Article
Engineering, Chemical
Jiahao Wang, Tao Wang, Xin Wang, Weizhi Yang, Ziting Wang, Meng Li, Liping Shi
Summary: In this study, an argon/oxygen/hexamethyldisiloxane atmospheric pressure plasma jet (APPJ) was used to deposit SiO2-like thin film on a stainless steel surface. The properties of the APPJ were investigated by adjusting the applied voltage, including optical, electrical, thermal, and particle properties. The surface morphology, thickness, roughness, element composition, and water contact angle properties of the deposited thin films were also studied. The results showed that there were two discharge states of the APPJ, namely partial filaments discharge (PFD) state and uniform filaments discharge (UFD) state, with different characteristics. The deposition of high-quality silicon-containing films on conductive substrates by APPJ was achieved.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Matteo Barcellona, Orazio Samperi, Davide Russo, Anna Battaglia, Dirk Fischer, Maria Elena Fragala
Summary: Hydrogenated silicon nitride (SiNx:H) thin films were deposited using different gas mixtures and plasma conditions. The wet etch rate (WER) in hydrofluoric acid (HF) was found to be closely related to the overall composition of the film, which is influenced by both hydrogen and oxygen content. The annealing of the nitride layers also affected the chemical resistivity against HF, with the crystalline structure and chemical evolution of oxidized components playing a role in the nucleophilic attack mechanism. Characterization techniques such as FE-SEM, XPS, FT-IR, and XRD were used, and WER was measured using a fast and straightforward FT-IR data treatment.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Chemistry, Inorganic & Nuclear
Rajesh Patra, Debajit Sarma
Summary: Thiol-containing biomolecules, such as cysteine and glutathione, have important roles in regulating polarity and reactivity. Thiol MOFs, a subclass of functional MOFs, are relatively unexplored due to synthetic challenges and stability and storage issues. However, they have advantages due to the reactivity and affinity of the thiol groups with soft metal ions. In this study, a thiol MOF was functionalized with silver ions to create a silver nanoparticle-functionalized heterogeneous catalyst (Ag@Zr-DMBD), which showed efficient CO2 fixation to cyclic carbonates under mild conditions.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Bruno Noschang Cabral, Jorge Luiz Sonego Milani, Alvaro Farias Arruda da Mata, Gustavo Fernandes Souza Andrade, Hudson Batista da Silva, Rafael Pavao das Chagas
Summary: This study developed a simple and cost-effective method for synthesizing indium(III) complexes and employing them to produce high-value chemicals from CO2. The experimental results showed that these complexes exhibited excellent catalytic performance and could promote the cycloaddition reaction between CO2 and styrene oxide under mild and solvent-free conditions.
INORGANIC CHEMISTRY COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Jiahui Xu, Shizheng Li, Wenjing Zhang, Shang Yan, Cui Liu, Xiao Yuan, Xiaojun Ye, Hongbo Li
Summary: This study investigates the effects of deposition and annealing temperature on the growth and surface passivation of ALD-SiO2 films. Higher deposition temperature improves growth rate and refractive index, while high-temperature annealing enhances surface passivation.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
F. Grigoriev, V. B. Sulimov, A. Tikhonravov
Summary: Increasing the flux of assisting ions can improve the density and refractive index of silicon dioxide films, while decreasing the concentration of point defects and stressed structural rings. Further increase in the flux of assisting ions has minor effects on the film properties.
Article
Energy & Fuels
Yi Liu, Yuhang Hu, Jingsheng Zhou, Zhiyong Zhu, Zhengkun Zhang, Yuanyuan Li, Li Wang, Jinglai Zhang
Summary: A novel polystyrene-supported ionic liquid was successfully synthesized and applied in catalyzing the cycloaddition of CO2 and epichlorohydrin, showing high activity and stability. Various analytical methods were used to elucidate the catalytic mechanism.
