Nanomaterials

19 pages, 2031 KiB

Open AccessReview

Unravelling Dynamics Involving Multiple Charge Carriers in Semiconductor Nanocrystals

by Krishan Kumar and Maria Wächtler

Nanomaterials 2023, 13(9), 1579; https://doi.org/10.3390/nano13091579 - 8 May 2023

Cited by 1 | Viewed by 2693

The use of colloidal nanocrystals as part of artificial photosynthetic systems has recently gained significant attention, owing to their strong light absorption and highly reproducible, tunable electronic and optical properties. The complete photocatalytic conversion of water to its components is yet to be [...] Read more.

The use of colloidal nanocrystals as part of artificial photosynthetic systems has recently gained significant attention, owing to their strong light absorption and highly reproducible, tunable electronic and optical properties. The complete photocatalytic conversion of water to its components is yet to be achieved in a practically suitable and commercially viable manner. To complete this challenging task, we are required to fully understand the mechanistic aspects of the underlying light-driven processes involving not just single charge carriers but also multiple charge carriers in detail. This review focuses on recent progress in understanding charge carrier dynamics in semiconductor nanocrystals and the influence of various parameters such as dimension, composition, and cocatalysts. Transient absorption spectroscopic studies involving single and multiple charge carriers, and the challenges associated with the need for accumulation of multiple charge carriers to drive the targeted chemical reactions, are discussed. Full article

(This article belongs to the Special Issue Colloidal Semiconductor Nanostructures for Light-Harvesting and Beyond)

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29 pages, 9266 KiB

Open AccessReview

Halloysite-TiO₂ Nanocomposites for Water Treatment: A Review

by Mahmoud Abid, Abdesslem Ben Haj Amara and Mikhael Bechelany

Nanomaterials 2023, 13(9), 1578; https://doi.org/10.3390/nano13091578 - 8 May 2023

Cited by 15 | Viewed by 2693

Abstract

Halloysite nanotubes (HNTs) are clay minerals with a tubular structure that can be used for many different applications in place of carbon nanotubes. Indeed, HNTs display low/non-toxicity, are biocompatible, and can be easily prepared. Moreover, the aluminum and silica groups present on HNTs’ [...] Read more.

Halloysite nanotubes (HNTs) are clay minerals with a tubular structure that can be used for many different applications in place of carbon nanotubes. Indeed, HNTs display low/non-toxicity, are biocompatible, and can be easily prepared. Moreover, the aluminum and silica groups present on HNTs’ inner and outer surfaces facilitate the interaction with various functional agents, such as alkalis, organosilanes, polymers, surfactants, and nanomaterials. This allows the deposition of different materials, for instance, metal and non-metal oxides, on different substrate types. This review article first briefly presents HNTs’ general structure and the various applications described in the last 20 years (e.g., drug delivery, medical implants, and energy storage). Then, it discusses in detail HNT applications for water purification (inorganic and organic pollutants). It focuses particularly on HNT-TiO₂ composites that are considered very promising photocatalysts due to their high specific surface area and adsorption capacity, large pore volume, good stability, and mechanical features. Full article

(This article belongs to the Section Nanofabrication and Nanomanufacturing)

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22 pages, 6809 KiB

Open AccessArticle

Effect of Mn_xO_y Nanoparticles Stabilized with Methionine on Germination of Barley Seeds (Hordeum vulgare L.)

by Andrey Blinov, Alexey Gvozdenko, Alexey Golik, Shahida A. Siddiqui, Fahrettin Göğüş, Anastasiya Blinova, David Maglakelidze, Irina Shevchenko, Maksim Rebezov and Andrey Nagdalian

Nanomaterials 2023, 13(9), 1577; https://doi.org/10.3390/nano13091577 - 8 May 2023

Cited by 4 | Viewed by 2057

Abstract

The aim of this research was to study the effect of Mn_xO_y nanoparticles stabilized with L-methionine on the morphofunctional characteristics of the barley (Hordeum vulgare L.) crop. Mn_xO_y nanoparticles stabilized with L-methionine were synthesized using potassium [...] Read more.

The aim of this research was to study the effect of Mn_xO_y nanoparticles stabilized with L-methionine on the morphofunctional characteristics of the barley (Hordeum vulgare L.) crop. Mn_xO_y nanoparticles stabilized with L-methionine were synthesized using potassium permanganate and L-methionine. We established that Mn_xO_y nanoparticles have a diameter of 15 to 30 nm. According to quantum chemical modeling and IR spectroscopy, it is shown that the interaction of Mn_xO_y nanoparticles with L-methionine occurs through the amino group. It is found that Mn_xO_y nanoparticles stabilized with L-methionine have positive effects on the roots and seedling length, as well as the seed germination energy. The effect of Mn_xO_y nanoparticles on Hordeum vulgare L. seeds is nonlinear. At a concentration of 0.05 mg/mL, there was a statistically significant increase in the length of seedlings by 68% compared to the control group. We found that the root lengths of samples treated with Mn_xO_y nanoparticle sols with a concentration of 0.05 mg/mL were 62.8%, 32.7%, and 158.9% higher compared to samples treated with L-methionine, KMnO₄, and the control sample, respectively. We have shown that at a concentration of 0.05 mg/mL, the germination energy of seeds increases by 50.0% compared to the control sample, by 10.0% compared to the samples treated with L-methionine, and by 13.8% compared to the samples treated with KMnO₄. Full article

(This article belongs to the Special Issue Metal-Based Nanomaterials for Biomedical, Agricultural, and Environmental Applications: Prospects and Uncertainties)

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13 pages, 6461 KiB

Open AccessArticle

Lattice Thermal Conductivity of Monolayer InSe Calculated by Machine Learning Potential

by Jinsen Han, Qiyu Zeng, Ke Chen, Xiaoxiang Yu and Jiayu Dai

Nanomaterials 2023, 13(9), 1576; https://doi.org/10.3390/nano13091576 - 8 May 2023

Cited by 8 | Viewed by 2482

Abstract

The two-dimensional post-transition-metal chalcogenides, particularly indium selenide (InSe), exhibit salient carrier transport properties and evince extensive interest for broad applications. A comprehensive understanding of thermal transport is indispensable for thermal management. However, theoretical predictions on thermal transport in the InSe system are found [...] Read more.

