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Nanomaterials, Volume 13, Issue 13 (July-1 2023) – 134 articles

Cover Story (view full-size image): Graphene grown on sapphire can be a sustainable process for developing ECO-friendly graphene-based devices. It eliminates the use of chemicals to remove catalytic metals and the same substrate can be employed several times. Sinusia Lozano et al. study how a plasma process induces different surface terminations on the sapphire surface and how their influence on defects is evident on graphene grown by plasma-enhanced chemical vapour deposition. The nature of these defects can be identified using Raman spectroscopy, together with the density and size of the defects. View this paper
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42 pages, 7755 KiB  
Review
Recent Progress in Multifunctional Graphene-Based Nanocomposites for Photocatalysis and Electrocatalysis Application
by Zanhe Yang, Siqi Zhou, Xiangyu Feng, Nannan Wang, Oluwafunmilola Ola and Yanqiu Zhu
Nanomaterials 2023, 13(13), 2028; https://doi.org/10.3390/nano13132028 - 7 Jul 2023
Cited by 4 | Viewed by 2080
Abstract
The global energy shortage and environmental degradation are two major issues of concern in today’s society. The production of renewable energy and the treatment of pollutants are currently the mainstream research directions in the field of photocatalysis. In addition, over the last decade [...] Read more.
The global energy shortage and environmental degradation are two major issues of concern in today’s society. The production of renewable energy and the treatment of pollutants are currently the mainstream research directions in the field of photocatalysis. In addition, over the last decade or so, graphene (GR) has been widely used in photocatalysis due to its unique physical and chemical properties, such as its large light-absorption range, high adsorption capacity, large specific surface area, and excellent electronic conductivity. Here, we first introduce the unique properties of graphene, such as its high specific surface area, chemical stability, etc. Then, the basic principles of photocatalytic hydrolysis, pollutant degradation, and the photocatalytic reduction of CO2 are summarized. We then give an overview of the optimization strategies for graphene-based photocatalysis and the latest advances in its application. Finally, we present challenges and perspectives for graphene-based applications in this field in light of recent developments. Full article
(This article belongs to the Special Issue Advances in Nano-Electrochemical Materials and Devices)
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32 pages, 9622 KiB  
Review
Plasmonic Nanomaterials in Dark Field Sensing Systems
by Wenjia Zhang, Xingyu Zi, Jinqiang Bi, Guohua Liu, Hongen Cheng, Kexin Bao, Liu Qin and Wei Wang
Nanomaterials 2023, 13(13), 2027; https://doi.org/10.3390/nano13132027 - 7 Jul 2023
Cited by 2 | Viewed by 1588
Abstract
Plasma nanoparticles offer promise in data storage, biosensing, optical imaging, photoelectric integration, etc. This review highlights the local surface plasmon resonance (LSPR) excitation mechanism of plasmonic nanoprobes and its critical significance in the control of dark-field sensing, as well as three main sensing [...] Read more.
Plasma nanoparticles offer promise in data storage, biosensing, optical imaging, photoelectric integration, etc. This review highlights the local surface plasmon resonance (LSPR) excitation mechanism of plasmonic nanoprobes and its critical significance in the control of dark-field sensing, as well as three main sensing strategies based on plasmonic nanomaterial dielectric environment modification, electromagnetic coupling, and charge transfer. This review then describes the component materials of plasmonic nanoprobes based on gold, silver, and other noble metals, as well as their applications. According to this summary, researchers raised the LSPR performance of composite plasmonic nanomaterials by combining noble metals with other metals or oxides and using them in process analysis and quantitative detection. Full article
(This article belongs to the Special Issue Synthesis and Application of Optical Nanomaterials)
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14 pages, 8698 KiB  
Article
Simulation of Capacitorless DRAM Based on the Polycrystalline Silicon Nanotube Structure with Multiple Grain Boundaries
by Jin Park, Sang-Ho Lee, Ga-Eon Kang, Jun-Hyeok Heo, So-Ra Jeon, Min-Seok Kim, Seung-Ji Bae, Jeong-Woo Hong, Jae-won Jang, Jin-Hyuk Bae, Sin-Hyung Lee and In-Man Kang
Nanomaterials 2023, 13(13), 2026; https://doi.org/10.3390/nano13132026 - 7 Jul 2023
Cited by 3 | Viewed by 1411
Abstract
In this study, a capacitorless one-transistor dynamic random-access memory (1T-DRAM), based on polycrystalline silicon (poly-Si) nanotube structure with a grain boundary (GB), is designed and analyzed using technology computer-aided design (TCAD) simulation. In the proposed 1T-DRAM, the 1T-DRAM cell exhibited a sensing margin [...] Read more.
In this study, a capacitorless one-transistor dynamic random-access memory (1T-DRAM), based on polycrystalline silicon (poly-Si) nanotube structure with a grain boundary (GB), is designed and analyzed using technology computer-aided design (TCAD) simulation. In the proposed 1T-DRAM, the 1T-DRAM cell exhibited a sensing margin of 422 μA/μm and a retention time of 213 ms at T = 358 K with a single GB. To investigate the effect of random GBs, it was assumed that the number of GB is seven, and the memory characteristics depending on the location and number of GBs were analyzed. The memory performance rapidly degraded due to Shockley–Read–Hall recombination depending on the location and number of GBs. In the worst case, when the number of GB is 7, the mean of the sensing margin was 194 µA/µm, and the mean of the retention time was 50.4 ms. Compared to a single GB, the mean of the sensing margin and the retention time decreased by 59.7% and 77.4%, respectively. Full article
(This article belongs to the Special Issue Innovation in Nanoelectronic Semiconductor Devices and Materials)
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12 pages, 4092 KiB  
Article
Hierarchical-Structured Fe2O3 Anode with Exposed (001) Facet for Enhanced Lithium Storage Performance
by Yanfei Liu, Jianfei Lei, Ying Chen, Chenming Liang and Jing Ni
Nanomaterials 2023, 13(13), 2025; https://doi.org/10.3390/nano13132025 - 7 Jul 2023
Cited by 1 | Viewed by 942
Abstract
The hierarchical structure is an ideal nanostructure for conversion-type anodes with drastic volume expansion. Here, we demonstrate a tin-doping strategy for constructing Fe2O3 brushes, in which nanowires with exposed (001) facets are stacked into the hierarchical structure. Thanks to the [...] Read more.
