Editorial

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11 pages, 5926 KiB

Open AccessEditorial

Advanced Carbon Nanostructures: Synthesis, Properties, and Applications

by Marianna V. Kharlamova, Christian Kramberger and Alexander I. Chernov

Nanomaterials 2023, 13(7), 1268; https://doi.org/10.3390/nano13071268 - 03 Apr 2023

Viewed by 1107

Abstract

Carbon nanomaterials are a class of materials that include allotropic modifications of carbon [...] Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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Research

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18 pages, 13612 KiB

Open AccessArticle

Carbon Hybrid Materials—Design, Manufacturing, and Applications

by Anuptha Pujari, Devika Chauhan, Megha Chitranshi, Ronald Hudepohl, Ashley Kubley, Vesselin Shanov and Mark Schulz

Nanomaterials 2023, 13(3), 431; https://doi.org/10.3390/nano13030431 - 20 Jan 2023

Cited by 3 | Viewed by 1564

Abstract

Carbon nanotubes (CNTs) have extraordinary properties and are used for applications in various fields of engineering and research. Due to their unique combination of properties, such as good electrical and thermal conductivity and mechanical strength, there is an increasing demand to produce CNTs [...] Read more.

Carbon nanotubes (CNTs) have extraordinary properties and are used for applications in various fields of engineering and research. Due to their unique combination of properties, such as good electrical and thermal conductivity and mechanical strength, there is an increasing demand to produce CNTs with enhanced and customized properties. CNTs are produced using different synthesis methods and have extraordinary properties individually at the nanotube scale. However, it is challenging to achieve these properties when CNTs are used to form macroscopic sheets, tapes, and yarns. To further improve the properties of macroscale forms of CNTs, various types of nanoparticles and microfibers can be integrated into the CNT materials. The nanoparticles and microfibers can be chosen to selectively enhance the properties of CNT materials at the macroscopic level. In this paper, we propose a technique to manufacture carbon hybrid materials (CHMs) by combining CNT non-woven fabric (in the form of sheets or tapes) with microfibers to form CNT-CF hybrid materials with new/improved properties. CHMs are formed by integrating or adding nanoparticles, microparticles, or fibers into the CNT sheet. The additive materials can be incorporated into the synthesis process from the inlet or the outlet of the reactor system. This paper focuses on CHMs produced using the gas phase pyrolysis method with microparticles/fibers integrated at the outlet of the reactor and continuous microfiber tapes integrated into the CNT sheet at the outlet using a tape feeding machine. After synthesis, characterizations such as microscopy and thermogravimetric analysis were used to study the morphology and composition of the CNTs, and examples for potential applications are discussed in this paper. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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18 pages, 2841 KiB

Open AccessArticle

Manifesting Epoxide and Hydroxyl Groups in XPS Spectra and Valence Band of Graphene Derivatives

by Maxim K. Rabchinskii, Vladimir V. Shnitov, Maria Brzhezinskaya, Marina V. Baidakova, Dina Yu. Stolyarova, Sergey A. Ryzhkov, Svyatoslav D. Saveliev, Alexander V. Shvidchenko, Denis Yu. Nefedov, Anastasiia O. Antonenko, Sergey V. Pavlov, Vitaliy A. Kislenko, Sergey A. Kislenko and Pavel N. Brunkov

Nanomaterials 2023, 13(1), 23; https://doi.org/10.3390/nano13010023 - 21 Dec 2022

Cited by 4 | Viewed by 1878

Abstract

The derivatization of graphene to engineer its band structure is a subject of significant attention nowadays, extending the frames of graphene material applications in the fields of catalysis, sensing, and energy harvesting. Yet, the accurate identification of a certain group and its effect [...] Read more.

