Nanomaterials

13 pages, 4083 KiB

Open AccessArticle

Hierarchical WS₂-WO₃ Nanohybrids with Flower-like p-n Heterostructures for Trimethylamine Detection

by Dan Meng, Shunjiang Ran, Lei Zhang, Xiaoguang San, Yue Zhang, Yu Zheng and Jian Qi

Nanomaterials 2024, 14(16), 1322; https://doi.org/10.3390/nano14161322 - 6 Aug 2024

The detection of trimethylamine (TMA) is critically important due to its toxic and flammable nature, which poses significant risks to human health and the environment. However, achieving high response, rapid kinetics, selectivity, and low operating temperatures in TMA sensing remains challenging. In this [...] Read more.

The detection of trimethylamine (TMA) is critically important due to its toxic and flammable nature, which poses significant risks to human health and the environment. However, achieving high response, rapid kinetics, selectivity, and low operating temperatures in TMA sensing remains challenging. In this study, WS₂/WO₃ nanohybrids with flower-like hierarchical structures were synthesized via an in situ sulfurization process, utilizing varying amounts of thioacetamide to control the sulfurization state of WO₃. These novel hierarchical WS₂/WO₃ nanohybrids exhibit remarkable selectivity towards TMA, as well as rapid response and recovery characteristics. Specially, the optimal WS₂/WO₃ sensor, composed of 5% WS₂/WO₃ nanohybrids, demonstrates exceptional TMA sensing performance, including a high response (19.45 at 10 ppm), good repeatability, reliable long-term stability, and a low theoretical detection limit (15.96 ppb). The superior sensing capabilities of the WS₂/WO₃ nanohybrids are attributed to the formation of p-n heterojunctions at the interface, the unique hierarchical structures, and the catalytic activity of WS₂. Overall, this work provides a straightforward and versatile approach for synthesizing multifunctional nanomaterials by combining metal oxide micro-flowers with transition metal dichalcogenide nanoflakes for applications in monitoring TMA in complex environments. Full article

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16 pages, 7976 KiB

Open AccessArticle

Design of All-Optical D Flip Flop Memory Unit Based on Photonic Crystal

by Yonatan Pugachov, Moria Gulitski and Dror Malka

Nanomaterials 2024, 14(16), 1321; https://doi.org/10.3390/nano14161321 - 6 Aug 2024

Abstract

This paper proposes a unique configuration for an all-optical D Flip Flop (D-FF) utilizing a quasi-square ring resonator (RR) and T-Splitter, as well as NOT and OR logic gates within a 2-dimensional square lattice photonic crystal (PC) structure. The components realizing the all-optical [...] Read more.

This paper proposes a unique configuration for an all-optical D Flip Flop (D-FF) utilizing a quasi-square ring resonator (RR) and T-Splitter, as well as NOT and OR logic gates within a 2-dimensional square lattice photonic crystal (PC) structure. The components realizing the all-optical D-FF comprise of optical waveguides in a 2D square lattice PC of 45 × 23 silicon (Si) rods in a silica (SiO₂) substrate. The utilization of these specific materials has facilitated the fabrication process of the design, diverging from alternative approaches that employ an air substrate, a method inherently unattainable in fabrication. The configuration underwent examination and simulation utilizing both plane-wave expansion (PWE) and finite-difference time-domain (FDTD) methodologies. The simulation outcomes demonstrate that the designed waveguides and RR effectively execute the operational principles of the D-FF by guiding light as intended. The suggested configuration holds promise as a logic block within all-optical arithmetic logic units (ALUs) designed for digital computing optical circuits. The design underwent optimization for operation within the C-band spectrum, particularly at 1550 nm. The outcomes reveal a distinct differentiation between logic states ‘1’ and ‘0’, enhancing robust decision-making on the receiver side and minimizing logic errors in the photonic decision circuit. The D-FF displays a contrast ratio (CR) of 4.77 dB, a stabilization time of 0.66 psec, and a footprint of 21 μm × 12 μm. Full article

(This article belongs to the Section Nanophotonics Materials and Devices)