The hierarchical structure is an ideal nanostructure for conversion-type anodes with drastic volume expansion. Here, we demonstrate a tin-doping strategy for constructing Fe2O3 brushes, in which nanowires with exposed (001) facets are stacked into the hierarchical structure. Thanks to the tin-doping, the conductivity of the Sn-doped Fe2O3 has been improved greatly. Moreover, the volume changes of the Sn-doped Fe2O3 anodes can be limited to ~4% vertical expansion and ~13% horizontal expansion, thus resulting in high-rate performance and long-life stability due to the exposed (001) facet and the unique hierarchical structure. As a result, it delivers a high reversible lithium storage capacity of 580 mAh/g at a current density of 0.2C (0.2 A/g), and excellent rate performance of above 400 mAh/g even at a high current density of 2C (2 A/g) over 500 cycles, which is much higher than most of the reported transition metal oxide anodes. This doping strategy and the unique hierarchical structures bring inspiration for nanostructure design of functional materials in energy storage. Full article
(This article belongs to the Section Synthesis, Interfaces and Nanostructures)
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24 pages, 4000 KiB  
Review
Perovskite-Based X-ray Detectors
by Chen-Fu Lin, Kuo-Wei Huang, Yen-Ting Chen, Sung-Lin Hsueh, Ming-Hsien Li and Peter Chen
Nanomaterials 2023, 13(13), 2024; https://doi.org/10.3390/nano13132024 - 7 Jul 2023
Cited by 4 | Viewed by 3404
Abstract
X-ray detection has widespread applications in medical diagnosis, non-destructive industrial radiography and safety inspection, and especially, medical diagnosis realized by medical X-ray detectors is presenting an increasing demand. Perovskite materials are excellent candidates for high-energy radiation detection based on their promising material properties [...] Read more.
X-ray detection has widespread applications in medical diagnosis, non-destructive industrial radiography and safety inspection, and especially, medical diagnosis realized by medical X-ray detectors is presenting an increasing demand. Perovskite materials are excellent candidates for high-energy radiation detection based on their promising material properties such as excellent carrier transport capability and high effective atomic number. In this review paper, we introduce X-ray detectors using all kinds of halide perovskite materials along with various crystal structures and discuss their device performance in detail. Single-crystal perovskite was first fabricated as an active material for X-ray detectors, having excellent performance under X-ray illumination due to its superior photoelectric properties of X-ray attenuation with μm thickness. The X-ray detector based on inorganic perovskite shows good environmental stability and high X-ray sensitivity. Owing to anisotropic carrier transport capability, two-dimensional layered perovskites with a preferred orientation parallel to the substrate can effectively suppress the dark current of the device despite poor light response to X-rays, resulting in lower sensitivity for the device. Double perovskite applied for X-ray detectors shows better attenuation of X-rays due to the introduction of high-atomic-numbered elements. Additionally, its stable crystal structure can effectively lower the dark current of X-ray detectors. Environmentally friendly lead-free perovskite exhibits potential application in X-ray detectors by virtue of its high attenuation of X-rays. In the last section, we specifically introduce the up-scaling process technology for fabricating large-area and thick perovskite films for X-ray detectors, which is critical for the commercialization and mass production of perovskite-based X-ray detectors. Full article
(This article belongs to the Special Issue New Horizon in Perovskite Nanocrystals)
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12 pages, 1928 KiB  
Article
Electronic Characteristics, Stability and Water Oxidation Selectivity of High-Index BiVO4 Facets for Photocatalytic Application: A First Principle Study
by Zhiyuan Zhang, Yuqi Xiang and Zhihong Zhu
Nanomaterials 2023, 13(13), 2023; https://doi.org/10.3390/nano13132023 - 7 Jul 2023
Viewed by 1065
Abstract
Some high-index facets of BiVO4, such as (012), (210), (115), (511), (121), (132) and (231), exhibit much better photocatalytic performance than conventional (010) and (110) surfaces for water splitting. However, the detailed mechanisms and stability of improved photocatalytic performance for these [...] Read more.
Some high-index facets of BiVO4, such as (012), (210), (115), (511), (121), (132) and (231), exhibit much better photocatalytic performance than conventional (010) and (110) surfaces for water splitting. However, the detailed mechanisms and stability of improved photocatalytic performance for these high-index BiVO4 surfaces are still not clear, which is important for designing photocatalysts with high efficiency. Here, based on first principle calculation, we carried out a systematic theoretical research on BiVO4 with different surfaces, especially high-index facets. The results show that all of the high-index facets in our calculated systems show an n-type behavior, and the band edge positions indicate that all of the high-index facets have enough ability to produce O2 without external bias. Electronic structures, band alignments and formation enthalpy indicate that (012), (115) and (132) could be equivalent to (210), (511) and (231), respectively, in the calculation. Oxidation and reduction potential show that only (132)/(231) is stable without strongly oxidative conditions, and the Gibbs free energy indicates that (012)/(210), (115)/(511), (121) and (132)/(231) have lower overpotential than (010) and (110). Our calculation is able to unveil insights into the effects of the surface, including electronic structures, overpotential and stability during the reaction process. Full article
(This article belongs to the Special Issue First-Principle Calculation Study of Nanomaterials)
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15 pages, 8835 KiB  
Article
Nanosurface Texturing for Enhancing the Antibacterial Effect of Biodegradable Metal Zinc: Surface Modifications
by Enmao Xiang, Corey S. Moran, Sašo Ivanovski and Abdalla Abdal-hay
Nanomaterials 2023, 13(13), 2022; https://doi.org/10.3390/nano13132022 - 7 Jul 2023
Cited by 4 | Viewed by 1326
Abstract
Zinc (Zn) as a biodegradable metal has attracted research interest for bone reconstruction, with the aim of eliminating the need for a second removal surgery and minimizing the implant-to-bone transfer of stress-shielding to maintain bone regeneration. In addition, Zn has been shown to [...] Read more.
Zinc (Zn) as a biodegradable metal has attracted research interest for bone reconstruction, with the aim of eliminating the need for a second removal surgery and minimizing the implant-to-bone transfer of stress-shielding to maintain bone regeneration. In addition, Zn has been shown to have antibacterial properties, particularly against Gram-negative bacteria, and is often used as a surface coating to inhibit bacterial growth and biofilm formation. However, the antibacterial property of Zn is still suboptimal in part due to low Zn ion release during degradation that has to be further improved in order to meet clinical requirements. This work aims to perform an innovative one-step surface modification using a nitric acid treatment to accelerate Zn ion release by increasing surface roughness, thereby endowing an effective antimicrobial property and biofilm formation inhibition. The antibacterial performance against Staphylococci aureus was evaluated by assessing biofilm formation and adhesion using quantitative assays. The surface roughness of acid-treated Zn (Ra ~ 30 nm) was significantly higher than polished Zn (Ra ~ 3 nm) and corresponded with the marked inhibition of bacterial biofilm, and this is likely due to the increased surface contact area and Zn ion accumulation. Overall, surface modification due to nitric acid etching appears to be an effective technique that can produce unique morphological surface structures and enhance the antibacterial properties of biodegradable Zn-based materials, thus increasing the translation potential toward multiple biomedical applications. Full article
(This article belongs to the Special Issue Nanostructured Biomaterials for Tissue Repair and Anti-infection)
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13 pages, 8171 KiB  
Article
Nanomaterial Production from Metallic Vapor Bubble Collapse in Liquid Nitrogen
by Chen Li, Ruoyu Han, Jingran Li, Yuchen Cao, Wei Yuan and Qifan Li
Nanomaterials 2023, 13(13), 2021; https://doi.org/10.3390/nano13132021 - 7 Jul 2023
Cited by 1 | Viewed by 948
Abstract
Nanomaterials with unique structural and properties can be synthesized by rapid transition of the thermodynamic state. One promising method is through electrical explosion, which possesses ultrafast heating/quenching rates (dT/dt~109 K/s) of the exploding conductor. In this study, experiments [...] Read more.
