Nanomaterials

32 pages, 7400 KiB

Open AccessArticle

Determination of the Transport Efficiency in spICP-MS Analysis Using Conventional Sample Introduction Systems: An Interlaboratory Comparison Study

by Otmar Geiss, Ivana Bianchi, Guillaume Bucher, Eveline Verleysen, Frédéric Brassinne, Jan Mast, Katrin Loeschner, Lucas Givelet, Francesco Cubadda, Francesca Ferraris, Andrea Raggi, Francesca Iacoponi, Ruud Peters, Anna Undas, Alexandra Müller, Ann-Katrin Meinhardt, Birgit Hetzer, Volker Gräf, Antonio R. Montoro Bustos and Josefa Barrero-Moreno

Nanomaterials 2022, 12(4), 725; https://doi.org/10.3390/nano12040725 - 21 Feb 2022

Cited by 15 | Viewed by 3465

Abstract

In single particle inductively coupled plasma mass spectrometry (spICP-MS), the transport efficiency is fundamental for the correct determination of both particle number concentration and size. In the present study, transport efficiency was systematically determined on three different days with six carefully characterised gold [...] Read more.

In single particle inductively coupled plasma mass spectrometry (spICP-MS), the transport efficiency is fundamental for the correct determination of both particle number concentration and size. In the present study, transport efficiency was systematically determined on three different days with six carefully characterised gold nanoparticle (AuNP) suspensions and in seven European and US expert laboratories using different ICP-MS instruments and spICP-MS software. Both particle size—(TES)—and particle frequency—(TEF)—methods were applied. The resulting transport efficiencies did not deviate much under ideal conditions. The TEF method however systematically resulted in lower transport efficiencies. The extent of this difference (0–300% rel. difference) depended largely on the choice and storage conditions of the nanoparticle suspensions used for the determination. The TES method is recommended when the principal measurement objective is particle size. If the main aim of the measurement is the determination of the particle number concentration, the TEF approach could be preferred as it might better account for particle losses in the sample introduction system. Full article

(This article belongs to the Special Issue Identification and Quantification of Nanomaterials)

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12 pages, 4497 KiB

Open AccessArticle

Composite Nanoarchitectonics with CoS₂ Nanoparticles Embedded in Graphene Sheets for an Anode for Lithium-Ion Batteries

by Tongjun Li, Hongyu Dong, Zhenpu Shi, Hongyun Yue, Yanhong Yin, Xiangnan Li, Huishuang Zhang, Xianli Wu, Baojun Li and Shuting Yang

Nanomaterials 2022, 12(4), 724; https://doi.org/10.3390/nano12040724 - 21 Feb 2022

Cited by 10 | Viewed by 2031

Abstract

Cobalt sulfides are attractive as intriguing candidates for anodes in Lithium-ion batteries (LIBs) due to their unique chemical and physical properties. In this work, CoS₂@rGO (CSG) was synthesized by a hydrothermal method. TEM showed that CoS₂ nanoparticles have an average [...] Read more.

Cobalt sulfides are attractive as intriguing candidates for anodes in Lithium-ion batteries (LIBs) due to their unique chemical and physical properties. In this work, CoS₂@rGO (CSG) was synthesized by a hydrothermal method. TEM showed that CoS₂ nanoparticles have an average particle size of 40 nm and were uniformly embedded in the surface of rGO. The battery electrode was prepared with this nanocomposite material and the charge and discharge performance was tested. The specific capacity, rate, and cycle stability of the battery were systematically analyzed. In situ XRD was used to study the electrochemical transformation mechanism of the material. The test results shows that the first discharge specific capacity of this nanocomposite reaches 1176.1 mAhg⁻¹, and the specific capacity retention rate is 61.5% after 100 cycles, which was 47.5% higher than that of the pure CoS₂ nanomaterial. When the rate changes from 5.0 C to 0.2 C, the charge-discharge specific capacity of the nanocomposite material can almost be restored to the initial capacity. The above results show that the CSG nanocomposites as a lithium-ion battery anode electrode has a high reversible specific capacity, better rate performance, and excellent cycle performance. Full article

(This article belongs to the Topic Nanoarchitectonics with Molecular and Materials Science: Functional Materials for Energy, Environment, Bio and Others)

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12 pages, 3123 KiB

Open AccessArticle

Flexible Piezoresistive Pressure Sensor Based on Electrospun Rough Polyurethane Nanofibers Film for Human Motion Monitoring

by Bin Xue, Haiyi Xie, Jinxu Zhao, Jianming Zheng and Chunye Xu

Nanomaterials 2022, 12(4), 723; https://doi.org/10.3390/nano12040723 - 21 Feb 2022

Cited by 20 | Viewed by 3130

Abstract

Flexible piezoresistive pressure sensors have been attracted a lot of attention due to their simple mechanism, easy fabrication, and convenient signal acquisition and analysis. Herein, a new flexible piezoresistive sensor based on microstructured electrospun rough polyurethane (PU) nanofibers film is assembled. The microstructured [...] Read more.

Flexible piezoresistive pressure sensors have been attracted a lot of attention due to their simple mechanism, easy fabrication, and convenient signal acquisition and analysis. Herein, a new flexible piezoresistive sensor based on microstructured electrospun rough polyurethane (PU) nanofibers film is assembled. The microstructured PU film with tiny bumps is prepared in one step via electrospinning technology, which imparts a microstructured rough upper surface and a smooth lower surface. With this unique microstructure, we have made it possible for PU/Ag films to serve as sensing layers for piezoresistive sensors by introducing a silver conductive layer on the surface of electrospun PU film. The fabricated piezoresistive pressure sensor delivers high sensitivity (10.53 kPa⁻¹ in the range of 0–5 kPa and 0.97 kPa⁻¹ in the range of 6–15 kPa), fast response time (60 ms), fast recovery time (30 ms), and long-time stability (over 10,000 cycles). This study presents a fabrication strategy to prepare the microstructured PU nanofiber film using electrospinning technology directly, and the as-developed sensor shows promise in applications such as wrist pulse measurement, finger movement monitoring, etc., proving its great potential for monitoring human activities. Full article

(This article belongs to the Section Nanoelectronics, Nanosensors and Devices)

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13 pages, 4193 KiB

Open AccessArticle

A Molecular Communication Platform Based on Body Area Nanonetwork

by Wenxin Pan, Xiaokang Chen, Xiaodong Yang, Nan Zhao, Lingguo Meng and Fiaz Hussain Shah

Nanomaterials 2022, 12(4), 722; https://doi.org/10.3390/nano12040722 - 21 Feb 2022

Cited by 11 | Viewed by 1828

Abstract

With the development of nanotechnology and biotechnology, the nanomachine can be applied to the interior of the human body. In order to achieve the goal of completing complex tasks, measures to connect multiple nanomachines that can complete more simple tasks are taken. This [...] Read more.