The derivatization of graphene to engineer its band structure is a subject of significant attention nowadays, extending the frames of graphene material applications in the fields of catalysis, sensing, and energy harvesting. Yet, the accurate identification of a certain group and its effect on graphene’s electronic structure is an intricate question. Herein, we propose the advanced fingerprinting of the epoxide and hydroxyl groups on the graphene layers via core-level methods and reveal the modification of their valence band (VB) upon the introduction of these oxygen functionalities. The distinctive contribution of epoxide and hydroxyl groups to the C 1s X-ray photoelectron spectra was indicated experimentally, allowing the quantitative characterization of each group, not just their sum. The appearance of a set of localized states in graphene’s VB related to the molecular orbitals of the introduced functionalities was signified both experimentally and theoretically. Applying the density functional theory calculations, the impact of the localized states corresponding to the molecular orbitals of the hydroxyl and epoxide groups was decomposed. Altogether, these findings unveiled the particular contribution of the epoxide and hydroxyl groups to the core-level spectra and band structure of graphene derivatives, advancing graphene functionalization as a tool to engineer its physical properties. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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12 pages, 4832 KiB

Open AccessArticle

Strengthening Ni-Coated CNT/Mg Composites by Optimizing the CNT Content

by Jilei Xu, Yizhuang Zhang, Zhiyuan Li, Yunpeng Ding, Xin Zhao, Xinfang Zhang, Hanying Wang, Changhong Liu and Xiaoqin Guo

Nanomaterials 2022, 12(24), 4446; https://doi.org/10.3390/nano12244446 - 14 Dec 2022

Cited by 4 | Viewed by 1024

Abstract

The dispersion of carbon nanotubes (CNTs) is the bottleneck in CNT-reinforced metal matrix composites. In this work, CNT/Mg composites were prepared by grinding Mg powder and then dispersing CNTs via ball milling and hot pressing. The uniform distribution of Ni-coated CNTs in the [...] Read more.

The dispersion of carbon nanotubes (CNTs) is the bottleneck in CNT-reinforced metal matrix composites. In this work, CNT/Mg composites were prepared by grinding Mg powder and then dispersing CNTs via ball milling and hot pressing. The uniform distribution of Ni-coated CNTs in the matrix was achieved by optimizing the content of CNTs. Scanning electron microscope, high-resolution transmission electron microscopy and X-ray diffraction, optical microscopy, and compression tests were employed. With the CNT content being less than 1%, the CNTs can be evenly distributed in CNT/Mg composites, resulting in a sharp increase in strength. However, with the higher CNT content, the CNTs gradually cluster, leading decreased fracture strain and strength. Furthermore, the coated Ni in the CNTs reacts with the magnesium matrix and completely transforms into Mg₂Ni, significantly enhancing the interface bonding. This strong interface bonding and the diffusely distributed Mg₂Ni in the matrix significantly strengthen the CNT/Mg composite. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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13 pages, 11706 KiB

Open AccessArticle

Influence of Soft Phase and Carbon Nanotube Content on the Properties of Hierarchical AZ61 Matrix Composite with Isolated Soft Phase

by Yunpeng Ding, Sijia Jiao, Yizhuang Zhang, Zhiai Shi, Jinbiao Hu, Xulei Wang, Zhiyuan Li, Hanying Wang and Xiaoqin Guo

Nanomaterials 2022, 12(16), 2877; https://doi.org/10.3390/nano12162877 - 21 Aug 2022

Cited by 4 | Viewed by 1297

Abstract

Carbon nanotube-reinforced magnesium matrix (CNTs/Mg) composite has great application potential in the transportation industry, but the trade-off between strength and ductility inhibits its widespread application. In order to balance the strength and plasticity of the composite, in this work, on the basis of [...] Read more.