Nanomaterials with unique structural and properties can be synthesized by rapid transition of the thermodynamic state. One promising method is through electrical explosion, which possesses ultrafast heating/quenching rates (dT/dt~109 K/s) of the exploding conductor. In this study, experiments were performed with fine metallic wire exploding in liquid nitrogen (liq N2, 77 K) under different applied voltages. For the first time in the literature, the physical image of the electrical explosion dynamics in liq N2 is depicted using electro-physical diagnostics and spatial-temporal-resolved photography. Specifically, the pulsation and collapse processes of the vapor bubble (explosion products) have been carefully observed and analyzed. As a comparison, an underwater electrical explosion was also performed. The experimental results suggest that the vapor bubble behavior in liq N2 differs from that in water, especially in the collapse phase, characterized by secondary small-scale bubbles in liq N2, but multiple bubble pulses in water; correspondingly, the products’ characteristics are discrepant. Full article
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3 pages, 175 KiB  
Editorial
Editorial for Special Issue: “Synthesis and Application of Biomass-Derived Carbon-Based Nanomaterial”
by Mengmeng Zhang, Pengfei Li and Dapeng Wu
Nanomaterials 2023, 13(13), 2020; https://doi.org/10.3390/nano13132020 - 7 Jul 2023
Viewed by 965
Abstract
Biomass-derived carbon-based nanomaterials represent a group of green and high-quality materials which can be potentially employed in the fields of environmental protection, energy conversion and clean energy storage [...] Full article
31 pages, 6992 KiB  
Review
Eucalyptus globulus Mediated Green Synthesis of Environmentally Benign Metal Based Nanostructures: A Review
by Muhammad Usman Sadiq, Afzal Shah, Abdul Haleem, Syed Mujtaba Shah and Iltaf Shah
Nanomaterials 2023, 13(13), 2019; https://doi.org/10.3390/nano13132019 - 6 Jul 2023
Cited by 4 | Viewed by 2643
Abstract
The progress in nanotechnology has effectively tackled and overcome numerous global issues, including climate change, environmental contamination, and various lethal diseases. The nanostructures being a vital part of nanotechnology have been synthesized employing different physicochemical methods. However, these methods are expensive, polluting, eco-unfriendly, [...] Read more.
The progress in nanotechnology has effectively tackled and overcome numerous global issues, including climate change, environmental contamination, and various lethal diseases. The nanostructures being a vital part of nanotechnology have been synthesized employing different physicochemical methods. However, these methods are expensive, polluting, eco-unfriendly, and produce toxic byproducts. Green chemistry having exceptional attributes, such as cost-effectiveness, non-toxicity, higher stability, environment friendliness, ability to control size and shape, and superior performance, has emerged as a promising alternative to address the drawbacks of conventional approaches. Plant extracts are recognized as the best option for the biosynthesis of nanoparticles due to adherence to the environmentally benign route and sustainability agenda 2030 of the United Nations. In recent decades, phytosynthesized nanoparticles have gained much attention for different scientific applications. Eucalyptus globulus (blue gum) is an evergreen plant belonging to the family Myrtaceae, which is the targeted point of this review article. Herein, we mainly focus on the fabrication of nanoparticles, such as zinc oxide, copper oxide, iron oxide, lanthanum oxide, titanium dioxide, magnesium oxide, lead oxide, nickel oxide, gold, silver, and zirconium oxide, by utilizing Eucalyptus globulus extract and its essential oils. This review article aims to provide an overview of the synthesis, characterization results, and biomedical applications of nanoparticles synthesized using Eucalyptus globulus. The present study will be a better contribution to the readers and the students of environmental research. Full article
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10 pages, 6072 KiB  
Article
Polyethylene Terephthalate Composite Films with Enhanced Flame Retardancy and Gas Barrier Properties via Self-Assembly Nanocoating
by Tao Zou, Lei Kang, Dongqiao Zhang, Jieyi Li, Zefeng Zheng and Xiaohong Peng
Nanomaterials 2023, 13(13), 2018; https://doi.org/10.3390/nano13132018 - 6 Jul 2023
Cited by 1 | Viewed by 1258
Abstract
The flammability and gas barrier properties are essential for package material. Herein, a highly-oriented self-assembly nanocoating composed of polyvinyl alcohol (PVA) and montmorillonite (MMT) was prepared for endowing polyethylene terephthalate (PET) films with excellent flame retardancy and gas barrier properties. The specific regular [...] Read more.
The flammability and gas barrier properties are essential for package material. Herein, a highly-oriented self-assembly nanocoating composed of polyvinyl alcohol (PVA) and montmorillonite (MMT) was prepared for endowing polyethylene terephthalate (PET) films with excellent flame retardancy and gas barrier properties. The specific regular nanosheet structure of the PVA/MMT composite nanocoating was confirmed by Fourier transform infrared (FTIR) and X-ray diffraction (XRD). Thermogravimetric analysis (TGA) and the vertical burning test (VBT) suggested that the thermal stability and flame-retardancy of the coated PET films were considerably improved with more pick-up of the resulting nanocoating. When reaching 650 °C, there was still 22.6% char residual left for coated PET film, while only 6% char residual left for pristine PET film. During the vertical burning test, the flame did not spread through the whole PET film with the protection of PVA/MMT nanocoating, and no afterflame was observed. Scanning electron microscopy (SEM) is consistent with vertical burning test, proving that the thermal stability and flame retardancy of coated PET films were considerably enhanced with the increment of PVA/MMT. Thanks to the multi-layer structure, PVA/MMT nanocoating could effectively improve the gas barrier properties of PET films, and the oxygen vapor transmittance rate and water vapor transmittance rate of PET films were more than four hundred times lower and 30% lower than those of neat PET film. Our work demonstrates that bi-functional flame retardant and gas barrier materials could be gained via constructing inorganic/organic highly-oriented self-assembly nanocoating, which is promising in the area of packaging. Full article
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14 pages, 2321 KiB  
Article
Liquid-Metal Core–Shell Particles Coated with Folate and Phospholipids for Targeted Drug Delivery and Photothermal Treatment of Cancer Cells
by Suyeon Ahn, Seung Hyun Kang, Hyunjeong Woo, Kyobum Kim, Hyung-Jun Koo, Hee-Young Lee, Yonghyun Choi, Shin Hyuk Kang and Jonghoon Choi
Nanomaterials 2023, 13(13), 2017; https://doi.org/10.3390/nano13132017 - 6 Jul 2023
Cited by 2 | Viewed by 1657
Abstract
Recently, several methods have been used for cancer treatment. Among them, chemotherapy is generally used, but general anticancer drugs may affect normal cells and tissues, causing various side effects. To reduce the side effects and increase the efficacy of anticancer drugs, a folate-based [...] Read more.
