Article
Chemistry, Multidisciplinary
Ming-Hao Du, Dong-Hui Wang, Ling-Wei Wu, Lin-Peng Jiang, Jun-Ping Li, La-Sheng Long, Lan-Sun Zheng, Xiang-Jian Kong
Summary: The discovered giant clusters are highly symmetric due to the spontaneous assembly of one or two basic units. In this study, Gd44Co28 crown and Gd95Co60 cage were reported, which have atypical geometry compared to clusters directly assembled by regular units. These clusters not only increase the size of Ln-Co clusters, but also exhibit enhanced magnetic entropy change at ultra-low temperatures. This work provides an effective way to fabricate cluster compounds with giant size and geometry complexity simultaneously.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
H. L. Tan, P. R. Ng, M. Trushin, G. K. W. Koon, K. Z. Donato, M. C. F. Costa, R. K. Donato, A. H. Castro Neto
Summary: 2D materials can be functionalised with ionisable functional groups to form 2D electrolytes. In this study, heterostructures were formed by self-assembly of functionalised graphene oxide (GO) with cationic groups and molybdenum disulfide (MoS2) with anionic groups. The application of sonication allowed the continuous assembly of the 2D materials into heterostructured nanofibers, which resemble naturally occurring polyelectrolytes. This method offers a facile approach for the continuous processing of low-cost heterostructured nanofibers with potential applications in various fields.
MATERIALS TODAY CHEMISTRY
(2023)
Article
Chemistry, Physical
Shanshan Ma, Zequan Huang, Bingyan Qu, Dongdong Li, Rulong Zhou
Summary: The study reveals that vanadium oxide clusters supported on anatase TiO2(101) surface exhibit different aggregation behaviors based on coverage, with monomeric clusters predominant at low coverage and polymeric clusters more popular at higher coverage. The molecular adsorption of NH3 can be enhanced on all supported structures, but NH3 dissociation only occurs on VO3/A(101).
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Tao Xu, Kraen C. Adamsen, Zheshen Li, Lutz Lammich, Jeppe Lauritsen, Stefan Wendt
Summary: We used STM and XPS to investigate the molecular and electronic structure of submonolayer tungsten oxide on different TiO2 surfaces. The results show that the geometry of the tungsten oxide species depends on the supporting facet, and surface diffusion occurs at elevated temperatures. Additionally, the oxidation and reduction properties of thick and thin layers of tungsten oxide are different, with the reduction being influenced by the TiO2 surface and substrate defects.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Li Zhang, Ming Deng, Yu Duan, Xin Wen, Yuqian Jiang, Hejin Jiang, Yuqiang Ma, Minghua Liu
Summary: The study found that tree-shaped fractal patterns could be self-assembled from Fmoc-Glu and ZnTPyP, composed of nanorod aggregate arranged in a spiral fractal way. The formation and growth of initial nucleon led to the fractal patterns, and the spiral packing and their branches were closely related to the absolute configuration of Fmoc-Glu.
Article
Chemistry, Physical
Maria-Athina Apostolaki, Elias Sakellis, Polychronis Tsipas, Maria Giannouri, Spiros Gardelis, Nikos Boukos, Athanasios Dimoulas, Vlassis Likodimos
Summary: Heterostructured WO3/TiO2 photonic crystal films in the form of three-dimensional macroporous inverse opals were developed by single-step, three-phase co-assembly of colloidal templates with water soluble precursors. The properties of the inverse opals could be controlled by adjusting the W/Ti molar ratio and macropore diameter. This method provides a promising route for the development of heterostructured inverse opal networks with tailored electronic properties and improved solar light harvesting.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Ao Cheng, Yan Shen, Tianzeng Hong, Runze Zhan, Enzi Chen, Zengrui Chen, Guowang Chen, Muyuan Liang, Xin Sun, Donghang Wang, Linchen Xu, Yu Zhang, Shaozhi Deng
Summary: A strategy to combine vertical graphene (VG) with MoO3 nanosheets to form a composite structure has been proposed, the prepared VG/MoO3 nanosheets exhibit excellent electrochemical properties, such as high reversible capacitance, better cycling performance, and high-rate capability.
