Article
Chemistry, Multidisciplinary
Praveen N. Gunawardene, Julia Martin, Jonathan M. Wong, Zhifeng Ding, John F. Corrigan, Mark S. Workentin
Summary: In this study, we synthesized the o, m, and p regioisomeric forms of the anionic azide-functionalized [Au-25(SCH2CH2-C6H4-N-3)(18)](1-) platform to fine-tune the structure-property correlations of thiolate-protected gold nanoclusters through post-assembly surface modifications. These regioisomers can undergo cluster-surface strain-promoted alkyne-azide cycloaddition (CS-SPAAC) chemistry with complementary strained-alkynes. It was found that the electrochemical properties of the clusters appear to be correlated with the position of the azido group.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Ming-Yen Tsai, Ming-Chen Chang, Hsiu-Wen Chien
Summary: This study explored the effects of polydopamine formation on catalytic activity. Different molecular weights of PEI or PEG were mixed with dopamine at varying concentrations to obtain different PDA/PEI or PDA/PEG codepositions. AgNPs were observed on the surface of these codepositions after soaking in silver nitrate solution, and their catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol was examined. Results showed that AgNPs on PDA/PEI or PDA/PEG codepositions were smaller and more dispersed compared to those on PDA coatings. The catalytic activity of AgNPs on all codepositions was better than that on PDA, and it was related to the size of AgNPs.
Article
Chemistry, Physical
Peter M. Spurgeon, Da-Jiang Liu, Theresa L. Windus, James W. Evans, Patricia A. Thiel
Summary: Chemisorbed species, particularly sulfur, can enhance the decay rate of 2D Au islands on metal surfaces, leading to surface pitting and reconstruction. The formation and diffusion of Au-S complexes contribute to the enhanced coarsening of Au islands at lower sulfur coverages.
Article
Chemistry, Multidisciplinary
Yongkai Lu, Yangyang Zhou, Junjie Xia, Suyun Zhong, Yawen Liu, Qiang Chen, Hongxia Chen
Summary: A facile synthetic strategy is used to construct raspberry-like gold nanoparticles, which are then used to develop an efficient and sensitive electrochemical sensor for the detection of Cr(VI). The sensor exhibits a wide linear range and an extremely low detection limit, suggesting potential applications in other ultrasensitive electrochemical sensors.
Review
Biochemistry & Molecular Biology
T. Ngake, S. Nqayi, M. Gulumian, S. Cronje, R. A. Harris
Summary: Recent studies have shown that the uptake and toxicity of gold and silver nanostructures in drug delivery systems are influenced by their physicochemical properties. These properties, including size, shape, coordination chemistry, surface charge, and surface chemistry, affect the reactivity, surface energetics, and electronic properties of the nanomaterials.
BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS
(2022)
Article
Chemistry, Multidisciplinary
Mengying Wang, Zixiang Cui, Yongqiang Xue
Summary: This paper presents a novel method to determine the interfacial tension, temperature coefficient, and Tolman lengths of nanomaterials using adsorption thermodynamics and kinetics. The experimental results indicate that the particle size of nanoparticles has significant effects on the interfacial tension and its temperature coefficient, as well as the Tolman length. The effects of particle size on interfacial tension and Tolman length become more significant when the particle radius approaches or reaches the order of magnitudes of molecular (or atomic) radius.
Article
Chemistry, Multidisciplinary
Loubna El Faroudi, Latifa Saadi, Abdellatif Barakat, Mohammed Mansori, Karima Abdelouahdi, Abderrahim Solhy
Summary: The aim of this study was to synthesize nanostructured ZnO using a soft-chemical method through biopolymer gelation, and then utilize the prepared oxides as photocatalysts for the oxidation of the Orange G dye. The difference in gelation mechanisms of four tested biopolymers and various experimental parameters were investigated to control the growth of nanostructured ZnO. The sample prepared with chitosan showed the best photocatalytic performance with 99.3% degradation of the Orange G dye in 180 minutes, due to its specific surface area and morphology.
