Article
Materials Science, Ceramics
Anand Gupta, Shikhar Nigam, Vijay M. Shinde
Summary: The gas-phase thermal decomposition of BCl3+CH4+H-2 mixtures, which is important for the chemical vapor deposition of boron carbide, was modeled using a detailed chemical kinetic mechanism. A reduced mechanism was derived from the detailed mechanism to facilitate reactor design.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Nanoscience & Nanotechnology
Emily Jeng, Zhen Qi, Ajay R. Kashi, Sara Hunegnaw, Ziyang Huo, John S. Miller, Leonardus B. Bayu Aji, Byung Hee Ko, Haeun Shin, Sichao Ma, Kendra P. Kuhl, Feng Jiao, Juergen Biener
Summary: This study systematically investigated the effect of thickness and morphology of Cu catalyst coatings on electrochemical CO2 reduction (ECR) performance. The results showed that electron beam (EB) Cu outperformed magnetron-sputtered (MS) Cu in terms of current density, selectivity, and energy efficiency, with 400 nm thick catalyst coatings performing the best. The superior performance of EB-Cu catalysts was attributed to their faceted surface morphology and sharper Cu/gas diffusion layer interface.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Maciej Gubernat, Marcel Zambrzycki
Summary: The catalytic activity of K10 montmorillonite during the CVD of carbon nanotubes was investigated, and the influence of free iron on CNT synthesis was studied. Before Fe removal, K10-Mt was covered with pyrolytic carbon deposits, while after purification, regular forms of CNT were formed. Multi-walled carbon nanotubes were observed on the surface of pure K10-Mt, and after extraction of free iron, nucleation sites for CNT growth were identified.
APPLIED CLAY SCIENCE
(2021)
Article
Chemistry, Physical
I. Jenisha Daisy Priscillal, Sea-Fue Wang, Satoshi Kameoka
Summary: The aim of this work is to study the impact of catalytic reaction temperature on the properties of carbon nanotubes (CNTs) synthesized through catalytic chemical vapor deposition (CCVD). LaNi5Pt0.5 alloy catalyst was used to mediate the formation of CNTs at three different reaction temperatures. X-ray diffraction and Raman spectroscopy confirmed the successful formation of carbon material under the reported parameters. Field emission scanning electron microscopy and transmission electron microscopy verified the morphological diversity of CNTs produced at different reaction temperatures. A detailed study of the growth mechanism based on temperature and its influence on the catalyst bed and decomposition of the carbon source was proposed. The magnetic properties of the prepared CNTs were also investigated.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Jian Meng, Zhichao Miao, Jie Zhang, Zhao Wang, Runce Zhang, Leilei Xu, Lechen Diao, Jin Zhou, Shuping Zhuo
Summary: We synthesized a carbon nanotubes-en-capsulated Ni nanoparticles catalyst through a facile chemical vapor deposition approach for electrochemical CO2 reduction (ECR). The Ni@N-C catalyst exhibited the highest CO Faraday efficiency (FECO%) of 90% at -0.77 V vs. RHE in the H-type cell. Moreover, it showed a high FECO% of over 93% within the range of -0.37 to -0.77 V vs. RHE in the flow cell. The excellent catalytic performance of Ni@N-C suggests that N-doped carbon nanotubes coated on Ni nanoparticles play a vital role in promoting ECR activity. This work provides insights into the development of a simple and efficient electrocatalyst for ECR.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Analytical
N. Harith, R. S. R. M. Hafriz, N. A. Arifin, Ee Sann Tan, A. Salmiaton, A. H. Shamsuddin
Summary: Co-pyrolysis is an effective method to utilize plastic waste and generate oil, gas, and char. This study found that doping dolomite with transition metals can improve the yield and quality of oil in co-pyrolysis.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2022)
Article
Chemistry, Physical
Xueting Zhang, Liu Qian, Xiaojing Yao, Lili Zhang, Qianru Wu, Dong Li, Chen Ma, Nan Zhao, Liantao Xin, Chang Liu, Xiuyun Zhang, Jin Zhang, Maoshuai He
Summary: The past two decades have seen significant progress in the catalytic synthesis of single-walled carbon nanotubes (SWNTs) using non-conventional nanoparticles. This study presents the use of a solid magnesia (MgO) supported ruthenium (Ru) catalyst for chemical vapor deposition (CVD) growth of SWNTs. The results show successful synthesis of enriched (6, 5) SWNTs at high temperatures, partially attributed to the high activity of Ru clusters. The study also reveals the mechanism behind the activation of Ru clusters through charge transfer from the MgO support.
