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Nanomaterials
Volume 14
Issue 12
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Nanomaterials, Volume 14, Issue 12 (June-2 2024) – 74 articles

Cover Story (view full-size image): Electromagnetic waves propagating in a layered superconductor with arbitrary momentum, with respect to the main crystallographic directions, exhibit unavoidable mixing between longitudinal and transverse degrees of freedom. Here, we show that this basic physical mechanism explains the emergence of a well-defined absorption peak in the in-plane optical conductivity when light propagates at small tilting angles relative to the stacking direction in layered cuprates. We suggest that an all-optical tilted geometry measurement can be used as an alternative way to access plasma-wave dispersion, usually measured by means of large-momentum scattering techniques. View this paper
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25 pages, 5396 KiB  
Review
Understanding of Lanthanide-Doped Core–Shell Structure at the Nanoscale Level
by Qing Zhao, **nle Tian, Langtao Ren, Yan Su and Qianqian Su
Nanomaterials 2024, 14(12), 1063; https://doi.org/10.3390/nano14121063 - 20 Jun 2024
Viewed by 383
Abstract
The groundbreaking development of lanthanide-doped core–shell nanostructures have successfully achieved precise optical tuning of rare-earth nanocrystals, leading to significant improvements in energy transfer efficiency and facilitating multifunctional integration. Exploring the atomic-level structural, physical, and optical properties of rare-earth core–shell nanocrystals is essential for [...] Read more.
The groundbreaking development of lanthanide-doped core–shell nanostructures have successfully achieved precise optical tuning of rare-earth nanocrystals, leading to significant improvements in energy transfer efficiency and facilitating multifunctional integration. Exploring the atomic-level structural, physical, and optical properties of rare-earth core–shell nanocrystals is essential for advancing our understanding of their fundamental principles and driving the development of emerging applications. However, our knowledge of the atomic-level structural details of rare-earth nanocrystal core–shell structures remains limited. This review provides a comprehensive discussion of synthesis strategies, characterization techniques, interfacial ion-mixing phenomena, strain effects, and spectral modulation in core–shell structures of rare-earth-doped nanocrystals. Additionally, we prospectively discuss the challenges encountered in studying the fine structures of rare-earth-doped core–shell nanocrystals, particularly the increasing demand for researchers to integrate interdisciplinary knowledge and utilize high-end precision instruments. Full article
(This article belongs to the Special Issue Luminescent Nanomaterials: Functional Design, Advantages, and Applications)
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23 pages, 7418 KiB  
Article
Advanced Optoelectronic Modeling and Optimization of HTL-Free FASnI3/C60 Perovskite Solar Cell Architecture for Superior Performance
by Tariq AlZoubi, Wasan J. Kadhem, Mahmoud Al Gharram, Ghaseb Makhadmeh, Mohamed A. O. Abdelfattah, Abdulsalam Abuelsamen, Ahmad M. AL-Diabat, Osama Abu Noqta, Bojan Lazarevic, Samer H. Zyoud and Bachar Mourched
Nanomaterials 2024, 14(12), 1062; https://doi.org/10.3390/nano14121062 - 20 Jun 2024
Viewed by 504
Abstract
In this study, a novel perovskite solar cell (PSC) architecture is presented that utilizes an HTL-free configuration with formamide tin iodide (FASnI3) as the active layer and fullerene (C60) as the electron transport layer (ETL), which represents a pioneering approach within [...] Read more.
In this study, a novel perovskite solar cell (PSC) architecture is presented that utilizes an HTL-free configuration with formamide tin iodide (FASnI3) as the active layer and fullerene (C60) as the electron transport layer (ETL), which represents a pioneering approach within the field. The elimination of hole transport layers (HTLs) reduces complexity and cost in PSC heterojunction structures, resulting in a simplified and more cost-effective PSC structure. In this context, an HTL-free tin HC(NH2)2SnI3-based PSC was simulated using the solar cell capacitance simulator (SCAPS) within a one-dimensional framework. Through this approach, the device performance of this novel HTL-free FASnI3-based PSC structure was engineered and evaluated. Key performance parameters, including the open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), power conversion efficiency (PCE), I-V characteristics, and quantum efficiency (QE), were systematically assessed through the modulation of physical parameters across various layers of the device. A preliminary analysis indicated that the HTL-free configuration exhibited improved I-V characteristics, with a PCE increase of 1.93% over the HTL configuration due to improved electron and hole extraction characteristics, reduced current leakage at the back contact, and reduced trap-induced interfacial recombination. An additional boost to the device’s key performance parameters has been achieved through the further optimization of several physical parameters, such as active layer thickness, bulk and interface defects, ETL thickness, carrier concentration, and back-contact materials. For instance, increasing the thickness of the active layer PSC up to 1500 nm revealed enhanced PV performance parameters; however, further increases in thickness have resulted in performance saturation due to an increased rate of hole–electron recombination. Moreover, a comprehensive correlation study has been conducted to determine the optimum thickness and donor do** level for the C60-ETL layer in the range of 10–200 nm and 1012–1019 cm−3, respectively. Optimum device performance was observed at an ETL-C60 ultra-thin thickness of 10 nm and a carrier concentration of 1019 cm−3. To maintain improved PCEs, bulk and interface defects must be less than 1016 cm−3 and 1015 cm−3, respectively. Additional device performance improvement was achieved with a back-contact work function of 5 eV. The optimized HTL-free FASnI3 structure demonstrated exceptional photovoltaic performance with a PCE of 19.63%, Voc of 0.87 V, Jsc of 27.86 mA/cm2, and FF of 81%. These findings highlight the potential for highly efficient photovoltaic (PV) technology solutions based on lead-free perovskite solar cell (PSC) structures that contribute to environmental remediation and cost-effectiveness. Full article
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28 pages, 8489 KiB  
Article
Microstructural, Electrical, and Tribomechanical Properties of Mo-W-C Nanocomposite Films
by Kateryna Smyrnova, Volodymyr I. Ivashchenko, Martin Sahul, Ľubomír Čaplovič, Petro Skrynskyi, Andrii Kozak, Piotr Konarski, Tomasz N. Koltunowicz, Piotr Galaszkiewicz, Vitalii Bondariev, Pawel Zukowski, Piotr Budzynski, Svitlana Borba-Pogrebnjak, Mariusz Kamiński, Lucia Bónová, Vyacheslav Beresnev and Alexander Pogrebnjak
Nanomaterials 2024, 14(12), 1061; https://doi.org/10.3390/nano14121061 - 20 Jun 2024
Viewed by 596
Abstract
This study investigates the phase composition, microstructure, and their influence on the properties of Mo-W-C nanocomposite films deposited by dual-source magnetron sputtering. The synthesised films consist of metal carbide nanograins embedded in an amorphous carbon matrix. It has been found that nanograins are [...] Read more.