Article
Chemistry, Physical
Waleed Yaseen, Meng Xie, Bashir Adegbemiga Yusuf, Yuanguo Xu, Madiha Rafiq, Nabi Ullah, Puyang Zhou, Xiang Li, Jimin Xie
Summary: This study develops a hierarchical Co/MoO2@nitrogen-doped carbon nanosheets electrocatalyst derived from lotus leaves biomass for water splitting. The optimized catalyst exhibits a low overpotential and notable water splitting activity. The hierarchical flower-like morphology and synergistic effects contribute to the improved electrocatalytic performance and stability.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Nanoscience & Nanotechnology
S. Xie, K. Lai, C. Gu, T. Jiang, L. Zhou, X. Zheng, X. Shen, J. Han, J. Zhou
Summary: In this study, TiO2@MoOx nanorods were prepared and used to construct TiO2/MoOx nano-heterojunctions for efficient charge transfer and enhanced SERS performance. Experimental results showed that the Raman signal intensity of R6G was gradually improved with an increase in the number of nano-heterojunctions on TiO2@MoOx nanorods. The optimal TiO2@MoOx nanorods achieved a detection limit as low as 10(-8) M and a Raman enhancement factor of 1.445 x 10(8). The mechanism of SERS enhancement was investigated by analyzing the band diagrams of TiO2 and MoOx, confirming the formation of staggered gap heterojunctions. Surface potential measurements further confirmed the accumulation of free electrons on the MoOx surface, enhancing the charge transfer between the molecules and heterojunctions.
MATERIALS TODAY NANO
(2022)
Article
Engineering, Electrical & Electronic
Zakir Caldiran, Lutfi Bilal Tasyurek
Summary: In this study, Cr/MoO3/n-Si/Al heterojunction devices were successfully obtained by coating MoO3 between Cr metal and n-Si semiconductor. The MoO3 layer exhibited ideal current transmission mechanism and increased barrier height in the devices.
SENSORS AND ACTUATORS A-PHYSICAL
(2021)
Article
Chemistry, Multidisciplinary
Qingda Liu, Xun Wang
Summary: The self-assembly of clusters provides a feasible approach for the bottom-up fabrication of functional materials with tailored properties. This paper introduces recent progress on cluster-based assemblies, including noble metal and polyoxometalate (POM) clusters, and discusses their structures, formation mechanism, and properties from experimental and theoretical aspects. The research aims to provide new insights into the design and manufacture of sub-nanometer materials based on clusters.
Article
Engineering, Chemical
Changkun Ding, Xiwen Qin, Yingying Tian, Bowen Cheng
Summary: Novel polyethersulfone/graphene oxide@titanium dioxide photocatalytic membranes were developed via layer-by-layer self-assembly technique. The membranes exhibited improved photocatalytic activity and stability, high water flux, and degradation rate, making them ideal candidates for wastewater treatment.
JOURNAL OF MEMBRANE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Andreas Frank, Christian Hils, Melina Weber, Klaus Kreger, Holger Schmalz, Hansooo-Werner Schmidt
Summary: By matching the functional groups of the surface patches on polymer fibers with the corresponding substituents of BTAs, specific superstructures can be induced.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Thermodynamics
Yuhuan Zheng, Zhikang Liu, Bin Liu, Shan Wang, Chuanxi Xiong
Summary: In this study, cactus-like CNT/SiO2/MoO3 composites were successfully synthesized, demonstrating improved rate capability and cycling stability. CNTs acted as electron transporters, while SiO2 and MoO3 stored lithium, with MoO3 also serving as a support to stabilize the electrode structure.
