Synthesis Of Carbon Nanomaterials Research Articles

Copper-catalyzed plastic waste synthesized graphene nanosheets/polypyrrole nanocomposites for efficient thermoelectric applications

Presently, various catalysts have been reported for the synthesis of carbon nanomaterials from a variety of plastic waste, which needs to be removed at the end of the synthesis process by using chemical techniques and hence make the process more typical from the aspect of cost-benefit and circular economic aspects. Herewith, we report copper turnings as the cost-effective and greener catalytic templates for synthesizing highly conducting graphene nanosheets (GNs). The synthesis of the GNs from plastic waste was done as we previously reported in the steps of the pyrolytic process, where the copper turnings are used as catalytic templates in the present study. Because of the excellent catalytic efficiency towards breaking old carbon-carbon bonds and forming new carbon-carbon bonds, the copper turnings act as an excellent degradation catalyst and promote the growth of graphitic skeletons and, consequently, graphene nanosheets. The synthesized GNs showed a high conductivity of ∼ 1730 S/m. GNs thus synthesized is implemented for synthesizing GNs/polypyrrole nanocomposites, which is later investigated for the TE applications. The values of the Seebeck coefficient showed that the composite of GNs/polypyrrole performs as a p-type semiconductor. The TE figure of merit (ZT) for GNs/polypyrrole demonstrated good thermoelectric characteristics and showed a value of 3.75 × 10−6 at the temperature. Thus, the present method of synthesis of GNs showed a more convenient, industrial friendly technique for the production of plastic waste derived graphene nanosheets and its application for thermal energy conversion applications.

Green synthesis of carbon nanomaterials from Chondrus crispus and Palmaria palmata algae biomass for ciprofloxacin and malachite green uptake from water

Green synthesis of carbon nanomaterials from Chondrus crispus and Palmaria palmata algae biomass for ciprofloxacin and malachite green uptake from water

Importance of gas heating in capacitively coupled radiofrequency plasma-assisted synthesis of carbon nanomaterials

Importance of gas heating in capacitively coupled radiofrequency plasma-assisted synthesis of carbon nanomaterials

Fabrication of Novel Carbon-based Polymers by On-surface Cycloaromatization of Isopropyl Substituents

Surface-catalyzed reactions have been employed for the synthesis of carbon nanomaterials featuring precisely defined atomic structures. A recent breakthrough involves the gold surface-catalyzed [3 + 3] cycloaromatization of isopropyl-substituted arenes, allowing for on-surface synthesis of novel carbon-based polymers[1-3]. In this process, the surface plays a crucial role in activating the isopropyl substituents, facilitating the formation of phenylene rings through intermolecular coupling. For instance, such investigations might open new avenues in the field of carbon magnetism, which has gained an increased attention in view of the recent progress made in the synthesis and characterization of open-shell polycyclic aromatic hydrocarbons[2]. Under this scenario, the comprehensive fabrication of magnetic polymers emerges as a highly appealing field of research.Here, we introduce exemplary approaches toward the bottom-up fabrication of different carbon-based polymers homocoupled via surface-catalyzed [3 + 3] cycloaromatization of isopropyl substituents studied on Au(111) under ultra-high vacuum (UHV) conditions. The chemical structures of the polymers have been clearly elucidated by non-contact atomic force microscopy (nc-AFM). Scanning tunneling spectroscopy (STS), complemented by computational investigations reveals their ground state. Our approach can be a highly relevant step towards the on-surface synthesis of covalently linked 1D organic polymers with prospects in sensing, catalysis and nanoscale spintronic devices.

On-Surface Covalent Synthesis of Carbon Nanomaterials by Harnessing Carbon gem-Polyhalides.

The design of innovative carbon-based nanostructures stands at the forefront of both chemistry and materials science. In this context, π-conjugated compounds are of great interest due to their impact in a variety of fields, including optoelectronics, spintronics, energy storage, sensing and catalysis. Despite extensive research efforts, substantial knowledge gaps persist in the synthesis and characterization of new π-conjugated compounds with potential implications for science and technology. On-surface synthesis has emerged as a powerful discipline to overcome limitations associated with conventional solution chemistry methods, offering advanced tools to characterize the resulting nanomaterials. This review specifically highlights recent achievements in the utilization of molecular precursors incorporating carbon geminal (gem)-polyhalides as functional groups to guide the formation of π-conjugated 0D species, as well as 1D, quasi-1D π-conjugated polymers, and 2D nanoarchitectures. By delving into reaction pathways, novel structural designs, and the electronic, magnetic, and topological features of the resulting products, the review provides fundamental insights for a new generation of π-conjugated materials.