This study investigates the phase composition, microstructure, and their influence on the properties of Mo-W-C nanocomposite films deposited by dual-source magnetron sputtering. The synthesised films consist of metal carbide nanograins embedded in an amorphous carbon matrix. It has been found that nanograins are composed of the hexagonal β-(Mo2 + W2)C phase at a low carbon source power. An increase in the power results in the change in the structure of the carbide nanoparticles from a single-phase to a mixture of the β-(Mo2 + W2)C and NaCl-type α-(Mo + W)C(0.65≤k≤1) solid-solution phases. The analysis of electrical properties demonstrates that the nanograin structure of the films favours the occurrence of hop** conductivity. The double-phase structure leads to a twofold increase in the relaxation time compared to the single-phase one. Films with both types of nanograin structures exhibit tunnelling conductance without the need for thermal activation. The average distance between the potential wells produced by the carbide nanograins in nanocomposite films is approximately 3.4 ± 0.2 nm. A study of tribomechanical properties showed that Mo-W-C films composed of a mixture of the β-(Mo2 + W2)C and α-(Mo + W)C(0.65≤k≤1) phases have the highest hardness (19–22 GPa) and the lowest friction coefficient (0.15–0.24) and wear volume (0.00302–0.00381 mm2). Such a combination of electrical and tribomechanical properties demonstrates the suitability of Mo-W-C nanocomposite films for various micromechanical devices and power electronics. Full article
(This article belongs to the Special Issue Novel Nanocomposites: Optical, Electrical, Mechanical and Surface-Related Properties (2nd Edition))
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18 pages, 1142 KiB  
Review
Research on the Migration and Adsorption Mechanism Applied to Microplastics in Porous Media: A Review
by Lin Zeng, Cong Yuan, Taoyu **ang, **angwei Guan, Li Dai, Dingliang Xu, Danhui Yang, Long Li and Chengcheng Tian
Nanomaterials 2024, 14(12), 1060; https://doi.org/10.3390/nano14121060 - 20 Jun 2024
Viewed by 521
Abstract
In recent years, microplastics (MPs) have emerged as a significant environmental pollutant, garnering substantial attention for their migration and transformation behaviors in natural environments. MPs frequently infiltrate natural porous media such as soil, sediment, and rock through various pathways, posing potential threats to [...] Read more.
In recent years, microplastics (MPs) have emerged as a significant environmental pollutant, garnering substantial attention for their migration and transformation behaviors in natural environments. MPs frequently infiltrate natural porous media such as soil, sediment, and rock through various pathways, posing potential threats to ecological systems and human health. Consequently, the migration and adsorption mechanisms applied to MPs in porous media have been extensively studied. This paper aims to elucidate the migration mechanisms of MPs in porous media and their influencing factors through a systematic review. The review encompasses the characteristics of MPs, the physical properties of porous media, and hydrodynamic factors. Additionally, the paper further clarifies the adsorption mechanisms of MPs in porous media to provide theoretical support for understanding their environmental behavior and fate. Furthermore, the current mainstream detection techniques for MPs are reviewed, with an analysis of the advantages, disadvantages, and applications of each technique. Finally, the paper identifies the limitations and shortcomings of current research and envisions future research directions. Full article
(This article belongs to the Special Issue Control of New Pollutants by Functional Nanomaterials and Their Ecological Risk Assessment)
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15 pages, 3802 KiB  
Article
Magnetic Particle Imaging-Guided Thermal Simulations for Magnetic Particle Hyperthermia
by Hayden Carlton, Nageshwar Arepally, Sean Healy, Anirudh Sharma, Sarah Ptashnik, Maureen Schickel, Matt Newgren, Patrick Goodwill, Anilchandra Attaluri and Robert Ivkov
Nanomaterials 2024, 14(12), 1059; https://doi.org/10.3390/nano14121059 - 20 Jun 2024
Viewed by 735
Abstract
Magnetic particle hyperthermia (MPH) enables the direct heating of solid tumors with alternating magnetic fields (AMFs). One challenge with MPH is the unknown particle distribution in tissue after injection. Magnetic particle imaging (MPI) can measure the nanoparticle content and distribution in tissue after [...] Read more.
Magnetic particle hyperthermia (MPH) enables the direct heating of solid tumors with alternating magnetic fields (AMFs). One challenge with MPH is the unknown particle distribution in tissue after injection. Magnetic particle imaging (MPI) can measure the nanoparticle content and distribution in tissue after delivery. The objective of this study was to develop a clinically translatable protocol that incorporates MPI data into finite element calculations for simulating tissue temperatures during MPH. To verify the protocol, we conducted MPH experiments in tumor-bearing mouse cadavers. Five 8–10-week-old female BALB/c mice bearing subcutaneous 4T1 tumors were anesthetized and received intratumor injections of Synomag®-S90 nanoparticles. Immediately following injection, the mice were euthanized and imaged, and the tumors were heated with an AMF. We used the Mimics Innovation Suite to create a 3D mesh of the tumor from micro-computerized tomography data and spatial index MPI to generate a scaled heating function for the heat transfer calculations. The processed imaging data were incorporated into a finite element solver, COMSOL Multiphysics®. The upper and lower bounds of the simulated tumor temperatures for all five cadavers demonstrated agreement with the experimental temperature measurements, thus verifying the protocol. These results demonstrate the utility of MPI to guide predictive thermal calculations for MPH treatment planning. Full article
(This article belongs to the Special Issue Applications of Nanomaterials in Biomedical Imaging and Cancer Therapy II)
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13 pages, 3817 KiB  
Article
The Effect of Surface Oxygen Coverage on the Oxygen Evolution Reaction over a CoFeNiCr High-Entropy Alloy
by Geng Yuan and Luis Ruiz Pestana
Nanomaterials 2024, 14(12), 1058; https://doi.org/10.3390/nano14121058 - 19 Jun 2024
Viewed by 480
Abstract
Develo** cost-effective and highly active electrocatalysts for the oxygen evolution reaction (OER) is crucial for advancing sustainable energy applications. High-entropy alloys (HEAs) made from earth-abundant transition metals, thanks to their remarkable stability and electrocatalytic performance, provide a promising alternative to expensive electrocatalysts typically [...] Read more.
Develo** cost-effective and highly active electrocatalysts for the oxygen evolution reaction (OER) is crucial for advancing sustainable energy applications. High-entropy alloys (HEAs) made from earth-abundant transition metals, thanks to their remarkable stability and electrocatalytic performance, provide a promising alternative to expensive electrocatalysts typically derived from noble metals. While pristine HEA surfaces have been theoretically investigated, and the effect of oxygen coverage on conventional metal electrocatalysts has been examined, the impact of surface oxygen coverage on the electrocatalytic performance of HEAs remains poorly understood. To bridge this gap, we employ density functional theory (DFT) calculations to reconstruct the free energy diagram of OER intermediates on CoFeNiCr HEA surfaces with varying oxygen coverages, evaluating their impact on the rate-limiting step and theoretical overpotential. Our findings reveal that increased oxygen coverage weakens the adsorption of HO* and O*, but not HOO*. As a result, the theoretical overpotential for the OER decreases with higher oxygen coverage, and the rate-limiting step shifts from the third oxidation step (HOO* formation) at low coverage to the first oxidation step (HO* formation) at higher coverage. Full article
(This article belongs to the Special Issue Modeling, Simulation and Optimization of Nanomaterials)
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15 pages, 4477 KiB  
Article
Flow Behavior of Nanoparticle Agglomerates in a Fluidized Bed Simulated with Porous-Structure-Based Drag Laws
by Shaowei Wang, **aobing Hu, Niannian Liu and Huanpeng Liu
Nanomaterials 2024, 14(12), 1057; https://doi.org/10.3390/nano14121057 - 19 Jun 2024
Viewed by 417
Abstract
Fluidization bed reactor is an attractive method to synthesize and process quantities of functional nanoparticles, due to the large gas–solid contact area and its potential scalability. Nanoparticles fluidize not individually but as a form of porous agglomerates with a typical porosity above 90%. [...] Read more.