The two-dimensional post-transition-metal chalcogenides, particularly indium selenide (InSe), exhibit salient carrier transport properties and evince extensive interest for broad applications. A comprehensive understanding of thermal transport is indispensable for thermal management. However, theoretical predictions on thermal transport in the InSe system are found in disagreement with experimental measurements. In this work, we utilize both the Green–Kubo approach with deep potential (GK-DP), together with the phonon Boltzmann transport equation with density functional theory (BTE-DFT) to investigate the thermal conductivity (

κ

) of InSe monolayer. The

κ

calculated by GK-DP is 9.52 W/mK at 300 K, which is in good agreement with the experimental value, while the

κ

predicted by BTE-DFT is 13.08 W/mK. After analyzing the scattering phase space and cumulative

κ

by mode-decomposed method, we found that, due to the large energy gap between lower and upper optical branches, the exclusion of four-phonon scattering in BTE-DFT underestimates the scattering phase space of lower optical branches due to large group velocities, and thus would overestimate their contribution to

κ

. The temperature dependence of

κ

calculated by GK-DP also demonstrates the effect of higher-order phonon scattering, especially at high temperatures. Our results emphasize the significant role of four-phonon scattering in InSe monolayer, suggesting that combining molecular dynamics with machine learning potential is an accurate and efficient approach to predict thermal transport. Full article

(This article belongs to the Special Issue First-Principle Calculation Study of Nanomaterials)

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13 pages, 43414 KiB

Open AccessArticle

High-Bonding-Strength Polyimide Films Achieved via Thermal Management and Surface Activation

by Pin-Syuan He, Dinh-Phuc Tran, Ting-Yu Kuo, Wei-You Hsu, Huai-En Lin, Kai-Cheng Shie and Chih Chen

Nanomaterials 2023, 13(9), 1575; https://doi.org/10.3390/nano13091575 - 8 May 2023

Cited by 4 | Viewed by 2872

Abstract

In this study, thermal and argon (Ar) plasma/wetting treatments were combined to enhance the bonding strength of polyimide (PI) films. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) was used to analyze the changes in the PI imidization degrees. The contact angles of the [...] Read more.

In this study, thermal and argon (Ar) plasma/wetting treatments were combined to enhance the bonding strength of polyimide (PI) films. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) was used to analyze the changes in the PI imidization degrees. The contact angles of the PI films were also measured. The results show that the contact angles of the fully cured PI films markedly decreased from 78.54° to 26.05° after the Ar plasma treatments. X-ray photoelectron spectroscopy (XPS) analysis was also conducted on the PI surfaces. We found that the intensities of the C-OH and C-N-H bonds increased from 0% to 13% and 29% to 57%, respectively, after Ar plasma activation. Such increases in the C-OH and C-N-H intensities could be attributed to the generation of dangling bonds and the breakage of the imide ring or polymer long chains. Shear tests were also conducted to characterize the bonding strength of the PI films, which, after being treated with the appropriate parameters of temperature, plasma power, and wetting droplets, was found to be excellent at greater than 35.3 MPa. Full article

(This article belongs to the Special Issue Nano Surface Engineering)

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12 pages, 2488 KiB

Open AccessArticle

Structural, Electronic and Optical Properties of Some New Trilayer Van de Waals Heterostructures

by Beitong Cheng, Yong Zhou, Ruomei Jiang, Xule Wang, Shuai Huang, Xingyong Huang, Wei Zhang, Qian Dai, Liujiang Zhou, Pengfei Lu and Hai-Zhi Song

Nanomaterials 2023, 13(9), 1574; https://doi.org/10.3390/nano13091574 - 8 May 2023

Cited by 2 | Viewed by 2087

Abstract

Constructing two-dimensional (2D) van der Waals (vdW) heterostructures is an effective strategy for tuning and improving the characters of 2D-material-based devices. Four trilayer vdW heterostructures, BP/BP/MoS₂, BlueP/BlueP/MoS₂, BP/graphene/MoS₂ and BlueP/graphene/MoS₂, were designed and simulated using the [...] Read more.

Constructing two-dimensional (2D) van der Waals (vdW) heterostructures is an effective strategy for tuning and improving the characters of 2D-material-based devices. Four trilayer vdW heterostructures, BP/BP/MoS₂, BlueP/BlueP/MoS₂, BP/graphene/MoS₂ and BlueP/graphene/MoS₂, were designed and simulated using the first-principles calculation. Structural stabilities were confirmed for all these heterostructures, indicating their feasibility in fabrication. BP/BP/MoS₂ and BlueP/BlueP/MoS₂ lowered the bandgaps further, making them suitable for a greater range of applications, with respect to the bilayers BP/MoS₂ and BlueP/MoS₂, respectively. Their absorption coefficients were remarkably improved in a wide spectrum, suggesting the better performance of photodetectors working in a wide spectrum from mid-wave (short-wave) infrared to violet. In contrast, the bandgaps in BP/graphene/MoS₂ and BlueP/graphene/MoS₂ were mostly enlarged, with a specific opening of the graphene bandgap in BP/graphene/MoS₂, 0.051 eV, which is much larger than usual and beneficial for optoelectronic applications. Accompanying these bandgap increases, BP/graphene/MoS₂ and BlueP/graphene/MoS₂ exhibit absorption enhancement in the whole infrared, visible to deep ultraviolet or solar blind ultraviolet ranges, implying that these asymmetrically graphene-sandwiched heterostructures are more suitable as graphene-based 2D optoelectronic devices. The proposed 2D trilayer vdW heterostructures are prospective new optoelectronic devices, possessing higher performance than currently available devices. Full article

(This article belongs to the Special Issue Amorphous and Nanocrystalline Semiconductors: Selected Papers from ICANS 29)

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15 pages, 3937 KiB

Open AccessReview

Recent Advances in Nanopore Technology for Copper Detection and Their Potential Applications

by Alexander N. Vaneev, Roman V. Timoshenko, Petr V. Gorelkin, Natalia L. Klyachko and Alexander S. Erofeev

Nanomaterials 2023, 13(9), 1573; https://doi.org/10.3390/nano13091573 - 8 May 2023

Cited by 12 | Viewed by 2634

Abstract

Recently, nanopore technology has emerged as a promising technique for the rapid, sensitive, and selective detection of various analytes. In particular, the use of nanopores for the detection of copper ions has attracted considerable attention due to their high sensitivity and selectivity. This [...] Read more.

Recently, nanopore technology has emerged as a promising technique for the rapid, sensitive, and selective detection of various analytes. In particular, the use of nanopores for the detection of copper ions has attracted considerable attention due to their high sensitivity and selectivity. This review discusses the principles of nanopore technology and its advantages over conventional techniques for copper detection. It covers the different types of nanopores used for copper detection, including biological and synthetic nanopores, and the various mechanisms used to detect copper ions. Furthermore, this review provides an overview of the recent advancements in nanopore technology for copper detection, including the development of new nanopore materials, improvements in signal amplification, and the integration of nanopore technology with other analytical methods for enhanced detection sensitivity and accuracy. Finally, we summarize the extensive applications, current challenges, and future perspectives of using nanopore technology for copper detection, highlighting the need for further research in the field to optimize the performance and applicability of the technique. Full article

(This article belongs to the Special Issue Nanomaterials for Sensing Application)

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10 pages, 1643 KiB

Open AccessArticle

Towards Bright Single-Photon Emission in Elliptical Micropillars

by Aidar Galimov, Michail Bobrov, Maxim Rakhlin, Yuriy Serov, Dmitrii Kazanov, Alexey Veretennikov, Grigory Klimko, Sergey Sorokin, Irina Sedova, Nikolai Maleev, Yuriy Zadiranov, Marina Kulagina, Yulia Guseva, Daryia Berezina, Ekaterina Nikitina and Alexey Toropov

Nanomaterials 2023, 13(9), 1572; https://doi.org/10.3390/nano13091572 - 8 May 2023

Viewed by 1728

Abstract

In recent years, single-photon sources (SPSs) based on the emission of a single semiconductor quantum dot (QD) have been actively developed. While the purity and indistinguishability of single photons are already close to ideal values, the high brightness of SPSs remains a challenge. [...] Read more.