Recently, several methods have been used for cancer treatment. Among them, chemotherapy is generally used, but general anticancer drugs may affect normal cells and tissues, causing various side effects. To reduce the side effects and increase the efficacy of anticancer drugs, a folate-based liquid-metal drug nanodelivery system was used to target the folate receptor, which is highly expressed in cancer cells. A phospholipid-based surface coating was formed on the surface of liquid-metal nanoparticles to increase their stability, and doxorubicin was loaded as a drug delivery system. Folate on the lipid shell surface increased the efficiency of targeting cancer cells. The photothermal properties of liquid metal were confirmed by near-infrared (NIR) laser irradiation. After treating cancerous and normal cells with liquid-metal particles and NIR irradiation, the particles were specifically bound to cancer cells for drug uptake, confirming photothermal therapy as a drug delivery system that is expected to induce cancer cell death through comprehensive effects such as vascular embolization in addition to targeting cancer cells. Full article
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18 pages, 4818 KiB  
Article
Self-Assembled Bifunctional Copper Hydroxide/Gold-Ordered Nanoarray Composites for Fast, Sensitive, and Recyclable SERS Detection of Hazardous Benzene Vapors
by Yanyan Lu, Xuzhou Yuan, Cuiping Jia, Biao Lei, Hongwen Zhang, Zhipeng Zhao, Shuyi Zhu, Qian Zhao and Weiping Cai
Nanomaterials 2023, 13(13), 2016; https://doi.org/10.3390/nano13132016 - 6 Jul 2023
Cited by 3 | Viewed by 1434
Abstract
Volatile organic compounds (VOCs), particularly monoaromatic hydrocarbon compounds (MACHs), pose a potential risk to the atmospheric environment and human health. Therefore, the progressive development of efficient detection methodologies is a pertinent need, which is still a challenge at present. In this study, we [...] Read more.
Volatile organic compounds (VOCs), particularly monoaromatic hydrocarbon compounds (MACHs), pose a potential risk to the atmospheric environment and human health. Therefore, the progressive development of efficient detection methodologies is a pertinent need, which is still a challenge at present. In this study, we present a rapid and sensitive method to detect trace amounts of MACHs using a bifunctional SERS composite substrate. We prepared an Au/SiO2 enhanced layer and a porous Cu(OH)2 adsorption layer via microfluidic-assisted gas-liquid interface self-assembly. The composite substrate effectively monitored changes in benzaldehyde using time-varying SERS spectra, and track-specifically identified various VOCs such as benzene, xylene, styrene, and nitrobenzene. In general, the substrate exhibited a rapid response time of 20 s to gaseous benzaldehyde, with a minimum detection concentration of less than 500 ppt. Further experimental assessments revealed an optimum Cu(OH)2 thickness of the surrounding adsorption layer of 150 nm, which can achieve an efficient SERS response to MACHs. Furthermore, the recoverable and reusable property of the composite substrate highlights its practicality. This study presents a straightforward and efficient approach for detecting trace gaseous VOCs using SERS, with significant implications in the designing of SERS substrates for detecting other VOCs. Full article
(This article belongs to the Special Issue Nanotechnology for Pollutant Detection and Removal)
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16 pages, 11165 KiB  
Article
Dual-Band, Wide-Angle, and High-Capture Efficiency Metasurface for Electromagnetic Energy Harvesting
by Abdulrahman Ahmed Ghaleb Amer, Nurmiza Othman, Syarfa Zahirah Sapuan, Arokiaswami Alphones, Mohd Fahrul Hassan, Ahmed Jamal Abdullah Al-Gburi and Zahriladha Zakaria
Nanomaterials 2023, 13(13), 2015; https://doi.org/10.3390/nano13132015 - 6 Jul 2023
Cited by 6 | Viewed by 1478
Abstract
A dual-band metasurface (MS) with a wide reception angle operating at Wi-Fi bands (2.4 GHz and 5.4 GHz) is presented for electromagnetic (EM) energy harvesting applications. The MS unit cell comprises a subwavelength circular split ring resonator printed on the low-loss substrate. An [...] Read more.
A dual-band metasurface (MS) with a wide reception angle operating at Wi-Fi bands (2.4 GHz and 5.4 GHz) is presented for electromagnetic (EM) energy harvesting applications. The MS unit cell comprises a subwavelength circular split ring resonator printed on the low-loss substrate. An air layer is sandwiched between two low-loss substrates to enhance the harvesting efficiency at operating frequencies. One of the main advantages of the proposed MS is that it uses only one harvesting port (via) to channel the captured power to the optimized load (50 Ω), which simplifies the design of a combined power network. According to the results of full-wave EM simulations, the proposed MS has a near-unity efficiency of 97% and 94% at 2.4 GHz and 5.4 GHz, respectively, for capturing the power of incident EM waves with normal incidence. Furthermore, the proposed MS harvester achieves good performance at up to 60° oblique incidence. To validate simulations, the MS harvester with 5 × 5-unit cells is fabricated and tested, and its EM properties are measured, showing good agreement with the simulation results. Because of its high efficiency, the proposed MS harvester is suitable for use in various microwave applications, such as energy harvesting and wireless power transfer. Full article
(This article belongs to the Special Issue New Trends in Metamaterials)
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9 pages, 2002 KiB  
Communication
Power-Dependent Optical Characterization of the InGaN/GaN-Based Micro-Light-Emitting-Diode (LED) in High Spatial Resolution
by Haifeng Yang, Yufeng Li, Jiawei Wang, Aixing Li, Kun Li, Chuangcheng Xu, Minyan Zhang, Zhenhuan Tian, Qiang Li and Feng Yun
Nanomaterials 2023, 13(13), 2014; https://doi.org/10.3390/nano13132014 - 6 Jul 2023
Viewed by 1215
Abstract
Spatially resolved photoluminescence at the sub-micro scale was used to study the optical non-uniformity of the micro-LED under varied power density excitation levels. The trend of the efficiency along injection levels were found to be highly dependent on the location of the chip [...] Read more.
Spatially resolved photoluminescence at the sub-micro scale was used to study the optical non-uniformity of the micro-LED under varied power density excitation levels. The trend of the efficiency along injection levels were found to be highly dependent on the location of the chip mesa. The sidewall was 80% lower than the center under low-power density excitation, but was 50% higher under high-power density excitation. The external quantum efficiency droop at the center and the sidewall was 86% and 52%, respectively. A 2 µm band area near the sidewall was characterized where the efficiency and its trends changed rapidly. Beyond such band, the full width at half maximum and peak wavelength variation across the chip varied less than 1 nm, indicating high uniformity of the material composition. The sudden change = in the band, especially under high level excitation indicates the indium composition change formed by ion residues on the sidewall affect the distribution of charge carriers. These findings contribute to the understanding of cause of efficiency disadvantage and non-uniformity problems in small-size micro-LEDs. Full article
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29 pages, 11906 KiB  
Review
Advanced Photocatalytic Uranium Extraction Strategies: Progress, Challenges, and Prospects
by Wangchuan Zhu, Xiang Li, Danjun Wang, Feng Fu and Yucang Liang
Nanomaterials 2023, 13(13), 2005; https://doi.org/10.3390/nano13132005 - 6 Jul 2023
Cited by 5 | Viewed by 2371
Abstract
Nuclear energy with low carbon emission and high-energy density is considered as one of the most promising future energy sources for human beings. However, the use of nuclear energy will inevitably lead to the discharge of nuclear waste and the consumption of uranium [...] Read more.