Article
Chemistry, Physical
Nassar Doudin, Greg Collinge, Rudradatt R. Persaud, Pradeep Kumar Gurunathan, Mal-Soon Lee, Vassiliki-Alexandra Glezakou, David A. Dixon, Roger Rousseau, Zdenek Dohnalek
Summary: The study demonstrates a method to deposit MgO monomers on the TiO2(101) surface through the sublimation of MgO powder, and employs a combination of techniques to investigate properties such as monomer binding, electronic and vibrational properties, and thermal stability. The most stable configuration involves binding of MgO monomer to surface oxygens and undercoordinated surface titanium, weakening the bond and enhancing thermal stability up to 600 K before diffusion occurs. These monomeric MgO species on TiO2(101) represent an ideal atomically precise system with modified acid-base properties for future catalytic studies.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Applied
Simuck F. Yuk, Mal-Soon Lee, Sneha A. Akhade, Manh-Thuong Nguyen, Vassiliki-Alexandra Glezakou, Roger Rousseau
Summary: Understanding the hydrogenation of organic compounds in the aqueous phase is crucial for carbon neutral pathways. This study investigated the thermodynamic and kinetic profiles of benzaldehyde hydrogenation over Pd(111) and Pt(111) metal surfaces. The presence of surface charge and solvent greatly influenced the reaction.
Article
Chemistry, Applied
Sneha A. Akhade, Mal-Soon Lee, Laura C. Meyer, Simuck F. Yuk, Manh-Thuong Nguyen, Udishnu Sanyal, Jonathan D. Egbert, Oliver Y. Gutierrez, Vassiliki-Alexandra Glezakou, Roger Rousseau
Summary: In this study, the adsorption and reduction processes of organic molecules on a charged Pd surface were investigated using density-functional-theory based molecular dynamics simulations. The results show that the functional groups and electrode charge have a strong impact on the adsorption and reduction of organic molecules, and the solvent effect also significantly influences the interaction between the organic molecules and the electrode.
Article
Chemistry, Multidisciplinary
Daniil Naberezhnyi, Lukas Mai, Nassar Doudin, Inga Ennen, Andreas Hutten, Eric Altman, Anjana Devi, Petr Dementyev
Summary: This study investigates the mass transport properties of freestanding 2D SiO2 using atomic layer deposition (ALD) to grow large-area films and transfer onto Si3N4 windows. The experimental results show that while the suspended material is porous, the membrane selectivity differs from the size exclusion principle and allows condensable species like water to permeate a thousand times faster than inert gas molecules.
Review
Chemistry, Physical
GiovanniMaria Piccini, Mal-Soon Lee, Simuck F. Yuk, Difan Zhang, Greg Collinge, Loukas Kollias, Manh-Thuong Nguyen, Vassiliki-Alexandra Glezakou, Roger Rousseau
Summary: Ab initio molecular dynamics simulations combined with enhanced sampling techniques are becoming widespread methods to investigate chemical phenomena in catalytic systems. These methods automatically consider finite temperature effects, anharmonicity, and collective dynamics, which significantly affect reaction free energy landscapes. In contrast, standard ab initio static approaches rely on coarse-grained descriptions of reaction potential energy surfaces to assess reaction free energies. Enhanced sampling ab initio molecular dynamics allows for first principles simulations of increasingly complex systems, such as solid/liquid catalytic interfaces.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Gregory S. Hutchings, Xin Shen, Chao Zhou, Petr Dementyev, Daniil Naberezhnyi, Inga Ennen, Andreas Huetten, Nassar Doudin, Jesse H. Hsu, Zachary S. Fishman, Udo D. Schwarz, Shu Hu, Eric Altman
Summary: In this paper, it is demonstrated that a single layer of 2D-VDW SiO2 can be grown by ALD on Au and Pd polycrystalline foils and epitaxial films. The choice of Si source in ALD can enable phase control, with ALD growth on Au producing predominantly the amorphous phase and SiO deposition in UHV leading to only the crystalline phase.
Article
Chemistry, Physical
Guang-Jie Xia, Mal-Soon Lee, Vassiliki-Alexandra Glezakou, Roger Rousseau, Yang-Gang Wang
Summary: Interstitial Ti defects and O vacancies are common in TiO2-x catalytic support materials and play significant roles in catalytic performance. Au clusters on TiO2-x surface can induce outward diffusion and surface segregation of interstitial Ti defects, promoting the regrowth of TiO2 islands. The interaction between different metal clusters and interstitial Ti affects the diffusion rates and provides insights into reaction mechanisms.