In recent years, single-photon sources (SPSs) based on the emission of a single semiconductor quantum dot (QD) have been actively developed. While the purity and indistinguishability of single photons are already close to ideal values, the high brightness of SPSs remains a challenge. The widely used resonant excitation with cross-polarization filtering usually leads to at least a two-fold reduction in the single-photon counts rate, since single-photon emission is usually unpolarized, or its polarization state is close to that of the exciting laser. One of the solutions is the use of polarization-selective microcavities, which allows one to redirect most of the QD emission to a specific polarization determined by the optical mode of the microcavity. In the present work, elliptical micropillars with distributed Bragg reflectors are investigated theoretically and experimentally as a promising design of such polarization-selective microcavities. The impact of ellipticity, ellipse area and verticality of the side walls on the splitting of the optical fundamental mode is investigated. The study of the near-field pattern allows us to detect the presence of higher-order optical modes, which are classified theoretically. The possibility of obtaining strongly polarized single-photon QD radiation associated with the short-wavelength fundamental cavity mode is shown. Full article

(This article belongs to the Special Issue Quantum Materials for Photonic Devices)

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12 pages, 7551 KiB

Open AccessArticle

Nanostructured N, S, and P-Doped Elaeagnus Angustifolia Gum-Derived Porous Carbon with Electrodeposited Silver for Enhanced Electrochemical Sensing of Acetaminophen

by Xamxikamar Mamat, Haji Akber Aisa and Longyi Chen

Nanomaterials 2023, 13(9), 1571; https://doi.org/10.3390/nano13091571 - 8 May 2023

Cited by 2 | Viewed by 1725

Abstract

Acetaminophen (N-acetyl-p-aminophenol, APAP) is regularly used for antipyretic and analgesic purposes. Overdose or long-term exposure to APAP could lead to liver damage and hepatotoxicity. In this study, the approach of enhanced electrochemical detection of APAP by nanostructured biomass carbon/silver was developed. Porous biomass [...] Read more.

Acetaminophen (N-acetyl-p-aminophenol, APAP) is regularly used for antipyretic and analgesic purposes. Overdose or long-term exposure to APAP could lead to liver damage and hepatotoxicity. In this study, the approach of enhanced electrochemical detection of APAP by nanostructured biomass carbon/silver was developed. Porous biomass carbon derived from Elaeagnus Angustifolia gum was prepared by pyrolysis with co-doping of electron-rich elements of nitrogen, sulfur, and phosphorus. The electrodeposition of silver onto a glassy carbon electrode modified with porous carbon could enhance the sensing signal towards APAP. Two linear ranges from 61 nM to 500 μM were achieved with a limit of detection of 33 nM. The developed GCE sensor has good anti-interference, stability, reproducibility, and human urine sample analysis performance. The silver-enhanced biomass carbon GCE sensor extends the application of biomass carbon, and its facile preparation approach could be used in constructing disposable sensing chips in the future. Full article

(This article belongs to the Special Issue Nanostructured Materials: Preparation and Application in Electrochemistry)

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12 pages, 7381 KiB

Open AccessArticle

Efficient Anti-Fog and Anti-Reflection Functions of the Bio-Inspired, Hierarchically-Architectured Surfaces of Multiscale Columnar Structures

by Weixuan Li, You Chen and Zhibin Jiao

Nanomaterials 2023, 13(9), 1570; https://doi.org/10.3390/nano13091570 - 7 May 2023

Cited by 7 | Viewed by 2501

Abstract

Today, in the fields of optical precision instruments, medical devices, and automotive engineering, the demand for anti-reflection and anti-fog surfaces is growing rapidly. However, the anti-fog function often compromises the efficiency of the anti-reflection function. Therefore, optical precision instruments are always restricted by [...] Read more.

Today, in the fields of optical precision instruments, medical devices, and automotive engineering, the demand for anti-reflection and anti-fog surfaces is growing rapidly. However, the anti-fog function often compromises the efficiency of the anti-reflection function. Therefore, optical precision instruments are always restricted by the inability to combine high anti-reflection efficiency and excellent anti-fog performance into one material. In addition, the synergistic mechanism of harmonizing anti-fogging and anti-reflection is currently unclear, which has a negative impact on the development and optimization of multifunctional surfaces. Herein, bio-inspired anti-fogging and anti-reflection surfaces (BFRSs) possessing multiscale hierarchical columnar structures (MHCS) were obtained using a brief and effective preparation technique, combining the biotemplating method and sol-gel method. Specifically, condensed fog droplets distributed on the BFRS can be absolutely removed within 6 s. In addition, the BFRSs endow the glass substrate with a relatively higher reflectance (17%) than flat glass surfaces (41%). Furthermore, we demonstrated the synergistic mechanism of the anti-fogging and anti-reflection functions of BFRSs. On the one hand, the high transparency benefits from the multiple refraction and scattering of light in the MHCS array. On the other hand, the excellent anti-fogging performance is attributed to the imbalance of the capillary force of the MHCS acting on the liquid film. The explanation for these two mechanisms provides more possibilities for the subsequent preparation of multifunctional surfaces. At the same time, the bionic research concept provides new solutions for the researcher to conquer the combination of high transmission and anti-fog properties for precision optical surfaces. Full article

(This article belongs to the Special Issue Bionic Nano Engineering)

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13 pages, 4178 KiB

Open AccessArticle

Bi₂MoO₆ Embedded in 3D Porous N,O-Doped Carbon Nanosheets for Photocatalytic CO₂ Reduction

by Xue Bai, Lang He, Wenyuan Zhang, Fei Lv, Yayun Zheng, Xirui Kong, Du Wang and Yan Zhao

Nanomaterials 2023, 13(9), 1569; https://doi.org/10.3390/nano13091569 - 6 May 2023

Cited by 3 | Viewed by 2432

Abstract

Artificial photosynthesis is promising to convert solar energy and CO₂ into valuable chemicals, and to alleviate the problems of the greenhouse effect and the climate change crisis. Here, we fabricated a novel photocatalyst by directly growing Bi₂MoO₆ nanosheets on [...] Read more.