Article
Chemistry, Physical
Igor Kowalec, Lara Kabalan, C. Richard A. Catlow, Andrew J. Logsdail
Summary: The reaction mechanism of CO2 hydrogenation to methanol on Pd surfaces (111), (100), and (110) has been investigated. The results show that the Pd (110) surface has lower activation energies compared to Pd (111) and (100) surfaces, suggesting its potential as a catalyst for methanol synthesis.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Energy & Fuels
Yanli Huang, Xiaodong Li, Qian Zhang, Vladimir A. Vinokurov, Wei Huang
Summary: The study revealed that the stability of catalyst declines rapidly at elevated reaction pressure, with differences in the sources and types of carbon deposition between atmospheric pressure and pressurized conditions. Carbon nanotubes were produced by CH4 decomposition reaction and CO disproportionation reaction at atmospheric pressure, while at high pressure, filamentous carbon was formed regardless of the reaction temperature, and accompanied by encapsulated graphitic carbon.
Article
Chemistry, Multidisciplinary
Ting Yu, Bowen Jiang, Leizhi Zheng, Ying Liu, Jigang An, Jia Liu, Zhibing Zhang
Summary: In this study, a novel process for efficient conversion of CO2 to cyclic carbonates under atmospheric pressure in the absence of solvents has been achieved using PS-PEI as a catalyst. PS-PEI, as a metal-free catalyst, showed excellent catalytic activity and CO2 absorption capacity, enabling high yields in the cycloaddition of various epoxides and CO2. The possible mechanism was proposed based on experimental and characterization results, highlighting the collaboration of amine groups and chloride ion in promoting CO2 and epoxides activation. The reaction conditions were further optimized by investigating various reaction parameters.
JOURNAL OF CO2 UTILIZATION
(2022)
Article
Nanoscience & Nanotechnology
Carl Arne Thomann, Adrian Wittrock, Alexandra Wittig, Nelson Filipe Lopes Dias, Dominic Stangier, Wolfgang Tillmann, Joerg Debus
Summary: Amorphous carbon (a-C) is widely studied in tribology and thin film technologies for its versatile properties. This study presents an optical method to induce structural ordering and investigate solid-to-solid structural transitions of element modified a-C films. By using a pump laser to control heat introduction and a second laser to probe Raman scattering signatures, the research reveals the reduction of defects and non-sixfold aromatic rings with low pump power, a transition to defected graphite and hydrogen effusion with increased laser power, and progressive graphitization with rising laser power. Chemical modification of the films with Si or Cu enhances thermal stability, while a-C:W film shows efficient enrichment of nanocrystalline graphitic clusters.
Article
Agriculture, Dairy & Animal Science
Xi Wang, Dan Zhao, Allison C. Milby, Gregory S. Archer, E. David Peebles, Shailesh Gurung, Morgan B. Farnell
Summary: The study explores the use of gases and a vacuum system to euthanize chicks, finding that carbon dioxide or vacuum systems are more favorable for welfare compared to nitrogen. While maceration is the main euthanasia method at hatcheries, it is not seen as humane by the public. Behavior and physiological responses suggest that carbon dioxide inhalation and negative pressure stunning can be utilized for humane euthanasia of neonatal male layer chicks.
Article
Chemistry, Physical
Shiqing Hu, Bingjie Pang, Liming Zhang, Zhongwei Cao, Peng Zhang, Yunjie Ding, Ryan O'Hayre, Xuefeng Zhu, Weishen Yang
Summary: Preventing Ni oxidation and carbon deposition in CO2 electrolysis is a critical challenge for solid oxide electrolysis cells (SOECs). This study reveals that the Nernst voltage, in relation to the operating voltage, controls these reactions and enables the establishment of a reaction phase diagram. The successful demonstration of pure CO2 electrolysis without Ni oxidation and carbon deposition is achieved in Ni-based cathode supported SOECs.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Tatiana N. Myasoedova, Mikhail N. Grigoryev, Tatiana S. Mikhailova
Summary: Silicon-carbon films as electrode materials for supercapacitors were studied. Doping with manganese and nickel increased specific capacitance but also raised equivalent serial resistance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Analytical
Yuka Fujito, Yoshihiro Izumi, Kohta Nakatani, Masatomo Takahashi, Yoshihiro Hayakawa, Mitsuo Takayama, Takeshi Bamba
Summary: Supercritical fluid chromatography (SFC) is often coupled with electrospray ionization mass spectrometry (ESIMS) for analyte detection. The ionization mechanism in SFC/ESI-MS is different from liquid chromatography due to the use of CO2 as a mobile phase. The formation of methoxylcarbonic acid contributes to ion generation and detection in positive-ion mode, but interferes with ionization in negative-ion mode.
