ti3C2Tx with more exposed edge facets exhibited higher catalytic activity than that with more exposed basal facets and resulted in different rate-controlling steps during the de/hydrogenation process of MgH2.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Article
Chemistry, Inorganic & Nuclear
Guilherme S. L. Fabris, Carlos A. Paskocimas, Julio R. Sambrano, Ricardo Paupitz
Summary: This study proposed and theoretically investigated the physical and chemical properties of non-conventional 2D and tubular structures constructed with combinations of Ga/N atoms. Density Functional Theory was used to determine their mechanical and electronic properties, showing good mechanical stability and characteristics of large band-gap semiconductors.
JOURNAL OF SOLID STATE CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Qingsong Deng, Yumei Zeng, Jiming Wang, Song Chen, Yu Xiao, Shuhua Zhang
Summary: The synthesis, structure, and luminescent properties of two novel heterometallic one-dimensional tetranuclear Cu-Na cluster-based polymers were studied, revealing the coordination mode of the bridged ligand L to be mu(5)-L-kappa O-7(1), O-2:O-2, N-1, N-2, N-3, N-4 in both complexes.
JOURNAL OF CLUSTER SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Rhone Brocha P. Silalahi, Yongsung Jo, Jian-Hong Liao, Tzu-Hao Chiu, Eunsaem Park, Woojun Choi, Hao Liang, Samia Kahlal, Jean-Yves Saillard, Dongil Lee, C. W. Liu
Summary: The first hydride-containing 2-electron palladium/copper alloys, PdHCu11 and PdHCu12, were synthesized. X-ray diffraction reveals that the PdHCu11 and PdHCu12 kernels consist of a central PdH unit encapsulated within a vertex-missing Cu-11 cuboctahedron and complete Cu-12 cuboctahedron, respectively. PdHCu11 shows excellent HER activity, with an onset potential of -0.05 V (at 10 mA cm(-2)) and consistent HER activity during 1000 cycles in 0.5 M H2SO4.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Unni Engedahl, Henrik Gronbeck, Anders Hellman
JOURNAL OF PHYSICAL CHEMISTRY C
(2019)
Article
Chemistry, Physical
Adam A. Arvidsson, Philipp N. Plessow, Felix Studt, Anders Hellman
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Chemistry, Physical
Mikael Valter, Egon Campos dos Santos, Lars G. M. Pettersson, Anders Hellman
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Chemistry, Multidisciplinary
Magnus Fant, Mattias Angqvist, Anders Hellman, Paul Erhart
Summary: Loewenstein's rule states that Al-O-Al motifs are energetically unstable, however, this rule can become invalid under certain circumstances, and can be extended using the chabasite framework.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Unni Engedahl, Adam A. Arvidsson, Henrik Gronbeck, Anders Hellman
Summary: Research on the partial oxidation of methane over small-pore copper-exchanged zeolite SSZ-13 shows that the Z2[Cu2O] motif has an exergonic reaction path, but micro-kinetic modeling indicates that neither Z2[Cu2O] nor Z2[Cu2OH] are notably active under the reaction conditions. These findings emphasize the importance of the detailed structure of the active site in catalytic reactions.
Article
Chemistry, Physical
Mikael Valter, Egon Campos dos Santos, Lars G. M. Pettersson, Anders Hellman
Summary: The study investigates the chemical selectivity of various metallic catalysts for glycerol and outlines the method for establishing selectivity maps.
Article
Chemistry, Multidisciplinary
Christopher Tiburski, Astrid Boje, Sara Nilsson, Zafer Say, Joachim Fritzsche, Henrik Strom, Anders Hellman, Christoph Langhammer
Summary: This study investigates the differential effects of photothermal rate enhancement on various catalysts and demonstrates how this effect can be controlled by adjusting the catalyst operation point. Experimental results show that small fluctuations in reactor temperature or temperature gradients across a sample may significantly impact photothermal rate enhancement.
