Article
Physics, Applied
Tae Soo Kim, Taemin Ahn, Tae-Hwan Kim, Hee Cheul Choi, Han Woong Yeom
Summary: Recent research shows that atomic oxygen can oxidize epitaxial graphene in a vacuum without causing damage. In this study, the effects of chemisorbed atomic oxygen on the electronic properties of graphene were investigated using scanning tunneling microscopy (STM). The results reveal that oxygen atoms can modify the electronic states of graphene, creating a bandgap at its Dirac point. Additionally, it was demonstrated that selective desorption or hopping of oxygen atoms can be induced with atomic precision using appropriate bias sweeps with an STM tip. These findings suggest the potential for atomic-scale tailoring of graphene oxide and the development of graphene-based atomic-scale electronic devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Sergio Vlaic, Dimitris Mousadakos, Safia Ouazi, Stefano Rusponi, Harald Brune
Summary: In this study, the magnetic properties and atomic morphology of bimetallic two-dimensional nanoislands grown on metal surfaces were investigated. The blocking temperature was found to be greatly increased by modifying the interfaces and capping the islands with different materials.
Article
Chemistry, Multidisciplinary
Yi-Ying Sung, Harmina Vejayan, Christopher J. Baddeley, Neville V. Richardson, Federico Grillo, Renald Schaub
Summary: On-surface synthesis with designer precursor molecules is an effective method for preparing graphene nanoribbons (GNRs) with tunable electronic properties. The band gap of GNRs doped with heteroatoms remains unchanged, but hydrogenation can engineer a tunable band gap. Surface-confined hydrogenation studies on 7-armchair GNRs grown on Au(111) surfaces reveal a self-limited hydrogenation process. The electronic properties of the GNR/Au(111) system can be modified by edge and basal-plane hydrogenation, and a mechanism for the hydrogenation process is proposed.
Article
Chemistry, Multidisciplinary
Sergey Y. Sarvadii, Andrey K. Gatin, Vasiliy A. Kharitonov, Nadezhda Dokhlikova, Sergey A. Ozerin, Maxim Grishin, Boris R. Shub
Summary: The study investigated the adsorption of CO on the surface of Cu-based nanoparticles under the presence of an external electric field. It was demonstrated that the size of the nanoparticle is a key factor affecting the adsorption process, particularly the strength of the local electric field close to the surface.
Article
Multidisciplinary Sciences
Alexander Kerelsky, Carmen Rubio-Verdu, Lede Xian, Dante M. Kennes, Dorri Halbertal, Nathan Finney, Larry Song, Simon Turkel, Lei Wang, Kenji Watanabe, Takashi Taniguchi, James Hone, Cory Dean, Dmitri N. Basov, Angel Rubio, Abhay N. Pasupathy
Summary: This study demonstrates the formation of emergent correlated phases in multilayer rhombohedral graphene without the need for twisted van der Waals layers. The study shows that two layers of bilayer graphene twisted by a tiny angle can host large regions of uniform rhombohedral four-layer graphene with a sharp van Hove singularity. Furthermore, the study suggests that the broken symmetry state in ABCA graphene could be attributed to a charge-transfer excitonic insulator or a ferrimagnet.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Physical
V. Carnevali, A. Sala, P. Biasin, M. Panighel, G. Comelli, M. Peressi, C. Africh
Summary: The electronic properties of graphene can be modified by local interaction with a metal substrate. This article proposes a reliable method of evaluating the interaction between graphene and substrate by testing the tunneling current. This method expands the capabilities of standard STM systems for studying graphene/substrate complexes.
Article
Chemistry, Multidisciplinary
Andrey K. Gatin, Sergey Y. Sarvadii, Nadezhda V. Dokhlikova, Vasiliy A. Kharitonov, Sergey A. Ozerin, Boris R. Shub, Maxim V. Grishin
Summary: The oxidation of Ni nanoparticles supported on highly oriented pyrolytic graphite under low exposure to oxygen was studied. It was found that charge transfer effects at the Ni-C interface influenced the surface activity of the nanoparticles. O-2 dissociation and Ni oxidation occurred only at the top of the nanoparticle.