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27 pages, 8737 KiB

Open AccessArticle

Ni-Based Molecular Sieves Nanomaterials for Dry Methane Reforming: Role of Porous Structure and Active Sites Distribution on Hydrogen Production

by Ahmed S. Al-Fatesh, Ahmed A. Ibrahim, Anis H. Fakeeha, Ahmed I. Osman, Yousef M. Alanazi, Fahad Saleh Almubaddel and Ahmed E. Abasaeed

Nanomaterials 2024, 14(15), 1320; https://doi.org/10.3390/nano14151320 - 5 Aug 2024

Abstract

Global warming, driven by greenhouse gases like CH₄ and CO₂, necessitates efficient catalytic conversion to syngas. Herein, Ni containing different molecular sieve nanomaterials are investigated for dry reforming of methane (DRM). The reduced catalysts are characterized by surface area porosity, [...] Read more.

Global warming, driven by greenhouse gases like CH₄ and CO₂, necessitates efficient catalytic conversion to syngas. Herein, Ni containing different molecular sieve nanomaterials are investigated for dry reforming of methane (DRM). The reduced catalysts are characterized by surface area porosity, X-ray diffraction, Raman infrared spectroscopy, CO₂ temperature-programmed desorption techniques, and transmission electron microscopy. The active sites over each molecular sieve remain stable under oxidizing gas CO₂ during DRM. The reduced 5Ni/CBV10A catalyst, characterized by the lowest silica–alumina ratio, smallest surface area and pore volume, and narrow 8-ring connecting channels, generated the maximum number of active sites on its outer surface. In contrast, the reduced-5Ni/CBV3024E catalyst, with the highest silica–alumina ratio, more than double the surface area and pore volume, 12-ring sinusoidal porous channels, and smallest Ni crystallite, produced the highest H₂ output (44%) after 300 min of operation at 700 °C, with a CH₄:CO₂ = 1:1, P = 1 atom, gas hour space velocity (GHSV) = 42 L gcat⁻¹ h⁻¹. This performance was achieved despite having 25% fewer initial active sites, suggesting that a larger fraction of these sites is stabilized within the pore channels, leading to sustained catalytic activity. Using central composite design and response surface methodology, we successfully optimized the process conditions for the 5Ni/CBV3024E catalyst. The optimized conditions yielded a desirable H₂ to CO ratio of 1.00, with a H₂ yield of 91.92% and a CO yield of 89.16%, indicating high efficiency in gas production. The experimental results closely aligned with the predicted values, demonstrating the effectiveness of the optimization approach. Full article

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15 pages, 895 KiB

Open AccessArticle

Superconductivity of Co-Doped CaKFe₄As₄ Investigated via Point-Contact Spectroscopy and London Penetration Depth Measurements

by Erik Piatti, Daniele Torsello, Francesca Breccia, Tsuyoshi Tamegai, Gianluca Ghigo and Dario Daghero

Nanomaterials 2024, 14(15), 1319; https://doi.org/10.3390/nano14151319 - 5 Aug 2024

Abstract

The iron-based superconductors (IBSs) of the recently discovered 1144 class, unlike many other IBSs, display superconductivity in their stoichiometric form and are intrinsically hole doped. The effects of chemical substitutions with electron donors are thus particularly interesting to investigate. Here, we study the [...] Read more.

The iron-based superconductors (IBSs) of the recently discovered 1144 class, unlike many other IBSs, display superconductivity in their stoichiometric form and are intrinsically hole doped. The effects of chemical substitutions with electron donors are thus particularly interesting to investigate. Here, we study the effect of Co substitution in the Fe site of

{CaKFe}_{4}

{As}_{4}

single crystals on the critical temperature, on the energy gaps, and on the superfluid density by using transport, point-contact Andreev-reflection spectroscopy (PCARS), and London penetration depth measurements. The pristine compound (

T_{c} ≃ 36

K) shows two isotropic gaps whose amplitudes (

Δ_{1}

= 1.4–3.9 meV and

Δ_{2}

= 5.2–8.5 meV) are perfectly compatible with those reported in the literature. Upon Co doping (up to ≈7% Co),

T_{c}

decreases down to ≃20 K, the spin-vortex-crystal order appears, and the low-temperature superfluid density is gradually suppressed. PCARS and London penetration depth measurements perfectly agree in demonstrating that the nodeless multigap structure is robust upon Co doping, while the gap amplitudes decrease as a function of