Article
Chemistry, Physical
Unni Engedahl, Astrid Boje, Henrik Strom, Henrik Gronbeck, Anders Hellman
Summary: This study examines the complete reaction cycle for methane-to-methanol conversion over the Cu-SSZ-13 system using density functional theory, finding that the presence of water increases reaction activity and highlighting the importance of selectivity in improving methanol yields from humid systems.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Materials Science, Multidisciplinary
Mattias Flygare, Krister Svensson
Summary: Electrical characterization of nanostructures is essential for future applications of nanomaterials. Reliable measurement methods and standards are needed for accurate analysis. This study focuses on a two-probe method performed inside a transmission electron microscope to determine the electrical conductivity of carbon nanotubes. The results show that this method can accurately determine the linear resistance of the outermost nanotube wall, even for high crystallinity materials.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Energy & Fuels
Ivana Stanicic, Joakim Brorsson, Anders Hellman, Tobias Mattisson, Rainer Backman
Summary: Chemical looping combustion (CLC) enables efficient combustion of hydrocarbon fuels while producing a gas stream with high CO2 concentrations. This paper investigates the fate of ash elements in a system using iron-based oxygen carriers and provides a comprehensive comparison with previous experimental data. The study finds that the choice of oxygen carriers significantly influences the behavior of ash elements.
Article
Chemistry, Multidisciplinary
Sune Levin, Sarah Lerch, Astrid Boje, Joachim Fritzsche, K. K. Sriram, Henrik Strom, Kasper Moth-Poulsen, Henrik Sunden, Anders Hellman, Fredrik Westerlund, Christoph Langhammer
Summary: Catalytic activity can be significantly influenced by the size and shape of nano-particles. In this study, single-particle resolution experiments were conducted using nanofluidic channels to selectively trap individual spherical, cubic, and octahedral colloidal Au nanocrystals. The results show distinct structure sensitivity of the catalytic reactions, which can be attributed to the different edge site abundance on the three particle types.
Article
Chemistry, Multidisciplinary
Matej Hus, Miha Grilc, Janvit Terzan, Saso Gyergyek, Blaz Likozar, Anders Hellman
Summary: Ethylene epoxidation is a crucial selective oxidation process in industry and commerce. In this study, we computationally screened metals in the periodic table, identified promising catalysts (Ag/CuPb, Ag/CuCd, and Ag/CuTl), and experimentally demonstrated their superior performance compared to pure-Ag catalysts. We also emphasized the importance of considering relevant in situ conditions for accurate catalyst design and showed that the combination of ab initio calculations, scaling relations, and rigorous reactor microkinetic modeling bridged the gap between first-principles simulations and industrial applications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Joakim Brorsson, Viktor Rehnberg, Adam A. Arvidsson, Henrik Leion, Tobias Mattisson, Anders Hellman
Summary: Chemical looping is an innovative technique that requires new oxygen carriers. To speed up the process of finding these carriers, we used a computational screening approach based on energetic data from the Open Quantum Materials Database. From an initial list of 300,000 materials, we narrowed down to 1,000 by filtering out rare, radioactive, toxic, or harmful elements. The highest ranking phases contain elements such as Cu, Mn, and Fe.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Aadesh P. Singh, Richard Baochang Wang, Camilla Tossi, Ilkka Tittonen, Bjorn Wickman, Anders Hellman
Summary: Semiconductor heterostructures in PEC cells show improved water oxidation performance, with different band alignment types affecting charge separation. Fe2O3-TiO2 heterostructures with type I band alignment were found to be detrimental, but H-treated TiO2 in the heterostructure led to a type II alignment, significantly increasing the photocurrent density. This work demonstrates the importance of hydrogen doping in tailoring band alignments and provides valuable insights for similar material development.
Article
Materials Science, Multidisciplinary
Mattias Flygare, Krister Svensson
MATERIALS TODAY COMMUNICATIONS
(2019)