Nuclear energy with low carbon emission and high-energy density is considered as one of the most promising future energy sources for human beings. However, the use of nuclear energy will inevitably lead to the discharge of nuclear waste and the consumption of uranium resources. Therefore, the development of simple, efficient, and economical uranium extraction methods is of great significance for the sustainable development of nuclear energy and the restoration of the ecological environment. Photocatalytic U(VI) extraction technology as a simple, highly efficient, and low-cost strategy, received increasing attention from researchers. In this review, the development background of photocatalytic U(VI) extraction and several photocatalytic U(VI) reduction mechanisms are briefly described and the identification methods of uranium species after photocatalytic reduction are addressed. Subsequently, the modification strategies of several catalysts used for U(VI) extraction are summarized and the advantages and disadvantages of photocatalytic U(VI) extraction are compared. Additionally, the research progress of photocatalytic technology for U(VI) extraction in actual uranium-containing wastewater and seawater are evaluated. Finally, the current challenges and the developments of photocatalytic U(VI) extraction technology in the future are prospected. Full article
(This article belongs to the Special Issue Nanocatalysts for Environmental Remediation)
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30 pages, 4937 KiB  
Review
New Insights into N-Doped Porous Carbons as Both Heterogeneous Catalysts and Catalyst Supports: Opportunities for the Catalytic Synthesis of Valuable Compounds
by Elena Pérez Mayoral, Marina Godino Ojer, Márcia Ventura and Ines Matos
Nanomaterials 2023, 13(13), 2013; https://doi.org/10.3390/nano13132013 - 5 Jul 2023
Cited by 3 | Viewed by 1728
Abstract
Among the vast class of porous carbon materials, N-doped porous carbons have emerged as promising materials in catalysis due to their unique properties. The introduction of nitrogen into the carbonaceous matrix can lead to the creation of new sites on the carbon [...] Read more.
Among the vast class of porous carbon materials, N-doped porous carbons have emerged as promising materials in catalysis due to their unique properties. The introduction of nitrogen into the carbonaceous matrix can lead to the creation of new sites on the carbon surface, often associated with pyridinic or pyrrolic nitrogen functionalities, which can facilitate various catalytic reactions with increased selectivity. Furthermore, the presence of N dopants exerts a significant influence on the properties of the supported metal or metal oxide nanoparticles, including the metal dispersion, interactions between the metal and support, and stability of the metal nanoparticles. These effects play a crucial role in enhancing the catalytic performance of the N-doped carbon-supported catalysts. Thus, N-doped carbons and metals supported on N-doped carbons have been revealed to be interesting heterogeneous catalysts for relevant synthesis processes of valuable compounds. This review presents a concise overview of various methods employed to produce N-doped porous carbons with distinct structures, starting from diverse precursors, and showcases their potential in various catalytic processes, particularly in fine chemical synthesis. Full article
(This article belongs to the Special Issue Functional Carbon-Based Nanocomposite and Applications)
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27 pages, 8505 KiB  
Review
Metal-Oxides- and Metal-Oxyhydroxides-Based Nanocomposites for Water Splitting: An Overview
by Tse-Wei Chen, Shen-Ming Chen, Ganesan Anushya, Ramanujam Kannan, Pitchaimani Veerakumar, Mohammed Mujahid Alam, Saranvignesh Alargarsamy and Rasu Ramachandran
Nanomaterials 2023, 13(13), 2012; https://doi.org/10.3390/nano13132012 - 5 Jul 2023
Cited by 5 | Viewed by 2292
Abstract
Water electrolysis is an important alternative technology for large-scale hydrogen production to facilitate the development of green energy technology. As such, many efforts have been devoted over the past three decades to producing novel electrocatalysis with strong electrochemical (EC) performance using inexpensive electrocatalysts. [...] Read more.
Water electrolysis is an important alternative technology for large-scale hydrogen production to facilitate the development of green energy technology. As such, many efforts have been devoted over the past three decades to producing novel electrocatalysis with strong electrochemical (EC) performance using inexpensive electrocatalysts. Transition metal oxyhydroxide (OxH)-based electrocatalysts have received substantial interest, and prominent results have been achieved for the hydrogen evolution reaction (HER) under alkaline conditions. Herein, the extensive research focusing on the discussion of OxH-based electrocatalysts is comprehensively highlighted. The general forms of the water-splitting mechanism are described to provide a profound understanding of the mechanism, and their scaling relation activities for OxH electrode materials are given. This paper summarizes the current developments on the EC performance of transition metal OxHs, rare metal OxHs, polymers, and MXene-supported OxH-based electrocatalysts. Additionally, an outline of the suggested HER, OER, and water-splitting processes on transition metal OxH-based electrocatalysts, their primary applications, existing problems, and their EC performance prospects are discussed. Furthermore, this review article discusses the production of energy sources from the proton and electron transfer processes. The highlighted electrocatalysts have received substantial interest to boost the synergetic electrochemical effects to improve the economy of the use of hydrogen, which is one of best ways to fulfill the global energy requirements and address environmental crises. This article also provides useful information regarding the development of OxH electrodes with a hierarchical nanostructure for the water-splitting reaction. Finally, the challenges with the reaction and perspectives for the future development of OxH are elaborated. Full article
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54 pages, 10594 KiB  
Review
Advancing Thermoelectric Materials: A Comprehensive Review Exploring the Significance of One-Dimensional Nano Structuring
by Mustafa Majid Rashak Al-Fartoos, Anurag Roy, Tapas K. Mallick and Asif Ali Tahir
Nanomaterials 2023, 13(13), 2011; https://doi.org/10.3390/nano13132011 - 5 Jul 2023
Cited by 12 | Viewed by 2560
Abstract
Amidst the global challenges posed by pollution, escalating energy expenses, and the imminent threat of global warming, the pursuit of sustainable energy solutions has become increasingly imperative. Thermoelectricity, a promising form of green energy, can harness waste heat and directly convert it into [...] Read more.