With the development of nanotechnology and biotechnology, the nanomachine can be applied to the interior of the human body. In order to achieve the goal of completing complex tasks, measures to connect multiple nanomachines that can complete more simple tasks are taken. This can expand the ability of a single nanomachine to cooperate and share information to complete more complex tasks—namely, the emergence of the Body Area Network (BAN). In response to the requirements of building a BAN, we must first need to solve the communication problem between two nanomachines. Communication networks based on molecular communication (MC), known as “natural body area networks”, are widely used in biomedical fields. With the considerable development of MC theory, it is urgent to set up an experimental platform to verify and guide theoretical modeling. In this paper, a nanomaterial-based MC platform is designed and built to simulate the cardiovascular system. The platform uses the diffusion of nanoscale pigment particles in water solution in silicone tube to achieve communication process and modulates binary sequence information to messenger molecules by on-off keying (OOK). The platform successfully transmits and receives a 17-bit binary sequence to prove its communication possibilities. To assess the platform capabilities, this paper tests the effects of different solution concentrations, pipeline flow rates, and pressure on platform communications. These factors can be used to expand the modulation schemes that the platform can implement. In future work, some nanomaterials that can be used for molecular communication can be applied to the platform to characterize their channel characteristics. Full article

(This article belongs to the Special Issue Metallic and Metal Oxide Nanoparticles and Their Applications)

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11 pages, 3000 KiB

Open AccessArticle

An Array of Flag-Type Triboelectric Nanogenerators for Harvesting Wind Energy

by Zhiqiang Zhao, Bin Wei, Yan Wang, Xili Huang, Bo Li, Fang Lin, Long Ma, Qianxi Zhang, Yongjiu Zou, Fang Yang, Hongchen Pang, Jin Xu and Xinxiang Pan

Nanomaterials 2022, 12(4), 721; https://doi.org/10.3390/nano12040721 - 21 Feb 2022

Cited by 12 | Viewed by 2401

Abstract

Harvesting wind energy from the ambient environment is a feasible method for powering wireless sensors and wireless transmission equipment. Triboelectric nanogenerators (TENGs) have proven to be a stable and promising technology for harvesting ambient wind energy. This study explores a new method for [...] Read more.

Harvesting wind energy from the ambient environment is a feasible method for powering wireless sensors and wireless transmission equipment. Triboelectric nanogenerators (TENGs) have proven to be a stable and promising technology for harvesting ambient wind energy. This study explores a new method for the performance enhancement and practical application of TENGs. An array of flag-type triboelectric nanogenerators (F-TENGs) for harvesting wind energy is proposed. An F-TENG consists of one piece of polytetrafluoroethylene (PTFE) membrane, which has two carbon-coated polyethylene terephthalate (PET) membranes on either side with their edges sealed. The PTFE was pre-ground to increase the initial charge on the surface and to enhance the effective contact area by improving the surface roughness, thus achieving a significant improvement in the output performance. The vertical and horizontal arrays of F-TENGs significantly improved the power output performance. The optimal power output performance was achieved when the vertical parallel distance was approximately 4D/15 (see the main text for the meaning of D), and the horizontal parallel distance was approximately 2D. We found that the peak output voltage and current of a single flag-type TENG of constant size were increased by 255% and 344%, respectively, reaching values of 64 V and 8 μA, respectively. Full article

(This article belongs to the Topic Electromaterials for Environment & Energy)

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12 pages, 4293 KiB

Open AccessArticle

ZnO Electrodeposition Model for Morphology Control

by Javier Orozco-Messana and Rubens Camaratta

Nanomaterials 2022, 12(4), 720; https://doi.org/10.3390/nano12040720 - 21 Feb 2022

Cited by 4 | Viewed by 1761

Abstract

In this research, a model for electrodeposition of zinc oxide (ZnO) nanostructures over indium-doped tin-oxide (ITO) glass using pulsed current and zinc chloride as source of zinc was proposed. For the model, reactions kinetics rate constants were evaluated by obtaining the reaction product [...] Read more.

In this research, a model for electrodeposition of zinc oxide (ZnO) nanostructures over indium-doped tin-oxide (ITO) glass using pulsed current and zinc chloride as source of zinc was proposed. For the model, reactions kinetics rate constants were evaluated by obtaining the reaction product solid mass of the various species through time using an electrochemical quartz crystal microbalance (EQCM). To obtain a mathematical model of the electrodeposition using Ansys CFX 2D simulation software, the reaction kinetics rates were used to calculate mass transfer in the volume closest to the surface. The model was applied to the experimental electrodeposition conditions to validate its accuracy. Dense wurtzite nanostructures with controlled morphology were obtained on a indium-doped tin-oxide (ITO) glass. Sample characterization was performed using high-resolution field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) on focused ion beam milled (FIBed) sheets from wurtzite mono-crystals. Average crystallite size was evaluated by X-ray diffraction (XRD) using the Scherrer equation, and superficial areas were evaluated by Brunauer, Emmett, and Teller (BET) method. Through the experimental results, a chemical model was developed for the competing reactions based on the speciation of zinc considering pH evolution, and kinetic constants, on the oxygen rich aqueous environment. Owing to the model, an accurate prediction of thickness and type of electrodeposited layers, under given conditions, is achieved. This allows an excellent control of the optical properties of Wurtzite as a photon absorber, for an efficient separation of the electron-hole pair for conduction of the electric charges formed. The large surface area, and small wurtzite crystallites evenly distributed on the thin film electrodeposited over the ITO conductive layer are promising features for later dye-sensitized photovoltaic cell production. Full article

(This article belongs to the Topic Synthesis and Applications of Nanostructured Metals and Metal Oxides)

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6 pages, 1327 KiB

Open AccessArticle

Dimension-Dependent Phenomenological Model of Excitonic Electric Dipole in InGaAs Quantum Dots

by Petr Steindl and Petr Klenovský

Nanomaterials 2022, 12(4), 719; https://doi.org/10.3390/nano12040719 - 21 Feb 2022

Cited by 2 | Viewed by 1450

Abstract

Permanent electric dipole is a key property for effective control of semiconductor quantum-dot-based sources of quantum light. For theoretical prediction of that, complex geometry-dependent quantum simulations are necessary. Here, we use

k \cdot p

simulations of exciton transition in InGaAs quantum dots to [...] Read more.

Permanent electric dipole is a key property for effective control of semiconductor quantum-dot-based sources of quantum light. For theoretical prediction of that, complex geometry-dependent quantum simulations are necessary. Here, we use

k \cdot p

simulations of exciton transition in InGaAs quantum dots to derive a simple geometry-dependent analytical model of dipole. Our model, discussed here, enables reasonably good estimation of the electric dipole, caused in quantum dot by the elastic strain, including an externally induced one. Due to its apparent simplicity, not necessitating elaborate and time-consuming simulations, it might after experimental verification serve as a preferred choice for experimentalists enabling them to make quick estimates of built-in and induced electric dipole in quantum dots. Full article

(This article belongs to the Special Issue Actual Problems of Solid State Physics: Nanomaterials and Nanotechnologies)

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9 pages, 1858 KiB

Open AccessArticle

Compact SnO₂/Mesoporous TiO₂ Bilayer Electron Transport Layer for Perovskite Solar Cells Fabricated at Low Process Temperature

by Junyeong Lee, Jongbok Kim, Chang-Su Kim and Sungjin Jo

Nanomaterials 2022, 12(4), 718; https://doi.org/10.3390/nano12040718 - 21 Feb 2022

Cited by 8 | Viewed by 3357

Abstract

Charge transport layers have been found to be crucial for high-performance perovskite solar cells (PSCs). SnO₂ has been extensively investigated as an alternative material for the traditional TiO₂ electron transport layer (ETL). The challenges facing the successful application of SnO₂ [...] Read more.