T_{c}

in a linear way with almost constant values of the gap ratios

2 Δ_{i} / k_{B} T_{c}

. Full article

(This article belongs to the Special Issue Superconductivity and Magnetism in Two-Dimensional and Layered Materials)

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14 pages, 3306 KiB

Open AccessReview

Fluorescent Nanodiamonds for High-Resolution Thermometry in Biology

by Anna Ermakova

Nanomaterials 2024, 14(15), 1318; https://doi.org/10.3390/nano14151318 - 5 Aug 2024

Abstract

Optically active color centers in diamond and nanodiamonds can be utilized as quantum sensors for measuring various physical parameters, particularly magnetic and electric fields, as well as temperature. Due to their small size and possible surface functionalization, fluorescent nanodiamonds are extremely attractive systems [...] Read more.

Optically active color centers in diamond and nanodiamonds can be utilized as quantum sensors for measuring various physical parameters, particularly magnetic and electric fields, as well as temperature. Due to their small size and possible surface functionalization, fluorescent nanodiamonds are extremely attractive systems for biological and medical applications since they can be used for intracellular experiments. This review focuses on fluorescent nanodiamonds for thermometry with high sensitivity and a nanoscale spatial resolution for the investigation of living systems. The current state of the art, possible further development, and potential limitations of fluorescent nanodiamonds as thermometers will be discussed here. Full article

(This article belongs to the Section 2D and Carbon Nanomaterials)

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12 pages, 4849 KiB

Open AccessArticle

Design of Ultra-Compact and Multifunctional Optical Logic Gate Based on Sb₂Se₃-SOI Hybrid Platform

by Liuni Yang, Qiang Liu, Haoyuan Liang, Minming Geng, Kejin Wei and Zhenrong Zhang

Nanomaterials 2024, 14(15), 1317; https://doi.org/10.3390/nano14151317 - 5 Aug 2024

Abstract

Optical logic devices are essential functional devices for achieving optical signal processing. In this study, we design an ultra-compact (4.92 × 2.52 μm²) reconfigurable optical logic gate by using inverse design method with DBS algorithm based on Sb₂Se₃ [...] Read more.

Optical logic devices are essential functional devices for achieving optical signal processing. In this study, we design an ultra-compact (4.92 × 2.52 μm²) reconfigurable optical logic gate by using inverse design method with DBS algorithm based on Sb₂Se₃-SOI integrated platform. By selecting different amorphous/crystalline distributions of Sb₂Se₃ via programmable electrical triggers, the designed structure can switch between OR, XOR, NOT or AND logic gate. This structure works well for all four logic functions in the wavelength range of 1540–1560 nm. Especially at the wavelength of 1550 nm, the Contrast Ratios for XOR, NOT and AND logic gate are 13.77 dB, 11.69 dB and 3.01 dB, respectively, indicating good logical judgment ability of the device. Our design is robust to a certain range of fabrication imperfections. Even if performance weakens due to deviations, improvements can be obtained by rearranging the configurations of Sb₂Se₃ without reproducing the whole device. Full article

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12 pages, 3384 KiB

Open AccessArticle

A Mid-Infrared Perfect Metasurface Absorber with Tri-Band Broadband Scalability

by Yongtu Zou, Shaolin Zhou, Jingxi Li, Shanri Chen and Zhijian Chen

Nanomaterials 2024, 14(15), 1316; https://doi.org/10.3390/nano14151316 - 5 Aug 2024

Abstract

Metasurfaces have emerged as a unique group of two-dimensional ultra-compact subwavelength devices for perfect wave absorption due to their exceptional capabilities of light modulation. Nonetheless, achieving high absorption, particularly with multi-band broadband scalability for specialized scenarios, remains a challenge. As an example, the [...] Read more.