Article
Chemistry, Physical
Angie Quevedo, Juan Bussi, Nestor Tancredi, Rosalba Fuentes-Ramirez, Rosario Galindo, Juan L. Fajardo-Diaz, Florentino Lopez-Urias, Emilio Munoz-Sandoval
Summary: The combination of different nanomaterials, such as La2Zr2O7 (LZO) and NiO, can be used as a catalyst for carbon nanotube fabrication. In this study, N-doped multiwalled carbon nanotubes were successfully produced using Ni/LZO material, exhibiting bamboo shape morphology and ferromagnetic behavior.
Article
Energy & Fuels
Ivan Pedroarena, Lucia Grande, Jonathan J. Torrez-Herera, Sophia A. Korili, Antonio Gil
Summary: This research investigates the interactions between alumina-supported nickel catalysts and other metals, and their impact on the catalyst's performance. The reduction capacity of oxide phases has been analyzed, revealing that Pd facilitates the formation of easily reducible NiO species. Furthermore, the impregnation order of Mo and Pd does not significantly affect the catalysts' properties.
Review
Chemistry, Multidisciplinary
Peng-Xiang Hou, Feng Zhang, Lili Zhang, Chang Liu, Hui-Ming Cheng
Summary: The FCCVD is an important technique for synthesizing high-quality CNTs with various morphologies, offering advantages of simplicity, controllability, and scalability. Researchers review the controlled growth, properties, and applications of CNTs, discussing key challenges and prospects for the future.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Meruyert Nazhipkyzy, Renata R. Nemkayeva, Araylim Nurgain, Aigerim R. Seitkazinova, Balaussa K. Dinistanova, Almagul T. Issanbekova, Nurzhamal Zhylybayeva, Nurgul S. Bergeneva, Gulnar U. Mamatova
Summary: This article investigates the synthesis of multiwalled carbon nanotubes on the surface of diatomite mineral using a chemical vapor deposition method. The effects of catalyst concentration and synthesis temperature on the formation and morphology of carbon nanotubes are studied. Diatomite, chosen as a catalyst carrier due to its elemental composition, consists mainly of amorphous silica, quartz, and various metals.
Article
Chemistry, Physical
Daniel Rui Chen, Paa Kwasi Adusei, Megha Chitranshi, Yanbo Fang, Kevin Johnson, Mark Schulz, Vesselin Shanov
Summary: By utilizing electrochemical activation to chemically functionalize the surface of CNTs, the active material density was increased, showing significant improvement in the charge storage capacity and energy storage performance of CNT-PANI composite material. The fabricated device with PVDF-EMIMBF4 electrolyte exhibited a volumetric energy density of 833.3 mu M/h/cm(3) at a current density of 0.5 mA/cm(2) and demonstrated good mechanical flexibility with high capacitance retention (75% after 5000 cycles), showcasing the advantages of the electrochemical activation method.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Leonid Filatov, Pavel Vishniakov, Ilya Ezhov, Ivan Gorbov, Denis Nazarov, Denis Olkhovskii, Rajesh Kumar, Shengjie Peng, Gang He, Vladislav Chernyavsky, Marina Gushchina, Maxim Maximov
Summary: This article investigates the impact of atomic layer deposition method on the growth of carbon nanotubes, and found that the initial NiO layer thickness plays a significant role in achieving intensive growth of carbon nanotubes.
Article
Chemistry, Multidisciplinary
Thuan Minh Huynh, Sura Nguyen, Ngan Thi Kim Nguyen, Huan Manh Nguyen, Noa Uy Pham Do, Danh Cong Nguyen, Luong Huu Nguyen, Cattien V. Nguyen
Summary: The synthesis of carbon nanotubes using methane as a carbon source via chemical vapor deposition on a stainless-steel foil catalyst revealed that the catalyst pretreatment temperature significantly influences the formation of CNTs and their diameter. A shorter pretreatment time results in the growth of semiconducting CNTs, while a longer pretreatment time leads to the formation of metallic CNTs, providing insights for improving the quality of CNTs grown on steel foil catalysts.