ANALYTICA CHIMICA ACTA
(2023)
Article
Physics, Applied
Oguz Han Asnaz, Niklas Kohlmann, Hauke Folger, Franko Greiner, Jan Benedikt
Summary: This study uses a parallel-plate, low-pressure plasma to grow hydrogenated amorphous carbon nanoparticles using an argon-acetylene gas mixture. The effects of prolonged treatment with noble gas and reactive gas mixtures on the particles are investigated, and their size and surface morphology are analyzed using scanning electron microscopy. The results indicate that prolonged treatment with argon leads to an increase in particle size and incorporation of oxygen from gas impurities, while the reactive gas mixtures cause etching of the nanoparticle material without exchange reactions between deuterium and hydrogen atoms.
PLASMA PROCESSES AND POLYMERS
(2022)
Article
Physics, Fluids & Plasmas
R. Buschhaus, M. Prenzel, A. von Keudell
Summary: This study investigated the impact of ion-induced secondary electron emission on copper and nickel surfaces and found that the electron emission efficiency differs between oxidized and untreated surfaces, with oxidized surfaces having lower electron yields. A model for electron emission from partially oxidized surfaces was proposed, which agreed with the experimental data.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Coatings & Films
E. Jungling, K. Grosse, A. von Keudell
Summary: The ignition mechanism of nanosecond plasmas in liquids remains an open question. Researchers used intensified imaging and modeling to investigate the dynamics of these plasmas and found that the electric field plays a crucial role in the propagation of liquid streamers.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Physics, Fluids & Plasmas
M. George, W. Breilmann, J. Held, A. von Keudell
Summary: It has been found that in magnetron sputtering discharges, the movement of spokes can be controlled by applying an external control signal at a given frequency, resulting in a dual effect on ion flux. The ion flux towards the substrate increases by 15% regardless of the control frequency, and within a specific frequency range, an overall increase of ion flux towards the substrate of up to 30% can be achieved.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Fluids & Plasmas
J. Held, M. George, A. von Keudell
Summary: Spokes are observed in the magnetized region of DC magnetron sputtering, HiPIMS, and other discharges. Measuring spokes quantitatively is difficult due to their high velocities. However, synchronizing Langmuir probe measurements with the movement of spokes in DCMS allows for obtaining the probe current-voltage characteristics without averaging out the spoke influence. The plasma parameter modulation caused by spokes is revealed through the evaluation of the I-V curves. The comparison between DCMS and HiPIMS spokes shows that the modulation strength is weaker in HiPIMS due to the higher collision frequency of electrons.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Applied
Maren Dworschak, Niklas Kohlmann, Filip Matejka, Pavel Galar, Lorenz Kienle, Jan Schaefer, Jan Benedikt
Summary: The HelixJet plasma source was utilized to synthesize silicon nanoparticles (Si-NPs) operating under atmospheric pressure. By adjusting the operational parameters, Si-NPs with different sizes, crystallinity, structure, and photoluminescence properties were achieved. The addition of H-2 and high RF powers led to the formation of crystalline nanoparticles with strong photoluminescence intensity, which could be tuned by controlling the synthesis parameters. Post-synthesis annealing allowed for the synthesis of large crystalline nanoparticles. The study also involved design improvements for the HelixJet plasma source, enhancing its stability and enabling continuous long-term operation.
PLASMA PROCESSES AND POLYMERS
(2023)
Article
Physics, Applied
Simon Kreuznacht, Maximilian Purcel, Simon Boeddeker, Peter Awakowicz, Wei Xia, Martin Muhler, Marc Boeke, Achim von Keudell
Summary: This study investigates hydrogen production through plasma methane pyrolysis using a microwave plasma torch (MPT) and a gliding arc plasmatron (GAP). The performance of the two plasma sources is compared in terms of methane conversion, product spectrum, and energy efficiency. The physical and chemical properties of the produced carbon particles are also compared. The results show that the methane conversion is higher in the GAP compared to the MPT. Amorphous spherical carbon particles are produced in the volume of the plasma source in the MPT, while in the GAP, methane pyrolysis stops after the production of acetylene and the conversion of acetylene into solid carbon takes place on top of the electrode surfaces, leading to different characteristics of the carbon particles.