Artificial photosynthesis is promising to convert solar energy and CO₂ into valuable chemicals, and to alleviate the problems of the greenhouse effect and the climate change crisis. Here, we fabricated a novel photocatalyst by directly growing Bi₂MoO₆ nanosheets on three-dimensional (3D) N,O-doped carbon (NO-C). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the designed photocatalyst ensured the close contact between Bi₂MoO₆ and NO-C, and reduced the stacking of the NO-C layers to provide abundant channels for the diffusion of CO₂, while NO-C can allow for fast electron transfer. The charge transfer in this composite was determined to follow a step-scheme mechanism, which not only facilitates the separation of charge carriers but also retains a strong redox capability. Benefiting from this unique 3D structure and the synergistic effect, BMO/NO-C showed excellent performance in photocatalytic CO₂ reductions. The yields of the best BMO/NO-C catalysts for CH₄ and CO were 9.14 and 14.49 μmol g⁻¹ h⁻¹, respectively. This work provides new insights into constructing step-scheme photocatalytic systems with the 3D nanostructures. Full article

(This article belongs to the Special Issue Nanostructured Materials for Carbon Neutrality)

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13 pages, 6568 KiB

Open AccessArticle

Investigation of Reducing Interface State Density in 4H-SiC by Increasing Oxidation Rate

by Shuai Li, Jun Luo and Tianchun Ye

Nanomaterials 2023, 13(9), 1568; https://doi.org/10.3390/nano13091568 - 6 May 2023

Cited by 4 | Viewed by 2037

Abstract

Detailed investigations of the pre-oxidation phosphorus implantation process are required to increase the oxidation rate in 4H-SiC metal-oxide-semiconductor (MOS) capacitors. This study focuses on the SiO₂/SiC interface characteristics of pre-oxidation using phosphorus implantation methods. The inversion channel mobility of a metal-oxide-semiconductor [...] Read more.

Detailed investigations of the pre-oxidation phosphorus implantation process are required to increase the oxidation rate in 4H-SiC metal-oxide-semiconductor (MOS) capacitors. This study focuses on the SiO₂/SiC interface characteristics of pre-oxidation using phosphorus implantation methods. The inversion channel mobility of a metal-oxide-semiconductor field effect transistor (MOSFET) was decreased via a high interface state density and the coulomb-scattering mechanisms of the carriers. High-resolution transmission electron microscopy (HRTEM) and scanning transmission electron microscopy (STEM) were used to evaluate the SiO₂/SiC interface’s morphology. According to the energy-dispersive X-ray spectrometry (EDS) results, it was found that phosphorus implantation reduced the accumulation of carbon at the SiO₂/SiC interface. Moreover, phosphorus distributed on the SiO₂/SiC interface exhibited a Gaussian profile, and the nitrogen concentration at the SiO₂/SiC interface may be correlated with the content of phosphorus. This research presents a new approach for increasing the oxidation rate of SiC and reducing the interface state density. Full article

(This article belongs to the Special Issue Silicon-Based Nanostructures: Fabrication and Characterization)

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15 pages, 4716 KiB

Open AccessArticle

Synthesis and Sensing Performance of Chitin Fiber/MoS₂ Composites

by Yuzhi Zhang, Zhaofeng Wu, Jun Sun, Qihua Sun, Fengjuan Chen, Min Zhang and Haiming Duan

Nanomaterials 2023, 13(9), 1567; https://doi.org/10.3390/nano13091567 - 6 May 2023

Viewed by 1833

Abstract

In this study, chitin fibers (CFs) were combined with molybdenum sulfide (MoS₂) to develop high-performance sensors, and chitin carbon materials were innovatively introduced into the application of gas sensing. MoS₂/CFs composites were synthesized via a one-step hydrothermal method. The [...] Read more.

In this study, chitin fibers (CFs) were combined with molybdenum sulfide (MoS₂) to develop high-performance sensors, and chitin carbon materials were innovatively introduced into the application of gas sensing. MoS₂/CFs composites were synthesized via a one-step hydrothermal method. The surface properties of the composites were greatly improved, and the fire resistance effect was remarkable compared with that of the chitin monomer. In the gas-sensitive performance test, the overall performance of the MoS₂/CFs composite was more than three times better than that of the MoS₂ monomer and showed excellent long-term stability, with less than 10% performance degradation in three months. Extending to the field of strain sensing, MoS₂/CFs composites can realize real-time signal conversion in tensile and motion performance tests, which can help inspectors make analytical judgments in response to the analysis results. The extensive application of sensing materials in more fields is expected to be further developed. Based on the recycling of waste chitin textile materials, this paper expands the potential applications of chitin materials in the fields of gas monitoring, biomedicine, behavioral discrimination and intelligent monitoring. Full article

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11 pages, 9292 KiB

Open AccessArticle

The Adsorption Effect of Methane Gas Molecules on Monolayer PbSe with and without Vacancy Defects: A First-Principles Study

by Xing Zhou and Yuliang Mao

Nanomaterials 2023, 13(9), 1566; https://doi.org/10.3390/nano13091566 - 6 May 2023

Cited by 2 | Viewed by 1737

Abstract

In this paper, the adsorption effect of methane (CH₄) gas molecular on monolayer PbSe with and without vacancy defects is studied based on first-principles calculations. The effects of the adsorption of methane molecular on monolayer PbSe and on the Se vacancy [...] Read more.

In this paper, the adsorption effect of methane (CH₄) gas molecular on monolayer PbSe with and without vacancy defects is studied based on first-principles calculations. The effects of the adsorption of methane molecular on monolayer PbSe and on the Se vacancy (V_Se) and Pb vacancy (V_Pb) of monolayer PbSe are also explored. Our results show that methane molecules exhibit a good physical adsorption effect on monolayer PbSe with and without vacancy defects. Moreover, our simulations indicate that the adsorption capacity of CH₄ molecules on monolayer PbSe can be enhanced by applying strain. However, for the monolayer PbSe with Vse, the adsorption capacity of CH₄ molecules on the strained system decreases sharply. This indicates that applying strain can promote the dissociation of CH₄ from V_Se. Our results show that the strain can be used as an effective means to regulate the interaction between the substrate material and the methane gas molecules. Full article

(This article belongs to the Special Issue Innovative Nanomaterial Properties and Applications in Chemistry, Physics, Medicine, or Environment)

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13 pages, 3416 KiB

Open AccessArticle

Facile Fabrication of TiO₂ Quantum Dots-Anchored g-C₃N₄ Nanosheets as 0D/2D Heterojunction Nanocomposite for Accelerating Solar-Driven Photocatalysis

by Jin-Hyoek Lee, Sang-Yun Jeong, Young-Don Son and Sang-Wha Lee

Nanomaterials 2023, 13(9), 1565; https://doi.org/10.3390/nano13091565 - 6 May 2023

Cited by 3 | Viewed by 1967

Abstract

TiO₂ semiconductors exhibit a low catalytic activity level under visible light because of their large band gap and fast recombination of electron–hole pairs. This paper reports the simple fabrication of a 0D/2D heterojunction photocatalyst by anchoring TiO₂ quantum dots (QDs) on graphite-like C₃N₄ [...] Read more.