Charge transport layers have been found to be crucial for high-performance perovskite solar cells (PSCs). SnO₂ has been extensively investigated as an alternative material for the traditional TiO₂ electron transport layer (ETL). The challenges facing the successful application of SnO₂ ETLs are degradation during the high-temperature process and voltage loss due to the lower conduction band. To achieve highly efficient PSCs using a SnO₂ ETL, low-temperature-processed mesoporous TiO₂ (LT m-TiO₂) was combined with compact SnO₂ to construct a bilayer ETL. The use of LT m-TiO₂ can prevent the degradation of SnO₂ as well as enlarge the interfacial contacts between the light-absorbing layer and the ETL. SnO₂/TiO₂ bilayer-based PSCs showed much higher power conversion efficiency than single SnO₂ ETL-based PSCs. Full article

(This article belongs to the Special Issue Advances in Nanomaterials for Photovoltaic Applications)

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18 pages, 5765 KiB

Open AccessArticle

Toxic Effects and Mechanisms of Silver and Zinc Oxide Nanoparticles on Zebrafish Embryos in Aquatic Ecosystems

by Yen-Ling Lee, Yung-Sheng Shih, Zi-Yu Chen, Fong-Yu Cheng, Jing-Yu Lu, Yuan-Hua Wu and Ying-Jan Wang

Nanomaterials 2022, 12(4), 717; https://doi.org/10.3390/nano12040717 - 21 Feb 2022

Cited by 22 | Viewed by 2875

Abstract

The global application of engineered nanomaterials and nanoparticles (ENPs) in commercial products, industry, and medical fields has raised some concerns about their safety. These nanoparticles may gain access into rivers and marine environments through industrial or household wastewater discharge and thereby affect the [...] Read more.

The global application of engineered nanomaterials and nanoparticles (ENPs) in commercial products, industry, and medical fields has raised some concerns about their safety. These nanoparticles may gain access into rivers and marine environments through industrial or household wastewater discharge and thereby affect the ecosystem. In this study, we investigated the effects of silver nanoparticles (AgNPs) and zinc oxide nanoparticles (ZnONPs) on zebrafish embryos in aquatic environments. We aimed to characterize the AgNP and ZnONP aggregates in natural waters, such as lakes, reservoirs, and rivers, and to determine whether they are toxic to developing zebrafish embryos. Different toxic effects and mechanisms were investigated by measuring the survival rate, hatching rate, body length, reactive oxidative stress (ROS) level, apoptosis, and autophagy. Spiking AgNPs or ZnONPs into natural water samples led to significant acute toxicity to zebrafish embryos, whereas the level of acute toxicity was relatively low when compared to Milli-Q (MQ) water, indicating the interaction and transformation of AgNPs or ZnONPs with complex components in a water environment that led to reduced toxicity. ZnONPs, but not AgNPs, triggered a significant delay of embryo hatching. Zebrafish embryos exposed to filtered natural water spiked with AgNPs or ZnONPs exhibited increased ROS levels, apoptosis, and lysosomal activity, an indicator of autophagy. Since autophagy is considered as an early indicator of ENP interactions with cells and has been recognized as an important mechanism of ENP-induced toxicity, developing a transgenic zebrafish system to detect ENP-induced autophagy may be an ideal strategy for predicting possible ecotoxicity that can be applied in the future for the risk assessment of ENPs. Full article

(This article belongs to the Special Issue Nanoparticles in the Environment and Nanotoxicology)

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12 pages, 5056 KiB

Open AccessArticle

High Curie Temperature Achieved in the Ferromagnetic Mn_xGe_1−x/Si Quantum Dots Grown by Ion Beam Co-Sputtering

by Xiaoxiao Duan, Shuming Ye, Jing Yang, Chen Li, Chunjiang Lu, Xinpeng He, Luran Zhang, Rongfei Wang, Feng Qiu, Jie Yang, Haoyang Cui and Chong Wang

Nanomaterials 2022, 12(4), 716; https://doi.org/10.3390/nano12040716 - 21 Feb 2022

Cited by 3 | Viewed by 1598

Abstract

Ferromagnetic semiconductors (FMSs) exhibit great potential in spintronic applications. It is believed that a revolution of microelectronic techniques can take off, once the challenges of FMSs in both the room-temperature stability of the ferromagnetic phase and the compatibility with Si-based technology are overcome. [...] Read more.

Ferromagnetic semiconductors (FMSs) exhibit great potential in spintronic applications. It is believed that a revolution of microelectronic techniques can take off, once the challenges of FMSs in both the room-temperature stability of the ferromagnetic phase and the compatibility with Si-based technology are overcome. In this article, the Mn_xGe_1−x/Si quantum dots (QDs) with the Curie temperature (T_C) higher than the room temperature were grown by ion beam co-sputtering (IBCS). With the Mn doping level increasing, the ripening growth of MnGe QDs occurs due to self-assembly via the Stranski–Krastanov (SK) growth mode. The surface-enhanced Raman scattering effect of Mn sites observed in MnGe QDs are used to reveal the distribution behavior of Mn atoms in QDs and the Si buffer layer. The Curie temperature of Mn_xGe_1−x QDs increases, then slightly decreases with increasing the Mn doping level, and reaches its maximum value of 321 K at the doping level of 0.068. After a low-temperature and short-time annealing, the T_C value of Mn_0.068Ge_0.932 QDs increases from 321 K to 383 K. The higher Ge composition and residual strain in the IBCS grown Mn_xGe_1−x QDs are proposed to be responsible for maintaining the ferromagnetic phase above room temperature. Full article

(This article belongs to the Special Issue State-of-the-Art Nanophotonics Materials and Devices in China)

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19 pages, 1987 KiB

Open AccessArticle

Elevated Urinary Biomarkers of Oxidative Damage in Photocopier Operators following Acute and Chronic Exposures

by Yipei Zhang, Anila Bello, David K. Ryan, Philip Demokritou and Dhimiter Bello

Nanomaterials 2022, 12(4), 715; https://doi.org/10.3390/nano12040715 - 21 Feb 2022

Cited by 7 | Viewed by 1947

Abstract

Inhalation exposures to nanoparticles (NPs) from printers and photocopiers have been associated with upper airway and systemic inflammation, increased blood pressure, and cases of autoimmune and respiratory disorders. In this study we investigate oxidative stress induced by exposures to copier-emitted nanoparticles using a [...] Read more.

Inhalation exposures to nanoparticles (NPs) from printers and photocopiers have been associated with upper airway and systemic inflammation, increased blood pressure, and cases of autoimmune and respiratory disorders. In this study we investigate oxidative stress induced by exposures to copier-emitted nanoparticles using a panel of urinary oxidative stress (OS) biomarkers representing DNA damage (8-hydroxydeoxyguanosine, 8-OHdG; 8-hydroxyguanosine, 8-OHG; 5-hydroxymethyl uracil 5-OHMeU), lipid peroxidation (8-isoprostane; 4-hydroxynonenal, HNE), and protein oxidation biomarkers (o-tyrosine, 3-chlorotyrosine, and 3-nitrotyrosine) under conditions of acute (single 6 h exposure, 9 volunteers, 110 urine samples) and chronic exposures (6 workers, 11 controls, 81 urine samples). Urinary biomarkers were quantified with liquid chromatography–tandem mass spectrometry after solid phase extraction sample cleanup. 8-OHdG, 8-OHG, 8-isoprostane, and HNE were significantly elevated in both the acute and chronic exposure study participants relative to the controls. In the acute exposure study, the geometric mean ratios post-/pre-exposure were 1.42, 1.10, 2.0, and 2.25, respectively. Urinary 8-OHG and HNE increased with time to at least 36 h post-exposure (post-/pre-exposure GM ratios increased to 3.94 and 2.33, respectively), suggesting slower generation and/or urinary excretion kinetics for these biomarkers. In chronically exposed operators, the GM ratios of urinary biomarkers relative to controls ranged from 1.52 to 2.94, depending on the biomarker. O-Tyrosine and 5-OHMeU biomarkers were not significantly different from the controls. 3-chlorotyrosine and 3-nitrotyrosine were not detected in the urine samples. We conclude that NPs from photocopiers induce systemic oxidative stress by damaging DNA, RNA, and lipids. Urinary levels of 8-OHdG, 8-OHG, HNE, and 8-isoprostane were orders of magnitude higher than in nanocomposite processing workers, comparable to nano titanium dioxide and fiberglass manufacturing workers, but much lower than in shipyard welding and carbon nanotube synthesis workers. Biomarkers 8-OHdG, 8-OHG, 8-isoprostane, and HNE appear to be more sensitive and robust urinary biomarkers for monitoring oxidative stress to NPs from photocopiers. Full article