PLASMA PROCESSES AND POLYMERS
(2023)
Article
Physics, Fluids & Plasmas
C. Schulze, Z. Donko, J. Benedikt
Summary: A new method is presented for determining surface coefficients through energy-selective mass spectrometry measurements and numerical simulations, analyzing the bimodal peak structure in the ion flux-energy distribution function in a symmetric capacitively coupled plasma. The method allows for simultaneous determination of effective ion-induced secondary electron yield and effective elastic electron reflection coefficient under realistic plasma conditions, with good agreement to literature data.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Oguz Han Asnaz, Jonas Drewes, Marie Elis, Thomas Strunskus, Franko Greiner, Oleksandr Polonskyi, Franz Faupel, Lorenz Kienle, Alexander Vahl, Jan Benedikt
Summary: A novel combined setup of a Haberland type gas aggregation source and a secondary radio frequency discharge is used to generate, confine, and coat nanoparticles over much longer time scales than traditional in-flight treatment. The process is precisely monitored using localized surface plasmon resonance and Fourier-transform infrared spectroscopy as in situ diagnostics. Surface coating is shown to occur in two phases: first, singular seeds appear on the particle surface which then grow to cover the entire particle surface over 3 to 5 minutes.
NANOSCALE ADVANCES
(2023)
Article
Optics
T. A. Hahn, J. Benedikt, H. Kersten
Summary: The absolute densities of O and O-3 in the effluent of a kINPen are measured using molecular beam mass spectrometry. The use of a nitrogen gas curtain and different gas mixtures ensure stable conditions and higher densities of reactive species are generated when operated in argon. A new molecular beam chopper design has also been successfully tested in the setup.
EUROPEAN PHYSICAL JOURNAL D
(2023)
Article
Chemistry, Physical
He Li, Sadegh Askari, Jihao Wang, Niklas Wolff, Malte Behrens, Lorenz Kienle, Jan Benedikt
Summary: A noble-metal-free bifunctional electrocatalyst was developed through a facile strategy for rechargeable zinc-air batteries. The nitrogen-doped NiCo2O4 nanostructures on carbon paper exhibited enhanced electrocatalytic activities for oxygen evolution and reduction reactions. The plasma treatment optimized the N doping process without changing the morphology and specific surface area of the catalyst. The resulting air cathode showed improved stability and performance compared to noble-metal catalyst counterparts.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Engineering, Chemical
Soad Mohsenimehr, Achim von Keudell
Summary: This study investigates the application of surface dielectric barrier discharge (sDBD) in gas conversion, aiming to optimize the interaction between plasma and gas for improved mixing efficiency. Experimental results show that the electrode design induces significant plasma force on the fluid, resulting in the formation of vortices, which characterize the mixing process.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2023)
Article
Physics, Fluids & Plasmas
S. Thiemann-Monje, J. Held, S. Schuettler, A. von Keudell, V Schulz-von der Gathen
Summary: In magnetron sputtering discharges, ions and neutral particles exhibit high velocities in the azimuthal direction. The ion velocities increase with target distance. Experimental results are in good agreement with simulations, indicating that the momentum transfer from electrons to ions via Coulomb collisions is the main source of azimuthal acceleration.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
C. Stewig, L. Chauvet, A. von Keudell
Summary: This study investigates the complex interactions between catalyst, plasma, and oxygen through the plasma catalytic oxidation of n-butane. The catalyst enhances power coupling but also consumes oxygen atoms. Reactions between radicals and excited species from the plasma dominate the surface processes on the catalyst. However, despite the slight enhancement of n-butane oxidation with the catalyst, it is more efficient without the catalyst.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
Christian Schulze, He Li, Leonie Mohn, Martin Muller, Jan Benedikt
Summary: This study proposes a new plasma reactor chamber that allows for measurements of ion flux-energy distribution functions at high sheath potential. By adjusting the electrode geometry and diluting the working gas, the ion flux and ion energy can be controlled. This setup opens up possibilities for studying the effects of ion treatment on various substrates.