Carbon nanotube-reinforced magnesium matrix (CNTs/Mg) composite has great application potential in the transportation industry, but the trade-off between strength and ductility inhibits its widespread application. In order to balance the strength and plasticity of the composite, in this work, on the basis of the AZ61 matrix composite homogeneously reinforced by Ni-coated CNTs (hard phase), 30 vol.% large-size AZ61 particles are introduced as an isolated soft phase to fabricate hierarchical CNTs/AZ61 composites. The compression tests show the fracture strain and compressive strength of this composite increases by 54% and 8%, respectively, compared with homogeneous CNTs/AZ61 composite. During deformation, the hard phase is mainly responsible for bearing the load and bringing high strength, due to the precipitation of the Mg₁₇Al₁₂ phase, uniformly dispersed CNT and strong interfacial bonding of the CNTs/Mg interface through nickel plating and interfacial chemical reaction. Furthermore, the toughening of the soft phase results in high ductility. With the increase in CNT content, the compressive strength of composites is nearly unchanged but the fracture strain gradually decreases due to the stress concentration of CNT and its agglomeration. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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11 pages, 2678 KiB

Open AccessArticle

The Effect of sp² Content in Carbon on Its Catalytic Activity for Acetylene Hydrochlorination

by Fangjie Lu, Chengcheng Wei, Xue Yin, Lihua Kang, Mingyuan Zhu and Bin Dai

Nanomaterials 2022, 12(15), 2619; https://doi.org/10.3390/nano12152619 - 29 Jul 2022

Cited by 3 | Viewed by 1275

Abstract

We report the influence of sp² content in carbon catalyst on the catalytic activity for acetylene hydrochlorination. Nanodiamonds (NDs) were used as the precursor and calcinated under different temperatures. The resulting ND500, ND700, ND900, and ND1100 catalysts were characterized, and the sp [...] Read more.

We report the influence of sp² content in carbon catalyst on the catalytic activity for acetylene hydrochlorination. Nanodiamonds (NDs) were used as the precursor and calcinated under different temperatures. The resulting ND500, ND700, ND900, and ND1100 catalysts were characterized, and the sp² content increased with increasing calcination temperature. The specific activities of the catalysts first increased and then decreased with increasing sp² content. The highest catalytic activity could be obtained in the ND-900 catalyst with a sp² value of 43.9%. The density functional theory results showed that the adsorption sites for acetylene and hydrogen chloride were located at the interface between sp² and sp³ configuration. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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10 pages, 6247 KiB

Open AccessArticle

Effect of CNT Content on Microstructure and Properties of CNTs/Refined-AZ61 Magnesium Matrix Composites

by Yunpeng Ding, Zhiai Shi, Zhiyuan Li, Sijia Jiao, Jinbiao Hu, Xulei Wang, Yizhuang Zhang, Hanying Wang and Xiaoqin Guo

Nanomaterials 2022, 12(14), 2432; https://doi.org/10.3390/nano12142432 - 15 Jul 2022

Cited by 11 | Viewed by 1256

Abstract

Carbon nanotubes (CNTs) reinforced magnesium matrix composites have great application potential in the transportation industry, but the low absolute strength is the main obstacle to its application. In this paper, copper-coated CNTs and AZ61 powder were used as raw materials to prepare CNTs/refined-AZ61 [...] Read more.

Carbon nanotubes (CNTs) reinforced magnesium matrix composites have great application potential in the transportation industry, but the low absolute strength is the main obstacle to its application. In this paper, copper-coated CNTs and AZ61 powder were used as raw materials to prepare CNTs/refined-AZ61 composites with good interfacial bonding, uniformly dispersed CNTs and fine grains by the process of ball milling refinement of AZ61 powder, ball milling dispersion and hot-pressing sintering. When the volume fraction of CNTs is less than or equal to 1 vol.%, CNTs can be uniformly dispersed and the yield strength and compressive strength of composites increase with higher CNT content. When the volume fraction of CNTs is 1 vol.%, the compressive strength and yield strength of composites reach 439 MPa and 361 MPa, respectively, which are 14% and 9% higher than those of matrix composites with nearly the same value of fracture strain. When the volume fraction of CNTs is greater than 1 vol.%, with the increase in CNT content, CNT clustering becomes more and more serious, resulting in a decrease in the strength and fracture strain of composites. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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9 pages, 1600 KiB