Unveiling the pathways of ethanol decomposition to carbon radicals by nanosecond pulse bubble discharge in liquid: a two-step hybrid model

In recent years, bubble discharge in liquid has become a novel approach for the synthesis of carbon nanomaterials; however, the fundamental discharge process and synthesis mechanism are still not well understood. In this work, we build a two-step simulation model (combining 2D fluid dynamics and zero-dimensional plasma kinetics) to investigate nanosecond pulse discharge in an Ar bubble immersed in liquid ethanol and chemical reaction processes inside. The 2D simulation results show that discharge develops along the gas‒liquid interface where ethanol decomposes, resulting in much higher densities of active species (CH3, C2H5 and OH). The electric field of the selected reference point near the interface obtained by the 2D model is transmitted into the 0D model. The numerical results show that the decomposition of ethanol mainly occurs at the discharge stage, in which electron impact dissociation (e.g. C2H5OH + e → CH2OH + CH3 + e) and Penning dissociation (e.g. C2H5OH + Ar* → CH2OH + CH3 + Ar) dominate. The density of all carbonaceous species rapidly increases during discharge, while that of some carbon radicals (CH and C) continues to increase due to neutral species reactions when discharge ceases. By quantitative analysis of the reaction contributions, the dominant pathways of C2, CH and C are revealed, i.e. C2H5OH → C2H5 → [C2H, C2H2, C2H3] → C2 and C2H5OH → CH3 → CH2 → CH → C. In addition, the formation pathways of H and OH radicals, which are indispensable for the transformation of carbonaceous intermediates, are also analysed.

In-Situ Flame-Synthesized Carbon Nanomaterials via an Impinging Swirl Flow with an N-Butanol Pool

ABSTRACT This study aims to investigate the impact of flow rotation and oxygen concentration on the synthesis of carbon nanomaterials using n-butanol diffusion flames in a rotating stagnation flow with a liquid pool and a catalytic Ni substrate. With increasing angular velocity (ω), the diffusion flame shifts slightly toward the upper oxidizer nozzle, experiences a lower strain rate, and becomes stronger with a higher maximum flame temperature at a fixed oxygen concentration (ΩO). Meanwhile, the soot layer thickens and gradually turns yellowish. Field Emission Scanning Electron Microscopy (FESEM) analyses confirm that carbon nanotubes (CNTs) can only be fabricated at ω = 2 or 3 rps when ΩO = 21%, highlighting the critical role of flow rotation. Interestingly, the optimal positions for CNT synthesis consistently occur at the same sampling position (1.5 mm below the upper edge of the blue flame) for all values of oxygen concentration (ΩO). The corresponding temperature ranges for ΩO = 19%, 18%, and 17% are approximately 950°C, 820–920°C, and 800–850°C, respectively, which align with existing literature. High-resolution transmission electron microscopy (HRTEM) images reveal both typical straight tubular and bamboo-like CNT structures. Raman spectra indicate superior graphitization at high angular velocities (ω). Notably, at ω = 0 rps, the intensity ratio of the D- and G-bands is greater than 1 (ID/IG >1); however, as ω increases, the opposite holds (ID/IG <1), with its value gradually decreasing. This suggests that the swirl effect enhances graphite layer crystallization. Importantly, the strain rate controlled by flow rotation significantly influences CNT fabrication, considering both residence time and carbon source. The key finding of this study is that swirl flow enhances both the quality and quantity of CNTs synthesized via n-butanol diffusion flames.

Получение порошковых углеродных композитных наноматериалов термическим разложением ароматических карбоксилатов Fe (III)

The article discusses the principal methods for obtaining carbon composite nanomaterials and highlights the thermolysis method as one of them. In order to understand the essence of thermal decomposition processes as a method for synthesis of carbon nanomaterials, aromatic iron(III) carboxylates have been considered. These are iron(III) 8-hydroxyquinolinate, benzoate, salicylate, phthalate, and p-aminobenzoate. The article discusses the procedure for the synthesis of these iron(III) carboxylates under standard conditions in detail. The thermal decomposition process was carried out in two media (air as oxidizing one and argon as neutral one) to compare the obtained products. For a detailed study of the processes of decomposition of iron(III) carboxylates, the thermal analysis methods (TG and DSC) were used on a Netzsch 449 Jupiter synchronous thermal analyzer. In order to study the morphology and composition of the products, X-ray phase analysis, optical and scanning electron microscopy, as well as X-ray fluorescence microanalysis were used. We used a Rigaku Ultima IV X-ray diffractometer and a scanning electron microscope with a Jeol JSM-7001F elemental microanalysis attachment. Based on the obtained results, the expected formulas of the initial iron(III) carboxylates were calculated. The mechanisms of the processes occurring during the thermal decomposition of iron(III) aromatic carboxylates were also proposed. For a more accurate determination of the composition of the synthesized iron(III) carboxylates and a more appropriate description of the processes of thermal decomposition of these salts, the corresponding aromatic carboxylic acids were also subjected to thermal decomposition. The appendix to the article contains the data for a more accurate interpretation of the results and a more detailed description of the thermal decomposition processes.