Amidst the global challenges posed by pollution, escalating energy expenses, and the imminent threat of global warming, the pursuit of sustainable energy solutions has become increasingly imperative. Thermoelectricity, a promising form of green energy, can harness waste heat and directly convert it into electricity. This technology has captivated attention for centuries due to its environmentally friendly characteristics, mechanical stability, versatility in size and substrate, and absence of moving components. Its applications span diverse domains, encompassing heat recovery, cooling, sensing, and operating at low and high temperatures. However, developing thermoelectric materials with high-performance efficiency faces obstacles such as high cost, toxicity, and reliance on rare-earth elements. To address these challenges, this comprehensive review encompasses pivotal aspects of thermoelectricity, including its historical context, fundamental operating principles, cutting-edge materials, and innovative strategies. In particular, the potential of one-dimensional nanostructuring is explored as a promising avenue for advancing thermoelectric technology. The concept of one-dimensional nanostructuring is extensively examined, encompassing various configurations and their impact on the thermoelectric properties of materials. The profound influence of one-dimensional nanostructuring on thermoelectric parameters is also thoroughly discussed. The review also provides a comprehensive overview of large-scale synthesis methods for one-dimensional thermoelectric materials, delving into the measurement of thermoelectric properties specific to such materials. Finally, the review concludes by outlining prospects and identifying potential directions for further advancements in the field. Full article
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12 pages, 403 KiB  
Review
Slater–Pauling Behavior in Half-Metallic Heusler Compounds
by Iosif Galanakis
Nanomaterials 2023, 13(13), 2010; https://doi.org/10.3390/nano13132010 - 5 Jul 2023
Cited by 9 | Viewed by 1695
Abstract
Heusler materials have become very popular over the last two decades due to the half-metallic properties of a large number of Heusler compounds. The latter are magnets that present a metallic behavior for the spin-up and a semiconducting behavior for the spin-down electronic [...] Read more.
Heusler materials have become very popular over the last two decades due to the half-metallic properties of a large number of Heusler compounds. The latter are magnets that present a metallic behavior for the spin-up and a semiconducting behavior for the spin-down electronic band structure leading to a variety of spintronic applications, and Slater–Pauling rules have played a major role in the development of this research field. These rules have been derived using ab initio electronic structure calculations and directly connecting the electronic properties (existence of spin-down energy gap) to the magnetic properties (total spin magnetic moment). Their exact formulation depends on the half-metallic family under study and can be derived if the hybridization of the orbitals at various sites is taken into account. In this review, the origin and formulation of the Slater–Pauling rules for various families of Heusler compounds, derived during these two last decades, is presented. Full article
(This article belongs to the Special Issue First-Principle Calculation Study of Nanomaterials)
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12 pages, 3512 KiB  
Article
A Hexadecanuclear Cobalt-Added Tungstogermanate Containing Counter Cobalt Hydrates: Synthesis, Structure and Photocatalytic Properties
by Qing Zhao, Xuyan Li, Yu Wang, Hongjin Lv and Guoyu Yang
Nanomaterials 2023, 13(13), 2009; https://doi.org/10.3390/nano13132009 - 5 Jul 2023
Viewed by 1121
Abstract
The synthesis and exploration of the properties of structurally-new polyoxometalates (POMs) has been attracting considerable research interest. In this work, a hexadecanuclear cobalt-added tungstogermanate, H31(NH4)5Na16{Co(H2O)6}4{[Co4 [...] Read more.
The synthesis and exploration of the properties of structurally-new polyoxometalates (POMs) has been attracting considerable research interest. In this work, a hexadecanuclear cobalt-added tungstogermanate, H31(NH4)5Na16{Co(H2O)6}4{[Co43-OH)3(PO4)]4(A-α-GeW9O34)4}2·23-H2O (1), was synthesized under hydrothermal conditions and characterized by various techniques. Compound 1 can effectively drive the heterogeneous photocatalytic hydrogen evolution reaction in the presence of [Ir(ppy)2(dtbbpy)][PF6] as the photosensitizer, with triethanolamine (TEOA) and N-Hydroxy succinimide (NHS) used as the dual sacrificial reagents. Control experiments revealed the important role of NHS in enhancing the hydrogen-evolution activities. Under optimal catalytic conditions, a hydrogen yield of 54.21 μmol was achieved after 10-h photocatalysis, corresponding to a hydrogen evolution rate of 1807.07 μmol·g−1·h−1. Stability studies demonstrated that catalyst 1 can be isolated and reused for three successive photocatalytic cycles with negligible decline of the H2 yield, indicating the stability and recycling robustness of catalyst 1. Full article
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40 pages, 9793 KiB  
Review
Direct Optical Patterning of Quantum Dots: One Strategy, Different Chemical Processes
by Francesco Antolini
Nanomaterials 2023, 13(13), 2008; https://doi.org/10.3390/nano13132008 - 5 Jul 2023
Viewed by 1660
Abstract
Patterning, stability, and dispersion of the semiconductor quantum dots (scQDs) are three issues strictly interconnected for successful device manufacturing. Recently, several authors adopted direct optical patterning (DOP) as a step forward in photolithography to position the scQDs in a selected area. However, the [...] Read more.
Patterning, stability, and dispersion of the semiconductor quantum dots (scQDs) are three issues strictly interconnected for successful device manufacturing. Recently, several authors adopted direct optical patterning (DOP) as a step forward in photolithography to position the scQDs in a selected area. However, the chemistry behind the stability, dispersion, and patterning has to be carefully integrated to obtain a functional commercial device. This review describes different chemical strategies suitable to stabilize the scQDs both at a single level and as an ensemble. Special attention is paid to those strategies compatible with direct optical patterning (DOP). With the same purpose, the scQDs’ dispersion in a matrix was described in terms of the scQD surface ligands’ interactions with the matrix itself. The chemical processes behind the DOP are illustrated and discussed for five different approaches, all together considering stability, dispersion, and the patterning itself of the scQDs. Full article
(This article belongs to the Special Issue Study on Quantum Dot and Quantum Dot-Based Device)
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16 pages, 3493 KiB  
Article
Au-Nanorods Supporting Pd and Pt Nanocatalysts for the Hydrogen Evolution Reaction: Pd Is Revealed to Be a Better Catalyst than Pt
by Ayoub Laghrissi and Mohammed Es-Souni
Nanomaterials 2023, 13(13), 2007; https://doi.org/10.3390/nano13132007 - 5 Jul 2023
Cited by 1 | Viewed by 1208
Abstract
Ordered thin films of Au nanorods (NRs) on Ti/Au/Si heterostructure substrates are electrodeposited in thin film aluminum oxide templates and, after template removal, serve as supports for Pd and Pt nanocatalysts. Based on previous work which showed a better electrocatalytic performance for layered [...] Read more.