Article
Chemistry, Physical
Jiaquan Huang, Xinyi Zhao, Xunkun Huang, WanZhen Liang
Summary: The study investigates the mechanism and dynamics of utilizing plasmon-generated hot carriers to drive chemical reactions, including factors influencing the reaction rate and variations under different field strengths. The conclusion reveals that electron injection is a key factor in increasing the water splitting rate, and the linear relationship between reaction rate and field amplitude is limited.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Hyeokjun Park, Hayoung Park, Kyung Song, Seok Hyun Song, Sungsu Kang, Kun-Hee Ko, Donggun Eum, Yonggoon Jeon, Jihoon Kim, Won Mo Seong, Hyungsub Kim, Jungwon Park, Kisuk Kang
Summary: Nickel-rich layered oxides are important cathode materials for lithium-ion batteries. The synthesis process is influenced by the kinetic competition between thermal decomposition and lithiation, which leads to the formation of spatially heterogeneous intermediates. Thermal decomposition results in defective structures, while promoting lithiation can mitigate their generation and suppress chemo-mechanical failures.
Article
Chemistry, Physical
Wei Liu, Hongpeng Liu, Yatian Liu, Zejian Dong, Langli Luo
Summary: Specific surface planes of metals and/or supports in heterogeneous catalysis have significant effects on catalytic processes. This study synthesized ZnO nanoplates and nanorods with different surface planes and used them as supports for Au/ZnO catalysts. The activity of Au/p-ZnO was found to be superior to that of Au/r-ZnO due to more O(2) activation sites on polar surfaces.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Wei Liu, Hongpeng Liu, Yatian Liu, Zejian Dong, Langli Luo
Summary: In heterogeneous catalysis, the specific surface planes of metals and/or supports play a significant role in catalytic processes. This study demonstrated the surface plane effect of ZnO by synthesizing ZnO nanoplates (p-ZnO) with mostly polar surfaces and ZnO nanorods (r-ZnO) with non-polar surfaces, and using them as supports for Au/ZnO catalysts. The activity of Au/p-ZnO was found to be superior to that of Au/r-ZnO, attributed to the presence of more O2 activation sites on the polar surfaces. Furthermore, Au can activate both polar and non-polar surfaces of ZnO through the creation of oxygen vacancies.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Yifeng Gao, Jiaoxia Zhang, Zhihao Zhang, Zicheng Li, Qiu Xiong, Longhui Deng, Qin Zhou, Lingyi Meng, Yitian Du, Tao Zuo, Yaming Yu, Zhang Lan, Peng Gao
Summary: To enhance light absorbance and maintain the quality of perovskite films, researchers adopted an asynchronous synergistic effect strategy by adding gold nanorods to perovskite precursor solutions. This approach led to a high power conversion efficiency of 21.73% and outstanding long-term stability.
Article
Chemistry, Multidisciplinary
P. P. Praveen Kumar, Atikur Rahman, Tanmay Goswami, Hirendra N. Ghosh, Prakash P. Neelakandan
Summary: The study presents supramolecular nanocomposites composed of BODIPY, tryptophan, and gold nanoparticles, showing that the photostability and photosensitization properties of the nanocomposites are influenced by the chemical composition of the BODIPY molecules. Structural variations in BODIPY molecules impact the singlet oxygen quantum yield of the nanocomposites, with a higher efficiency observed when compared to individual components. Ultrafast spectroscopy studies reveal efficient generation of singlet oxygen through electron transfer from photoexcited BODIPY to plasmonic photoexcitation.
Article
Polymer Science
Karabo Kamogelo Khoza, Thabang Calvin Lebepe, Gracia it Mwad Mbaz, Oluwatobi Samuel Oluwafemi
Summary: The application of gold nanorods (AuNRs) as a photothermal agent has become popular due to their optical, photothermal and biological properties. However, the use of a toxic surfactant in their synthesis limits their biological applications. This study evaluated the effect of different polymers or stabilizers on the stability and photothermal properties of AuNRs, and found that choosing polymers with fewer functional groups is crucial for coating nanoparticles for biological applications.
JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS
(2023)
Article
Physics, Multidisciplinary
Anna Niggas, Janine Schwestka, Karsten Balzer, David Weichselbaum, Niclas Schluenzen, Rene Heller, Sascha Creutzburg, Heena Inani, Mukesh Tripathi, Carsten Speckmann, Niall McEvoy, Toma Susi, Jani Kotakoski, Ziyang Gan, Antony George, Andrey Turchanin, Michael Bonitz, Friedrich Aumayr, Richard A. Wilhelm
Summary: We compared the ion-induced electron emission from freestanding monolayers of graphene and MoS2 and found that graphene emitted six times more electrons, despite both materials having similar work functions. This can be explained by a charge-up in MoS2 that prevents low energy electrons from escaping the surface within a few femtoseconds after ion impact.
PHYSICAL REVIEW LETTERS
(2022)
Article
Engineering, Environmental
Jose A. Hernandez Lalinde, Pakpong Roongruangsree, Jan Ilsemann, Marcus Baeumer, Jan Kopyscinski
CHEMICAL ENGINEERING JOURNAL
(2020)
Article
Chemistry, Physical
Yong Li, Shikun Li, Marcus Baeumer, Elena A. Ivanova-Shor, Lyudmila V. Moskaleva
Article
Chemistry, Applied
Andrew S. Jones, Daniel Aziz, Jan Ilsemann, Marcus Baumer, Helena Hagelin-Weaver
Summary: The research showed that transition metal dopants can enhance the activity and selectivity of samarium oxide xerogel catalysts in the oxidative coupling of methane, with differences in performance between different dopants and potential for alkali metal dopants under certain conditions. Dopants have a significant impact on the structure and stability of the catalyst, with transition metal dopants generally resulting in more active and selective catalysts.
Article
Chemistry, Physical
Sarah Neumann, Hans Hannes Doebler, Simona Keil, Alexandra J. Erdt, Christian Gutsche, Holger Borchert, Joanna Kolny-Olesiak, Juergen Parisi, Marcus Baeumer, Sebastian Kunz
Article
Chemistry, Applied
Andrew S. Jones, Daniel Aziz, Jan Ilsemann, Marcus Baeumer, Helena Hagelin-Weaver
Summary: High-valence dopants have a significant impact on the catalytic properties of samarium oxide xerogels, improving their activity and selectivity in OCM reactions. However, maintaining low concentrations of dopants is crucial, as higher concentrations and temperatures above 700°C can lead to inferior catalyst performance.
Article
Chemistry, Physical
Jakob Stahl, Jan Ilsemann, Suman Pokhrel, Marco Schowalter, Christian Tessarek, Andreas Rosenauer, Martin Eickhoff, Marcus Baeumer, Lutz Maedler
Summary: The impact of different co-catalytically acting promoters (Pt, ZrOx and SmOx) on alumina supported Co-based model catalysts during COx methanation was studied. Double flame spray pyrolysis was used for synthesis to obtain samples with identical structure and morphology. Promoters (Pt, ZrOx, and SmOx) improved methanation yields within a wide temperature range in CO2 methanation, with zirconia and platinum showing the best performance. In CO methanation, all catalysts deactivated rapidly above 310 degrees C, with Pt exhibiting the best results.