TiO₂ semiconductors exhibit a low catalytic activity level under visible light because of their large band gap and fast recombination of electron–hole pairs. This paper reports the simple fabrication of a 0D/2D heterojunction photocatalyst by anchoring TiO₂ quantum dots (QDs) on graphite-like C₃N₄ (g-C₃N₄) nanosheets (NSs); the photocatalyst is denoted as TiO₂ QDs@g-C₃N₄. The nanocomposite was characterized via analytical instruments, such as powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, t orange (MO) under solar light were compared. The TiO₂ QDs@g-C₃N₄ photocatalyst exhibited 95.57% MO degradation efficiency and ~3.3-fold and 5.7-fold higher activity level than those of TiO₂ QDs and g-C₃N₄ NSs, respectively. Zero-dimensional/two-dimensional heterojunction formation with a staggered electronic structure leads to the efficient separation of photogenerated charge carriers via a Z-scheme pathway, which significantly accelerates photocatalysis under solar light. This study provides a facile synthetic method for the rational design of 0D/2D heterojunction nanocomposites with enhanced solar-driven catalytic activity. Full article

(This article belongs to the Special Issue Nanocatalysts for Environmental Remediation)

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19 pages, 4232 KiB

Open AccessArticle

Catalytic Hydrodechlorination of 4-Chlorophenol by Palladium-Based Catalyst Supported on Alumina and Graphene Materials

by Jintae Jeon, Yuri Park and Yuhoon Hwang

Nanomaterials 2023, 13(9), 1564; https://doi.org/10.3390/nano13091564 - 6 May 2023

Cited by 3 | Viewed by 2106

Abstract

Hydrodechlorination (HDC) is a reaction that involves the use of hydrogen to cleave the C−Cl bond in chlorinated organic compounds such as chlorophenols and chlorobenzenes, thus reducing their toxicity. In this study, a palladium (Pd) catalyst, which is widely used for HDC due [...] Read more.

Hydrodechlorination (HDC) is a reaction that involves the use of hydrogen to cleave the C−Cl bond in chlorinated organic compounds such as chlorophenols and chlorobenzenes, thus reducing their toxicity. In this study, a palladium (Pd) catalyst, which is widely used for HDC due to its advantageous physical and chemical properties, was immobilized on alumina (Pd/Al) and graphene-based materials (graphene oxide and reduced graphene oxide; Pd/GO and Pd/rGO, respectively) to induce the HDC of 4-chlorophenol (4-CP). The effects of the catalyst dosage, initial 4-CP concentration, and pH on 4-CP removal were evaluated. We observed that 4-CP was removed very rapidly when the HDC reaction was induced by Pd/GO and Pd/rGO. The granulation of Pd/rGO using sand was also investigated as a way to facilitate the separation of the catalyst from the treated aqueous solution after use, which is to improve practicality and effectiveness of the use of Pd catalysts with graphene-based support materials in an HDC system. The granulated catalyst (Pd/rGOSC) was employed in a column to induce HDC in a continuous flow reaction, leading to the successful removal of most 4-CP after 48 h. The reaction mechanisms were also determined based on the oxidation state of Pd, which was observed using X-ray photoelectron spectroscopy. Based on the results as a whole, the proposed granulated catalyst has the potential to greatly enhance the practical applicability of HDC for water purification. Full article

(This article belongs to the Special Issue New Trends in Mesoporous Materials for Catalysis and Sensors)

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11 pages, 1426 KiB

Open AccessArticle

Laser-Activated Second Harmonic Generation in Flexible Membrane with Si Nanowires

by Viktoriia Mastalieva, Vladimir Neplokh, Arseniy Aybush, Vladimir Fedorov, Anastasiya Yakubova, Olga Koval, Alexander Gudovskikh, Sergey Makarov and Ivan Mukhin

Nanomaterials 2023, 13(9), 1563; https://doi.org/10.3390/nano13091563 - 6 May 2023

Cited by 2 | Viewed by 1945

Abstract

Nonlinear silicon photonics has a high compatibility with CMOS technology and therefore is particularly attractive for various purposes and applications. Second harmonic generation (SHG) in silicon nanowires (NWs) is widely studied for its high sensitivity to structural changes, low-cost fabrication, and efficient tunability [...] Read more.

Nonlinear silicon photonics has a high compatibility with CMOS technology and therefore is particularly attractive for various purposes and applications. Second harmonic generation (SHG) in silicon nanowires (NWs) is widely studied for its high sensitivity to structural changes, low-cost fabrication, and efficient tunability of photonic properties. In this study, we report a fabrication and SHG study of Si nanowire/siloxane flexible membranes. The proposed highly transparent flexible membranes revealed a strong nonlinear response, which was enhanced via activation by an infrared laser beam. The vertical arrays of several nanometer-thin Si NWs effectively generate the SH signal after being exposed to femtosecond infrared laser irradiation in the spectral range of 800–1020 nm. The stable enhancement of SHG induced by laser exposure can be attributed to the functional modifications of the Si NW surface, which can be used for the development of efficient nonlinear platforms based on silicon. This study delivers a valuable contribution to the advancement of optical devices based on silicon and presents novel design and fabrication methods for infrared converters. Full article

(This article belongs to the Special Issue Optical Properties of Nanomaterials: Experimental and Computational Studies)

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11 pages, 12792 KiB

Open AccessArticle

Hillock Related Degradation Mechanism for AlGaN-Based UVC LEDs

by Juntong Chen, Jianxun Liu, Yingnan Huang, Ruisen Liu, Yayu Dai, Leming Tang, Zheng Chen, Xiujian Sun, Chenshu Liu, Shuming Zhang, Qian Sun, Meixin Feng, Qiming Xu and Hui Yang

Nanomaterials 2023, 13(9), 1562; https://doi.org/10.3390/nano13091562 - 6 May 2023

Cited by 9 | Viewed by 1924

Abstract

Heteroepitaxial growth of high Al-content AlGaN often results in a high density of threading dislocations and surface hexagonal hillocks, which degrade the performance and reliability of AlGaN-based UVC light emitting diodes (LEDs). In this study, the degradation mechanism and impurity/defect behavior of UVC [...] Read more.

Heteroepitaxial growth of high Al-content AlGaN often results in a high density of threading dislocations and surface hexagonal hillocks, which degrade the performance and reliability of AlGaN-based UVC light emitting diodes (LEDs). In this study, the degradation mechanism and impurity/defect behavior of UVC LEDs in relation to the hexagonal hillocks have been studied in detail. It was found that the early degradation of UVC LEDs is primarily caused by electron leakage. The prominent contribution of the hillock edges to the electron leakage is unambiguously evidenced by the transmission electron microscopy measurements, time-of-flight secondary ion mass spectrometry, and conductive atomic force microscopy. Dislocations bunching and segregation of impurities, including C, O, and Si, at the hillock edges are clearly observed, which facilitate the trap-assisted carrier tunneling in the multiple quantum wells and subsequent recombination in the p-AlGaN. This work sheds light on one possible degradation mechanism of AlGaN-based UVC LEDs. Full article

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10 pages, 1419 KiB

Open AccessArticle

Over Two-Fold Photoluminescence Enhancement from Single-Walled Carbon Nanotubes Induced by Oxygen Doping

by Timofei Eremin, Valentina Eremina, Yuri Svirko and Petr Obraztsov

Nanomaterials 2023, 13(9), 1561; https://doi.org/10.3390/nano13091561 - 6 May 2023

Cited by 4 | Viewed by 1938

Abstract

Covalent functionalization of single-walled carbon nanotubes (SWCNTs) is a promising way to improve their photoluminescent (PL) brightness and thus make them applicable as a base material for infrared light emitters. We report as high as over two-fold enhancement of the SWCNT PL brightness [...] Read more.