Synthesis of Newly Discovered Carbon Nanoframes: A Self‐Assembly Strategy Based on DTAB @ NaCl

AbstractCarbon nanomaterials have attracted much attention in the field of science and technology for their excellent properties; however, developing a simple, environmentally friendly, and versatile synthesis strategy for the preparation of carbon nanomaterials with novel structures remains a great challenge. Herein, a surfactant @ salt (dodecyltrimethylammonium bromide DTAB @ NaCl) self‐assembly strategy for the synthesis of carbon nanomaterials with novel structures, i.e., carbon nanoframes is reported. The synthesis differs from the traditional template method in that it is characterized by the introduction of surfactants for separation and protection, and the salt can be recycled. In addition, the carbon frame size in this system can be adjusted on demand by simply adjusting the concentration of surfactant, thus realizing that the carbon nanoframe size is adjustable in the range of 232.58–322.51 nm. Impressively, the carbon nanoframe has purple, blue, and green PL emission behavior. It is anticipated that this research will provide new insights into the development of novel carbon nanomaterials.

An electron transfer tuning strategy for the efficient degradation of tetracycline hydrochloride by Fe-N co-doped carbon materials activated with peroxymonosulfate

In order to address the problems of metal leaching and low electron transfer efficiency, the iron (Fe) nitrogen (N) co-doped MOFs derived carbon catalysts presented a promising strategy to activate peroxymonosulfate (PMS) for water purification. In this work, using the MOF-5 as a template and iron phthalocyanine (FePc) and dicyandiamide (DCD) as a source, Fe, N co-doped carbons were prepared through milling and two-step pyrolysis. The catalytic performance and mechanism of the materials on tetracycline hydrochloride (TC) degradation in the PMS activation system (0.1Fe/N-CPMS) was systematically investigated. The results showed that the stable framework structure of MOFs-derived carbon conduced to encapsulate the Fe nanoparticles within the carbon skeleton, and then the xFe/N-C catalyst with hierarchical pore structure and good electrical conductivity was obtained, which significantly improved the TC catalytic performance. Notably, the 0.1Fe/N-C exhibited the greatest degradation performance achieving a degradation rate of 0.6315 min-1, which was approximately five times higher than that of N-C. Moreover, the degradation performance of the 0.1Fe/N-C kept the stability in various interference conditions, and still remained over 80% after three cycles test. Combine with the characterization and DFT calculation, the mechanism of the TC degradation in 0.1Fe/N-CPMS system was revealed by a non-radical process dominated by electron transfer, and the degradation efficiency was greatly improved by the synergistic effect of Fe/N on the as-prepared material. The received findings provide an electron transfer tuning strategy of Fe/N co-doped carbon nanomaterials synthesis for promoting the non-radical degradation pathways in the application of organic pollutants removal.

Flow variation impact in the synthesis of carbon nanomaterials from polystyrene recycling

Flow variation impact in the synthesis of carbon nanomaterials from polystyrene recycling

SYNTHESIS OF NITROGEN-CONTAINING CARBON BY SOLUTION PLASMA PROCESS AT VARIOUS PULSE REPETITION RATES

The solution plasma process (SPP) has attracted considerable attention for the synthesis of carbon nanomaterials; the SPP uses electrical discharges generated directly by a bipolar pulsed power supply for various combinations of the solvents and solutes in the solution. However, the SPP requires high-temperature heat treatment for enhancing conductivity and exhibiting catalyst activity. Furthermore, the metal used as the electrode in the SPP is generally sputtered during discharge. This study presents the feasibility of reducing the heat-treatment step and solving the problem of sputtering of the metal electrodes by simply increasing the repetition frequency of the bipolar pulsed power. During synthesis, the pulse frequency acts as the graphitization catalyst. The enhancement of crystallinity was further confirmed by X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM). The findings of this study are expected to contribute toward research on improving the properties of carbon for various applications of the SPP synthesis methods.

