Next Nanotechnology最新文献

Copper oxide nanoparticles (CuO NPs) have been prepared via sol-gel synthetic approach using aqueous leaves extract of Musa paradisiacal and copper chloride dehydrate salt. UV visible spectroscopy showed maximum peak for CuO NPs at 535 nm. Additionally, the SEM XRD techniques confirmed spherical shape of CuO NPs with average size of 15 nm. Nitro compounds have been carefully chosen as a tested contaminant to study performance of CuO NPs. Catalytic reduction of nitro compounds was investigated under different temperatures to evaluate thermodynamic studies. According to the results, catalytic reduction of nitro compounds obeys Langmuir–Hinshelwood mechanism. The value of apparent rate constant shows a linear trend with catalyst concentration. The catalytic pyrolysis of corncob biomass in the presence of CuO NPs showed more bio-oil (46.13 %) yield as compared to ZSM-5 (40.07 %) and without catalyst (37.09 %) reactions. The data also confirmed that CuO NPs showed excellent performance as a micro-reactor for catalytic degradation of nitro compounds and catalytic pyrolysis. The CuO NPs have been isolated and reused in 5 consecutive cycles with good and reproducible excellent performance.

All-inorganic cesium lead bromide (CsPbBr₃) quantum dots (QDs) have received a surge of attention in the field of light-emitting diode (LED) display and lighting. Hence, it is interesting to study the composite film composed of CsPbBr₃ and light-emitting MDMO-PPV matrix polymer. In this study, we investigate the phase behavior among the components, MDMO-PPV, toluene (solvent), and oleic acid and oleylamine (the surface ligands for QDs) based on the Flory-Huggins theory with the group contribution method for the first time. Here we find that the MDMO-PPV and ligand molecules are immiscible whereas MDMO-PPV and toluene are partially miscible. Then through the x-ray diffraction (XRD) patterns, we demonstrate that CsPbBr₃ QDs form a nanoscale domain with ∼33–52 nm crystallites in the MDMO-PPV matrix. Furthermore, the scanning electron microscope (SEM) images display that CsPbBr₃ QDs can be highly aggregated at MDMO-PPV:CsPbBr₃= 50:50 composition. Then, through the ultraviolet-visible (UV–vis) and photoluminescence (PL) spectra, the enhancement of PL intensity is observed at ∼30–50 wt% CsPbBr₃. Finally, the electrochemical impedance spectra indicate that the composite film exhibits less resistance (∼3.2×10⁴ Ω) than the pure MDMO-PPV film (∼1.4×10⁷ Ω), suggesting that the MDMO-PPVCsPbBr₃ composite approach is promising for electrochemical and optoelectronic applications.

Highly porous and nanostructured metal-organic frameworks (MOFs) have fascinated enormous interest as electrode active materials for electrochemical energy storage systems, whereas their practical applications are significantly hindered by their relative inferior energy density and cyclability. In this study, MoS₂ with layered structure was successfully incorporated onto hierarchical Ni-MOFs via a facile hydrothermal approach. Moreover, sodium cations were introduced to improve electronic conductivity. The resulting nanocomposites (sodium ions and MoS₂ incorporated Ni-MOFs) exhibited hierarchical porous structures with varying dimensions, offering increased volume for charge storage and diffusion channels for electrolyte ions. Benefiting from the unique topological architectures, the as-synthesized porous nanocomposites delivered an excellent supercapacitive performance, achieving a superlative energy of 33.33 Wh kg⁻¹ and a power density of 3390 W kg⁻¹. Furthermore, the as-fabricated symmetric supercapacitor device delivered a remarkable cycling durability where the acquired outstanding capacitance retention was 97.42% and coulombic efficiency was 97.82% respectively over more than 10,000 cycles in an aqueous electrolyte.