Covalent functionalization of single-walled carbon nanotubes (SWCNTs) is a promising way to improve their photoluminescent (PL) brightness and thus make them applicable as a base material for infrared light emitters. We report as high as over two-fold enhancement of the SWCNT PL brightness by using oxygen doping via the UV photodissociation of hypochlorite ions. By analyzing the temporal evolution of the PL and Raman spectra of SWCNTs in the course of the doping process, we conclude that the enhancement of SWCNTs PL brightness depends on the homogeneity of induced quantum defects distribution over the SWCNT surface. Full article

(This article belongs to the Special Issue Optical Properties of Semiconductor Nanomaterials)

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16 pages, 6756 KiB

Open AccessArticle

Rational Design of Lewis Base Electron Transport Materials for Improved Interface Property in Inverted Perovskite Solar Cells: A Theoretical Investigation

by Xueqin Ran, Jixuan Yang, Mohamad Akbar Ali, Lei Yang and Yonghua Chen

Nanomaterials 2023, 13(9), 1560; https://doi.org/10.3390/nano13091560 - 5 May 2023

Cited by 2 | Viewed by 1931

Abstract

Electron transport materials (ETMs) play a vital role in electron extraction and transport at the perovskite/ETM interface of inverted perovskite solar cells (PSCs) and are useful in power conversion efficiency (PCE), which is limited by interface carrier recombination. However, strategies for passivating undercoordinated [...] Read more.

Electron transport materials (ETMs) play a vital role in electron extraction and transport at the perovskite/ETM interface of inverted perovskite solar cells (PSCs) and are useful in power conversion efficiency (PCE), which is limited by interface carrier recombination. However, strategies for passivating undercoordinated Pb²⁺ at the perovskite/ETM interface employing ETMs remain a challenge. In this work, a variety of heteroatoms were used to strengthen the Lewis base property of new ETMs (asymmetrical perylene-diimide), aimed at deactivating non-bonded Pb²⁺ at the perovskite surface through Lewis acid-base coordination. Quantum chemical analysis revealed that novel ETMs have matched the energy level of perovskite, which enables electron extraction at the perovskite/ETM interface. The results also suggest that the large electron mobility (0.57~5.94 cm² V⁻¹ s⁻¹) of designed ETMs shows excellent electron transporting ability. More importantly, reinforced interaction between new ETMs and Pb²⁺ was found, which is facilitating to passivation of the defects induced by unsaturated Pb²⁺ at the perovskite/ETM interface. Furthermore, it is found that MA (CH₃NH₃⁺), Pb, and I_Pb (iodine substituted on the Pb site) defects at the perovskite/ETM interface could be effectively deactivated by the new ETMs. This study provides a useful strategy to design ETMs for improving the interface property in PSCs. Full article

(This article belongs to the Special Issue Nanomaterials for Optoelectronic Application)

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21 pages, 7072 KiB

Open AccessReview

Plasmonic Metal Nanostructures Meet Triplet–Triplet Annihilation-Based Photon Upconversion Systems: Performance Improvements and Application Trends

by Jotaro Honda, Kosuke Sugawa, Hironobu Tahara and Joe Otsuki

Nanomaterials 2023, 13(9), 1559; https://doi.org/10.3390/nano13091559 - 5 May 2023

Cited by 2 | Viewed by 2445

Abstract

Improving the performance of upconversion systems based on triplet–triplet annihilation (TTA-UC) can have far-reaching implications for various fields, including solar devices, nano-bioimaging, and nanotherapy. This review focuses on the use of localized surface plasmon (LSP) resonance of metal nanostructures to enhance the performance [...] Read more.

Improving the performance of upconversion systems based on triplet–triplet annihilation (TTA-UC) can have far-reaching implications for various fields, including solar devices, nano-bioimaging, and nanotherapy. This review focuses on the use of localized surface plasmon (LSP) resonance of metal nanostructures to enhance the performance of TTA-UC systems and explores their potential applications. After introducing the basic driving mechanism of TTA-UC and typical sensitizers used in these systems, we discuss recent studies that have utilized new sensitizers with distinct characteristics. Furthermore, we confirm that the enhancement in upconverted emission can be explained, at least in part, by the mechanism of “metal-enhanced fluorescence”, which is attributed to LSP resonance-induced fluorescence enhancement. Next, we describe selected experiments that demonstrate the enhancement in upconverted emission in plasmonic TTA-UC systems, as well as the emerging trends in their application. We present specific examples of studies in which the enhancement in upconverted emission has significantly improved the performance of photocatalysts under both sunlight and indoor lighting. Additionally, we discuss the potential for future developments in plasmonic TTA-UC systems. Full article

(This article belongs to the Special Issue State-of-the-Art Optical Properties and Applications of Metallic Nanostructures in Asia)

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11 pages, 7222 KiB

Open AccessArticle

Efficient and Broadband Emission in Dy³⁺-Doped Glass-Ceramic Fibers for Tunable Yellow Fiber Laser

by Qianyi Chen, Minbo Wu, Puxian Xiong, Yajing Zhao, Shuhang Tian, Yao Xiao, Yongsheng Sun, Dongdan Chen, Shanhui Xu and Zhongmin Yang

Nanomaterials 2023, 13(9), 1558; https://doi.org/10.3390/nano13091558 - 5 May 2023

Cited by 2 | Viewed by 2077

Abstract

Yellow lasers are of great interest in biology, medicine and display technology. However, nonlinear emission of near-infrared lasers at yellow still presents particularly complex optical alignment to date. Here, to the best of our knowledge, we demonstrate the fabrication of a NaLa(WO₄ [...] Read more.