Open AccessArticle

The Role of Temperature on the Degree of End-Closing and Filling of Single-Walled Carbon Nanotubes

by Magdalena Kierkowicz, Elzbieta Pach, Julio Fraile, Concepción Domingo, Belén Ballesteros and Gerard Tobias

Nanomaterials 2021, 11(12), 3365; https://doi.org/10.3390/nano11123365 - 11 Dec 2021

Cited by 3 | Viewed by 2568

Abstract

Carbon nanotubes (CNTs), owing to their high surface area-to-volume ratio and hollow core, can be employed as hosts for adsorbed and/or encapsulated molecules. At high temperatures, the ends of CNTs close spontaneously, which is relevant for several applications, including catalysis, gas storage, and [...] Read more.

Carbon nanotubes (CNTs), owing to their high surface area-to-volume ratio and hollow core, can be employed as hosts for adsorbed and/or encapsulated molecules. At high temperatures, the ends of CNTs close spontaneously, which is relevant for several applications, including catalysis, gas storage, and biomedical imaging and therapy. This study highlights the influence of the annealing temperature in the range between 400 and 1100 °C on the structure and morphology of single-walled CNTs. The nitrogen adsorption and density functional theory calculations indicate that the fraction of end-closed CNTs increases with temperature. Raman spectroscopy reveals that the thermal treatment does not alter the tubular structure. Insight is also provided into the efficacy of CNTs filling from the molten phase, depending on the annealing temperature. The CNTs are filled with europium (III) chloride and analyzed by using electron microscopy (scanning electron microscopy and high-resolution transmission electron microscopy) and energy-dispersive X-ray spectroscopy, confirming the presence of filling and closed ends. The filling yield increases with temperature, as determined by thermogravimetric analysis. The obtained results show that the apparent surface area of CNTs, fraction of closed ends, and amount of encapsulated payload can be tailored via annealing. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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12 pages, 2451 KiB

Open AccessArticle

Temperature-Dependent Growth of 36 Inner Nanotubes inside Nickelocene, Cobaltocene and Ferrocene-Filled Single-Walled Carbon Nanotubes

by Marianna V. Kharlamova and Christian Kramberger

Nanomaterials 2021, 11(11), 2984; https://doi.org/10.3390/nano11112984 - 06 Nov 2021

Cited by 4 | Viewed by 1729

Abstract

We have investigated the effects of temperature, diameter and metal catalyst type on the growth of inner nanotubes inside metallocene-filled single-walled carbon nanotubes (SWCNTs). The effects on the yield of different chiralities of inner nanotubes were scrutinized by multifrequency Raman spectroscopy. The investigated [...] Read more.

We have investigated the effects of temperature, diameter and metal catalyst type on the growth of inner nanotubes inside metallocene-filled single-walled carbon nanotubes (SWCNTs). The effects on the yield of different chiralities of inner nanotubes were scrutinized by multifrequency Raman spectroscopy. The investigated diameters range from ~0.7 to 1.3 nm and comprise 36 distinct chiralities. For all three investigated metals (Ni, Co, Fe), there is a linear correlation of growth temperature with nanotube diameter. The common slope for these metals is found to be 40.5 °C/Å. The temperature difference between the largest and the smallest diameter tubes amounts to ~230 °C for all three precursors. The growth temperatures are offset by 34 °C from Ni to Co and another 28 °C from Co to Fe. The quantified correlations of temperature, diameter and metal catalyst type provide the basis for engineering the diameter-specific growth of nanotubes. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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14 pages, 4813 KiB

Open AccessArticle

Analysis of the Piezoelectric Properties of Aligned Multi-Walled Carbon Nanotubes

by Marina V. Il’ina, Oleg I. Il’in, Nikolay N. Rudyk, Olga I. Osotova, Alexander A. Fedotov and Oleg A. Ageev

Nanomaterials 2021, 11(11), 2912; https://doi.org/10.3390/nano11112912 - 30 Oct 2021

Cited by 10 | Viewed by 1979

Abstract

Recent studies reveal that carbon nanostructures show anomalous piezoelectric properties when the central symmetry of their structure is violated. Particular focus is given to carbon nanotubes (CNTs) with initial significant curvature of the graphene sheet surface, which leads to an asymmetric redistribution of [...] Read more.