(This article belongs to the Special Issue Engineered Nanomaterials Exposure and Risk Assessment: Occupational Health and Safety)

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10 pages, 3618 KiB

Open AccessArticle

An Ionically Conductive, Self-Powered and Stable Organogel for Pressure Sensing

by Li Wang, Zhengduo Wang, Yingtao Li, Yu Luo, Bingheng Lu, Yiyang Gao, Wei Yu, Guoxin Gao and Shujiang Ding

Nanomaterials 2022, 12(4), 714; https://doi.org/10.3390/nano12040714 - 21 Feb 2022

Cited by 6 | Viewed by 2052

Abstract

Gel-based ionic conductors are promising candidates for flexible electronics, serving as stretchable sensors or electrodes. However, most of them suffer from a short operating life, low conductivity and rely on an external power supply, limiting their practical application. Herein, we report a stable [...] Read more.

Gel-based ionic conductors are promising candidates for flexible electronics, serving as stretchable sensors or electrodes. However, most of them suffer from a short operating life, low conductivity and rely on an external power supply, limiting their practical application. Herein, we report a stable organogel ionic conductor with high conductivity and self-powering ability. Briefly, lithium trifluoromethanesulfonate, as a conductive salt, provides high conductivity and the poly(1,1-difluoroethylene) layers, as a self-powering system, supply stable energy output under the influence of pressure. Moreover, the proposed conductors withstand long-term and multi-cycle durability tests. The prepared auxiliary training device can withstand the impact of a basketball and detect the impact force, showing potential in passive sensing during practical applications. Full article

(This article belongs to the Special Issue Advanced Materials and Technologies in Nanogenerators)

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19 pages, 6459 KiB

Open AccessArticle

Synthesis, Characterization, Photocatalysis, and Antibacterial Study of WO₃, MXene and WO₃/MXene Nanocomposite

by Al-Zoha Warsi, Fatima Aziz, Sonia Zulfiqar, Sajjad Haider, Imran Shakir and Philips O. Agboola

Nanomaterials 2022, 12(4), 713; https://doi.org/10.3390/nano12040713 - 21 Feb 2022

Cited by 35 | Viewed by 5125

Abstract

Tungsten oxide (WO₃), MXene, and an WO₃/MXene nanocomposite were synthesized to study their photocatalytic and biological applications. Tungsten oxide was synthesized by an easy and cost-effective hydrothermal method, and its composite with MXene was prepared through the sonication method. [...] Read more.

Tungsten oxide (WO₃), MXene, and an WO₃/MXene nanocomposite were synthesized to study their photocatalytic and biological applications. Tungsten oxide was synthesized by an easy and cost-effective hydrothermal method, and its composite with MXene was prepared through the sonication method. The synthesized tungsten oxide, MXene, and its composite were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR), energy-dispersive X-ray analysis (EDX), and Brunauer–Emmett–Teller (BET) for their structural, morphological, spectral, elemental and surface area analysis, respectively. The crystallite size of WO₃ calculated from XRD was ~10 nm, the particle size of WO₃ was 130 nm, and the average thickness of MXene layers was 175 nm, which was calculated from FESEM. The photocatalytic activity of as-synthesized samples was carried out for the degradation of methylene blue under solar radiation, MXene, the WO₃/MXene composite, and WO₃ exhibited 54%, 89%, and 99% photocatalytic degradation, respectively. WO₃ showed maximal degradation ability; by adding WO₃ to MXene, the degradation ability of MXene was enhanced. Studies on antibacterial activity demonstrated that these samples are good antibacterial agents against positive strains, and their antibacterial activity against negative strains depends upon their concentration. Against positive strains, the WO₃/MXene composite’s inhibition zone was at 7 mm, while it became 9 mm upon increasing the concentration. This study proves that WO₃, MXene, and the WO₃/MXene nanocomposite could be used in biological and environmental applications. Full article

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11 pages, 2271 KiB

Open AccessArticle

Photodetection Tuning with High Absorptivity Using Stacked 2D Heterostructure Films

by Umar Farooq, Kossi A. A. Min-Dianey, Pandey Rajagopalan, Muhammad Malik, Damgou Mani Kongnine, Jeong Ryeol Choi and Phuong V. Pham

Nanomaterials 2022, 12(4), 712; https://doi.org/10.3390/nano12040712 - 21 Feb 2022

Cited by 5 | Viewed by 1917

Abstract

Graphene-based photodetection (PD) devices have been broadly studied for their broadband absorption, high carrier mobility, and mechanical flexibility. Owing to graphene’s low optical absorption, the research on graphene-based PD devices so far has relied on hybrid heterostructure devices to enhance photo-absorption. Designing a [...] Read more.

Graphene-based photodetection (PD) devices have been broadly studied for their broadband absorption, high carrier mobility, and mechanical flexibility. Owing to graphene’s low optical absorption, the research on graphene-based PD devices so far has relied on hybrid heterostructure devices to enhance photo-absorption. Designing a new generation of PD devices supported by silicon (Si) film is considered as an innovative technique for PD devices; Si film-based devices are typically utilized in optical communication and image sensing owing to the remarkable features of Si, e.g., high absorption, high carrier mobility, outstanding CMOS integration. Here, we integrate (i) Si film via a splitting/printing transfer with (ii) graphite film grown by a pyrolysis method. Consequently, p-type Si film/graphite film/n-type Si-stacked PD devices exhibited a broadband detection of 0.4–4 μm (in computation) and obtained good experimental results such as the responsivity of 100 mA/W, specific detectivity of 3.44 × 10⁶ Jones, noise-equivalent power of 14.53 × 10⁻¹⁰ W/(Hz)^1/2, external quantum efficiency of 0.2, and rise/fall time of 38 μs/1 μs under 532 nm laser illumination. Additionally, our computational results also confirmed an enhanced light absorption of the above stacked 2D heterostructure film-based PD device compatible with the experimental results. Full article

(This article belongs to the Special Issue Characterization of Quantum Effects in Nanomaterials, Nano-Devices, and Nanophotonics)

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17 pages, 3425 KiB

Open AccessArticle

A Micro Electrochemical Sensor for Multi-Analyte Detection Based on Oxygenated Graphene Modified Screen-Printed Electrode

by Baiqing Yuan, Liju Gan, Gang Li, Chunying Xu and Gang Liu

Nanomaterials 2022, 12(4), 711; https://doi.org/10.3390/nano12040711 - 21 Feb 2022

Cited by 4 | Viewed by 1981

Abstract

Electrode interfaces with both antibiofouling properties and electrocatalytic activity can promote the practical application of nonenzymatic electrochemical sensors in biological fluids. Compared with graphene, graphene oxide (GO) possesses unique properties such as superior solubility (hydrophilicity) in water, negative charge, and abundant oxygenated groups [...] Read more.