Yellow lasers are of great interest in biology, medicine and display technology. However, nonlinear emission of near-infrared lasers at yellow still presents particularly complex optical alignment to date. Here, to the best of our knowledge, we demonstrate the fabrication of a NaLa(WO₄)₂: Dy³⁺ glass-ceramic fiber (GCF) for the first time. More importantly, the emission band of the GCF, which is around 575 nm, has a wide full-width half maximum (FWHM) of 18~22 nm, which is remarkably larger than that of the Dy³⁺-doped YAG crystal (<7 nm). The precursor fiber (PF) was drawn using the molten core drawing (MCD) method. In particular, benefiting from the in situ nanocrystals fabricated in the amorphous fiber core after thermal treatment, the resultant glass-ceramic fiber exhibits a five-times enhancement of luminescence intensity around 575 nm, compared with the precursor fiber, while retaining its broadband emission. Overall, this work is anticipated to offer a high potential GCF with prominent bandwidth for the direct access of a tunable yellow laser. Full article

(This article belongs to the Special Issue Luminescent Nanomaterials: Functional Design, Advantages, and Applications)

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37 pages, 6781 KiB

Open AccessReview

Current Applications of Liposomes for the Delivery of Vitamins: A Systematic Review

by Matheus A. Chaves, Letícia S. Ferreira, Lucia Baldino, Samantha C. Pinho and Ernesto Reverchon

Nanomaterials 2023, 13(9), 1557; https://doi.org/10.3390/nano13091557 - 5 May 2023

Cited by 16 | Viewed by 5324

Abstract

Liposomes have been used for several decades for the encapsulation of drugs and bioactives in cosmetics and cosmeceuticals. On the other hand, the use of these phospholipid vesicles in food applications is more recent and is increasing significantly in the last ten years. [...] Read more.

Liposomes have been used for several decades for the encapsulation of drugs and bioactives in cosmetics and cosmeceuticals. On the other hand, the use of these phospholipid vesicles in food applications is more recent and is increasing significantly in the last ten years. Although in different stages of technological maturity—in the case of cosmetics, many products are on the market—processes to obtain liposomes suitable for the encapsulation and delivery of bioactives are highly expensive, especially those aiming at scaling up. Among the bioactives proposed for cosmetics and food applications, vitamins are the most frequently used. Despite the differences between the administration routes (oral for food and mainly dermal for cosmetics), some challenges are very similar (e.g., stability, bioactive load, average size, increase in drug bioaccessibility and bioavailability). In the present work, a systematic review of the technological advancements in the nanoencapsulation of vitamins using liposomes and related processes was performed; challenges and future perspectives were also discussed in order to underline the advantages of these drug-loaded biocompatible nanocarriers for cosmetics and food applications. Full article

(This article belongs to the Special Issue Morphological Design and Synthesis of Nanoparticles)

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15 pages, 3609 KiB

Open AccessEditor’s ChoiceArticle

Increasing the Stability of Isolated and Dense High-Aspect-Ratio Nanopillars Fabricated Using UV-Nanoimprint Lithography

by Michael J. Haslinger, Oliver S. Maier, Markus Pribyl, Philipp Taus, Sonja Kopp, Heinz D. Wanzenboeck, Kurt Hingerl, Michael M. Muehlberger and Elena Guillén

Nanomaterials 2023, 13(9), 1556; https://doi.org/10.3390/nano13091556 - 5 May 2023

Cited by 3 | Viewed by 2518

Abstract

Structural anti-reflective coating and bactericidal surfaces, as well as many other effects, rely on high-aspect-ratio (HAR) micro- and nanostructures, and thus, are of great interest for a wide range of applications. To date, there is no widespread fabrication of dense or isolated HAR [...] Read more.

Structural anti-reflective coating and bactericidal surfaces, as well as many other effects, rely on high-aspect-ratio (HAR) micro- and nanostructures, and thus, are of great interest for a wide range of applications. To date, there is no widespread fabrication of dense or isolated HAR nanopillars based on UV nanoimprint lithography (UV-NIL). In addition, little research on fabricating isolated HAR nanopillars via UV-NIL exists. In this work, we investigated the mastering and replication of HAR nanopillars with the smallest possible diameters for dense and isolated arrangements. For this purpose, a UV-based nanoimprint lithography process was developed. Stability investigations with capillary forces were performed and compared with simulations. Finally, strategies were developed in order to increase the stability of imprinted nanopillars or to convert them into nanoelectrodes. We present UV-NIL replication of pillars with aspect ratios reaching up to 15 with tip diameters down to 35 nm for the first time. We show that the stability could be increased by a factor of 58 when coating them with a 20 nm gold layer and by a factor of 164 when adding an additional 20 nm thick layer of SiN. The coating of the imprints significantly improved the stability of the nanopillars, thus making them interesting for a wide range of applications. Full article

(This article belongs to the Special Issue Advance in Nanoimprint Technology)

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14 pages, 12135 KiB

Open AccessArticle

Experiments on the Electrical Conductivity of PEG 400 Nanocolloids Enhanced with Two Oxide Nanoparticles

by Elena Ionela Chereches and Alina Adriana Minea

Nanomaterials 2023, 13(9), 1555; https://doi.org/10.3390/nano13091555 - 5 May 2023

Cited by 6 | Viewed by 1534

Abstract

This paper aims to provide some insights into the pH and electrical conductivity of two classes of nanocolloids with PEG 400 as the base fluid. Thus, nanoparticles of two oxides—MgO and TiO₂—were added to the base fluid in 5 mass concentrations [...] Read more.

This paper aims to provide some insights into the pH and electrical conductivity of two classes of nanocolloids with PEG 400 as the base fluid. Thus, nanoparticles of two oxides—MgO and TiO₂—were added to the base fluid in 5 mass concentrations in the range 0.25–2.5 %wt. The stability was evaluated in terms of pH at ambient temperature, while the electrical conductivity was discussed at both ambient temperature and up to 333.15 K. The electrical conductivity of PEG 400 was previously discussed by this group, while the behavior of the new nanocolloids was debated in terms of the state of the art. More precisely, the influence of MgO increases electrical conductivity, and an enhancement of up to 48% for 0.25% MgO was found, while the influence of TiO₂ nanoparticles was found to be in similar ranges. In conclusion, electrical conductivity varies with temperature and the addition of nanoparticles to the base fluid, although the mechanisms that are driving the nanoparticle type and concentration influence are not yet entirely assumed in the available literature. Full article

(This article belongs to the Special Issue Current Advances in Nanoelectronics, Nanosensors and Devices)

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15 pages, 4822 KiB

Open AccessEditor’s ChoiceArticle

Selective Catalytic Epoxidation–Hydration of α-Pinene with Hydrogen Peroxide to Sobrerol by Durable Ammonium Phosphotungstate Immobilized on Imidazolized Activated Carbon

by Min Zheng, Xiangzhou Li, Youyi Xun, Jianhua Wang and Dulin Yin

Nanomaterials 2023, 13(9), 1554; https://doi.org/10.3390/nano13091554 - 5 May 2023

Cited by 2 | Viewed by 1750

Abstract

It is presented that the activated carbon was carboxylated with hydrogen peroxide and then acylated with 2-methylimidazole to prepare the porous carbon support with a surface imidazolated modification. Through the adsorption of phosphotungstic acid on the fundamental site of an imidazolyl group and [...] Read more.