Article
Chemistry, Physical
Jade Barreto, Niklas Nilius, Heloise Tissot, Shamil Shaikhutdinov, Hans Joachim Freund, Fernando Stavale
Summary: The interaction between atomically defined MnO(001) thin films and water has been investigated, revealing that water molecules adsorb on terraces and undergo dissociation at oxygen vacancies mediated by nearby Mn2+ sites. The importance of defects in the adsorption characteristics of MnO is also demonstrated.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Review
Chemistry, Multidisciplinary
Wenbing Peng, Haolin Wang, Hui Lu, Lei Yin, Yue Wang, Bruno Grandidier, Deren Yang, Xiaodong Pi
Summary: Understanding the band alignment, interface states, interface coupling, and carrier transport properties of semiconductor heterojunctions (SHs) is crucial for designing and fabricating semiconductor structures and devices. STM and STS have played significant roles in studying the properties of SHs, such as spatial structures and electronic band structures, to propose mechanisms for carrier transport.
Article
Chemistry, Physical
T. V. Pavlova, V. M. Shevlyuga, B. V. Andryushechkin, K. N. Eltsov
Summary: This study reports the removal of individual halogen atoms from Si(100)-2x1-Cl and -Br surfaces in STM. The charge states of DBs formed on the Si surface can be manipulated, allowing for tuning the reactivity of the Cl- and Br-terminated surfaces.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Yong Zhang, Jianchen Lu, Hangjing Zhou, Guang Zhang, Zilin Ruan, Yi Zhang, Hui Zhang, Shijie Sun, Geifei Niu, Boyu Fu, Bing Yang, Long Chen, Lei Gao, Jinming Cai
Summary: In this study, we investigated the regioselectivity of 2H-diphenylporphyrin (H-2-DPP) in the planarization reaction on Au(111) and Ag(111) substrates. We found that H-2-DPP monomer can form two configurations (anti- and syn-) via a dehydrogenation coupling, with the yield of the anti-configuration exceeding 90%. Through high-resolution scanning tunneling microscopy, DFT calculations, and comparative experiments, we determined that the regioselectivity of H-2-DPP is derived from the reaction energy barrier during the cyclodehydrogenation reaction of different tautomers.
Article
Physics, Multidisciplinary
M. Omidian, J. Brand, N. Neel, S. Crampin, J. Kroeger
Summary: Epitaxially grown Fe nanostructures on Pb(111) were studied using low-temperature scanning tunneling microscopy and spectroscopy. The Fe assemblies were categorized into two groups based on their electronic behavior near the Fermi energy. One group exhibited a metallic behavior with a wide energy gap of 0.7 eV that remained temperature-independent. These Fe islands lacked the superconductivity proximity effect in their interior. The other group displayed a metallic behavior at the Fermi level, with the substrate superconducting phase locally entering these islands, evidenced by sharp resonance at the Fermi energy indicating possible Andreev reflection at the magnet-superconductor interface.
NEW JOURNAL OF PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Meng-Kai Lin, Guan-Hao Chen, Ciao-Lin Ho, Wei-Chen Chueh, Joseph Andrew Hlevyack, Chia-Nung Kuo, Tsu-Yi Fu, Juhn-Jong Lin, Chin Shan Lue, Wen-Hao Chang, Noriaki Takagi, Ryuichi Arafune, Tai-Chang Chiang, Chun-Liang Lin
Summary: Monolayer transition metal dichalcogenides show tunability in electronic properties, with bandgap modulation possible through control of tunneling current. Monolayer PtTe2 exhibits a reversible semiconductor-to-metal transition at moderate tunneling current, attributed to its surface electronic structure coupling with the tunneling tip.
Article
Chemistry, Applied
Wugen Huang, Jun Cai, Jun Hu, Junfa Zhu, Fan Yang, Xinhe Bao
Summary: The atomic structures and electronic properties of Cr-doped ZnO(10 (1) over bar0) surfaces were investigated using a combined approach of STM and XPS, revealing the presence of isolated Cr atoms or Cr substituting Zn atoms. Thermal treatments above 600 K facilitated the redistribution of Cr atoms into the ZnO lattice, indicating a strong interaction between Cr and ZnO. Adsorption of CO at 78 K showed no preference for Cr3+ sites on the ZnO surface lattice, while re-dispersion of Cr atoms caused a significant band bending and negative XPS peak shifts.