Metasurfaces have emerged as a unique group of two-dimensional ultra-compact subwavelength devices for perfect wave absorption due to their exceptional capabilities of light modulation. Nonetheless, achieving high absorption, particularly with multi-band broadband scalability for specialized scenarios, remains a challenge. As an example, the presence of atmospheric windows, as dictated by special gas molecules in different infrared regions, highly demands such scalable modulation abilities for multi-band absorption and filtration. Herein, by leveraging the hybrid effect of Fabry–Perot resonance, magnetic dipole resonance and electric dipole resonance, we achieved multi-broadband absorptivity in three prominent infrared atmospheric windows concurrently, with an average absorptivity of 87.6% in the short-wave infrared region (1.4–1.7 μm), 92.7% in the mid-wave infrared region (3.2–5 μm) and 92.4% in the long-wave infrared region (8–13 μm), respectively. The well-confirmed absorption spectra along with its adaptation to varied incident angles and polarization angles of radiations reveal great potential for fields like infrared imaging, photodetection and communication. Full article

(This article belongs to the Special Issue Nonlinear Optics of Nanostructures and Metasurfaces)

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12 pages, 4481 KiB

Open AccessArticle

Large-Area Perovskite Solar Module Produced by Introducing Self-Assembled L-Histidine Monolayer at TiO₂ and Perovskite Interface

by Hung-Chieh Hsu, Jung-Che Tsao, Cheng-Hsien Yeh, Hsuan-Ta Wu, Chien-Te Wu, Shih-Hsiung Wu and Chuan-Feng Shih

Nanomaterials 2024, 14(15), 1315; https://doi.org/10.3390/nano14151315 - 4 Aug 2024

Abstract

Perovskite solar cells have been proven to enhance cell characteristics by introducing passivation materials that suppress defect formation. Defect states between the electron transport layer and the absorption layer reduce electron extraction and carrier transport capabilities, leading to a significant decline in device [...] Read more.

Perovskite solar cells have been proven to enhance cell characteristics by introducing passivation materials that suppress defect formation. Defect states between the electron transport layer and the absorption layer reduce electron extraction and carrier transport capabilities, leading to a significant decline in device performance and stability, as well as an increased probability of non-radiative recombination. This study proposes the use of an amino acid (L-Histidine) self-assembled monolayer material between the transport layer and the perovskite absorption layer. Surface analysis revealed that the introduction of L-Histidine improved both the uniformity and roughness of the perovskite film surface. X-ray photoelectron spectroscopic analysis showed a reduction in oxygen vacancies in the lattice and an increase in Ti⁴⁺, indicating that L-Histidine successfully passivated trap states at the perovskite and TiO₂ electron transport layer interface. In terms of device performance, the introduction of L-Histidine significantly improved the fill factor (FF) because the reduction in interface defects could suppress charge accumulation and reduce device hysteresis. The FF of large-area solar modules (25 cm²) with L-Histidine increased from 55% to 73%, and the power conversion efficiency (PCE) reached 16.5%. After 500 h of aging tests, the PCE still maintained 91% of its original efficiency. This study demonstrates the significant impact of L-Histidine on transport properties and showcases its potential for application in the development of large-area perovskite module processes. Full article

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Graphical abstract

9 pages, 1712 KiB

Open AccessArticle

An Organic Microcavity Laser Amplifier Integrated on the End Facet of an Optical Fiber

by Meng Wang, Zhuangzhuang Xu, Yaqi Ren, Xiaolei Bai and Xinping Zhang

Nanomaterials 2024, 14(15), 1314; https://doi.org/10.3390/nano14151314 - 4 Aug 2024

Abstract

We report a thin-film optical amplifier integrated on a fiber facet based on polymer-coated distributed feedback (DFB) microcavities, which are fabricated on a planar substrate and then transferred onto fiber tips by means of a flexible transfer technique. The amplified light directly couples [...] Read more.

We report a thin-film optical amplifier integrated on a fiber facet based on polymer-coated distributed feedback (DFB) microcavities, which are fabricated on a planar substrate and then transferred onto fiber tips by means of a flexible transfer technique. The amplified light directly couples into the fiber and is detected when coupled out at the other end after propagating along the fiber for about 20 cm. A prominently amplification factor of about 4.33 at 578.57 nm is achieved by sending supercontinuum pulses into the hundreds of micrometers’ DFB microcavities along the normal direction, which is also the axis direction of the fiber. The random distortions of grating lines generated during the transfer process result in a larger amplification spectral range and a less strict polarization dependence for injected light. Benefitting from the device size of hundreds of micrometers and the ease of integration, polymer amplifiers based on DFB microcavities demonstrate significant application potentials in optical communication systems and miniaturized optical devices. Full article