Fluidization bed reactor is an attractive method to synthesize and process quantities of functional nanoparticles, due to the large gas–solid contact area and its potential scalability. Nanoparticles fluidize not individually but as a form of porous agglomerates with a typical porosity above 90%. The porous structure has a significant effect on the hydrodynamic behavior of a single nanoparticle agglomerate, but its influence on the flow behavior of nanoparticle agglomerates in a fluidized bed is currently unclear. In the present study, a drag model was developed to consider the porous structure effects of nanoparticle agglomerates by incorporating porous-structure-based drag laws in the Eulerian–Eulerian two-fluid model. Numerical simulations were performed from particulate to bubbling fluidization state to evaluate the applicability of porous-structure-based drag laws. Results obtained for the minimum fluidization and bubbling velocities, bed expansion ratio, and agglomerate dispersion coefficient show that, compared with the drag law of solid sphere, the porous-structure-based drag laws, especially the drag law of fractal porous spheres, provide a closer fit to the experimental data. This indicates that the pore structures have a great impact on gas–solid flow behavior of nanoparticle agglomerates, and the porous-structure-based drag laws are more suitable for describing flows in nanoparticle agglomerate fluidized beds. Full article
(This article belongs to the Special Issue Nanomaterials for Chemical Engineering (Volume III))
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12 pages, 3186 KiB  
Article
Mixing Rules for Left-Handed Disordered Metamaterials: Effective-Medium and Dispersion Properties
by Ana Bărar, Stephen A. Maclean, Barry M. Gross, Doina Mănăilă-Maximean and Octavian Dănilă
Nanomaterials 2024, 14(12), 1056; https://doi.org/10.3390/nano14121056 - 19 Jun 2024
Viewed by 409
Abstract
Left-handed materials are known to exhibit exotic properties in controlling electromagnetic fields, with direct applications in negative reflection and refraction, conformal optical map**, and electromagnetic cloaking. While typical left-handed materials are constructed periodic metal-dielectric structures, the same effect can be obtained in composite [...] Read more.
Left-handed materials are known to exhibit exotic properties in controlling electromagnetic fields, with direct applications in negative reflection and refraction, conformal optical map**, and electromagnetic cloaking. While typical left-handed materials are constructed periodic metal-dielectric structures, the same effect can be obtained in composite guest–host systems with no periodicity or structural order. Such systems are typically described by the effective-medium approach, in which the components of the electric permittivity tensor are determined as a function of individual material properties and do** concentration. In this paper, we extend the discussion on the mixing rules to include left-handed composite systems and highlight the exotic properties arising from the effective-medium approach in this framework in terms of effective values and dispersion properties. Full article
(This article belongs to the Special Issue Metal-Based Nanomaterials: Fabrications, Optical Properties, and Ultrafast Photonics)
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20 pages, 14123 KiB  
Article
Potassium Iodide Do** for Vacancy Substitution and Dangling Bond Repair in InP Core-Shell Quantum Dots
by Ji-Eun Lee, Chang-** Lee, Seung-Jae Lee, Ui-Hyun Jeong and Jea-Gun Park
Nanomaterials 2024, 14(12), 1055; https://doi.org/10.3390/nano14121055 - 19 Jun 2024
Viewed by 475
Abstract
This work highlights the novel approach of incorporating potassium iodide (KI) do** during the synthesis of In0.53P0.47 core quantum dots (QDs) to significantly reduce the concentration of vacancies (i.e., In vacancies; VIn−) within the bulk of the [...] Read more.
This work highlights the novel approach of incorporating potassium iodide (KI) do** during the synthesis of In0.53P0.47 core quantum dots (QDs) to significantly reduce the concentration of vacancies (i.e., In vacancies; VIn−) within the bulk of the core QD and inhibit the formation of InPOx at the core QD–Zn0.6Se0.4 shell interfaces. The photoluminescence quantum yield (PLQY) of ~97% and full width at half maximum (FWHM) of ~40 nm were achieved for In0.53P0.47/Zn0.6Se0.4/Zn0.6Se0.1S0.3/Zn0.5S0.5 core/multi-shell QDs emitting red light, which is essential for a quantum-dot organic light-emitting diode (QD-OLED) without red, green, and blue crosstalk. KI do** eliminated VIn− in the core QD bulk by forming K+-VIn− substitutes and effectively inhibited the formation of InPO4(H2O)2 at the core QD–Zn0.6Se0.4 shell interface through the passivation of phosphorus (P)-dangling bonds by P-I bonds. The elimination of vacancies in the core QD bulk was evidenced by the decreased relative intensity of non-radiative unpaired electrons, measured by electron spin resonance (ESR). Additionally, the inhibition of InPO4(H2O)2 formation at the core QD and shell interface was confirmed by the absence of the {210} X-ray diffraction (XRD) peak intensity for the core/multi-shell QDs. By finely tuning the do** concentration, the optimal level was achieved, ensuring maximum K-VIn− substitution, minimal K+ and I− interstitials, and maximum P-dangling bond passivation. This resulted in the smallest core QD diameter distribution and maximized optical properties. Consequently, the maximum PLQY (~97%) and minimum FWHM (~40 nm) were observed at 3% KI do**. Furthermore, the color gamut of a QD-OLED display using R-, G-, and B-QD functional color filters (i.e., ~131.1%@NTSC and [email protected]) provided a nearly perfect color representation, where red-light-emitting KI-doped QDs were applied. Full article
(This article belongs to the Section Synthesis, Interfaces and Nanostructures)
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12 pages, 2984 KiB  
Article
Exploration and Optimization of the Polymer-Modified NiOx Hole Transport Layer for Fabricating Inverted Perovskite Solar Cells
by You-Wei Wu, Ching-Ying Wang and Sheng-Hsiung Yang
Nanomaterials 2024, 14(12), 1054; https://doi.org/10.3390/nano14121054 - 19 Jun 2024
Viewed by 555
Abstract
The recombination of charge carriers at the interface between carrier transport layers such as nickel oxide (NiOx) and the perovskite absorber has long been a challenge in perovskite solar cells (PSCs). To address this issue, we introduced a polymer additive poly(vinyl [...] Read more.
The recombination of charge carriers at the interface between carrier transport layers such as nickel oxide (NiOx) and the perovskite absorber has long been a challenge in perovskite solar cells (PSCs). To address this issue, we introduced a polymer additive poly(vinyl butyral) into NiOx and subjected it to high-temperature annealing to form a void-containing structure. The formation of voids is confirmed to increase light transmittance and surface area of NiOx, which is beneficial for light absorption and carrier separation within PSCs. Experimental results demonstrate that the incorporation of the polymer additive helped to enhance the hole conductivity and carrier extraction of NiOx with a higher Ni3+/Ni2+ ratio. This also optimized the energy levels of NiOx to match with the perovskite to raise the open-circuit voltage to 1.01 V. By incorporating an additional NiOx layer beneath the polymer-modified NiOx, the device efficiency was further increased as verified from the dark current measurement of devices. Full article
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22 pages, 5797 KiB  
Article
Composites of Titanium–Molybdenum Mixed Oxides and Non-Traditional Carbon Materials: Innovative Supports for Platinum Electrocatalysts for Polymer Electrolyte Membrane Fuel Cells
by Ilgar Ayyubov, Emília Tálas, Irina Borbáth, Zoltán Pászti, Cristina Silva, Ágnes Szegedi, Andrei Kuncser, M. Suha Yazici, István E. Sajó, Tamás Szabó and András Tompos
Nanomaterials 2024, 14(12), 1053; https://doi.org/10.3390/nano14121053 - 19 Jun 2024
Viewed by 422
Abstract
TiO2-based mixed oxide–carbon composite support for Pt electrocatalysts provides higher stability and CO tolerance under the working conditions of polymer electrolyte membrane fuel cells compared to traditional carbon supports. Non-traditional carbon materials like graphene nanoplatelets and graphite oxide used as the [...] Read more.