Article
Energy & Fuels
Fanghui Wang, Xiaoran Wang, Zhijun Guo, Jinghua Yu, Hong Zhu
Summary: A Mo-PtCu catalyst with an octahedral morphology was prepared through a hydrothermal reaction, showing higher catalytic activity and durability due to the addition of Mo. The Mo0.02-PtCu/C catalyst exhibited improved mass activity, excellent oxygen reduction reaction rate, and durability, with a small amount of Mo preventing platinum and copper atoms from dissolving, thus enhancing the ORR performance of the catalyst.
Article
Chemistry, Physical
Dmitry Levshov, Marina Avramenko, Maksiem Erkens, Huy-Nam Tran, Thi Thanh Cao, Van Chuc Nguyen, Emmanuel Flahaut, Valentin N. Popov, Ahmed-Azmi Zahab, Jean-Louis Sauvajol, Raul Arenal, Wim Wenseleers, Sofie Cambre, Matthieu Paillet
Summary: Measuring electronic Raman scattering (ERS) has become a efficient method for structural characterization of metallic single-wall carbon nanotubes (SWCNT), but its application to other types of SWCNT-based structures, such as double-wall carbon nanotubes (DWCNT), is not well studied. In this work, the authors combine electron diffraction, Rayleigh and Raman spectroscopies to investigate the ERS process in 21 individual DWCNTs with different electronic configurations. They observe partial suppression of ERS intensity in DWCNTs compared to SWCNTs, mainly due to dielectric screening of Coulomb interactions. Based on their experimental findings, the authors propose an adapted method for structural identification of DWCNT samples from ERS data, which can be applied to characterize emerging 1D VDW heterostructures based on metallic SWCNTs.
Article
Nanoscience & Nanotechnology
Nadzeya Valynets, Alesia G. Paddubskaya, Vitalii Sysoev, Dmitriy Gorodetskiy, Lyubov G. Bulusheva, Alexander Okotrub
Summary: We propose a novel laser treatment technique for fabricating grating metasurfaces using fluorinated graphene (FG) films, which significantly enhances their terahertz transmission properties. The treatment transforms the insulating FG into conductive material, resulting in a DC conductivity of 170 S·m(-1) in the treated areas. The resonance transmittance of the metasurfaces, studied using THz time-domain spectroscopy in the 100 GHz-1 THz frequency range, shows enhancement and tunability by changing the metasurface geometry. The fabricated metasurfaces also demonstrate efficient narrowband polarization rotation of 50 degrees.
Article
Chemistry, Physical
Vitalii I. Sysoev, Ruslan D. Yamaletdinov, Pavel E. Plyusnin, Alexander V. Okotrub, Lyubov G. Bulusheva
Summary: We report the fabrication of high-performance NO2 gas sensors based on oxyfluorinated graphene (OFG) layers. The sensors can detect NO2 molecules at sub-ppm level with a sensitivity of 0.15 ppm(-1). The presence of fluorine- and oxygen-containing groups on the graphene surface provides low-energy sites for NO2 adsorption.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Anna A. Vorfolomeeva, Svetlana G. Stolyarova, Igor P. Asanov, Elena V. Shlyakhova, Pavel E. Plyusnin, Evgeny A. Maksimovskiy, Evgeny Yu. Gerasimov, Andrey L. Chuvilin, Alexander V. Okotrub, Lyubov G. Bulusheva
Summary: This study compares the electrochemical performance of commercial single-walled carbon nanotubes (SWCNTs) with red phosphorus deposited on the outer surface and/or encapsulated in internal channels for lithium-ion batteries. Encapsulated phosphorus demonstrates higher reaction rates and slight loss of initial capacity compared to external phosphorus. The support of SWCNTs and tubular space contribute to the stable operation and formation of chain phosphorus structures.