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15 pages, 3526 KiB

Open AccessArticle

Plasma Modification of Biomass-Based Starfish Catalysts for Efficient Biodiesel Synthesis

by Sungho Lee, Jeyoung Ha and Oi Lun Li

Nanomaterials 2024, 14(15), 1313; https://doi.org/10.3390/nano14151313 - 4 Aug 2024

Abstract

This study investigated biodiesel production via the transesterification of grapeseed oil with plasma-modified biomass-based catalysts originating from starfish. Dried starfish was first converted into magnesium and calcium oxide through heat treatment and then further modified by plasma engineering to improve the catalyst’s surface [...] Read more.

This study investigated biodiesel production via the transesterification of grapeseed oil with plasma-modified biomass-based catalysts originating from starfish. Dried starfish was first converted into magnesium and calcium oxide through heat treatment and then further modified by plasma engineering to improve the catalyst’s surface area and active sites via zinc addition. The Zn content was added via plasma engineering in the ratios of starfish (Mg_0.1Ca_0.9CO₃): ZnO varying from 5:1, 10:1, to 20:1. The structure and morphology of the catalyst were confirmed through XRD, SEM, and XPS analysis. After the Zn addition and activation process, the surface area and the basicity of the synthesized catalysts were increased. The plasma-modified catalyst showed the highest basicity at the ratio of 10:1. Based on HPLC analyses, the optimized biodiesel yield in transesterification demonstrated 97.7% in fatty acid conversion, and its catalytic performance maintained 93.2% even after three repeated runs. Full article

(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)

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11 pages, 3214 KiB

Open AccessArticle

Highly Efficient Peroxymonosulfate Electroactivation on Co(OH)₂ Nanoarray Electrode for Pefloxacin Degradation

by Tonghui Bao, Hui Ke, Wanjiang Li, Linke Cai and Yi Huang

Nanomaterials 2024, 14(15), 1312; https://doi.org/10.3390/nano14151312 - 4 Aug 2024

Abstract

The activation of PMS to produce active species is an attractive technique for antibiotic degradation but is restricted to the low reaction kinetics and high costs. In this work, a cobalt-based catalyst was prepared by in situ electrodeposition to enhance the electrically activated [...] Read more.

The activation of PMS to produce active species is an attractive technique for antibiotic degradation but is restricted to the low reaction kinetics and high costs. In this work, a cobalt-based catalyst was prepared by in situ electrodeposition to enhance the electrically activated PMS process for the degradation of antibiotics. Almost 100% of pefloxacin (PFX) was removed within 10 min by employing Co(OH)₂ as the catalyst in the electrically activated peroxymonosulfate (PMS) process, and the reaction kinetic constant reached 0.52 min⁻¹. The redox processes of Co²⁺ and Co³⁺ in Co(OH)₂ catalysts were considered to be the main pathways for PMS activation, in which ¹O₂ was the main active species. Furthermore, this strategy could also achieve excellent degradation efficiency for other organic pollutants. This study provides an effective and low-cost strategy with no secondary pollution for pollutant degradation. Full article

(This article belongs to the Special Issue Functional Nanostructured Electro/Photocatalysts for Energy Conversion and Environmental Treatment)

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13 pages, 1507 KiB

Open AccessReview

Iron Oxide Nanoparticles as Promising Antibacterial Agents of New Generation

by Tian-Guang Zhang and Chao-Yu Miao

Nanomaterials 2024, 14(15), 1311; https://doi.org/10.3390/nano14151311 - 3 Aug 2024

Abstract

Antimicrobial resistance (AMR) is growing into a major public health crisis worldwide. The reducing alternatives to conventional agents starve for novel antimicrobial agents. Due to their unique magnetic properties and excellent biocompatibility, iron oxide nanoparticles (IONPs) are the most preferable nanomaterials in biomedicine, [...] Read more.