Recent Advances and Outlook in Nanotechnology

Presented work summarizes recent results of Institute of combustion problems in the field of synthesis of carbon nanomaterials and their application in various areas during the last 5 years: energy intensive nanocarbon materials; electroreduction of AuCl4- in the case of gold electrosorption using activated carbon; bio-waste-derived few-layered graphene/SrTiO3/PAN as an efficient photocatalytic system for water splitting; graphene based membranes for desalination; development and study of perovskite photocatalysts for hydrogen evolution; obtaining of biologically soluble membranes based on polymeric nanofibres and hydroxyapatite of calcium.

Non-emission hydrothermal low-temperature synthesis of carbon nanomaterials from poly (ethylene terephthalate) plastic waste for excellent supercapacitor applications

ABSTRACT Poly(ethylene terephthalate) (PET) has a wide range of applications that generate a lot of waste globally; thus, upcycling PET is important because it offers several industrial and economic advantages. This study describes a sustainable, emissions-free process for converting PET plastics into carbon nanomaterials (CNMs) named PT-nano powder. The thermal-hydrothermal method has employed the production of PT-nano powder above the glass transition temperature (Tg) of PET plastics. Under optimal conditions, PET plastics were efficiently converted into PT-nano powder with 86.6% crystallinity and an average particle size of 6.5 nm. The PT-nano powder was characterized for physical and chemical properties using different techniques, including UV-Vis, FTIR, Raman spectroscopy, XRD, FESEM, TEM, and proton NMR analysis. The characterization confirms the complete conversion of PET to solid fractions of carbon nanomaterial. The PT-nano powder was tested in supercapacitor performance application with electrochemical characterization. The symmetric fabrication showed a specific capacitance of 250.8 F/g, energy density of 34.83Wh/kg, and power density of 999.9W/kg with a current density of 0.5A/g. The device fabrication exhibited high cycle stability and high capacitance retention of 96.8% with a current density of 1.5A/g after 10000 cycles.

Особенности термолиза ароматических карбоксилатов Cr (III)

The article discusses the main methods for obtaining carbon composite nanomaterials and highlights the thermolysis method as one of the main methods. To understand the essence of thermal decomposition processes as a method for synthesis of carbon nanomaterials, chromium (III) aromatic carboxylates have been considered. These are chromium (III) 8-hydroxyquinolinate, benzoate, salicylate, phthalate, and p-aminobenzoate. The article thoroughly discusses the procedure for the synthesis of these chromium (III) carboxylates from the most common inorganic chromium (III) salts under simple conditions. The thermal decomposition process was carried out in two environments (in oxidizing air and neutral argon), the obtained products were compared. For a detailed study of the processes of decomposition of chromium (III) carboxylates, thermal analysis methods (TG and DSC) were used on a Netzsch 449 Jupiter synchronous thermal analyzer. To study the morphology and composition of the products, the methods of X-ray phase analysis, optical and scanning electron microscopy, and X-ray fluorescence microanalysis were used. We used a Rigaku Ultima IV X-ray diffractometer and a scanning electron microscope with a Jeol JSM-7001F elemental microanalysis attachment. On the basis of the obtained results, the estimated formulas of the initial chromium (III) carboxylates were calculated. The mechanisms of the processes occurring during the thermal decomposition of chromium (III) aromatic carboxylates were also proposed. For a more accurate determination of the composition of the synthesized chromium (III) carboxylates and a more accurate description of the processes of thermal decomposition of these salts, the corresponding aromatic carboxylic acids were also subjected to thermal decomposition. The appendix to the article contains all the obtained data for a more accurate interpretation of the results and a more detailed description of the thermal decomposition processes.

A review of the recent trend in the synthesis of carbon nanomaterials derived from oil palm by-product materials.

Grown only in humid tropical conditions, the palm tree provides high-quality oil essential for cooking and personal care or biofuel in the energy sector. After the refining process, this demand could cause numerous oil palm biomass waste management problems. However, the emergence of carbon nanomaterials or CNMs could be a great way to put this waste to a good cause. The composition of the palm waste can be used as a green precursor or starting materials for synthesizing CNMs. Hence, this review paper summarizes the recent progress for the CNMs production for the past 10 years. This review paper extensively discusses the method for processing CNMs, chemical vapor deposition, pyrolysis, and microwave by the current synthesis method. The parameters and conditions of the synthesis are also analyzed. The application of the CNMs from palm oil and future recommendations are also highlighted. Generally, this paper could be a handy guide in assisting the researchers in exploring economic yet simple procedures in synthesizing carbon-based nanostructured materials derived from palm oil that can fulfill the required applications.Graphical abstract