Article
Physics, Condensed Matter
Michael Gottschalk, Mal-Soon Lee, Eric Goodwin, Camille Mikolas, Thomas Chasapis, Duck Young Chung, Mercouri G. Kanatzidis, Subhendra D. Mahanti, Stuart Tessmer
Summary: Using scanning tunneling spectroscopy, the effects of nitrogen gas exposure on the electronic density of states of Bi2Se3 were investigated. Nitrogen gas molecules were observed to physisorb near Se vacancies, resulting in a saturation of the exposure effect after approximately 50 min. Density functional theory calculations and molecular dynamics simulations support the dissociative adsorption of N2 molecules and their strong binding to Se vacancies, which modifies the position of the Fermi energy relative to the Dirac point.
SOLID STATE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Runze Ma, Christopher R. O'Connor, Gregory Collinge, Sarah I. Allec, Mal-Soon Lee, Zdenek Dohnalek
Summary: The dynamics of acetic acid on anatase TiO2(101) were investigated using scanning tunneling microscopy experiments and density functional theory calculations. The study showed the simultaneous diffusion of bidentate acetate and a bridging hydroxyl, as well as the transient formation of molecular monodentate acetic acid. The diffusion rate was found to be strongly dependent on the position of hydroxyl and adjacent acetate(s). A three-step diffusion process involving acetate and hydroxyl recombination, acetic acid rotation, and acetic acid dissociation was proposed. This study provides insights into the importance of bidentate acetate dynamics in the formation of monodentate species, which drive selective ketonization.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Applied
Christopher R. O'Connor, Runze Ma, Gregory Collinge, Mal-Soon Lee, Greg A. Kimmel, Zdenek Dohnalek
Summary: In this study, the adsorption and reaction of acetic acid on anatase TiO2(101) were investigated using various techniques. It was found that acetic acid can form two intermediates: dissociated, bidentate acetate and molecular, monodentate acetic acid. The presence of both intermediates was observed at low temperatures, while only the bidentate acetate was observed at high temperatures. This research provides important insights into the stability and reactivity of carboxylic acid surface-bound intermediates, which play a role in biomass upgrading via ketonization reactions.
TOPICS IN CATALYSIS
(2023)
Article
Chemistry, Physical
Jinshu Tian, Gregory Collinge, Simuck F. F. Yuk, Jindong Lin, Vassiliki-Alexandra Glezakou, Mal-Soon Lee, Yong Wang, Roger Rousseau
Summary: Through density functional theory calculations, in situ Raman characterization, and microkinetic modeling, it is found that dimerized di-coordinated boron sites are the active species for O-2 activation and peroxy-like structures are responsible for propane activation. The formation of adsorbed C3H7* radicals was found to be the main rate-controlling step. These findings provide significant insights into the mechanisms of oxidative dehydrogenation of propane on boron-based catalysts.
Article
Chemistry, Physical
Vanessa Lebarbier Dagle, Gregory Collinge, Mohammed Rahmana, Austin Winkelman, Wenda Hu, Jian Zhi Hu, Libor Kovarik, Mark Engelhard, Jennifer Jocz, Yong Wang, Mal-Soon Lee, Vassiliki-Alexandra Glezakou, Debmalya Ray, Roger Rousseau, Robert Dagle
Summary: This study reports on a Cu/ZrO2/SBA-16 catalyst with remarkable olefins selectivity and enhanced stability compared to the Ag/ZrO2/SBA-16 catalyst. Replacing Ag with Cu shifts the reaction pathway of crotonaldehyde hydrogenation, leading to the formation of butyraldehyde. Experimental and computational tools were used to verify the performance and stability advantage of the Cu/ZrO2/SBA-16 catalyst.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Materials Science, Multidisciplinary
Nassar Doudin, Kayahan Saritas, Min Li, Inga Ennen, J. Anibal Boscoboinik, Petr Dementyev, Andreas Hutten, Sohrab Ismail-Beigi, Eric I. Altman
Summary: The intrinsic properties of two-dimensional SiO2 were revealed by forming the material on inert Au(111). The formation of a crystalline phase consisting of tetrahedral [SiO4] building units was enabled by SiO deposition. The twisting and rippling of the 2D kagome lattice provide 2D silica with the flexibility to adapt to strain and changes in the crystallographic direction without introducing defects.
ACS MATERIALS LETTERS
(2022)