Antimicrobial resistance (AMR) is growing into a major public health crisis worldwide. The reducing alternatives to conventional agents starve for novel antimicrobial agents. Due to their unique magnetic properties and excellent biocompatibility, iron oxide nanoparticles (IONPs) are the most preferable nanomaterials in biomedicine, including antibacterial therapy, primarily through reactive oxygen species (ROS) production. IONP characteristics, including their size, shape, surface charge, and superparamagnetism, influence their biodistribution and antibacterial activity. External magnetic fields, foreign metal doping, and surface, size, and shape modification improve the antibacterial effect of IONPs. Despite a few disadvantages, IONPs are expected to be promising antibacterial agents of a new generation. Full article

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14 pages, 10436 KiB

Open AccessArticle

Impact of Residual Strains on the Carrier Mobility and Sability of Perovskite Films

by Moulay Ahmed Slimani, Luis Felipe Gerlein, Ricardo Izquierdo and Sylvain G. Cloutier

Nanomaterials 2024, 14(15), 1310; https://doi.org/10.3390/nano14151310 - 3 Aug 2024

Abstract

Solution-based inorganic–organic halide perovskites are of great interest to researchers because of their unique optoelectronic properties and easy processing. However, polycrystalline perovskite films often show inhomogeneity due to residual strain induced during the film’s post-processing phase. In turn, these strains can impact both [...] Read more.

Solution-based inorganic–organic halide perovskites are of great interest to researchers because of their unique optoelectronic properties and easy processing. However, polycrystalline perovskite films often show inhomogeneity due to residual strain induced during the film’s post-processing phase. In turn, these strains can impact both their stability and performance. An exhaustive study of residual strains can provide a better understanding and control of how they affect the performance and stability of perovskite films. In this work, we explore this complex interrelationship between residual strains and electrical properties for methylammonium

{CH}_{3} {NH}_{3} {PbI}_{3 - x} {Cl}_{x}

films using grazing incidence X-ray diffraction (GIXRD). We correlate their resistivity and carrier mobility using the Hall effect. The

\sin^{2} (ψ)

technique is used to optimize the annealing parameters for the perovskite films. We also establish that temperature-induced relaxation can yield a significant enhancement of the charge carrier transports in perovskite films. Finally, we also use Raman micro-spectroscopy to assess the degradation of perovskite films as a function of their residual strains. Full article

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15 pages, 4063 KiB

Open AccessArticle

Nanotechnological Antibacterial and Conductive Wound Dressings for Pressure Ulcer Prevention

by Mauro Pollini, Raffaella Striani, Federica Paladini, Aida Kiani, Maria Rosaria Acocella and Carola Esposito Corcione

Nanomaterials 2024, 14(15), 1309; https://doi.org/10.3390/nano14151309 - 3 Aug 2024

Abstract

The development of pressure ulcers, associated with increased temperature and moisture in specific areas of the body, and the risk of microbial infections in patients lying in a static position for prolonged periods of time represents a serious issue in medicine. In order [...] Read more.

The development of pressure ulcers, associated with increased temperature and moisture in specific areas of the body, and the risk of microbial infections in patients lying in a static position for prolonged periods of time represents a serious issue in medicine. In order to prevent the formation of pressure ulcers, this work aims to present advanced nanostructured coatings developed by three research groups. Nanometric silver, ash and functionalized torrefied biomass were the basis for the treatment of wound dressings to improve thermal conductivity and antimicrobial properties of the conventional cotton gauzes. Each treatment was performed according to its own optimized method. The treated fabrics were characterized in terms of antimicrobial properties, heat transfer, morphology and hydrophobic behavior. The results demonstrated the effectiveness of the deposition treatments also in synergistic actions. In particular, the antibacterial efficacy was improved in all the samples by the addition of silver treatment, and the thermal conductivity was enhanced by around 58% with nanometric ashes. A further step of the study involved the designing of two multilayer systems evaluated using circuit models for determining the total thermal conductivity. In this way, both systems were designed with the aim to guarantee simultaneous efficacy: high antibacterial and hydrophilic properties at the skin level and more hydrophobic and conductive behaviors toward the external environment. Full article

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16 pages, 5814 KiB

Open AccessArticle

Nano-Biochar Prepared from High-Pressure Homogenization Improves Thermal Conductivity of Ethylene Glycol-Based Coolant

by Youheng Wang, Xianjun Hou, Hong Yu, Weiwei Guan, Yuxin Ma and Mohamed Kamal Ahmed Ali

Nanomaterials 2024, 14(15), 1308; https://doi.org/10.3390/nano14151308 - 3 Aug 2024

Abstract

As an environmentally friendly material, biochar is increasingly being utilized in the field of heat transfer and thermal conduction. In this study, nano-biochar was prepared from high-pressure homogenization (HPH) using sesame stalks as the raw material. It was incorporated into ethylene glycol (EG) [...] Read more.