TiO2-based mixed oxide–carbon composite support for Pt electrocatalysts provides higher stability and CO tolerance under the working conditions of polymer electrolyte membrane fuel cells compared to traditional carbon supports. Non-traditional carbon materials like graphene nanoplatelets and graphite oxide used as the carbonaceous component of the composite can contribute to its affordability and/or functionality. Ti(1−x)MoxO2-C composites involving these carbon materials were prepared through a sol–gel route; the effect of the extension of the procedure through a solvothermal treatment step was assessed. Both supports and supported Pt catalysts were characterized by physicochemical methods. Electrochemical behavior of the catalysts in terms of stability, activity, and CO tolerance was studied. Solvothermal treatment decreased the fracture of graphite oxide plates and enhanced the formation of a reduced graphene oxide-like structure, resulting in an electrically more conductive and more stable catalyst. In parallel, solvothermal treatment enhanced the growth of mixed oxide crystallites, decreasing the chance of formation of Pt–oxide–carbon triple junctions, resulting in somewhat less CO tolerance. The electrocatalyst containing graphene nanoplatelets, along with good stability, has the highest activity in oxygen reduction reaction compared to the other composite-supported catalysts. Full article
(This article belongs to the Special Issue Synthesis & Devices of Graphene-Based 2D Nanomaterials for Energy Storage and Conversion)
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18 pages, 3322 KiB  
Article
Protocrystallinity of Monodispersed Ultra-Small Templated Mesoporous Silica Nanoparticles
by Laurent Bonneviot, Belén Albela, Feifei Gao, Pascal Perriat, Thierry Epicier and Mohamad El Eter
Nanomaterials 2024, 14(12), 1052; https://doi.org/10.3390/nano14121052 - 19 Jun 2024
Viewed by 392
Abstract
Monodisperse and semi-faceted ultra-small templated mesoporous silica nanoparticles (US-MSNs) of 20–25 nm were synthesized using short-time hydrolysis of tetraethoxysilane (TEOS) at room temperature, followed by a dilution for nucleation quenching. According to dynamic light scattering (DLS), a two-step pH adjustment was necessary for [...] Read more.
Monodisperse and semi-faceted ultra-small templated mesoporous silica nanoparticles (US-MSNs) of 20–25 nm were synthesized using short-time hydrolysis of tetraethoxysilane (TEOS) at room temperature, followed by a dilution for nucleation quenching. According to dynamic light scattering (DLS), a two-step pH adjustment was necessary for growth termination and colloidal stabilization. The pore size was controlled by cetyltrimethylammonium bromide (CTAB), and a tiny amount of neutral surfactant F127 was added to minimize the coalescence between US-MSNs and to favor the transition towards internal ordering. Flocculation eventually occurred, allowing us to harvest a powder by centrifugation (~60% silica yield after one month). Scanning transmission electron microscopy (STEM) and 3D high-resolution transmission electron microscopy (3D HR-TEM) images revealed that the US-MSNs are partially ordered. The 2D FT transform images provide evidence for the coexistence of four-, five-, and sixfold patterns characterizing an “on-the-edge” crystallization step between amorphous raspberry and hexagonal pore array morphologies, typical of a protocrystalline state. Calcination preserved this state and yielded a powder characterized by packing, develo** a hierarchical porosity centered at 3.9 ± 0.2 (internal pores) and 68 ± 7 nm (packing voids) of high potential for support for separation and catalysis. Full article
(This article belongs to the Special Issue Advanced Porous Nanomaterials: Synthesis, Properties, and Application)
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14 pages, 1913 KiB  
Article
Investigating the Electronic Properties and Stability of Rh3 Clusters on Rutile TiO2 for Potential Photocatalytic Applications
by Moteb Alotaibi
Nanomaterials 2024, 14(12), 1051; https://doi.org/10.3390/nano14121051 - 19 Jun 2024
Viewed by 407
Abstract
Addressing the pressing needs for alternatives to fossil fuel-based energy sources, this research explores the intricate interplay between Rhodium (Rh3) clusters and titanium dioxide (TiO2) to improve photocatalytic water splitting for the generation of eco-friendly hydrogen. This research applies [...] Read more.
Addressing the pressing needs for alternatives to fossil fuel-based energy sources, this research explores the intricate interplay between Rhodium (Rh3) clusters and titanium dioxide (TiO2) to improve photocatalytic water splitting for the generation of eco-friendly hydrogen. This research applies the density functional theory (DFT) coupled with the Hartree–Fock theory to meticulously examine the structural and electronic structures of Rh3 clusters on TiO2 (110) interfaces. Considering the photocatalytic capabilities of TiO2 and its inherent limitations in harnessing visible light, the potential for metals such as Rh3 clusters to act as co-catalysts is assessed. The results show that triangular Rh3 clusters demonstrate remarkable stability and efficacy in charge transfer when integrated into rutile TiO2 (110), undergoing oxidation in optimal adsorption conditions and altering the electronic structures of TiO2. The subsequent analysis of TiO2 surfaces exhibiting defects indicates that Rh3 clusters elevate the energy necessary for the formation of an oxygen vacancy, thereby enhancing the stability of the metal oxide. Additionally, the combination of Rh3-cluster adsorption and oxygen-vacancy formation generates polaronic and localized states, crucial for enhancing the photocatalytic activity of metal oxide in the visible light range. Through the DFT analysis, this study elucidates the importance of Rh3 clusters as co-catalysts in TiO2-based photocatalytic frameworks, paving the way for empirical testing and the fabrication of effective photocatalysts for hydrogen production. The elucidated impact on oxygen vacancy formation and electronic structures highlights the complex interplay between Rh3 clusters and TiO2 surfaces, providing insightful guidance for subsequent studies aimed at achieving clean and sustainable energy solutions. Full article
(This article belongs to the Special Issue Metallic Nanomaterial Applications in Selective Catalysis and Clean Energy)
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12 pages, 1505 KiB  
Article
(Sub-)Picosecond Surface Correlations of Femtosecond Laser Excited Al-Coated Multilayers Observed by Grazing-Incidence X-ray Scattering
by Lisa Randolph, Mohammadreza Banjafar, Toshinori Yabuuchi, Carsten Baehtz, Michael Bussmann, Nicholas P. Dover, Lingen Huang, Yuichi Inubushi, Gerhard Jakob, Mathias Kläui, Dmitriy Ksenzov, Mikako Makita, Kohei Miyanishi, Mamiko Nishiuchi, Özgül Öztürk, Michael Paulus, Alexander Pelka, Thomas R. Preston, Jan-Patrick Schwinkendorf, Keiichi Sueda, Tadashi Togashi, Thomas E. Cowan, Thomas Kluge, Christian Gutt and Motoaki Nakatsutsumiadd Show full author list remove Hide full author list
Nanomaterials 2024, 14(12), 1050; https://doi.org/10.3390/nano14121050 - 19 Jun 2024
Viewed by 460
Abstract
Femtosecond high-intensity laser pulses at intensities surpassing 1014 W/cm2 can generate a diverse range of functional surface nanostructures. Achieving precise control over the production of these functional structures necessitates a thorough understanding of the surface morphology dynamics with nanometer-scale spatial resolution [...] Read more.
Femtosecond high-intensity laser pulses at intensities surpassing 1014 W/cm2 can generate a diverse range of functional surface nanostructures. Achieving precise control over the production of these functional structures necessitates a thorough understanding of the surface morphology dynamics with nanometer-scale spatial resolution and picosecond-scale temporal resolution. In this study, we show that single XFEL pulses can elucidate structural changes on surfaces induced by laser-generated plasmas using grazing-incidence small-angle X-ray scattering (GISAXS). Using aluminium-coated multilayer samples we distinguish between sub-picosecond (ps) surface morphology dynamics and subsequent multi-ps subsurface density dynamics with nanometer-depth sensitivity. The observed subsurface density dynamics serve to validate advanced simulation models representing matter under extreme conditions. Our findings promise to open new avenues for laser material-nanoprocessing and high-energy-density science. Full article
(This article belongs to the Special Issue Laser-Matter Interaction for Nanostructuration: From Fundamentals to Optical, Electrochemical, Magnetic and Electrical Quantum Sensing)
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13 pages, 3758 KiB  
Article
Enhancing Optical and Thermal Stability of Blue-Emitting Perovskite Nanocrystals through Surface Passivation with Sulfonate or Sulfonic Acid Ligands
by Shu-Han Huang, Sheng-Hsiung Yang, Wen-Cheng Tsai and Hsu-Cheng Hsu
Nanomaterials 2024, 14(12), 1049; https://doi.org/10.3390/nano14121049 - 18 Jun 2024
Viewed by 505
Abstract
This study aims to enhance the optical and thermal properties of cesium-based perovskite nanocrystals (NCs) through surface passivation with organic sulfonate (or sulfonic acid) ligands. Four different phenylated ligands, including sodium β-styrenesulfonate (SbSS), sodium benzenesulfonate (SBS), sodium p-toluenesulfonate (SPTS), and 4-dodecylbenzenesulfonic acid [...] Read more.