Electrode interfaces with both antibiofouling properties and electrocatalytic activity can promote the practical application of nonenzymatic electrochemical sensors in biological fluids. Compared with graphene, graphene oxide (GO) possesses unique properties such as superior solubility (hydrophilicity) in water, negative charge, and abundant oxygenated groups (oxo functionalities) in the plane and edge sites, which play an essential role in electrocatalysis and functionalization. In this work, a micro electrochemical sensor consisting of GO-modified screen-printed electrode and PDMS micro-cell was designed to achieve multi-analyte detection with excellent selectivity and anti-biofouling properties by electrochemically tuning the oxygen-containing functional species, hydrophilicity/hydrophobicity, and electrical conductivity. In particular, the presented electrodes demonstrated the potential in the analysis of biological samples in which electrodes often suffer from serious biofouling. The interaction of proteins with electrodes as well as uric acid was investigated and discussed. Full article

(This article belongs to the Special Issue Preparation of Nanomaterial Modified Electrode and Its Sensing Application)

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12 pages, 3327 KiB

Open AccessArticle

Highly Unidirectional Radiation Enhancement Based on a Hybrid Multilayer Dimer

by Dengchao Huang, Shilin Liu and Kang Yang

Nanomaterials 2022, 12(4), 710; https://doi.org/10.3390/nano12040710 - 21 Feb 2022

Viewed by 1414

Abstract

Dimers made of plasmonic particles support strong field enhancements but suffer from large absorption losses, while low-loss dielectric dimers are limited by relatively weak optical confinement. Hybrid dimers could utilize the advantages of both worlds. Here, we propose a hybrid nanoantenna that contains [...] Read more.

Dimers made of plasmonic particles support strong field enhancements but suffer from large absorption losses, while low-loss dielectric dimers are limited by relatively weak optical confinement. Hybrid dimers could utilize the advantages of both worlds. Here, we propose a hybrid nanoantenna that contains a dimer of core-dual shell nanoparticles known as the metal–dielectric–metal (MDM) structure. We discovered that the hybrid dimer sustained unidirectional forward scattering, which resulted in a nearly ideal Kerker condition in the frequency close to the resonance peak of the dimer due to enhancing the amplitude of the induced high-order electric multiples in the gap and effectively superimposing them with magnetic ones, which respond to the excitation of the plane wave in the dielectric layer of the dimer. Furthermore, when an electric quantum emitter is coupled to the dimer, our study shows that the optimal hybrid dimer simultaneously possesses high radiation directivity and low-loss features, which illustrates a back-to-front ratio of radiation 53 times higher than that of the pure dielectric dimer and an average radiation efficiency 80% higher than that of the pure metallic dimer. In addition, the unique structures of the hybrid hexamer direct almost decrease 75% of the radiation beamwidth, hence heightening the directivity of the nanoantenna based on a hybrid dimer. Full article

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17 pages, 4140 KiB

Open AccessArticle

Advanced Nanomechanical Characterization of Biopolymer Films Containing GNPs and MWCNTs in Hybrid Composite Structure

by Todor Batakliev, Evgeni Ivanov, Verislav Angelov, Giovanni Spinelli and Rumiana Kotsilkova

Nanomaterials 2022, 12(4), 709; https://doi.org/10.3390/nano12040709 - 21 Feb 2022

Cited by 5 | Viewed by 1558

Abstract

Nanomechanical definition of the properties of composite specimens based on polylactic acid (PLA) was made in the present study. Research activities with accent on biodegradable polymer nanocomposites have fundamental significance originated from the worldwide plastic waste pollution. To receive hybrid nanocomposites with high [...] Read more.

Nanomechanical definition of the properties of composite specimens based on polylactic acid (PLA) was made in the present study. Research activities with accent on biodegradable polymer nanocomposites have fundamental significance originated from the worldwide plastic waste pollution. To receive hybrid nanocomposites with high level of homogeneity, the low cost and environmentally friendly melt extrusion method has been applied. The role of graphene nanoplatelets (GNPs) and multiwall carbon nanotubes (MWCNTs) as reinforcing nanoparticles dispersed in the polymer matrix was thoroughly investigated. Quasi-static nanoindentation analysis was enriched by performance of accelerated property mapping and nanodynamic mechanical testing in order to fully describe the nanoscale surface homogeneity and stress relaxation behavior of the nanocomposite specimens. That novelty of the research approach had a well-marked contribution over the detection of the new samples’ nanomechanical features as a function of the type of carbon nanofiller. Refined nanoscratch experiments uncovered the resistance of the materials against notches by means of measurement of the coefficient of friction and accurate estimation of the residual penetration depth. Full article

(This article belongs to the Special Issue Hybrid Nano Polymer Composites)

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30 pages, 5560 KiB

Open AccessReview

Application of the Photoacoustic Approach in the Characterization of Nanostructured Materials

by Mykola Isaiev, Gauhar Mussabek, Pavlo Lishchuk, Kateryna Dubyk, Nazym Zhylkybayeva, Gulmira Yar-Mukhamedova, David Lacroix and Vladimir Lysenko

Nanomaterials 2022, 12(4), 708; https://doi.org/10.3390/nano12040708 - 21 Feb 2022

Cited by 13 | Viewed by 2486

Abstract

A new generation of sensors can be engineered based on the sensing of several markers to satisfy the conditions of the multimodal detection principle. From this point of view, photoacoustic-based sensing approaches are essential. The photoacoustic effect relies on the generation of light-induced [...] Read more.

A new generation of sensors can be engineered based on the sensing of several markers to satisfy the conditions of the multimodal detection principle. From this point of view, photoacoustic-based sensing approaches are essential. The photoacoustic effect relies on the generation of light-induced deformation (pressure) perturbations in media, which is essential for sensing applications since the photoacoustic response is formed due to a contrast in the optical, thermal, and acoustical properties. It is also particularly important to mention that photoacoustic light-based approaches are flexible enough for the measurement of thermal/elastic parameters. Moreover, the photoacoustic approach can be used for imaging and visualization in material research and biomedical applications. The advantages of photoacoustic devices are their compact sizes and the possibility of on-site measurements, enabling the online monitoring of material parameters. The latter has significance for the development of various sensing applications, including biomedical ones, such as monitoring of the biodistribution of biomolecules. To extend sensing abilities and to find reliable measurement conditions, one needs to clearly understand all the phenomena taking place during energy transformation during photoacoustic signal formation. Therefore, the current paper is devoted to an overview of the main measurement principles used in the photoacoustic setup configurations, with a special focus on the key physical parameters. Full article

(This article belongs to the Special Issue Photoacoustic and Photothermal Phenomena in Nanomaterials)

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8 pages, 3488 KiB

Open AccessCommunication

Slow-Relaxation Behavior of a Mononuclear Co(II) Complex Featuring Long Axial Co-O Bond

by Zhengyao Xia, Yan Li, Cheng Ji, Yucheng Jiang, Chunlan Ma, Ju Gao and Jinlei Zhang

Nanomaterials 2022, 12(4), 707; https://doi.org/10.3390/nano12040707 - 21 Feb 2022

Cited by 1 | Viewed by 1609

Abstract

Co(II) mononuclear complex with different coordination geometry would display various of field-induced single-ion magnet (SIM) behaviors. Here, we identify a field-induced single-ion magnet in a mononuclear complex Co(H₂DPA)₂·H₂O (H₂DPA = 2,6-pyridine-dicarboxylic acid) by the hydrothermal [...] Read more.