Recent studies reveal that carbon nanostructures show anomalous piezoelectric properties when the central symmetry of their structure is violated. Particular focus is given to carbon nanotubes (CNTs) with initial significant curvature of the graphene sheet surface, which leads to an asymmetric redistribution of the electron density. This paper presents the results of studies on the piezoelectric properties of aligned multi-walled CNTs. An original technique for evaluating the effective piezoelectric coefficient of CNTs is presented. For the first time, in this study, we investigate the influence of the growth temperature and thickness of the catalytic Ni layer on the value of the piezoelectric coefficient of CNTs. We establish the relationship between the effective piezoelectric coefficient of CNTs and their defectiveness and diameter, which determines the curvature of the graphene sheet surface. The calculated values of the effective piezoelectric coefficient of CNTs are shown to be between 0.019 and 0.413 C/m², depending on the degree of their defectiveness and diameter. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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35 pages, 9343 KiB

Open AccessArticle

Metal Cluster Size-Dependent Activation Energies of Growth of Single-Chirality Single-Walled Carbon Nanotubes inside Metallocene-Filled Single-Walled Carbon Nanotubes

by Marianna V. Kharlamova and Christian Kramberger

Nanomaterials 2021, 11(10), 2649; https://doi.org/10.3390/nano11102649 - 09 Oct 2021

Cited by 16 | Viewed by 1749

Abstract

By combining in situ annealing and Raman spectroscopy measurements, the growth dynamics of nine individual-chirality inner tubes (8,8), (12,3), (13,1), (9,6), (10,4), (11,2), (11,1), (9,3) and (9,2) with diameters from ~0.8 to 1.1 nm are monitored using a time resolution of several minutes. [...] Read more.

By combining in situ annealing and Raman spectroscopy measurements, the growth dynamics of nine individual-chirality inner tubes (8,8), (12,3), (13,1), (9,6), (10,4), (11,2), (11,1), (9,3) and (9,2) with diameters from ~0.8 to 1.1 nm are monitored using a time resolution of several minutes. The growth mechanism of inner tubes implies two successive stages of the growth on the carburized and purely metallic catalytic particles, respectively, which are formed as a result of the thermally induced decomposition of metallocenes inside the outer SWCNTs. The activation energies of the growth on carburized Ni and Co catalytic particles amount to 1.85–2.57 eV and 1.80–2.71 eV, respectively. They decrease monotonically as the tube diameter decreases, independent of the metal type. The activation energies of the growth on purely metallic Ni and Co particles equal 1.49–1.91 eV and 0.77–1.79 eV, respectively. They increase as the tube diameter decreases. The activation energies of the growth of large-diameter tubes (d_t = ~0.95–1.10 nm) on Ni catalyst are significantly larger than on Co catalyst, whereas the values of small-diameter tubes (d_t = ~0.80–0.95 nm) are similar. For both metals, no dependence of the activation energies on the chirality of inner tubes is observed. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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7 pages, 1447 KiB

Open AccessArticle

Nickelocene-Filled Purely Metallic Single-Walled Carbon Nanotubes: Sorting and Tuning the Electronic Properties

by Marianna V. Kharlamova

Nanomaterials 2021, 11(10), 2500; https://doi.org/10.3390/nano11102500 - 26 Sep 2021

Cited by 9 | Viewed by 1827

Abstract

We conducted the filling of single-walled carbon nanotubes (SWCNTs) with nickelocene molecules and separation of the filled SWCNTs by conductivity type by density-gradient ultracentrifugation. We tailored the electronic properties of nickelocene-filled purely metallic SWCNTs by thermal treatment in high vacuum. Our results demonstrated [...] Read more.