Ordered thin films of Au nanorods (NRs) on Ti/Au/Si heterostructure substrates are electrodeposited in thin film aluminum oxide templates and, after template removal, serve as supports for Pd and Pt nanocatalysts. Based on previous work which showed a better electrocatalytic performance for layered Au/Pd nanostructures than monolithic Pd, electrodeposited 20 nm Pd discs on Au-NRs are first investigated in terms of their catalytic activity for the hydrogen evolution reaction (HER) and compared to monolithic 20 nm Pd and Pt discs. To further boost performance, the interfacial interaction area between the Au-NRs supports and the active metals (Pt and Pd) was increased via magnetron sputtering an extremely thin layer of Pt and Pd (20 nm overall sputtered thickness) on the Au-NRs after template removal. In this way, the whole NR surface (top and lateral) was covered with Pt and Pd nanoparticles, ensuring a maximum interfacial contact between the support and the active metal. The HER performance obtained was substantially higher than that of the other nanostructures. A Salient result of the present work, however, is the superior activity obtained for sputtered Pd on Au in comparison to that of sputtered Pt on Au. The results also show that increasing the Au-NR length translates in a strong increase in performance. Density functional theory calculations show that the interfacial electronic interactions between Au and Pd lead to suitable values of hydrogen adsorption energy on all possible sites, thus promoting faster (barrier-free diffusion) hydrogen adsorption and its recombination to H2. A Volmer–Heyrovsky mechanism for HER is proposed, and a volcano plot is suggested based on the results of the Tafel plots and the calculated hydrogen adsorption energies. Full article
(This article belongs to the Special Issue 1D and 2D Nanomaterials for Energy Storage and Conversion)
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9 pages, 2352 KiB  
Article
Methods for Obtaining One Single Larmor Frequency, Either v1 or v2, in the Coherent Spin Dynamics of Colloidal Quantum Dots
by Meizhen Jiang, Yuanyuan Zhang, Rongrong Hu, Yumeng Men, Lin Cheng, Pan Liang, Tianqing Jia, Zhenrong Sun and Donghai Feng
Nanomaterials 2023, 13(13), 2006; https://doi.org/10.3390/nano13132006 - 5 Jul 2023
Cited by 2 | Viewed by 993
Abstract
The coexistence of two spin components with different Larmor frequencies in colloidal CdSe and CdS quantum dots (QDs) leads to the entanglement of spin signals, complicating the analysis of dynamic processes and hampering practical applications. Here, we explored several methods, including varying the [...] Read more.
The coexistence of two spin components with different Larmor frequencies in colloidal CdSe and CdS quantum dots (QDs) leads to the entanglement of spin signals, complicating the analysis of dynamic processes and hampering practical applications. Here, we explored several methods, including varying the types of hole acceptors, air or anaerobic atmosphere and laser repetition rates, in order to facilitate the obtention of one single Larmor frequency in the coherent spin dynamics using time-resolved ellipticity spectroscopy at room temperature. In an air or nitrogen atmosphere, manipulating the photocharging processes by applying different types of hole acceptors, e.g., Li[Et3BH] and 1-octanethiol (OT), can lead to pure spin components with one single Larmor frequency. For as-grown QDs, low laser repetition rates favor the generation of the higher Larmor frequency spin component individually, while the lower Larmor frequency spin component can be enhanced by increasing the laser repetition rates. We hope that the explored methods can inspire further investigations of spin dynamics and related photophysical processes in colloidal nanostructures. Full article
(This article belongs to the Special Issue Semiconductor Quantum Dots: Synthesis, Properties and Applications)
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15 pages, 11732 KiB  
Article
Amorphous/Nanocrystalline High-Entropy CoCrFeNiTix Thin Films with Low Thermal Coefficient of Resistivity Obtained via Magnetron Deposition
by Maksim Poliakov, Dmitry Kovalev, Sergei Vadchenko, Dmitry Moskovskikh, Philipp Kiryukhantsev-Korneev, Lidiya Volkova, Alexander Dudin, Andrey Orlov, Andrey Goryachev and Alexander Rogachev
Nanomaterials 2023, 13(13), 2004; https://doi.org/10.3390/nano13132004 - 4 Jul 2023
Cited by 6 | Viewed by 1459
Abstract
High-entropy alloys are promising materials for novel thin-film resistors since they have high resistivity and a low-temperature coefficient of resistivity (TCR). In this work, a new high-entropy thin-film CoCrFeNiTix was deposited on a Si/SiO2 substrate by means of magnetron sputtering of [...] Read more.
High-entropy alloys are promising materials for novel thin-film resistors since they have high resistivity and a low-temperature coefficient of resistivity (TCR). In this work, a new high-entropy thin-film CoCrFeNiTix was deposited on a Si/SiO2 substrate by means of magnetron sputtering of the multi-component target produced by hot pressing of the powder mixture. The samples possessed a thickness of 130–230 nm and an amorphous atomic structure with nanocrystallite traces. This structure persisted after being annealed up to 400 °C, which was confirmed using X-ray and electron diffraction. The film had a single-phase structure with a smooth surface and a uniform distribution of all elements. The obtained film served for microresistor elaboration, which was produced using the lithography technique and tested in a temperature range from −60 °C up to 200 °C. Resistivity at room temperature was estimated as 2.37 μOhm·m. The results have demonstrated that TCR depends on temperature according to the simple linear law in a range from −60 °C up to 130 °C, changing its value from −78 ppm/°C at low temperatures to −6.6 ppm/°C at 130 °C. Such characteristics show the possibility of using these high-entropy alloy films for resistive elements in contemporary and future micro-electronic devices. Full article
(This article belongs to the Special Issue Solid-State Reactions in Nanomaterials)
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22 pages, 6290 KiB  
Review
Contrast Agents of Magnetic Resonance Imaging and Future Perspective
by Jie Lv, Shubham Roy, Miao Xie, Xiulan Yang and Bing Guo
Nanomaterials 2023, 13(13), 2003; https://doi.org/10.3390/nano13132003 - 4 Jul 2023
Cited by 3 | Viewed by 2188
Abstract
In recent times, magnetic resonance imaging (MRI) has emerged as a highly promising modality for diagnosing severe diseases. Its exceptional spatiotemporal resolution and ease of use have established it as an indispensable clinical diagnostic tool. Nevertheless, there are instances where MRI encounters challenges [...] Read more.
In recent times, magnetic resonance imaging (MRI) has emerged as a highly promising modality for diagnosing severe diseases. Its exceptional spatiotemporal resolution and ease of use have established it as an indispensable clinical diagnostic tool. Nevertheless, there are instances where MRI encounters challenges related to low contrast, necessitating the use of contrast agents (CAs). Significant efforts have been made by scientists to enhance the precision of observing diseased body parts by leveraging the synergistic potential of MRI in conjunction with other imaging techniques and thereby modifying the CAs. In this work, our focus is on elucidating the rational designing approach of CAs and optimizing their compatibility for multimodal imaging and other intelligent applications. Additionally, we emphasize the importance of incorporating various artificial intelligence tools, such as machine learning and deep learning, to explore the future prospects of disease diagnosis using MRI. We also address the limitations associated with these techniques and propose reasonable remedies, with the aim of advancing MRI as a cutting-edge diagnostic tool for the future. Full article
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14 pages, 4132 KiB  
Article
Quasiepitaxial Aluminum Film Nanostructure Optimization for Superconducting Quantum Electronic Devices
by Mikhail Tarasov, Andrey Lomov, Artem Chekushkin, Mikhail Fominsky, Denis Zakharov, Andrey Tatarintsev, Sergey Kraevsky and Anton Shadrin
Nanomaterials 2023, 13(13), 2002; https://doi.org/10.3390/nano13132002 - 4 Jul 2023
Cited by 1 | Viewed by 838
Abstract
In this paper, we develop fabrication technology and study aluminum films intended for superconducting quantum nanoelectronics using AFM, SEM, XRD, HRXRR. Two-temperature-step quasiepitaxial growth of Al on (111) Si substrate provides a preferentially (111)-oriented Al polycrystalline film and reduces outgrowth bumps, peak-to-peak roughness [...] Read more.