Co(II) mononuclear complex with different coordination geometry would display various of field-induced single-ion magnet (SIM) behaviors. Here, we identify a field-induced single-ion magnet in a mononuclear complex Co(H₂DPA)₂·H₂O (H₂DPA = 2,6-pyridine-dicarboxylic acid) by the hydrothermal method. The long axial Co-O coordination bond (Co1‧‧‧O3) can be formed by Co1 and O3. Therefore, Co(II) ion is six-coordinated in a distorted elongated octahedron. AC magnetization susceptibilities show that the effective energy barrier is up to 43.28 K. This is much larger than most mononuclear Co(II). The distorted elongated octahedron caused by the axial Co-O coordination bond is responsible for the high effective energy barrier. The distribution of electron density in Co1 and O3 atoms in the long axial bond would influence the magnetic relaxation process in turn. Our work deepens the relationship between the effective energy barrier and the weak change of ligand field by long axial bonds, which would facilitate constructing SIM with high energy temperature. Full article

(This article belongs to the Special Issue Advances in Nanostructured Semiconductors and Heterojunctions)

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15 pages, 7420 KiB

Open AccessEditor’s ChoiceArticle

Joining of Ti6Al4V to Al₂O₃ Using Nanomultilayers

by Marcionilo Silva, Jr., Ana Sofia Ramos, Maria Teresa Vieira and Sónia Simões

Nanomaterials 2022, 12(4), 706; https://doi.org/10.3390/nano12040706 - 21 Feb 2022

Viewed by 1729

Abstract

Diffusion bonding of Ti6Al4V to Al₂O₃ using Ni/Ti reactive nanomultilayers as interlayer material was investigated. For this purpose, Ni/Ti multilayer thin films with 12, 25, and 60 nm modulation periods (bilayer thickness) were deposited by d.c. magnetron sputtering onto the [...] Read more.

Diffusion bonding of Ti6Al4V to Al₂O₃ using Ni/Ti reactive nanomultilayers as interlayer material was investigated. For this purpose, Ni/Ti multilayer thin films with 12, 25, and 60 nm modulation periods (bilayer thickness) were deposited by d.c. magnetron sputtering onto the base materials’ surface. The joints were processed at 750 and 800 °C with a dwell time of 60 min and under a pressure of 5 MPa. Microstructural characterization of the interfaces was conducted by scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), and electron backscatter diffraction (EBSD). The mechanical characterization of the joints was performed by nanoindentation, and hardness and reduced Young’s modulus distribution maps were obtained across the interfaces. The joints processed at 800 °C using the three modulation periods were successful, showing the feasibility of using these nanolayered films to improve the diffusion bonding of dissimilar materials. Using modulation periods of 25 and 60 nm, it was also possible to reduce the bonding temperature to 750 °C and obtain a sound interface. The interfaces are mainly composed of NiTi and NiTi₂ phases. The nanoindentation experiments revealed that the hardness and reduced Young’s modulus at the interfaces reflect the observed microstructure. Full article

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14 pages, 3627 KiB

Open AccessArticle

Microstructure and Superior Corrosion Resistance of an In-Situ Synthesized NiTi-Based Intermetallic Coating via Laser Melting Deposition

by Cheng Deng, Menglong Jiang, Di Wang, Yongqiang Yang, Vyacheslav Trofimov, Lianxi Hu and Changjun Han

Nanomaterials 2022, 12(4), 705; https://doi.org/10.3390/nano12040705 - 20 Feb 2022

Cited by 10 | Viewed by 2010

Abstract

A nickel–titanium (NiTi)-based intermetallic coating was in-situ synthesized on a Ti–6Al–4V (TC4) substrate via laser melting deposition (LMD) using Ni–20Cr and TC4 powders. Scanning electron microscopy, X-ray diffraction, a digital microhardness tester and an electrochemical analyzer were used to evaluate the microstructure, Vicker’s [...] Read more.

A nickel–titanium (NiTi)-based intermetallic coating was in-situ synthesized on a Ti–6Al–4V (TC4) substrate via laser melting deposition (LMD) using Ni–20Cr and TC4 powders. Scanning electron microscopy, X-ray diffraction, a digital microhardness tester and an electrochemical analyzer were used to evaluate the microstructure, Vicker’s microhardness and electrochemical corrosion resistance of the intermetallic coating. Results indicate that the microstructure of the intermetallic coating is composed of NiTi₂, NiTi and Ni₃Ti. The measured microhardness achieved is as high as ~850 HV_0.2, ~2.5 times larger than that of the TC4 alloy, which can be attributed to the solid solution strengthening of Al and Cr, dispersion strengthening of the intermetallic compounds, and grain refinement strengthening from the rapid cooling of LMD. During the electrochemical corrosion of 3.5% NaCl solution, a large amount of Ti ions were released from the intermetallic coating surface and reacted with Cl⁻ ions to form [TiCl₆]² with an increase in corrosion voltage. In further hydrolysis reactions, TiO₂ formation occurred when the ratio of [TiCl₆]²⁻ reached a critical value. The in-situ synthesized intermetallic coating can achieve a superior corrosion resistance compared to that of the TC4 alloy. Full article

(This article belongs to the Special Issue Energy Transport at the Micro/Nanoscale)

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15 pages, 3629 KiB

Open AccessArticle

MOFSocialNet: Exploiting Metal-Organic Framework Relationships via Social Network Analysis

by Mehrdad Jalali, Manuel Tsotsalas and Christof Wöll

Nanomaterials 2022, 12(4), 704; https://doi.org/10.3390/nano12040704 - 20 Feb 2022

Cited by 9 | Viewed by 4452

Abstract

The number of metal-organic frameworks (MOF) as well as the number of applications of this material are growing rapidly. With the number of characterized compounds exceeding 100,000, manual sorting becomes impossible. At the same time, the increasing computer power and established use of [...] Read more.

The number of metal-organic frameworks (MOF) as well as the number of applications of this material are growing rapidly. With the number of characterized compounds exceeding 100,000, manual sorting becomes impossible. At the same time, the increasing computer power and established use of automated machine learning approaches makes data science tools available, that provide an overview of the MOF chemical space and support the selection of suitable MOFs for a desired application. Among the different data science tools, graph theory approaches, where data generated from numerous real-world applications is represented as a graph (network) of interconnected objects, has been widely used in a variety of scientific fields such as social sciences, health informatics, biological sciences, agricultural sciences and economics. We describe the application of a particular graph theory approach known as social network analysis to MOF materials and highlight the importance of community (group) detection and graph node centrality. In this first application of the social network analysis approach to MOF chemical space, we created MOFSocialNet. This social network is based on the geometrical descriptors of MOFs available in the CoRE-MOFs database. MOFSocialNet can discover communities with similar MOFs structures and identify the most representative MOFs within a given community. In addition, analysis of MOFSocialNet using social network analysis methods can predict MOF properties more accurately than conventional ML tools. The latter advantage is demonstrated for the prediction of gas storage properties, the most important property of these porous reticular networks. Full article

(This article belongs to the Topic Deep Learning Applied on Functional Materials Characterization)

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13 pages, 4691 KiB

Open AccessEditor’s ChoiceArticle

Laser-Induced Morphological and Structural Changes of Cesium Lead Bromide Nanocrystals

by Athanasia Kostopoulou, Konstantinos Brintakis, Maria Sygletou, Kyriaki Savva, Nikolaos Livakas, Michaila Akathi Pantelaiou, Zhiya Dang, Alexandros Lappas, Liberato Manna and Emmanuel Stratakis

Nanomaterials 2022, 12(4), 703; https://doi.org/10.3390/nano12040703 - 20 Feb 2022

Cited by 4 | Viewed by 2526

Abstract

Metal halide perovskite nanocrystals, an emerging class of materials for advanced photonic and optoelectronic applications, are mainly fabricated with colloidal chemistry routes. On the quest for new properties according to application needs, new perovskite systems of various morphologies and levels of doping and [...] Read more.