This study aims to enhance the optical and thermal properties of cesium-based perovskite nanocrystals (NCs) through surface passivation with organic sulfonate (or sulfonic acid) ligands. Four different phenylated ligands, including sodium β-styrenesulfonate (SbSS), sodium benzenesulfonate (SBS), sodium p-toluenesulfonate (SPTS), and 4-dodecylbenzenesulfonic acid (DBSA), were employed to modify blue-emitting CsPbBr1.5Cl1.5 perovskite NCs, resulting in improved size uniformity and surface functionalization. Transmission electron microscopy and X-ray photoelectron spectroscopy confirmed the successful anchoring of sulfonate or sulfonic acid ligands on the surface of perovskite NCs. Moreover, the photoluminescence quantum yield increased from 32% of the original perovskite NCs to 63% of the SPTS-modified ones due to effective surface passivation. Time-resolved photoluminescence decay measurements revealed extended PL lifetimes for ligand-modified NCs, indicative of reduced nonradiative recombination. Thermal stability studies demonstrated that the SPTS-modified NCs retained nearly 80% of the initial PL intensity when heated at 60 °C for 10 min, surpassing the performance of the original NCs. These findings emphasize the optical and thermal stability enhancement of cesium-based perovskite NCs through surface passivation with suitable sulfonate ligands. Full article
(This article belongs to the Special Issue Synthesis and Applications of Perovskite Nanocrystals)
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13 pages, 5110 KiB  
Article
Polarization and Incident Angle Independent Multifunctional and Multiband Tunable THz Metasurface Based on VO2
by Rehmat Iqbal, Ubaid Ur Rahman Qureshi, Cao Jie, Zia Ur Rahman and Naveed Jafar
Nanomaterials 2024, 14(12), 1048; https://doi.org/10.3390/nano14121048 - 18 Jun 2024
Viewed by 462
Abstract
Aiming at the limitations of single-functionality, limited-applicability, and complex designs prevalent in current metasurfaces, we propose a terahertz multifunctional and multiband tunable metasurface utilizing a VO2-metal hybrid structure. This metasurface structure comprises a top VO2-metal resonance layer, a middle [...] Read more.
Aiming at the limitations of single-functionality, limited-applicability, and complex designs prevalent in current metasurfaces, we propose a terahertz multifunctional and multiband tunable metasurface utilizing a VO2-metal hybrid structure. This metasurface structure comprises a top VO2-metal resonance layer, a middle polyimide dielectric layer, and a gold film reflective layer at the bottom. This metasurface exhibits multifunctionality, operating independently of polarization and incident angle. The varying conductivity states of the VO2 layers, enabling the metasurface to achieve various terahertz functionalities, including single-band absorption, broadband THz absorption, and multiband perfect polarization conversion for linear (LP) and circularly polarized (CP) incident waves. Finally, we believe that the functional adaptability of the proposed metasurface expands the repertoire of options available for future terahertz device designs. Full article
(This article belongs to the Topic Optical and Optoelectronic Properties of Materials and Their Applications)
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21 pages, 7013 KiB  
Article
Degradation and Recondensation of Metal Oxide Nanoparticles in Laminar Premixed Flames
by Nadine May, Werner Baumann, Manuela Hauser, Zhiyao Yin, Klaus Peter Geigle and Dieter Stapf
Nanomaterials 2024, 14(12), 1047; https://doi.org/10.3390/nano14121047 - 18 Jun 2024
Viewed by 341
Abstract
The behavior of technical nanoparticles at high temperatures was measured systematically to detect morphology changes under conditions relevant to the thermal treatment of end-of-life products containing engineered nanomaterials. The focus of this paper is on laboratory experiments, where we used a Bunsen-type burner [...] Read more.
The behavior of technical nanoparticles at high temperatures was measured systematically to detect morphology changes under conditions relevant to the thermal treatment of end-of-life products containing engineered nanomaterials. The focus of this paper is on laboratory experiments, where we used a Bunsen-type burner to add titania and ceria particles to a laminar premixed flame. To evaluate the influence of temperature on particle size distributions, we used SMPS, ELPI and TEM analyses. To measure the temperature profile of the flame, we used coherent anti-Stokes Raman spectroscopy (CARS). The comprehensible data records show high temperatures by measurement and equilibrium calculation for different stoichiometries and argon admixtures. With this, we show that all technical metal oxide nanoparticle agglomerates investigated reform in flames at high temperatures. The originally large agglomerates of titania and ceria build very small nanoparticles (<10 nm/“peak 2”) at starting temperatures of <2200 K and <1475 K, respectively (ceria: Tmelt = 2773 K, Tboil = 3873 K/titania: Tmelt = 2116 K, Tboil = 3245 K). Since the maximum flame temperatures are below the evaporation temperature of titania and ceria, enhanced vaporization of titania and ceria in the chemically reacting flame is assumed. Full article
(This article belongs to the Special Issue Environmental Analysis and Environmental Processes of Nanomaterials)
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15 pages, 4092 KiB  
Article
Preparation of Hybrid Magnetic Nanoparticles for Sensitive and Rapid Detection of Phorate Residue in Celery Using SERS Immunochromatography Assay
by **angyang Li, Hean Qian, ** Tao, Mingshuo Cao, Meng Wang and Wenlei Zhai
Nanomaterials 2024, 14(12), 1046; https://doi.org/10.3390/nano14121046 - 18 Jun 2024
Viewed by 404
Abstract
Extensive use of pesticides in agricultural production has been causing serious health threats to humans and animals. Among them, phorate is a highly toxic organophosphorus insecticide that has been widely used in planting. Due to its harmful effects on human and animal health, [...] Read more.
Extensive use of pesticides in agricultural production has been causing serious health threats to humans and animals. Among them, phorate is a highly toxic organophosphorus insecticide that has been widely used in planting. Due to its harmful effects on human and animal health, it has been restricted for use in many countries. Analytical methods for the rapid and sensitive detection of phorate residues in agricultural products are urgently needed. In this study, a new method was developed by combining surface-enhanced Raman spectroscopy (SERS) and immunochromatography assay (ICA). Hybrid magnetic Fe3O4@Au@DTNB-Ab nanoprobes were prepared by modifying and growing Au nanoseeds on an Fe3O4 core. SERS activity of the nanoprobe was optimized by adjusting the concentration of the Au precursor. A rapid and sensitive assay was established by replacing the traditional colloidal gold-based ICA with hybrid SERS nanoprobes for SERS-ICA. After optimizing parameters including coating antibody concentrations and the composition and pH of the buffer solution, the limit of detection (LOD) for phorate could reach 1 ng/mL, with a linear range of 5~100 ng/mL. This LOD is remarkably lower than the maximum residue limit in vegetables and fruits set by the Chinese government. The feasibility of this method was further examined by conducting a spiking test with celery as the real sample. The result demonstrated that this method could serve as a promising platform for rapid and sensitive detection of phorate in agricultural products. Full article
(This article belongs to the Special Issue Novel Nanomaterials and Nanotechnology for Food Safety)
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31 pages, 16978 KiB  
Article
Synthesis and Characterization of Composite WO3 Fibers/g-C3N4 Photocatalysts for the Removal of the Insecticide Clothianidin in Aquatic Media
by Christos Lykos, Feidias Bairamis, Christina Efthymiou and Ioannis Konstantinou
Nanomaterials 2024, 14(12), 1045; https://doi.org/10.3390/nano14121045 - 18 Jun 2024
Viewed by 412
Abstract
Photocatalysis is a prominent alternative wastewater treatment technique that has the potential to completely degrade pesticides as well as other persistent organic pollutants, leading to detoxification of wastewater and thus paving the way for its efficient reuse. In addition to the more conventional [...] Read more.