A series of wide-ranging single phase YPO₄:xTb³⁺ phosphor was prepared by wet chemical route. In order to maximise the use of YPO₄:Tb³⁺ nanoparticles in WLED, this work used Li⁺ sensitization to interstitially modify the particles' photoluminescence intensity. The prepared nanoparticles are characterized using X-Ray diffraction, FT-IR, TEM and Photoluminescence. The annealing effect on the particle size, morphology and its luminescence intensities are studied. This increased crystallinity led to a rise in the photoluminescence intensity of the nanoparticles. YPO₄:Tb³⁺ nanoparticles' excitation and emission spectra were shown by photoluminescence investigations. Optical absorption and emission spectra confirmed all peaks associated to various transitions of the Tb³⁺ ions. Because of the increased crystallinity and decreased water content, the emission intensity rose with the annealing temperature. Li⁺ co-doping increased the emission intensity even more; where the emission intensity showed seven times. The results emphasise the significance of Li⁺ sensitization and annealing temperature in adjusting the luminous properties for possible uses in WLED and other display systems

Flexible sensors play an important role in simulation, brain-computer interaction, intelligent robots, and biological detection. Due to the progress of modern medical means, the construction of wearable flexible sensors to realize remote and continuous monitoring of human physical indicators and physiological parameters has become a hot research topic. Non-invasive sensor is a device that can detect physiological parameters without cutting the skin or puncturing the body. They have wide application prospects in the fields of medical treatment, fitness, and daily care due to the following advantages: real-time monitoring, portability, accuracy, and cost reduction. Liquid metal has become a great candidate for constructing flexible biosensors because of its high conductivity, deformability, self-healing, and bio-friendly properties, its spontaneous formation of an oxide film due to exposure to oxygen provides a convenient reaction platform for the preparation of other materials. Two-dimensional materials are inherently superior in preparing sensors due to their great advantages unique chemical and physical properties, their high surface area-to-volume ratios and ultra-high surface sensitivity to the environment also can be used to prepare flexible sensor. This study presents an overview and introduction of biosensors fabricated by liquid metal and two-dimensional materials, including how to prepare specific two-dimensional materials based on liquid metal, and the stripping method is also included. Three kinds of applications are discussed in detail, including the detection of human glucose concentration, pulse detection, and sweat analysis, whose sensing principles depend on piezoelectric, optical, and electrochemical. At the end of the article, we summarized the current challenges faced by biosensors based on liquid metal and looked forward to its future development and future directions of advances.

By the semipolar blue single GaN μ-LED and blended Ir(piq)2(acac) + CC-MP5 polymer thin film color converter, a high-speed white-light μ-LED-based system is built up for the applications of short-distance VLC. The characteristics and properties of both devices are analyzed to understand the requirements for transmission and illumination. By selecting the growing orient, the influence of QCSE is reduced in this GaN μ-LED. Meanwhile, possessing the low reflection characteristic, it is beneficial for signal modulation. For the polymer thin film color converter with a lifetime of 7.8 ns, low surface reflection and high conversion efficiency are thought of good properties. Color-converted cool white light has a CCT of around 7000 K and high color accuracy with a CRI of about 90. The APD-combined frequency responses of the GaN μ-LED and GaN μ-LED + polymer are measured as 750 MHz and 600 MHz, respectively. After the optimization by utilizing the adaptive SNR-flattening pre-emphasis algorithm, the transmission performance of the white-light μ-LED is significantly promoted. For NRZ-OOK encoding, a 1.4 Gbps 0.15-m free-space transmission is achieved with a rising time of 656.33 ps, a falling time of 493.32 ps, and a Q-factor of 4.75. Besides, in more advanced data formats, the performance of this white-light μ-LED can be better highlighted. For the same 0.15-m free-space VLC, a high-speed 3 Gbps broadband 8-QAM-OFDM transmission is fulfilled with an EVM of 23.9%, an average SNR of 12.5, and a BER below 3.8 × 10^-3; while to the best of our knowledge, a record 3.5 Gbps BL-DMT transmission is implemented as well. This white-light μ-LED can also be integrated into large-scale arrays for multi-functional VLC applications.