We conducted the filling of single-walled carbon nanotubes (SWCNTs) with nickelocene molecules and separation of the filled SWCNTs by conductivity type by density-gradient ultracentrifugation. We tailored the electronic properties of nickelocene-filled purely metallic SWCNTs by thermal treatment in high vacuum. Our results demonstrated that annealing at low temperatures (360–600 °C) leads to n-doping of SWCNTs, whereas annealing at high temperatures (680–1200 °C) results in p-doping of SWCNTs. We found a correlation between the chemical state of the incorporated substances at different annealing temperatures and its influence on the electronic properties of SWCNTs. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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10 pages, 3249 KiB

Open AccessArticle

Oxidative Desulfurization Catalyzed by Phosphotungstic Acid Supported on Hierarchical Porous Carbons

by Bao Wang, Lihua Kang and Mingyuan Zhu

Nanomaterials 2021, 11(9), 2369; https://doi.org/10.3390/nano11092369 - 12 Sep 2021

Cited by 6 | Viewed by 1646

Abstract

A hierarchical porous carbon material (HPC) with an ultra-high specific surface area was synthesized with sisal fiber (SF) as a precursor, and then H₃PW₁₂O₄₀·24H₂O (HPW) was immobilized on the support of SF-HPC by a simple [...] Read more.

A hierarchical porous carbon material (HPC) with an ultra-high specific surface area was synthesized with sisal fiber (SF) as a precursor, and then H₃PW₁₂O₄₀·24H₂O (HPW) was immobilized on the support of SF-HPC by a simple impregnation method. A series characterization technology approved that the obtained SF-HPC had a high surface area of 3152.46 m²g⁻¹ with micropores and macropores. HPW was well-dispersed on the surface of the SF-HPC support, which reduced the loading of HPW to as low as 5%. HPW/SF-HPW showed excellent catalytic performance for oxidative desulfurization, and the desulfurization rate reached almost 100% under the optimal reaction conditions. The desulfurization rate of HPW/SF-HPW could be maintained at above 94% after four recycles. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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15 pages, 5395 KiB

Open AccessArticle

Organic–Inorganic Ternary Nanohybrids of Single-Walled Carbon Nanohorns for Room Temperature Chemiresistive Ethanol Detection

by Cornel Cobianu, Bogdan-Catalin Serban, Niculae Dumbravescu, Octavian Buiu, Viorel Avramescu, Cristina Pachiu, Bogdan Bita, Marius Bumbac, Cristina-Mihaela Nicolescu and Cosmin Cobianu

Nanomaterials 2020, 10(12), 2552; https://doi.org/10.3390/nano10122552 - 18 Dec 2020

Cited by 17 | Viewed by 2320

Abstract

Organic–inorganic ternary nanohybrids consisting of oxidized-single walled carbon nanohorns-SnO₂-polyvinylpyrrolidone (ox-SWCNH/SnO₂/PVP) with stoichiometry 1/1/1 and 2/1/1 and ox-SWCNH/ZnO/PVP = 5/2/1 and 5/3/2 (all mass ratios) were synthesized and characterized as sensing films of chemiresistive test structures for ethanol vapor detection [...] Read more.