CHINESE JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Shi-Wen Li, Ruo-Xi Zhang, Li-Xia Kang, Deng-Yuan Li, Yu-Li Xie, Cheng-Xin Wang, Pei-Nian Liu
Summary: The study explores the construction of metal-organic networks (MONs) by the coordination self-assembly of isocyanides on Cu(111) and Ag(111) surfaces, showing that surface stereochemistry plays a crucial role in steering the structures. Nodes with heterotactic configurations are able to grow into larger subunits and form complex fractal structures.
Article
Chemistry, Multidisciplinary
James H. Carter, Ali M. Abdel-Mageed, Dan Zhou, David J. Morgan, Xi Liu, Joachim Bansmann, Shilong Chen, R. Jurgen Behm, Graham J. Hutchings
Summary: Supported gold nanoparticles are widely studied catalysts known for their high activity in the low temperature water-gas shift reaction. However, their practical application has been limited due to poor thermal stability. This study demonstrates that the deactivation process of the catalysts can be reversed by an oxidative treatment, restoring their catalytic activity.
Article
Biochemical Research Methods
Beatriz Fresco-Cala, Angela Lopez-Lorente, Alex D. Batista, Mehmet Dinc, Joachim Bansmann, R. Juergen Behm, Soledad Cardenas, Boris Mizaikoff
Summary: The development of synthetic particles that mimic real viruses is essential for the advancement of molecularly imprinted polymer-based sorbent materials. In this study, gold nanoparticles were synthesized and modified to serve as surrogates for adenovirus type 5. The successful attachment of the most abundant protein of the virus, hexon protein, to the surface of the nanoparticles was achieved through both non-covalent and covalent methods. This research demonstrates the importance of developing synthetic particles that closely resemble viruses for the development of advanced sorbent materials.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Sebastian Cisneros, Shilong Chen, Corinna Fauth, Ali M. Abdel-Mageed, Simone Pollastri, Joachim Bansmann, Luca Olivi, Giuliana Aquilanti, Hanan Atia, Jabor Rabeah, Magdalena Parlinska-Wojtan, Angelika Bruckner, R. Jurgen Behm
Summary: The influence of Si doping on the CO2 reduction reaction of Ru/TiO2 catalysts was systematically studied. Si doping stabilizes the formation of CH4 and improves its selectivity.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Physics, Applied
Andreas Hoffmann, Matthias Uhl, Maximilian Ceblin, Joachim Bansmann, Timo Jacob, Alexander J. C. Kuehne
Summary: Carbon nanofiber nonwovens are electrode materials with exceptional performance in energy storage devices. Plasma activation using an atmospheric pressure plasma-jet is an environmental-friendly method to improve the capacitance of nanofiber nonwovens.
PLASMA PROCESSES AND POLYMERS
(2022)
Article
Chemistry, Multidisciplinary
Michael Usselmann, Joachim Bansmann, Alexander J. C. Kuehne
Summary: Polyacrylonitrile (PAN) is commonly used as the precursor for carbon fibers and carbon materials. These carbon materials have high mechanical performance, excellent electrical conductivity and high surface area, making them suitable for various applications. However, the processing of PAN is limited to fibers, films, and non-wovens, which restricts its design freedom. In this study, a PAN-copolymer with intrinsic plasticizer is developed to enable melt extrusion-based additive manufacturing (EAM) and mold-free rapid prototyping.
ADVANCED MATERIALS
(2023)
Article
Electrochemistry
Florian Klein, Claudia Pfeifer, Joachim Bansmann, Zenonas Jusys, R. Juergen Behm, Margret Wohlfahrt-Mehrens, Mika Linden, Peter Axmann
Summary: The electrochemical activation of Li2MnO3 domains in Li- and Mn-rich layered oxides (LRLO) is highly important, and can be tuned by surface modification of the active materials to improve their cycling performance. In this study, citric acid was employed as a combined organic acid, reducing agent, and carbon precursor to enhance the electrochemical discharge capacities of the post-treated materials with successful creation of an oxygen deficient near-surface region covered by carbon-containing deposits.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Ali M. Abdel-Mageed, Bunyarat Rungtaweevoranit, Sarawoot Impeng, Joachim Bansmann, Jabor Rabeah, Shilong Chen, Thomas Haering, Supawadee Namuangrak, Kajornsak Faungnawakij, Angelika Brueckner, R. Juergen Behm
Summary: Elucidating the reaction mechanism of CO oxidation using a molecularly defined copper single-atom catalyst supported by UiO-66 metal-organic framework (Cu/UiO-66) was achieved through a combination of in situ/operando spectroscopies, kinetic measurements, and density-functional-theory-based calculations. The study identified the active site, reaction intermediates, and transition states of the dominant reaction cycle, as well as changes in oxidation/spin state during the reaction. The reaction involves the continuous dissociation of adsorbed O-2, leading to the formation of an O atom connecting the Cu center with a neighboring Zr4+ ion as the rate-limiting step.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Hanna Braun, Dariusz Mitoraj, Joanna Kuncewicz, Andreas Hellmann, Mohamed M. Elnagar, Joachim Bansmann, Christine Kranz, Timo Jacob, Wojciech Macyk, Radim Beranek
Summary: Polymeric carbon nitrides (PCN) are sustainable, tunable, non-toxic, and chemically stable materials that show great potential as photocatalysts for light-driven hydrogen peroxide production. However, most studies have used PCN powder suspensions and sacrificial electron donors. In this study, we report the first multicomponent hybrid photocathode based on PCN that can selectively reduce dioxygen to H2O2 under visible light irradiation. Our study demonstrates the intrinsic photocatalytic activity of PCN in H2O2 production and opens up possibilities for the development of more efficient PCN-based photocathodes.