Carbon Erosion of a Bulk Nickel\u2013Copper Alloy as an Effective Tool to Synthesize Carbon Nanofibers from Hydrocarbons

Carbon erosion of bulk metals and alloys in a carbon-containing atmosphere can be used as an effective tool for the targeted synthesis of carbon nanomaterials. In this study, a set of bulk Ni0.89Cu0.11 (11 at % Cu) alloys has been synthesized by the mechanochemical alloying of metal powders in an Activator 2S planetary mill. The synthesized samples have been studied as precursors of catalyst for the synthesis of carbon nanofibers (CNFs) from ethylene at 550°C. The effect of the activation time on the particle morphology and phase composition of the alloys, the kinetics of growth, and the carbon product yield in C2H4 decomposition has been studied. For the most active samples, the CNF yield has exceeded 100 g/gcat within 30 min of reaction. The early stage of carbon erosion of a bulk Ni0.89Cu0.11 alloy has been studied by electron microscopy methods. It has been found that the nucleation of carbon fiber growth active sites occurs during a short-term contact of the sample with the reaction mixture (less than 1 min); the complete disintegration of the alloy is observed in a few minutes. The carbon product is represented by nanofibers having a submicrometer diameter and characterized by a dense “stacked” and coaxial-conical packing of graphene layers. The material has a developed specific surface area (140–170 m2/g) and a low bulk density (less than 30 g/L).

Study of the carbon nanomaterials synthesis on the cement binder

Study of the carbon nanomaterials synthesis on the cement binder

Microwave-assisted pyrolysis for carbon catalyst, nanomaterials and biofuel production

The current scenario of environment urgently needs alternative biologically synthesized fuels, value-added products, and preparation of catalyst to create a pollution free environment. Usually, several methods are available for the synthesis of various commodities from many biological resources. Microwave-assisted pyrolysis (MAP) is a relatively new process and has emerged as a promising technique to transform biomass feedstock into biofuels, including bio-oil, syngas and biochar. This paper provides a state-of-art review on MAP of several wastes such as lignocellulosic biomass, waste oils, municipal solid waste and electronic waste, discussing on the biofuels produced (bio-oil, syngas and biochar) as well as the synthesis of carbon nanomaterials (carbon nanotubes and carbon nanofibers). The use of microwave adsorbent and catalyst in MAP process are reviewed, including utilization of biochar as one of the microwave absorbers. Life cycle analysis and scale-up process with the global view of MAP are presented to contribute to the further advancement and commercialization of this technology. Although there are several challenges to be resolved, MAP has a high energy efficiency and is an increasingly feasible technique to be scalable, economical and environmental friendly.

Green synthesis of carbon nanomaterials from sugarcane bagasse using bio-silica supported bimetallic nickel-based catalysts

Sugarcane bagasse (SCB) can be considered as an inexpensive and abundant source for the production of valuable carbon nanomaterials (CNMs). Herein, the synthesis of CNMs via sugarcane bagasse (SCB) pyrolysis was investigated using a simple two-stage process. Bio-silica extracted from rice husk (RH-SiO2) was loaded with 50%Ni, 40%Ni-10%Cu, 40%Ni-10%Mo, and 40%Ni-10%Co and evaluated as catalysts for the production of CNMs from pyrolysis products. The fresh catalysts were characterized by XRD, H2-TPR, and CO2-TPD analyses, while the spent catalysts were characterized using TEM and Raman spectroscopy. The XRD and TPR results of the fresh catalysts demonstrated the existence of non-interacted NiO species in the monometallic Ni/RH-SiO2 catalyst. However, mixed oxides of NixCu1-xO, NiMoO4, and NiCo2O4 species were presented in Ni-Cu, Ni-Mo, and Ni-Co catalysts, respectively, in addition to non-interacted NiO species. TEM images revealed the presence of both carbon nanotubes (CNTs) and graphene nanosheets (GNSs) depending on the catalyst type. The results showed that the presence of mixed oxide species in the catalyst was associated with CNTs formation, while the existence of agglomerated Ni particles was correlated to GNSs formation. The catalytic activity of the catalysts in terms of carbon yield was arranged as follows: 50%Ni > 40%Ni-10%Co > 40%Ni-10%Cu > 40%Ni-10%Mo. Raman spectra proved the production of high-quality CNMs using all Ni-based catalysts.