Photocatalysis is a prominent alternative wastewater treatment technique that has the potential to completely degrade pesticides as well as other persistent organic pollutants, leading to detoxification of wastewater and thus paving the way for its efficient reuse. In addition to the more conventional photocatalysts (e.g., TiO2, ZnO, etc.) that utilize only UV light for activation, the interest of the scientific community has recently focused on the development and application of visible light-activated photocatalysts like g-C3N4. However, some disadvantages of g-C3N4, such as the high recombination rate of photogenerated charges, limit its utility. In this light, the present study focuses on the synthesis of WO3 fibers/g-C3N4 Z-scheme heterojunctions to improve the efficiency of g-C3N4 towards the photocatalytic removal of the widely used insecticide clothianidin. The effect of two different g-C3N4 precursors (urea and thiourea) and of WO3 fiber content on the properties of the synthesized composite materials was also investigated. All aforementioned materials were characterized by a number of techniques (XRD, SEM-EDS, ATR-FTIR, Raman spectroscopy, DRS, etc.). According to the results, mixing 6.5% W/W WO3 fibers with either urea or thiourea derived g-C3N4 significantly increased the photocatalytic activity of the resulting composites compared to the precursor materials. In order to further elucidate the effect of the most efficient composite photocatalyst in the degradation of clothianidin, the generated transformation products were tentatively identified through UHPLC tandem high-resolution mass spectroscopy. Finally, the detoxification effect of the most efficient process was also assessed by combining the results of an in-vitro methodology and the predictions of two in-silico tools. Full article
(This article belongs to the Section Environmental Nanoscience and Nanotechnology)
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11 pages, 2757 KiB  
Article
Evaluating Fluorinated-Aniline Units with Functionalized Spiro[Fluorene-9,9′-Xanthene] as Hole-Transporting Materials in Perovskite Solar Cells and Light-Emitting Diodes
by Kuo Liu, Liang Sun, Qing-Lin Liu, Bao-Yi Ren, Run-Da Guo, Lei Wang, Ya-Guang Sun and You-Sheng Wang
Nanomaterials 2024, 14(12), 1044; https://doi.org/10.3390/nano14121044 - 18 Jun 2024
Viewed by 421
Abstract
In the field of perovskite optoelectronics, develo** hole-transporting materials (HTMs) on the spiro[fluorene-9,9′-xanthene] (SFX) platform is one of the current research focuses. The SFX inherits the merits of spirobifluorene in terms of the configuration and property, but it is more easily derivatized and [...] Read more.
In the field of perovskite optoelectronics, develo** hole-transporting materials (HTMs) on the spiro[fluorene-9,9′-xanthene] (SFX) platform is one of the current research focuses. The SFX inherits the merits of spirobifluorene in terms of the configuration and property, but it is more easily derivatized and regulated by virtue of its binary structure. In this work, we design and synthesize four isomeric SFX-based HTMs, namely m-SFX-mF, p-SFX-mF, m-SFX-oF, and p-SFX-oF, through varying the positions of fluorination on the peripheral aniline units and their substitutions on the SFX core, and the optoelectronic performance of the resulting HTMs is evaluated in both perovskite solar cells (PSCs) and light-emitting diodes (PeLEDs) by the vacuum thermal evaporating hole-transporting layers (HTLs). The HTM p-SFX-oF exhibits an improved power conversion efficiency of 15.21% in an inverted PSC using CH3NH3PbI3 as an absorber, benefiting from the deep HOMO level and good HTL/perovskite interface contact. Meanwhile, the HTM m-SFX-mF provides a maximum external quantum efficiency of 3.15% in CsPb(Br/Cl)3-based PeLEDs, which is attributed to its perched HOMO level and shrunken band-gap for facilitating charge carrier injection and then exciton combination. Through elucidating the synergistic position effect of fluorination on aniline units and their substitutions on the SFX core, this work lays the foundation for develo** low-cost and efficient HTMs in the future. Full article
(This article belongs to the Topic Organic and Perovskite Optoelectronic Materials and Devices)
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12 pages, 11900 KiB  
Article
Morphology Control and Mechanism of Different Bath Systems in Cu/SiCw Composite Electroplating
by Bing Niu, Dongdong **e, Yanxin Zhang, Yuxiao Bi, Yigui Li, Guifu Ding and Liyan Lai
Nanomaterials 2024, 14(12), 1043; https://doi.org/10.3390/nano14121043 - 18 Jun 2024
Viewed by 440
Abstract
With the rapid development of electronic technology and large-scale integrated circuit devices, it is very important to develop thermal management materials with high thermal conductivity. Silicon carbide whisker-reinforced copper matrix (Cu/SiCw) composites are considered to be one of the best candidates for future [...] Read more.
With the rapid development of electronic technology and large-scale integrated circuit devices, it is very important to develop thermal management materials with high thermal conductivity. Silicon carbide whisker-reinforced copper matrix (Cu/SiCw) composites are considered to be one of the best candidates for future electronic device radiators. However, at present, most of these materials are produced by high-temperature and high-pressure processes, which are expensive and prone to interfacial reactions. To explore the plating solution system suitable for SiCw and Cu composite electroplating, we tried two different Cu-based plating solutions, namely a Systek UVF 100 plating solution of the copper sulfate (CuSO4) system and a Through Silicon Via (TSV) plating solution of the copper methanesulfonate (Cu(CH3SO3)2) system. In this paper, Cu/SiCw composites were prepared by composite electrodeposition. The morphology of the coating under two different plating liquid systems was compared, and the mechanism of formation of the different morphologies was analyzed. The results show that when the concentration of SiCw in the bath is 1.2 g/L, the surface of the Cu/SiCw composite coating prepared by the CuSO4 bath has more whiskers with irregular distribution and the coating is very smooth, but there are pores at the junction of the whiskers and Cu. There are a large number of irregularly distributed whiskers on the surface of the Cu/SiCw composite coating prepared with the copper methanesulfonate (Cu(CH3SO3)2) system. The surface of the composite is flat, and Cu grows along the whisker structure. The whisker and Cu form a good combination, and there is no pore in the cross-section of the coating. The observation at the cross-section also reveals some characteristics of the toughening mechanism of SiCw, including crack deflection, bridging and whisker pull-out. The existence of these mechanisms indicates that SiCw plays a toughening role in the composites. A suitable plating solution system was selected for the preparation of high-performance Cu/SiCw thermal management materials with the composite electrodeposition process. Full article
(This article belongs to the Special Issue Controlled Growth and Properties of Semiconductor Nanomaterials)
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16 pages, 3101 KiB  
Article
Candle Soot as a Novel Support for Nickel Nanoparticles in the Electrocatalytic Ethanol Oxidation
by Muliani Mansor, Siti Noorleila Budiman, Azran Mohd Zainoodin, Mohd Paad Khairunnisa, Shinya Yamanaka, Nurfatehah Wahyuny Che Jusoh and Shahira Liza
Nanomaterials 2024, 14(12), 1042; https://doi.org/10.3390/nano14121042 - 18 Jun 2024
Viewed by 685
Abstract
The enhancement of carbon-supported components is a crucial factor in augmenting the interplay between carbon-supported and metal-active components in the utilization of catalysts for direct ethanol fuel cells (DEFCs). Here, we propose a strategy for designing a catalyst by modifying candle soot (CS) [...] Read more.