In this paper, we develop fabrication technology and study aluminum films intended for superconducting quantum nanoelectronics using AFM, SEM, XRD, HRXRR. Two-temperature-step quasiepitaxial growth of Al on (111) Si substrate provides a preferentially (111)-oriented Al polycrystalline film and reduces outgrowth bumps, peak-to-peak roughness from 70 to 10 nm, and texture coefficient from 3.5 to 1.7, while increasing hardness from 5.4 to 16 GPa. Future progress in superconducting current density, stray capacitance, relaxation time, and noise requires a reduction in structural defect density and surface imperfections, which can be achieved by improving film quality using such quasiepitaxial growth techniques. Full article
(This article belongs to the Section Synthesis, Interfaces and Nanostructures)
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9 pages, 2224 KiB  
Communication
Enrichment of Large-Diameter Semiconducting Single-Walled Carbon Nanotubes by Conjugated Polymer-Assisted Separation
by Piao Xie, Yun Sun, Chao Chen, Shu-Yu Guo, Yiming Zhao, Xinyu Jiao, Peng-Xiang Hou, Chang Liu and Hui-Ming Cheng
Nanomaterials 2023, 13(13), 2001; https://doi.org/10.3390/nano13132001 - 4 Jul 2023
Cited by 1 | Viewed by 1587
Abstract
Semiconducting single-walled carbon nanotubes (s-SWCNTs) with large diameters are highly desired in the construction of high performance optoelectronic devices. However, it is difficult to selectively prepare large-diameter s-SWCNTs since their structure and chemical stability are quite similar with their metallic counterparts. In this [...] Read more.
Semiconducting single-walled carbon nanotubes (s-SWCNTs) with large diameters are highly desired in the construction of high performance optoelectronic devices. However, it is difficult to selectively prepare large-diameter s-SWCNTs since their structure and chemical stability are quite similar with their metallic counterparts. In this work, we use SWCNTs with large diameter as a raw material, conjugated polymer of regioregular poly-(3-dodecylthiophene) (rr-P3DDT) with long side chain as a wrapping agent to selectively separate large-diameter s-SWCNTs. It is found that s-SWCNTs with a diameter of ~1.9 nm are effectively enriched, which shows a clean surface. By using the sorted s-SWCNTs as a channel material, we constructed thin-film transistors showing charge-carrier mobilities higher than 10 cm2 V−1 s−1 and on/off ratios higher than 103. Full article
(This article belongs to the Special Issue Current State-of-the-Art of SWCNT, MWCNT, and Mixed CNT)
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13 pages, 4092 KiB  
Article
Fabrication and Characterization of Polylactic Acid Electrospun Wound Dressing Modified with Polyethylene Glycol, Rosmarinic Acid and Graphite Oxide
by Chengyi Liu, Guicai Du, Qunqun Guo, Ronggui Li, Changming Li and Hongwei He
Nanomaterials 2023, 13(13), 2000; https://doi.org/10.3390/nano13132000 - 3 Jul 2023
Cited by 3 | Viewed by 1263
Abstract
Polylactic acid (PLA) is a biodegradable polymer made from natural sources, and its electrospinning (e-spinning) nanofiber membrane doped with antibacterial ingredients is widely used in the field of medical dressings. In this research, 9 wt% of rosmarinic acid (RosA) and 0.04 wt% of [...] Read more.
Polylactic acid (PLA) is a biodegradable polymer made from natural sources, and its electrospinning (e-spinning) nanofiber membrane doped with antibacterial ingredients is widely used in the field of medical dressings. In this research, 9 wt% of rosmarinic acid (RosA) and 0.04 wt% of graphite oxide (GO) with synergistic antibacterial activity were introduced into the e-spinning PLA precursor solution, and the obtained PLA nanofiber membrane showed good antibacterial properties and wound healing effects. At the same time, a nonionic amphiphilic polymer, polyethylene glycol (PEG), was also introduced into this system to improve the hydrophilicity of the e-spinning membrane for wound healing application. The morphological characterization showed the RosA/GO and PEG did not affect the e-spinning of PLA. The tests of mechanical performance and wettability demonstrated that PEG and RosA/GO incorporated in PLA have migrated easily to the surface of the fiber. The e-spun PLA/PEG/RosA/GO membrane showed good antibacterial activity and promoted initial wound healing quickly, which would be a promising application in wound dressing. Full article
(This article belongs to the Special Issue Advance in Electrospun Nanofibers)
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17 pages, 4680 KiB  
Article
Intracellular Localization during Blood–Brain Barrier Crossing Influences Extracellular Release and Uptake of Fluorescent Nanoprobes
by Ornella Muscetti, Naym Blal, Valentina Mollo, Paolo Antonio Netti and Daniela Guarnieri
Nanomaterials 2023, 13(13), 1999; https://doi.org/10.3390/nano13131999 - 3 Jul 2023
Viewed by 1152
Abstract
To improve the efficacy of nanoparticles (NPs) and boost their theragnostic potential for brain diseases, it is key to understand the mechanisms controlling blood–brain barrier (BBB) crossing. Here, the capability of 100 nm carboxylated polystyrene NPs, used as a nanoprobe model, to cross [...] Read more.
To improve the efficacy of nanoparticles (NPs) and boost their theragnostic potential for brain diseases, it is key to understand the mechanisms controlling blood–brain barrier (BBB) crossing. Here, the capability of 100 nm carboxylated polystyrene NPs, used as a nanoprobe model, to cross the human brain endothelial hCMEC/D3 cell layer, as well as to be consequently internalized by human brain tumor U87 cells, is investigated as a function of NPs’ different intracellular localization. We compared NPs confined in the endo-lysosomal compartment, delivered to the cells through endocytosis, with free NPs in the cytoplasm, delivered by the gene gun method. The results indicate that the intracellular behavior of NPs changed as a function of their entrance mechanism. Moreover, by bypassing endo-lysosomal accumulation, free NPs were released from cells more efficiently than endocytosed NPs. Most importantly, once excreted by the endothelial cells, free NPs were released in the cell culture medium as aggregates smaller than endocytosed NPs and, consequently, they entered the human glioblastoma U87 cells more efficiently. These findings prove that intracellular localization influences NPs’ long-term fate, improving their cellular release and consequent cellular uptake once in the brain parenchyma. This study represents a step forward in designing nanomaterials that are able to reach the brain effectively. Full article
(This article belongs to the Special Issue Nanoparticles for Biosensor Application)
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