Metal halide perovskite nanocrystals, an emerging class of materials for advanced photonic and optoelectronic applications, are mainly fabricated with colloidal chemistry routes. On the quest for new properties according to application needs, new perovskite systems of various morphologies and levels of doping and alloying have been developed, often also involving post-synthesis reactions. Recently, laser irradiation in liquids has been utilized as a fast method to synthesize or transform materials and interesting laser-induced transformations on nanocrystals were induced. These studies in general have been limited to small nanocrystals (~15 nm). In the case of halide perovskites, fragmentation or anion exchange have been observed in such laser-based processes, but no crystal structure transformations were actually observed or deliberately studied. Nanocrystals are more sensitive to light exposure compared to the corresponding bulk crystals. Additional factors, such as size, morphology, the presence of impurities, and others, can intricately affect the photon absorption and heat dissipation in nanocrystal suspensions during laser irradiation. All these factors can play an important role in the final morphologies and in the time required for these transformations to unfold. In the present work, we have employed a 513 nm femtosecond (fs) laser to induce different transformations in large nanocrystals, in which two phases coexist in the same particle (Cs₄PbBr₆/CsPbBr₃ nanohexagons of ~100 nm), dispersed in dichlorobenzene. These transformations include: (i) the exfoliation of the primary nanohexagons and partial anion exchange; (ii) fragmentation in smaller nanocubes and partial anion exchange; (iii) side-by-side-oriented attachment, fusion, and formation of nanoplatelets and complete anion exchange; (iv) side-by-side attachment, fusion, and formation of nanosheets. Partial or complete Br-Cl anion exchange in the above transformations was triggered by the partial degradation of dichlorobenzene. In addition to the detailed analysis of the various nanocrystal morphologies observed in the various transformations, the structure–photoluminescence relationships for the different samples were analyzed and discussed. Full article

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13 pages, 2253 KiB

Open AccessArticle

Preparation and Characterization of Photoluminescent Graphene Quantum Dots from Watermelon Rind Waste for the Detection of Ferric Ions and Cellular Bio-Imaging Applications

by Chatchai Rodwihok, Tran Van Tam, Won Mook Choi, Mayulee Suwannakaew, Sang Woon Woo, Duangmanee Wongratanaphisan and Han S. Kim

Nanomaterials 2022, 12(4), 702; https://doi.org/10.3390/nano12040702 - 20 Feb 2022

Cited by 13 | Viewed by 2665

Abstract

Graphene quantum dots (GQDs) were synthesized using watermelon rind waste as a photoluminescent (PL) agent for ferric ion (Fe

^{3 +}

) detection and in vitro cellular bio-imaging. A green and simple one-pot hydrothermal technique was employed to prepare the GQDs. Their crystalline [...] Read more.

Graphene quantum dots (GQDs) were synthesized using watermelon rind waste as a photoluminescent (PL) agent for ferric ion (Fe

^{3 +}

) detection and in vitro cellular bio-imaging. A green and simple one-pot hydrothermal technique was employed to prepare the GQDs. Their crystalline structures corresponded to the lattice fringe of graphene, possessing amide, hydroxyl, and carboxyl functional groups. The GQDs exhibited a relatively high quantum yield of approximately 37%. Prominent blue emission under UV excitation and highly selective PL quenching for Fe

^{3 +}

were observed. Furthermore, Fe

^{3 +}

could be detected at concentrations as low as 0.28

μ

M (limit of detection), allowing for high sensitivity toward Fe

^{3 +}

detection in tap and drinking water samples. In the bio-imaging experiment, the GQDs exhibited a low cytotoxicity for the HeLa cells, and they were clearly illuminated at an excitation wavelength of 405 nm. These results can serve as the basis for developing an environment-friendly, simple, and cost-effective approach of using food waste by converting them into photoluminescent nanomaterials for the detection of metal ions in field water samples and biological cellular studies. Full article

(This article belongs to the Special Issue Application of Carbon-Based Nanostructures and Nanocomposites for Sustainable Development)

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12 pages, 9635 KiB

Open AccessArticle

Extremely Narrow and Actively Tunable Mie Surface Lattice Resonances in GeSbTe Metasurfaces: Study

by Lei Xiong, Hongwei Ding, Yuanfu Lu and Guangyuan Li

Nanomaterials 2022, 12(4), 701; https://doi.org/10.3390/nano12040701 - 20 Feb 2022

Cited by 7 | Viewed by 2090

Abstract

Mie surface lattice resonances (SLRs) supported by periodic all-dielectric nanoparticles emerge from the radiative coupling of localized Mie resonances in individual nanoparticles through Rayleigh anomaly diffraction. To date, it remains challenging to achieve narrow bandwidth and active tuning simultaneously. In this work, we [...] Read more.

Mie surface lattice resonances (SLRs) supported by periodic all-dielectric nanoparticles emerge from the radiative coupling of localized Mie resonances in individual nanoparticles through Rayleigh anomaly diffraction. To date, it remains challenging to achieve narrow bandwidth and active tuning simultaneously. In this work, we report extremely narrow and actively tunable electric dipole SLRs (ED-SLRs) in Ge₂Se₂Te₅ (GST) metasurfaces. Simulation results show that, under oblique incidence with TE polarization, ED-SLRs with extremely narrow linewidth down to 12 nm and high quality factor up to 409 can be excited in the mid-infrared regime. By varying the incidence angle, the ED-SLR can be tuned over an extremely large spectral region covering almost the entire mid-infrared regime. We further numerically show that, by changing the GST crystalline fraction, the ED-SLR can be actively tuned, leading to nonvolatile, reconfigurable, and narrowband filtering, all-optical multilevel modulation, or all-optical switching with high performance. We expect that this work will advance the engineering of Mie SLRs and will find intriguing applications in optical telecommunication, networks, and microsystems. Full article

(This article belongs to the Special Issue Materials Science and Nanoengineering (ICMSN-2022))

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13 pages, 3305 KiB

Open AccessArticle

SnO₂ Anchored in S and N Co-Doped Carbon as the Anode for Long-Life Lithium-Ion Batteries

by Shuli Zhou, Hongyan Zhou, Yunpeng Zhang, Keke Zhu, Yanjun Zhai, Denghu Wei and Suyuan Zeng

Nanomaterials 2022, 12(4), 700; https://doi.org/10.3390/nano12040700 - 19 Feb 2022

Cited by 8 | Viewed by 1923

Abstract

Tin dioxide (SnO₂) has been the focus of attention in recent years owing to its high theoretical capacity (1494 mAh g⁻¹). However, the application of SnO₂ has been greatly restricted because of the huge volume change during charge/discharge [...] Read more.

Tin dioxide (SnO₂) has been the focus of attention in recent years owing to its high theoretical capacity (1494 mAh g⁻¹). However, the application of SnO₂ has been greatly restricted because of the huge volume change during charge/discharge process and poor electrical conductivity. In this paper, a composite material composed of SnO₂ and S, N co-doped carbon (SnO₂@SNC) was prepared by a simple solid-state reaction. The as-prepared SnO₂@SNC composite structures show enhanced lithium storage capacity as compared to pristine SnO₂. Even after cycling for 1000 times, the as-synthesized SnO₂@SNC can still deliver a discharge capacity of 600 mAh g⁻¹ (current density: 2 A g⁻¹). The improved electrochemical performance could be attributed to the enhanced electric conductivity of the electrode. The introduction of carbon could effectively improve the reversibility of the reaction, which will suppress the capacity fading resulting from the conversion process. Full article

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19 pages, 4856 KiB

Open AccessFeature PaperReview

Environmental Fate and Toxicity of Sunscreen-Derived Inorganic Ultraviolet Filters in Aquatic Environments: A Review

by Shengwu Yuan, Jingying Huang, Xia Jiang, Yuxiong Huang, Xiaoshan Zhu and Zhonghua Cai

Nanomaterials 2022, 12(4), 699; https://doi.org/10.3390/nano12040699 - 19 Feb 2022

Cited by 24 | Viewed by 6312

Abstract

An increasing number of inorganic ultraviolet filters (UVFs), such as nanosized zinc oxide (nZnO) and titanium dioxide (nTiO₂), are formulated in sunscreens because of their broad UV spectrum sunlight protection and because they limit skin damage. However, sunscreen-derived inorganic UVFs are [...] Read more.