The enhancement of carbon-supported components is a crucial factor in augmenting the interplay between carbon-supported and metal-active components in the utilization of catalysts for direct ethanol fuel cells (DEFCs). Here, we propose a strategy for designing a catalyst by modifying candle soot (CS) and loading nickel onto ordered carbon soot. The present study aimed to investigate the effect of the Ni nanoparticles content on the electrocatalytic performance of Ni–CS, ultimately leading to the identification of a maximum composition. The presence of an excessive quantity of nickel particles leads to a decrease in the number of active sites within the material, resulting in sluggishness of the electron transfer pathway. The electrocatalyst composed of nickel and carbon support, with a nickel content of 20 wt%, has demonstrated a noteworthy current activity of 18.43 mA/cm2, which is three times that of the electrocatalyst with a higher nickel content of 25 wt%. For example, the 20 wt% Ni–CS electrocatalytic activity was found to be good, and it was approximately four times higher than that of 20 wt% Ni–CB (nickel–carbon black). Moreover, the chronoamperometry (CA) test demonstrated a reduction in current activity of merely 65.80% for a 20 wt% Ni–CS electrocatalyst, indicating electrochemical stability. In addition, this demonstrates the great potential of candle soot with Ni nanoparticles to be used as a catalyst in practical applications. Full article
(This article belongs to the Special Issue Safety and Toxicity of Carbon Nanotubes, Nanoparticles and Other Nanomaterials)
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20 pages, 4575 KiB  
Article
Relevance of Platinum Underlayer Crystal Quality for the Microstructure and Magnetic Properties of the Heterostructures YbFeO3/Pt/YSZ(111)
by Sondes Bauer, Berkin Nergis, **aowei **, Lukáš Horák, Reinhard Schneider, Václav Holý, Klaus Seemann, Tilo Baumbach and Sven Ulrich
Nanomaterials 2024, 14(12), 1041; https://doi.org/10.3390/nano14121041 - 17 Jun 2024
Viewed by 448
Abstract
The hexagonal ferrite h-YbFeO3 grown on YSZ(111) by pulsed laser deposition is foreseen as a promising single multiferroic candidate where ferroelectricity and antiferromagnetism coexist for future applications at low temperatures. We studied in detail the microstructure as well as the temperature dependence [...] Read more.
The hexagonal ferrite h-YbFeO3 grown on YSZ(111) by pulsed laser deposition is foreseen as a promising single multiferroic candidate where ferroelectricity and antiferromagnetism coexist for future applications at low temperatures. We studied in detail the microstructure as well as the temperature dependence of the magnetic properties of the devices by comparing the heterostructures grown directly on YSZ(111) (i.e., YbPt_Th0nm) with h-YbFeO3 films deposited on substrates buffered with platinum Pt/YSZ(111) and in dependence on the Pt underlayer film thickness (i.e., YbPt_Th10nm, YbPt_Th40nm, YbPt_Th55nm, and YbPt_Th70nm). The goal was to deeply understand the importance of the crystal quality and morphology of the Pt underlayer for the h-YbFeO3 layer crystal quality, surface morphology, and the resulting physical properties. We demonstrate the relevance of homogeneity, continuity, and hillock formation of the Pt layer for the h-YbFeO3 microstructure in terms of crystal structure, mosaicity, grain boundaries, and defect distribution. The findings of transmission electron microscopy and X-ray diffraction reciprocal space map** characterization enable us to conclude that an optimum film thickness for the Pt bottom electrode is ThPt = 70 nm, which improves the crystal quality of h-YbFeO3 films grown on Pt-buffered YSZ(111) in comparison with h-YbFeO3 films grown on YSZ(111) (i.e., YbPt_Th0nm). The latter shows a disturbance in the crystal structure, in the up-and-down atomic arrangement of the ferroelectric domains, as well as in the Yb–Fe exchange interactions. Therefore, an enhancement in the remanent and in the total magnetization was obtained at low temperatures below 50 K for h-YbFeO3 films deposited on Pt-buffered substrates Pt/YSZ(111) when the Pt underlayer reached ThPt = 70 nm. Full article
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10 pages, 4405 KiB  
Article
ITO-Induced Nonlinear Optical Response Enhancement of Titanium Nitride Thin Films
by Peng Lu, Tingzhen Yan, Jialei Huang, Tian **ng, Hao Liu, Zhaoxia Han, Xueke Xu and Chunxian Tao
Nanomaterials 2024, 14(12), 1040; https://doi.org/10.3390/nano14121040 - 17 Jun 2024
Viewed by 502
Abstract
A series of TiN/ITO composite films with various thickness of ITO buffer layer were fabricated in this study. The enhancement of optical properties was realized in the composite thin films. The absorption spectra showed that absorption intensity in the near-infrared region was obviously [...] Read more.
A series of TiN/ITO composite films with various thickness of ITO buffer layer were fabricated in this study. The enhancement of optical properties was realized in the composite thin films. The absorption spectra showed that absorption intensity in the near-infrared region was obviously enhanced with the increase of ITO thickness due to the coupling of surface plasma between TiN and ITO. The epsilon-near-zero wavelength of this composite can be tuned from 935 nm to 1895 nm by varying the thickness of ITO thin films. The nonlinear optical property investigated by Z-scan technique showed that the nonlinear absorption coefficient (β = 3.03 × 10−4 cm/W) for the composite was about 14.02 times greater than that of single-layer TiN films. The theoretical calculations performed by finite difference time domain were in good agreement with those of the experiments. Full article
(This article belongs to the Special Issue Thin Films Based on Nanocomposites (2nd Edition))
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19 pages, 6601 KiB  
Review
Recent Progress in the Applications of Langmuir–Blodgett Film Technology
by Wenhui Gu, Qing Li, Ran Wang, Lexin Zhang, Zhiwei Liu and Tifeng Jiao
Nanomaterials 2024, 14(12), 1039; https://doi.org/10.3390/nano14121039 - 17 Jun 2024
Viewed by 612
Abstract
Langmuir–Blodgett (LB) film technology is an advanced technique for the preparation of ordered molecular ultra-thin films at the molecular level, which transfers a single layer of film from the air/water interface to a solid substrate for the controlled assembly of molecules. LB technology [...] Read more.
Langmuir–Blodgett (LB) film technology is an advanced technique for the preparation of ordered molecular ultra-thin films at the molecular level, which transfers a single layer of film from the air/water interface to a solid substrate for the controlled assembly of molecules. LB technology has continually evolved over the past century, revealing its potential applications across diverse fields. In this study, the latest research progress of LB film technology is reviewed, with emphasis on its latest applications in gas sensors, electrochemical devices, and bionic films. Additionally, this review evaluates the strengths and weaknesses of LB technology in the application processes and discusses the promising prospects for future application of LB technology. Full article
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11 pages, 3684 KiB  
Article
Distinguishing the Charge Trap** Centers in CaF2-Based 2D Material MOSFETs
by Zhe Zhao, Tao **ong, Jian Gong and Yue-Yang Liu
Nanomaterials 2024, 14(12), 1038; https://doi.org/10.3390/nano14121038 - 16 Jun 2024
Viewed by 552
Abstract
Crystalline calcium fluoride (CaF2) is drawing significant attention due to its great potential of being the gate dielectric of two-dimensional (2D) material MOSFETs. It is deemed to be superior to boron nitride and traditional silicon dioxide (SiO2) because of [...] Read more.