It is presented that the activated carbon was carboxylated with hydrogen peroxide and then acylated with 2-methylimidazole to prepare the porous carbon support with a surface imidazolated modification. Through the adsorption of phosphotungstic acid on the fundamental site of an imidazolyl group and then adjusting the acid strength with the ammonia molecule, a catalytic carbon material immobilized with ammonium phosphotungstate (AC-COIMO-NH₄PW) was obtained, which was used to catalyze a one-pot reaction of convenient α-pinene and hydrogen peroxide to sobrerol. The bifunctional active site originated from the dual property of ammonium phosphotungstate, as the oxidant and acid presenting a cooperatively catalytic performance, which effectively catalyzes the tandem epoxidation–isomerization–hydration of α-pinene to sobrerol, in which the solvent effect of catalysis simultaneously exists. The sobrerol selectivity was significantly improved after the acid strength weakening by ammonia. Monomolecular chemical bonding and anchoring of ammonium phosphotungstate at the basic site prevented the loss of the active catalytic species, and the recovered catalyst showed excellent catalytic stability in reuse. Using acetonitrile as the solvent at 40 °C for 4 h, the conversion of α-pinene could reach 90.6%, and the selectivity of sobrerol was 40.5%. The results of five cycles show that the catalyst presents excellent stability due to the tight immobilization of ammonium phosphotungstate bonding on the imidazolized activated carbon, based on which a catalytic-cycle mechanism is proposed for the tandem reaction. Full article

(This article belongs to the Special Issue Advanced Carbon Chemistry and Its Applications)

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12 pages, 19551 KiB

Open AccessArticle

Monolayer AsC₅ as the Promising Hydrogen Storage Material for Clean Energy Applications

by Qiang Lu, Binyuan Zhang, Lianlian Zhang, Yulian Zhu and Weijiang Gong

Nanomaterials 2023, 13(9), 1553; https://doi.org/10.3390/nano13091553 - 5 May 2023

Cited by 8 | Viewed by 2013

Abstract

One of the critical techniques for developing hydrogen storage applications is the advanced research to build novel two-dimensional materials with significant capacity and effective reversibility. In this work, we perform first-principles unbiased structure search simulations to find a novel AsC

_{5}

monolayer with [...] Read more.

One of the critical techniques for developing hydrogen storage applications is the advanced research to build novel two-dimensional materials with significant capacity and effective reversibility. In this work, we perform first-principles unbiased structure search simulations to find a novel AsC

_{5}

monolayer with a variety of functionally advantageous characteristics. Based on theoretical simulations, the proposed AsC

_{5}

has been found to be energetically, dynamically, and thermally stable, supporting the viability of experiment. Since the coupling between H

_{2}

molecules and the AsC

_{5}

monolayer is quite weak due to physisorption, it is crucial to be enhanced by thoughtful material design. Hydrogen storage capacity can be greatly enhanced by decorating the AsC

_{5}

monolayer with Li atoms. Each Li atom on the AsC

_{5}

substrate is shown to be capable of adsorbing up to four H

_{2}

molecules with an advantageous average adsorption energy (E

_{a d}

) of 0.19 eV/H

_{2}

. The gravimetric density for hydrogen storage adsorption with 16Li and 64 H

_{2}

of a Li-decorated AsC

_{5}

monolayer is about 9.7 wt%, which is helpful for the possible application in hydrogen storage. It is discovered that the desorption temperature (T

_{D}

) is much greater than the hydrogen critical point. Therefore, such crucial characteristics make AsC

_{5}

-Li be a promising candidate for the experimental setup of hydrogen storage. Full article

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

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5 pages, 8682 KiB

Open AccessReply

Reply to Kaminski, N.E.; Cohen, S.M. Comment on “Bischoff et al. The Effects of the Food Additive Titanium Dioxide (E171) on Tumor Formation and Gene Expression in the Colon of a Transgenic Mouse Model for Colorectal Cancer. Nanomaterials 2022, 12, 1256”

by Nicolaj S. Bischoff, Héloïse Proquin, Marlon J. Jetten, Yannick Schrooders, Marloes C. M. Jonkhout, Jacco J. Briedé, Simone G. van Breda, Danyel G. J. Jennen, Estefany I. Medina-Reyes, Norma L. Delgado-Buenrostro, Yolanda I. Chirino, Henk van Loveren and Theo M. de Kok

Nanomaterials 2023, 13(9), 1552; https://doi.org/10.3390/nano13091552 - 5 May 2023

Viewed by 1459

Abstract

We appreciate the interest in our article describing transcriptome changes in a transgenic mouse model carrying an APC gene mutation and would like to reply to the reader [...] Full article

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3 pages, 196 KiB

Open AccessComment

Comment on Bischoff et al. The Effects of the Food Additive Titanium Dioxide (E171) on Tumor Formation and Gene Expression in the Colon of a Transgenic Mouse Model for Colorectal Cancer. Nanomaterials 2022, 12, 1256

by Norbert E. Kaminski and Samuel M. Cohen

Nanomaterials 2023, 13(9), 1551; https://doi.org/10.3390/nano13091551 - 5 May 2023

Cited by 1 | Viewed by 1576

Abstract

The publication by Bischoff et al., 2022 [...] Full article

12 pages, 4158 KiB

Open AccessArticle

Influence of WO₃-Based Antireflection Coatings on Current Density in Silicon Heterojunction Solar Cells

by Doowon Lee, Myoungsu Chae, Ibtisam Ahmad, Jong-Ryeol Kim and Hee-Dong Kim

Nanomaterials 2023, 13(9), 1550; https://doi.org/10.3390/nano13091550 - 5 May 2023

Cited by 4 | Viewed by 1692

Abstract

Antireflection coatings (ARCs) with an indium thin oxide (ITO) layer on silicon heterojunction solar cells (SHJ) have garnered significant attention, which is due to their potential for increasing current density (J_sc) and enhancing reliability. We propose an additional tungsten trioxide (WO [...] Read more.

Antireflection coatings (ARCs) with an indium thin oxide (ITO) layer on silicon heterojunction solar cells (SHJ) have garnered significant attention, which is due to their potential for increasing current density (J_sc) and enhancing reliability. We propose an additional tungsten trioxide (WO₃) layer on the ITO/Si structure in this paper in order to raise the J_sc and demonstrate the influence on the SHJ solar cell. First, we simulate the J_sc characteristics for the proposed WO₃/ITO/Si structure in order to analyze J_sc depending on the thickness of WO₃ using an OPAL 2 simulator. As a result, the OPAL 2 simulation shows an increase in J_sc of 0.65 mA/cm² after the 19 nm WO₃ deposition on ITO with a doping concentration of 6.1 × 10²⁰/cm². We then fabricate the proposed samples and observe an improved efficiency of 0.5% with an increased J_sc of 0.75 mA/cm² when using a 20 nm thick WO₃ layer on the SHJ solar cell. The results indicate that the WO₃ layer can be a candidate to improve the efficiency of SHJ solar cells with a low fabrication cost. Full article

(This article belongs to the Special Issue Recent Advances in Semiconductor Nanomaterials and Their Applications in Electronics and Optoelectronics)

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