Article
Electrochemistry
Yuliya V. Fedoseeva, Elena V. Shlyakhova, Anna A. Vorfolomeeva, Mariya A. Grebenkina, Vitalii I. Sysoev, Svetlana G. Stolyarova, Evgeny A. Maksimovskiy, Anna A. Makarova, Alexander V. Okotrub, Lyubov G. Bulusheva
Summary: In this work, mesopore-enriched nitrogen-doped carbon (NC) materials were synthesized using template-assisted chemical vapor deposition. The best electrochemical performance was observed in the NC-650 sample, which delivered a discharge capacity of 182 mA center dot h center dot g(-1) in sodium-ion batteries and 1158 mA center dot h center dot g(-1) in lithium-ion batteries at a current density of 0.05 A center dot g(-1). The study reveals the important role of defect sites in the binding and accumulation of sodium, providing a strategy for optimizing the carbon structure and nitrogen states to enhance the alkali-metal-ion storage capacity and cycling stability of NC materials.
Review
Chemistry, Physical
Mathieu Leroy, Emmanuel Flahaut, Camille Larue
Summary: The use of carbon based nanomaterials (CNMs) in various sectors is increasing, leading to their inevitable release into the environment. Terrestrial ecosystems, especially agrosystems, are considered major sinks for CNMs due to their accumulation in sewage sludge used for crop production. This study raises questions about the current risk assessment paradigm regarding the additive effects of a cocktail of contaminants and explores strategies to ensure food safety.
Article
Chemistry, Physical
E. S. Kobeleva, M. N. Uvarov, N. V. Kravets, S. A. Ponomarev, O. A. Gurova, A. V. Okotrub, M. S. Kazantzev, K. M. Degtyarenko, L. V. Kulik
Summary: Highly dispersed fluorinated SWCNTs of submicron length were used as nonvolatile additives in polymer/fullerene organic solar cells, resulting in reproducible improvements in the main performance parameters of the cells. The improvements are attributed to the geometric optimization of the active layer morphology by fluorinated SWCNTs, rather than modifications in the electronic structure or charge transfer. The absence of large CNT aggregates and metallic SWCNTs was confirmed through atomic force microscopy and optical spectra analysis.
FULLERENES NANOTUBES AND CARBON NANOSTRUCTURES
(2023)
Article
Chemistry, Physical
Mariya A. Grebenkina, Galina N. Chekhova, Dmitry V. Pinakov, Yury V. Shubin, Igor P. Asanov, Lyubov G. Bulusheva, Alexander Okotrub
Summary: The dielectric properties of fluorinated graphites with different fluorine contents and embedded bromine molecules were studied by impedance spectroscopy. The contributions of the fluorinated graphite matrix and bromine guests to the dielectric permittivity were estimated using the Maxwell-Garnett approximation. The permittivity of the fluorinated graphite matrix increased with decreasing fluorine content and was not temperature-dependent. The change in permittivity upon cooling/heating was caused by the polarization of bromine molecules. The temperature-dependent dielectric response of fluorinated graphite with a fluorine content of 0.60 was attributed to the formation of bromine and polybromide ions in the interlayer space, with a decrease in permittivity at low temperatures due to the freezing of ion mobility.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Alexander Okotrub, Dmitriy Gorodetskiy, Yuri N. Palyanov, Dmitry A. Smirnov, Lyubov G. Bulusheva
Summary: By controlling the transformation process of diamond into graphite at elevated temperatures, sp2/sp3 carbon hybrids can be created. This study examines the effect of a thin iron film coating on the reconstruction of a (100) diamond face. Various spectroscopic and microscopy techniques were used to analyze the electronic and structural changes on the diamond surface. The results show the formation of thin sp2-carbon fragments on the clean diamond surface and ordered graphite planes on the iron-coated surface. Iron catalyzes the transformation of diamond into graphitic layers growing vertically relative to the (100) face.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Mauricio Pavia, Melanie Emo, Fahad Alnjiman, Enrico Andreoli, Jean-Francois Pierson, Emmanuel Flahaut, Ewa Kazimierska, Brigitte Vigolo
Summary: This work explores a novel approach to disperse purified double-walled carbon nanotubes in high ionic strength aqueous media, i.e. a copper ion solution, to further prepare double-walled carbon nanotubes/Cu composites by co-electrodeposition. The capability of different surfactants to disperse the carbon nanotubes in the copper ion solution is analyzed, and Pluronic-P123 shows the best dispersive level. The dispersion mechanism suggests that the hydrophobic nature of Pluronic-P123 promotes efficient steric repulsions, enabling stable dispersion in the copper electrolyte.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Valentina Castagnola, Lieselot Deleye, Alice Podesta, Edra Jaho, Fabrizio Loiacono, Doriana Debellis, Martina Trevisani, Dinu Zinovie Ciobanu, Andrea Armirotti, Francesco Pisani, Emmanuel Flahaut, Ester Vazquez, Mattia Bramini, Fabrizia Cesca, Fabio Benfenati
Summary: Due to their biocompatibility and high cargo capability, graphene-based materials are considered as an ideal brain delivery system. In this study, we used two in vitro models to investigate the interactions between graphene oxide and few-layer graphene with the blood-brain barrier. Our results show that the two graphene materials have good biocompatibility and do not significantly affect the integrity and functionality of the barrier, but their translocation across the barrier is rare.