An increasing number of inorganic ultraviolet filters (UVFs), such as nanosized zinc oxide (nZnO) and titanium dioxide (nTiO₂), are formulated in sunscreens because of their broad UV spectrum sunlight protection and because they limit skin damage. However, sunscreen-derived inorganic UVFs are considered to be emerging contaminants; in particular, nZnO and nTiO₂ UVFs have been shown to undergo absorption and bioaccumulation, release metal ions, and generate reactive oxygen species, which cause negative effects on aquatic organisms. We comprehensively reviewed the current study status of the environmental sources, occurrences, behaviors, and impacts of sunscreen-derived inorganic UVFs in aquatic environments. We find that the associated primary nanoparticle characteristics and coating materials significantly affect the environmental behavior and fate of inorganic UVFs. The consequential ecotoxicological risks and underlying mechanisms are discussed at the individual and trophic transfer levels. Due to their persistence and bioaccumulation, more attention and efforts should be redirected to investigating the sources, fate, and trophic transfer of inorganic UVFs in ecosystems. Full article

(This article belongs to the Special Issue Nanomaterials Ecotoxicity Evaluation)

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27 pages, 7692 KiB

Open AccessEditor’s ChoiceReview

Light-Driven Charge Transport and Optical Sensing in Molecular Junctions

by Chaolong Tang, Mehrdad Shiri, Haixin Zhang, Ridwan Tobi Ayinla and Kun Wang

Nanomaterials 2022, 12(4), 698; https://doi.org/10.3390/nano12040698 - 19 Feb 2022

Cited by 10 | Viewed by 4452

Abstract

Probing charge and energy transport in molecular junctions (MJs) has not only enabled a fundamental understanding of quantum transport at the atomic and molecular scale, but it also holds significant promise for the development of molecular-scale electronic devices. Recent years have witnessed a [...] Read more.

Probing charge and energy transport in molecular junctions (MJs) has not only enabled a fundamental understanding of quantum transport at the atomic and molecular scale, but it also holds significant promise for the development of molecular-scale electronic devices. Recent years have witnessed a rapidly growing interest in understanding light-matter interactions in illuminated MJs. These studies have profoundly deepened our knowledge of the structure–property relations of various molecular materials and paved critical pathways towards utilizing single molecules in future optoelectronics applications. In this article, we survey recent progress in investigating light-driven charge transport in MJs, including junctions composed of a single molecule and self-assembled monolayers (SAMs) of molecules, and new opportunities in optical sensing at the single-molecule level. We focus our attention on describing the experimental design, key phenomena, and the underlying mechanisms. Specifically, topics presented include light-assisted charge transport, photoswitch, and photoemission in MJs. Emerging Raman sensing in MJs is also discussed. Finally, outstanding challenges are explored, and future perspectives in the field are provided. Full article

(This article belongs to the Special Issue Molecular Electronics: Challenges and Opportunities)

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18 pages, 4052 KiB

Open AccessArticle

Extended Line Defect Graphene Modified by the Adsorption of Mn Atoms and Its Properties of Adsorbing CH₄

by Chenxiaoyu Zhang, Shaobin Yang, Xu Zhang, Yingkai Xia and Jiarui Li

Nanomaterials 2022, 12(4), 697; https://doi.org/10.3390/nano12040697 - 19 Feb 2022

Cited by 5 | Viewed by 1825

Abstract

Extended line defect (ELD) graphene is a two-dimensional (2D) topologically defective graphene with alternate octagonal and quadrilateral carbon rings as basic defective units. This paper reports on the CH₄ adsorption properties of ELD graphene according to the first principles of density functional [...] Read more.

Extended line defect (ELD) graphene is a two-dimensional (2D) topologically defective graphene with alternate octagonal and quadrilateral carbon rings as basic defective units. This paper reports on the CH₄ adsorption properties of ELD graphene according to the first principles of density functional theory (DFT). The effects on the CH₄ adsorption of ELD graphene when modified by a single Mn atom or two Mn atoms were investigated, respectively. An ELD-42C graphene configuration consisting of 42 C atoms was first constructed. Then, the ELD-42C graphene configuration was used as a substrate, and a Mn-ELD-42C graphene configuration was obtained by modifying it with a single Mn atom. The results showed that the most stable adsorption site for Mn atoms was above the quadrilateral carbon ring. This Mn-ELD-42C graphene configuration could only stably adsorb up to 30 CH₄ molecules on each side, with an average adsorption energy of −0.867 eV/CH₄ and an adsorption capacity of 46.25 wt%. Three 2Mn-ELD-42C graphene configurations were then obtained by modifying the ELD-42C graphene substrate with two Mn atoms. When the two Mn atoms were located on either side of a 2Mn-ELD-42C graphene configuration and above the two octagonal carbon rings adjacent to the same quadrilateral carbon ring, it was able to adsorb up to 40 CH₄ molecules on each side, with an average adsorption energy of −0.862 eV/CH₄ and a CH₄ adsorption capacity of 51.09 wt%. Full article

(This article belongs to the Special Issue Nanomaterials for Chemical Engineering)

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26 pages, 42693 KiB

Open AccessArticle

Affibody Modified G-quadruplex DNA Micelles Incorporating Polymeric 5-Fluorodeoxyuridine for Targeted Delivery of Curcumin to Enhance Synergetic Therapy of HER2 Positive Gastric Cancer

by Chao Zhang, Shuangqing Fu, Fanghua Zhang, Mengnan Han, Xuming Wang, Jie Du, Honglei Zhang and Wei Li

Nanomaterials 2022, 12(4), 696; https://doi.org/10.3390/nano12040696 - 19 Feb 2022

Cited by 10 | Viewed by 2180

Abstract

Combination chemotherapy is emerging as an important strategy for cancer treatment with decreased side effects. However, chemotherapeutic drugs with different solubility are not easy to realize co-delivery in traditional nanocarriers. Herein, an affibody modified G-quadruplex DNA micellar prodrug (affi-F/GQs) of hydrophilic 5-fluorodeoxyuridine (FUdR) [...] Read more.

Combination chemotherapy is emerging as an important strategy for cancer treatment with decreased side effects. However, chemotherapeutic drugs with different solubility are not easy to realize co-delivery in traditional nanocarriers. Herein, an affibody modified G-quadruplex DNA micellar prodrug (affi-F/GQs) of hydrophilic 5-fluorodeoxyuridine (FUdR) by integrating polymeric FUdRs into DNA strands is developed for the first time. To achieve synergistic efficacy with hydrophobic drugs, curcumin (Cur) is co-loaded into affi-F/GQs micelles to prepare the dual drug-loaded DNA micelles (Cur@affi-F/GQs), in which affibody is employed as a targeting moiety to facilitate HER2 receptor-mediated uptake. Cur@affi-F/GQs have a small size of approximately 130 nm and exhibit excellent stability. The system co-delivers FUdR and Cur in a ratiometric manner, and the drug loading rates are 21.1% and 5.6%, respectively. Compared with the physical combination of FUdR and Cur, Cur@affi-F/GQs show higher cytotoxicity and greater synergistic effect on HER2 positive gastric cancer N87 cells. Surprisingly, Cur@affi-F/GQs significantly enhance the expression and activity of apoptosis-associated proteins in Bcl-2/Bax-caspase 8, 9-caspase 3 apoptotic pathway, which is the main factor in the death of tumor cells induced by FUdR. Overall, this nanoencapsulation is a promising candidate for the targeted co-delivery of drugs with significant differences in solubility. Full article

(This article belongs to the Topic Synthesis, Characterization and Performance of Materials for a Sustainable Future)

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