Organic–inorganic ternary nanohybrids consisting of oxidized-single walled carbon nanohorns-SnO₂-polyvinylpyrrolidone (ox-SWCNH/SnO₂/PVP) with stoichiometry 1/1/1 and 2/1/1 and ox-SWCNH/ZnO/PVP = 5/2/1 and 5/3/2 (all mass ratios) were synthesized and characterized as sensing films of chemiresistive test structures for ethanol vapor detection in dry air, in the range from 0 up to 50 mg/L. All the sensing films had an ox-SWCNH concentration in the range of 33.3–62.5 wt%. A comparison between the transfer functions and the response and recovery times of these sensing devices has shown that the structures with ox-SWCNH/SnO₂/PVP = 1/1/1 have the highest relative sensitivities of 0.0022 (mg/L)⁻¹, while the devices with ox-SWCNH/SnO₂/PVP = 2/1/1 have the lowest response time (15 s) and recovery time (50 s) for a room temperature operation, proving the key role of carbonic material in shaping the static and dynamic performance of the sensor. These response and recovery times are lower than those of “heated” commercial sensors. The sensing mechanism is explained in terms of the overall response of a p-type semiconductor, where ox-SWCNH percolated between electrodes of the sensor, shunting the heterojunctions made between n-type SnO₂ or ZnO and p-type ox-SWCNH. The hard–soft acid–base (HSAB) principle supports this mechanism. The low power consumption of these devices, below 2 mW, and the sensing performances at room temperature may open new avenues towards ethanol sensors for passive samplers of environment monitoring, alcohol test portable instruments and wireless network sensors for Internet of Things applications. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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Review

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18 pages, 3345 KiB

Open AccessReview

Metal and Metal Halogenide-Filled Single-Walled Carbon Nanotubes: Kinetics, Electronic Properties, Engineering the Fermi Level

by Marianna V. Kharlamova and Christian Kramberger

Nanomaterials 2023, 13(1), 180; https://doi.org/10.3390/nano13010180 - 30 Dec 2022

Cited by 4 | Viewed by 1569

Abstract

Here, we present a review of the major achievements in kinetics, electronic properties, and engineering in the Fermi level of single-walled carbon nanotubes (SWCNTs). Firstly, the kinetics of metal-filled SWCNTs were revealed with precision over several minutes. Secondly, the growth rates of nanotubes [...] Read more.

Here, we present a review of the major achievements in kinetics, electronic properties, and engineering in the Fermi level of single-walled carbon nanotubes (SWCNTs). Firstly, the kinetics of metal-filled SWCNTs were revealed with precision over several minutes. Secondly, the growth rates of nanotubes were calculated. Thirdly, the activation energies of nanotubes were measured. Fourthly, the methods of the quantitative analysis of the doping level were developed. Indeed, only qualitative analysis has been previously performed. The quantitative analysis allowed us to obtain quantitative data on charge transfer. Fifthly, the correlation between the physical properties, chemical properties, electronic properties of SWCNTs was elucidated. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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19 pages, 3515 KiB

Open AccessReview

A Review of Performance Prediction Based on Machine Learning in Materials Science

by Ziyang Fu, Weiyi Liu, Chen Huang and Tao Mei

Nanomaterials 2022, 12(17), 2957; https://doi.org/10.3390/nano12172957 - 26 Aug 2022

Cited by 6 | Viewed by 2510

Abstract

With increasing demand in many areas, materials are constantly evolving. However, they still have numerous practical constraints. The rational design and discovery of new materials can create a huge technological and social impact. However, such rational design and discovery require a holistic, multi-stage [...] Read more.

With increasing demand in many areas, materials are constantly evolving. However, they still have numerous practical constraints. The rational design and discovery of new materials can create a huge technological and social impact. However, such rational design and discovery require a holistic, multi-stage design process, including the design of the material composition, material structure, material properties as well as process design and engineering. Such a complex exploration using traditional scientific methods is not only blind but also a huge waste of time and resources. Machine learning (ML), which is used across data to find correlations in material properties and understand the chemical properties of materials, is being considered a new way to explore the materials field. This paper reviews some of the major recent advances and applications of ML in the field of properties prediction of materials and discusses the key challenges and opportunities in this cross-cutting area. Full article

(This article belongs to the Special Issue Advanced Carbon Nanostructures: Synthesis, Properties and Applications)

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