Article
Chemistry, Physical
Stefan Wild, Marcus Baeumer, Thomas Risse
Summary: Heterogeneous catalysts based on gold have shown high activities and selectivities in oxidation reactions. Nanoporous gold (npAu), as an alternative catalyst, exhibits similarly good catalytic performance, despite having a larger characteristic structural length. A reliable activation procedure has been discovered to achieve high conversion levels with short annealing steps, which improves the catalytic activity of npAu.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Yong Li, Shikun Li, Marcus Baeumer, Lyudmila Moskaleva
Summary: The study revealed that ceria nanoparticles transfer electrons to the gold support, reflecting a strong chemical interaction that stabilizes nanoporous gold against thermal coarsening observed experimentally. In catalytic CO oxidation, a CO molecule near the ceria/gold interface can extract a Au atom, resulting in a low activation energy and dynamic restructuring of the gold support. Compared to ceria particles supported on Au(111), the stepped structure of Au(321) enables a new low-energy mechanism, enhancing reactivity.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Stefan Wild, Christoph Mahr, Andreas Rosenauer, Thomas Risse, Sergey Vasenkov, Marcus Baeumer
Summary: This article introduces new perspectives to characterize and understand the interplay of mass transport and catalytic processes in gas phase metal catalysts. The study focuses on nanoporous gold and uses PFG NMR measurements to evaluate gas diffusivities and STEM tomography to analyze the pore structure. The quantitative knowledge about diffusion coefficients allows for separating mass transport contributions from measured reaction kinetics and determining the kinetic rate constant of the catalytic surface reaction. The study demonstrates the potential of novel porous materials combined with modern techniques for a comprehensive understanding of catalytic processes.
Article
Chemistry, Physical
Daniel Loof, Rouven von Elling, Anmona Shabnam Pranti, Walter Lang, Marcus Baeumer, Volkmar Zielasek
Summary: The thermal stability of microporous networks of Pt nanoparticles interlinked by p-Phenylenediamine (PDA) was studied using temperature-programmed desorption spectroscopy (TPD) and transmission electron microscopy (TEM). The decomposition of PDA was found to be mainly through cleavage of the C-N bonds, assisted by dehydrogenation reactions of PDA. The Pt nanoparticles catalytically promoted the decomposition of PDA links, with the thermal stability of PDA strongly correlating with the number of bonds formed by the amino groups of PDA with Pt. The results have important implications for the application of PDA-linked Pt nanoparticles as heterogeneous catalysts in hydrogen gas microsensors.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Review
Chemistry, Multidisciplinary
Gunther Wittstock, Marcus Baeumer, Wilke Dononelli, Thorsten Kluener, Lukas Luehrs, Christoph Mahr, Lyudmila Moskaleva, Mehtap Oezaslan, Thomas Risse, Andreas Rosenauer, Anne Staubitz, Joerg Weissmueller, Arne Wittstock
Summary: Nanoporous gold (NPG) is a nanoscale material with a network of metallic struts and interconnected pores formed from gold alloys through oxidative dissolution. It exhibits good catalytic activity, particularly in the aerobic partial oxidation of methanol. This review discusses methods to control NPG morphology and composition, explores mechanistic understanding from quantum chemical studies, and highlights best practices for material preparation and characterization.
Article
Chemistry, Physical
Shikun Li, Okikiola Olaniyan, Lenard L. Carroll, Marcus Baeumer, Lyudmila Moskaleva
Summary: The rich surface chemistry of gold at the nanoscale has made it an important catalyst for low-temperature applications. Recent studies suggest that self-organized structures formed by chemisorbed O atoms on the surface of gold catalysts may play a role in their catalytic activity and/or deactivation. In this study, the reactivity of a double O chain running along a step on a Au(221) surface with oxygen vacancies was investigated. Results show that O-2 adsorbs stronger and its dissociation barrier reduces significantly on the double oxygen vacancy compared to the regular Au(221) surface. Calculations suggest that CO oxidation should occur more efficiently on the double O vacancy due to stronger adsorption of O-2 and a low activation barrier for O-2 + CO surface reaction.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Jan Ilsemann, Mangir M. Murshed, Thorsten M. Gesing, Jan Kopyscinski, Marcus Baeumer
Summary: The influence of support basicity on Ru-catalyzed CO2 methanation was investigated, with different types of basic surface sites on the support playing a significant role in catalytic behavior. Basic supports can contribute to catalytic turnover by opening new pathways or promoting existing ones, depending on the type, density, and strength of basic sites available, which varies with temperature.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Physical
Shikun Li, Yong Li, Marcus Baeumer, Lyudmila Moskaleva
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Analytical
Anmona Shabnam Pranti, Daniel Loof, Sebastian Kunz, Volkmar Zielasek, Marcus Baeumer, Walter Lang
SENSORS AND ACTUATORS B-CHEMICAL
(2020)