Article
Chemistry, Physical
Alexander V. V. Okotrub, Olga V. V. Sedelnikova, Dmitriy V. V. Gorodetskiy, Anastasiya D. D. Fedorenko, Igor P. P. Asanov, Yury N. N. Palyanov, Alina V. V. Lapega, Olga A. A. Gurova, Lyubov G. G. Bulusheva
Summary: This study investigates the interaction between diamond and metals as well as the interface structure, especially at elevated temperatures. The experiments reveal uniform coating of titanium on the diamond surface and the formation of flattened molybdenum nanoparticles. Titanium is completely oxidized and transforms into a carbide state upon annealing, while molybdenum interacts with the diamond surface, leading to the carbidization of nanoparticles and catalytic graphitization. The conductivity of the resulting sample is improved compared to Ti-coated diamond substrates and Mo-coated (111) substrates annealed at 800 degrees C. These findings are valuable for the development of graphene-on-diamond electronics.
Article
Chemistry, Multidisciplinary
Ruben Acevedo, Brigitte Soula, Anne Marie Galibert, Emmanuel Flahaut
Summary: Oxidized carbon nanotubes were filled with an aqueous solution of nano-energetic materials using a simple impregnation method. The study compared different energetic materials, with a focus on an inorganic compound belonging to the Werner complexes. The research showed a significant increase in released energy upon heating, which was attributed to the confinement of the nano-energetic material either by filling the inner channel of carbon nanotubes or insertion in the triangular channels between adjacent nanotubes when they form bundles.
Article
Chemistry, Multidisciplinary
Petr Rozhin, Slavko Kralj, Brigitte Soula, Silvia Marchesan, Emmanuel Flahaut
Summary: Supramolecular hydrogels formed from simple peptides can be improved by the addition of carbon nanomaterials, although their interaction with the peptide structure needs to be investigated. This study compares the performance of single-walled and double-walled carbon nanotubes as additives for a tripeptide hydrogel, with the latter showing superior results. Various spectroscopic techniques, thermogravimetric analysis, microscopy, and rheology data provide detailed insights into the structure and behavior of these nanocomposite hydrogels.
Article
Chemistry, Physical
Vitalii I. I. Sysoev, Olga A. A. Gurova, Yuliya V. V. Fedoseeva, Artem V. V. Gusel'nikov, Anna A. A. Makarova, Alexander V. V. Okotrub, Lyubov G. G. Bulusheva
Summary: The effect of humidity on the electrical conductivity of SWCNT films depends on both the conductivity of individual nanotubes and the electrical contacts between them. Non-functionalized SWCNTs and contacts between them exhibit decreased conductivity upon adsorption of water molecules. Covalent fluorination reduces the conductivity of SWCNTs and increases the sensitivity of the film to low concentrations of water vapor. Nitrogen-containing groups added through substitution reactions improve intertube contacts and increase the surface area for water adsorption. Increasing the number of functional groups on the SWCNT surface enhances the sensor's sensitivity to low water concentrations but worsens the response at high humidity.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