As an environmentally friendly material, biochar is increasingly being utilized in the field of heat transfer and thermal conduction. In this study, nano-biochar was prepared from high-pressure homogenization (HPH) using sesame stalks as the raw material. It was incorporated into ethylene glycol (EG) and its dispersion stability, viscosity, and thermal conductivity were investigated. The nano-biochar was stably dispersed in EG for 28 days. When the concentration of the nano-biochar added to EG was less than 1%, the impact on viscosity was negligible. The addition of 5 wt.% nano-biochar to EG improved the thermal conductivity by 6.72%, which could be attributed to the graphitized structure and Brownian motion of the nano-biochar. Overall, nano-biochar has the potential to be applied in automotive thermal management. Full article

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12 pages, 5753 KiB

Open AccessArticle

A Study on Dual-Gate Dielectric Face Tunnel Field-Effect Transistor for Ternary Inverter

by Aoxuan Wang, Hongliang Lu, Yuming Zhang, Jiale Sun and Zhijun Lv

Nanomaterials 2024, 14(15), 1307; https://doi.org/10.3390/nano14151307 - 3 Aug 2024

Abstract

In this article, we propose a dual-gate dielectric face tunnel field-effect transistor (DGDFTFET) that can exhibit three different output voltage states. Meanwhile, according to the requirements of the ternary operation in the ternary inverter, four related indicators representing the performance of the DGDFTFET [...] Read more.

In this article, we propose a dual-gate dielectric face tunnel field-effect transistor (DGDFTFET) that can exhibit three different output voltage states. Meanwhile, according to the requirements of the ternary operation in the ternary inverter, four related indicators representing the performance of the DGDFTFET are proposed, and we explain the impact of these indicators on the inverter and confirm that better indicators can be obtained by choosing appropriate design parameters for the device. Then, the ternary inverter implemented with this device can exhibit voltage transfer characteristics (VTCs) with three stable output voltage levels and bigger static noise margins (SNMs). In addition, by comparing the indicators of the DGDFTFET and a face tunnel field-effect transistor (FTFET), as well as the SNM of inverters, it is demonstrated that the performance of the DGDFTFET far surpasses the FTFET. Full article

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11 pages, 3469 KiB

Open AccessArticle

Tunable Ag Nanocavity Enhanced Green Electroluminescence from SiN_x:O Light-Emitting Diode

by Zongyan Zuo, Zhongyuan Ma, Tong Chen, Wenping Zhang, Wei Li, Jun Xu, Ling Xu and Kunji Chen

Nanomaterials 2024, 14(15), 1306; https://doi.org/10.3390/nano14151306 - 3 Aug 2024

Abstract

As the driving source, highly efficient silicon-based light emission is urgently needed for the realization of optoelectronic integrated chips. Here, we report that enhanced green electroluminescence (EL) can be obtained from oxygen-doped silicon nitride (SiN_x:O) films based on an ordered and [...] Read more.

As the driving source, highly efficient silicon-based light emission is urgently needed for the realization of optoelectronic integrated chips. Here, we report that enhanced green electroluminescence (EL) can be obtained from oxygen-doped silicon nitride (SiN_x:O) films based on an ordered and tunable Ag nanocavity array with a high density by nanosphere lithography and laser irradiation. Compared with that of a pure SiN_xO device, the green electroluminescence (EL) from the SiN_x:O/Ag nanocavity array device can be increased by 7.1-fold. Moreover, the external quantum efficiency of the green electroluminescence (EL) is enhanced 3-fold for SiN_x:O/Ag nanocavity arrays with diameters of 300 nm. The analysis of absorption spectra and the FDTD calculation reveal that the localized surface plasmon (LSP) resonance of size-controllable Ag nanocavity arrays and SiN_x:O films play a key role in the strong green EL. Our discovery demonstrates that SiN_x:O films coupled with tunable Ag nanocavity arrays are promising for silicon-based light-emitting diode devices of the AI period in the future. Full article