APPLIED CATALYSIS A-GENERAL
(2023)
Article
Electrochemistry
Zenonas Jusys, R. Juergen Behm
Summary: Reversible Mg deposition/stripping and O-2 reduction/evolution reactions on a Pt film electrode immersed in neat and O-2-saturated 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMP-TFSI) electrolytes were studied using online differential electrochemical mass spectrometry (DEMS) and scanning electron microscopy/energy dispersed X-ray spectroscopy. The presence of Mg(TFSI)(2), Mg(BH4)(2), and the crown ether 18-c-6 as additives was also investigated. The results reveal a complex network of parallel reactions, including borohydride electro-oxidation, Mg deposition/stripping, and oxygen reduction/evolution, as well as electrolyte decomposition. These findings provide insights into the reactions occurring under these conditions and have implications for Mg-air battery applications.
Article
Electrochemistry
Katrin Forster-Tonigold, Florian Buchner, Axel Gross, R. Juergen Behm
Summary: By utilizing surface chemistry experiments and DFT calculations, this study investigates the initial stages of SEI formation in Na ion or Na metal batteries. The results reveal the interactions and reactions between a Na surface and the ionic liquid, leading to the formation of larger TFSI-based fragments and atomic adsorbates at the Na surface.
BATTERIES & SUPERCAPS
(2023)
Article
Electrochemistry
K. Forster-Tonigold, F. Buchner, J. Bansmann, R. J. Behm, A. Gross
Summary: By employing density functional theory calculations and X-ray photoelectron spectroscopy, the study identified products of the reaction between the ionic liquid BMP-TFSI and lithium to model the initial chemical processes in battery interphases. Lithium cyanide or cyanamide was found to be a possible stable product in the Li-poor regime, while LLN was stable in the Li-rich regime.
BATTERIES & SUPERCAPS
(2022)
Article
Materials Science, Multidisciplinary
A. Lennart Schleper, Sabina Hillebrandt, Christoph Bannwarth, Andreas Mischok, Seonil Kwon, Florian Buchner, Francisco Tenopala-Carmona, R. Jurgen Behm, Felix D. Goll, Philipp J. Welscher, Michael Usselmann, Ulrich Ziener, Malte C. Gather, Alexander J. C. Kuehne
Summary: Exciplexes formed by BTP isomers and TCTA were found to exhibit thermally activated delayed fluorescence (TADF). The nitrogen position in the pyridine of the BTP molecule was found to influence the optical and electronic properties of the exciplex. The molecular arrangement of the complex was studied using various techniques, and OLEDs with moderate external quantum efficiencies were fabricated.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Electrochemistry
Ananyo Roy, Vinayan Bhagavathi Parambath, Thomas Diemant, Gregor Neusser, Christine Kranz, R. Juergen Behm, Zhenyou Li, Zhirong Zhao-Karger, Maximilian Fichtner
Summary: In this study, the interaction between the magnesium (Mg) metal anode and chloride (Cl)-free electrolyte was investigated. The results showed the formation of a solid interphase layer, which played a crucial role in the reversible stripping and plating of Mg in a full-cell configuration. This study provides fundamental insights into the interfacial phenomena between Mg anode and Cl-free electrolyte.
BATTERIES & SUPERCAPS
(2022)