Crystalline calcium fluoride (CaF2) is drawing significant attention due to its great potential of being the gate dielectric of two-dimensional (2D) material MOSFETs. It is deemed to be superior to boron nitride and traditional silicon dioxide (SiO2) because of its larger dielectric constant, wider band gap, and lower defect density. Nevertheless, the CaF2-based MOSFETs fabricated in the experiment still present notable reliability issues, and the underlying reason remains unclear. Here, we studied the various intrinsic defects and adsorbates in CaF2/molybdenum disulfide (MoS2) and CaF2/molybdenum disilicon tetranitride (MoSi2N4) interface systems to reveal the most active charge-trap** centers in CaF2-based 2D material MOSFETs. An elaborate Table comparing the importance of different defects in both n-type and p-type devices is provided. Most impressively, the oxygen molecules (O2) adsorbed at the interface or surface, which are inevitable in experiments, are as active as the intrinsic defects in channel materials, and they can even change the MoSi2N4 to p-type spontaneously. These results mean that it is necessary to develop a high-vacuum packaging process, as well as prepare high-quality 2D materials for better device performance. Full article
(This article belongs to the Special Issue Dielectric, Ferroelectric and Piezoelectric Properties of Nanomaterials)
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33 pages, 8395 KiB  
Review
Recent Progress on the Adsorption of Heavy Metal Ions Pb(II) and Cu(II) from Wastewater
by Dikang Fan, Yang Peng, ** He, **g Ouyang, Liangjie Fu and Huaming Yang
Nanomaterials 2024, 14(12), 1037; https://doi.org/10.3390/nano14121037 - 16 Jun 2024
Viewed by 548
Abstract
With the processes of industrialization and urbanization, heavy metal ion pollution has become a thorny problem in water systems. Among the various technologies developed for the removal of heavy metal ions, the adsorption method is widely studied by researchers and various nanomaterials with [...] Read more.
With the processes of industrialization and urbanization, heavy metal ion pollution has become a thorny problem in water systems. Among the various technologies developed for the removal of heavy metal ions, the adsorption method is widely studied by researchers and various nanomaterials with good adsorption performances have been prepared during the past decades. In this paper, a variety of novel nanomaterials with excellent adsorption performances for Pb(II) and Cu(II) reported in recent years are reviewed, such as carbon-based materials, clay mineral materials, zero-valent iron and their derivatives, MOFs, nanocomposites, etc. The novel nanomaterials with extremely high adsorption capacity, selectivity and particular nanostructures are summarized and introduced, along with their advantages and disadvantages. And, some future research priorities for the treatment of wastewater are also prospected. Full article
(This article belongs to the Special Issue The Applications of Nanomaterials for the Treatment of Heavy Metal-Polluted Water and Soils)
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24 pages, 2658 KiB  
Review
Advances and Prospects of Nanomaterials for Solid-State Hydrogen Storage
by Yaohui Xu, Yuting Li, Liangjuan Gao, Yitao Liu and Zhao Ding
Nanomaterials 2024, 14(12), 1036; https://doi.org/10.3390/nano14121036 - 16 Jun 2024
Viewed by 519
Abstract
Hydrogen energy, known for its high energy density, environmental friendliness, and renewability, stands out as a promising alternative to fossil fuels. However, its broader application is limited by the challenge of efficient and safe storage. In this context, solid-state hydrogen storage using nanomaterials [...] Read more.
Hydrogen energy, known for its high energy density, environmental friendliness, and renewability, stands out as a promising alternative to fossil fuels. However, its broader application is limited by the challenge of efficient and safe storage. In this context, solid-state hydrogen storage using nanomaterials has emerged as a viable solution to the drawbacks of traditional storage methods. This comprehensive review delves into the recent advancements in nanomaterials for solid-state hydrogen storage, elucidating the fundamental principles and mechanisms, highlighting significant material systems, and exploring the strategies of surface and interface engineering alongside catalytic enhancement. We also address the primary challenges and provide future perspectives on the development of nanomaterial-based hydrogen storage technologies. Key discussions include the role of nanomaterial size effects, surface modifications, nanocomposites, and nanocatalysts in optimizing storage performance. Full article
(This article belongs to the Special Issue Nanomaterials for Sustainable Green Energy)
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20 pages, 8551 KiB  
Article
Migration Rules and Mechanisms of Nano-Biochar in Soil Columns under Various Transport Conditions
by Peng Li, Meifang Yan, Min Li, Tao Zhou, Huijie Li and Bingcheng Si
Nanomaterials 2024, 14(12), 1035; https://doi.org/10.3390/nano14121035 - 15 Jun 2024
Viewed by 464
Abstract
Compared to traditional biochar (BC), nano-biochar (NBC) boasts superior physicochemical properties, promising extensive applications in agriculture, ecological environments, and beyond. Due to its strong adsorption and migration properties, NBC may carry nutrients or pollutants to deeper soil layers or even groundwater, causing serious [...] Read more.
Compared to traditional biochar (BC), nano-biochar (NBC) boasts superior physicochemical properties, promising extensive applications in agriculture, ecological environments, and beyond. Due to its strong adsorption and migration properties, NBC may carry nutrients or pollutants to deeper soil layers or even groundwater, causing serious environmental risks. Nevertheless, the migration rules and mechanisms of NBC in soil are still unclear. Therefore, this study employed soil column migration experiments to systematically explore the migration rules and mechanisms of NBC under various flow rates, initial soil water contents, soil depths, and soil textures. The results showed that regulated by smaller particle size differences and greater surface charges, NBC exhibited a stronger migration ability compared with traditional BC. As the soil texture transitioned from fine to coarse, the migration capability of NBC significantly improved, driven by both pore structure and interaction forces as described by the DLVO theory. The migration ability of NBC was also greatly boosted as the soil transitioned from saturated to unsaturated conditions, primarily because of preferential flow. When the flow rate increased from 70% KS to 100% KS and 130% KS, the migration ability of NBC also increased accordingly, as changes in injection flow rates altered the velocity distribution of pore water. NBC in 25 cm soil columns was more prone to shallow retention compared with 10 cm soil columns, resulting in weaker overall migration ability. In addition, through fitting of the two-site kinetic model and related parameters, the penetration curves of NBC under various variable conditions were effectively characterized. These findings could offer valuable insights for NBC’s future efficient, rational, and sustainable utilization, facilitating the evaluation and mitigation of its potential environmental risks. Full article
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11 pages, 6744 KiB  
Article
Enhancing Efficiency of Dye Sensitized Solar Cells by Coinage Metal Do** of Cyanidin-Silver Trimer Hybrids at TiO2 Support Based on Theoretical Study
by Margarita Bužančić Milosavljević, Martina Perić Bakulić, Željka Sanader Maršić, Antonija Mravak and Vlasta Bonačić-Koutecký
Nanomaterials 2024, 14(12), 1034; https://doi.org/10.3390/nano14121034 - 15 Jun 2024
Viewed by 578
Abstract
Identification of a natural-based sensitizer with optimal stability and efficiency for dye-sensitized solar cell (DSSC) application remains a challenging task. Previously, we proposed a new class of sensitizers based on bio-nano hybrids. These systems composed of natural cyanidin dyes interacting with silver nanoclusters [...] Read more.
Identification of a natural-based sensitizer with optimal stability and efficiency for dye-sensitized solar cell (DSSC) application remains a challenging task. Previously, we proposed a new class of sensitizers based on bio-nano hybrids. These systems composed of natural cyanidin dyes interacting with silver nanoclusters (NCs) have demonstrated enhanced opto-electronic and photovoltaic properties. In this study, we explore the do** of silver nanocluster within a cyanidin-Ag3 hybrid employing Density Functional Theory (DFT) and its time-dependent counterpart (TDDFT). Specifically, we investigate the influence of coinage metal atoms (Au and Cu) on the properties of the cyanidin-Ag3 system. Our findings suggest that cyanidin-Ag2Au and cyanidin-AgAuCu emerge as the most promising candidates for improved light harvesting efficiency, increased two-photon absorption, and strong coupling to the TiO2 surface. These theoretical predictions suggest the viability of replacing larger silver NCs with heterometallic trimers such as Ag2Au or AgAuCu, presenting new avenues for utilizing bio-nano hybrids at the surface for DSSC application. Full article
(This article belongs to the Special Issue Advanced Studies in Bionanomaterials)
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