(This article belongs to the Section Nanocomposite Materials)

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22 pages, 3394 KiB

Open AccessReview

Cancer Treatment Using Nanofibers: A Review

by Muhammad Qamar Khan, Muhammad Abbas Alvi, Hafiza Hifza Nawaz and Muhammad Umar

Nanomaterials 2024, 14(15), 1305; https://doi.org/10.3390/nano14151305 - 2 Aug 2024

Abstract

Currently, the number of patients with cancer is expanding consistently because of a low quality of life. For this reason, the therapies used to treat cancer have received a lot of consideration from specialists. Numerous anticancer medications have been utilized to treat patients [...] Read more.

Currently, the number of patients with cancer is expanding consistently because of a low quality of life. For this reason, the therapies used to treat cancer have received a lot of consideration from specialists. Numerous anticancer medications have been utilized to treat patients with cancer. However, the immediate utilization of anticancer medicines leads to unpleasant side effects for patients and there are many restrictions to applying these treatments. A number of polymers like cellulose, chitosan, Polyvinyl Alcohol (PVA), Polyacrylonitrile (PAN), peptides and Poly (hydroxy alkanoate) have good properties for the treatment of cancer, but the nanofibers-based target and controlled drug delivery system produced by the co-axial electrospinning technique have extraordinary properties like favorable mechanical characteristics, an excellent release profile, a high surface area, and a high sponginess and are harmless, bio-renewable, biofriendly, highly degradable, and can be produced very conveniently on an industrial scale. Thus, nanofibers produced through coaxial electrospinning can be designed to target specific cancer cells or tissues. By modifying the composition and properties of the nanofibers, researchers can control the release kinetics of the therapeutic agent and enhance its accumulation at the tumor site while minimizing systemic toxicity. The core–shell structure of coaxial electrospun nanofibers allows for a controlled and sustained release of therapeutic agents over time. This controlled release profile can improve the efficacy of cancer treatment by maintaining therapeutic drug concentrations within the tumor microenvironment for an extended period. Full article

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16 pages, 6275 KiB

Open AccessArticle

Effect of Titanium Dioxide Particles on the Thermal Stability of Silica Aerogels

by Caide Fan, Jialu Lu, Chengjie Duan, Chengbin Wu, Jiming Lin, Ruoxiang Qiu, Zehui Zhang, Jianming Yang, Bin Zhou and Ai Du

Nanomaterials 2024, 14(15), 1304; https://doi.org/10.3390/nano14151304 - 2 Aug 2024

Abstract

Silica aerogels exhibit a unique nanostructure with low thermal conductivity and low density, making them attractive materials for thermal isolation under extreme conditions. The TiO₂ particle is one of the common industrial additives used to reduce the thermal radiation of aerogel composites [...] Read more.

Silica aerogels exhibit a unique nanostructure with low thermal conductivity and low density, making them attractive materials for thermal isolation under extreme conditions. The TiO₂ particle is one of the common industrial additives used to reduce the thermal radiation of aerogel composites under high-temperature environments, but its influence on thermal resistance is almost unknown. Herein, we report the effect of TiO₂ nanoparticles with different crystal phases and different sizes on the thermal stability of silica aerogel composites. By adding TiO₂ nanoparticles, the aerogel can significantly resist collapse at high temperatures (up to 1000 °C). And compared with the rutile phase TiO₂, the anatase phase TiO₂ shows much higher temperature resistance performance, with shrinkage of only one-sixth of the rutile phase after 800 °C treatment. Interestingly, energy-dispersive spectrometer mapping results show that after 800 °C treatment, silica nanoparticles (NPs) are squeezed out in between anatase TiO₂ particles, which resists the coarsening of silica NPs and ultimately enhances the stability of aerogel composites. The optimal anatase phase TiO₂-doped silica aerogel demonstrates the integrated properties of crack-free morphology (2.84% shrinkage), low thermal conductivity (29.30 mW/(m·K)) and low density (149.4 mg/cm³) after 800 °C treatment. This study may provide new insights for developing oxide-doped silica aerogels with both high-temperature resistance and low thermal radiation. Full article

(This article belongs to the Special Issue Nanomaterials in Aerogel Composites)

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