Au nanostructures offer a wide range of applications such as surface-enhanced Raman spectroscopy, photovoltaics, and biosensors. Effective integrating well-controlled Au nanostructures on chip via a self-assembly process remains challenging as most of the Au nanostructures were prepared by either chemical synthesis methods or lithography patterning techniques. This study introduces a simple two-step approach for fabricating Au nanostructures on substrate with well controlled morphology and density. First, epitaxial Au-Sr₃Al₂O₆ (SAO) vertically aligned nanocomposites (VANs) were deposited on SrTiO₃ substrates. Second, by subsequently dissolving the water-soluble SAO matrix, various Au nanostructures ranging from 0D nanoparticles to 1D nanopillars are demonstrated. The Au morphology tuning is achieved by varying the deposition parameters of the VANs. This method eliminates the need of harsh chemical solutions and tedious lithography/patterning steps. These findings provide a novel strategy for tailoring the Au nanostructures and their optical properties, and, demonstrating on-chip integration for advanced optical device applications.

Mechanistic insights into the interfacial evolution are essential for advancing rechargeable zinc metal batteries (RZMBs). Employing in situ atomic force microscopy (AFM), we observed the Zn plating and stripping processes on the Zn metal anode and investigated the effect of initial stripping over the interfacial evolution. During the initial stripping process, the interfacial evolution is uneven, and by-products form at the Zn anode, which contributes to the heterogeneous nucleation and quick dendrite growth during the subsequent plating, causing performance fading. In contrast, uniform Zn deposition and reversible dissolution can be achieved during the initial plating and following stripping processes. The Zn substrate remains flat without evident cracks or pits, which ensures the interfacial stability of the Zn metal anode during cycling. This work provides direct insights into the morphological evolution and interfacial mechanism of Zn metal anode, promoting the optimal design of advanced RZMBs.

Biological routes of nanoparticle synthesis, especially the use of plant-based extracts, have shown great potential for the production of silver nanoparticles (Ag NPs). Ag NPs synthesized in this way is a simple one-step method that is economical and environmentally friendly. With the increasing need to develop new and effective antibacterial agents, a novel and stable Ag NPs is synthesized using aqueous seed extract of Strychnos potatorum (SP). Ag NPs obtained at room temperature (S1) and under optimal microwave irradiation (S2) were compared in the present work. The as-synthesized Ag NPs are characterized by Ultraviolet-Visible (UV-Vis) spectroscopy, X-Ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). UV-Vis spectra showed Surface Plasmon Resonance (SPR) peaks at 430 nm (S1) and 438 nm (S2) associated with the formation of Ag NPs. XRD patterns indicate the crystallinity of Ag NPs, with an average crystallite size of approximately 23 nm (S1) and 15 nm (S2). FT-IR study revealed potential biomolecules to form Ag NPs. FESEM and TEM analysis revealed the spherical shape of Ag NPs. An average particle size of approximately 31 nm (S1) and 19 nm (S2) was revealed from TEM analysis. To the best of our understanding, this study is novel as Ag NPs synthesized from SP using a microwave oven are described in detail for the first time. The study also demonstrated the potential of Ag NPs for antibacterial effect against Gram-positive bacteria (Streptococcus pneumoniae, Staphylococcus aureus) and Gram-negative bacteria (Klebsiella pneumoniae, Vibrio vulnificus). Our findings show that at a specific concentration, small NPs are more efficient in inhibiting bacterial activity. This research indicates that Ag NPs synthesized from SP exhibit strong antibacterial activity for the treatment of bacterial infection.

Silver nanoparticles (AgNPs) have gained significant attention in recent years due to their unique physicochemical properties and wide-ranging applications. This study investigates the green synthesis of silver nanoparticles using the pathogen Shigella flexneri 29508 and evaluates their efficacy as both antioxidant and antifungal agents. The pure strain of the bacterium was identified as a potential nanoparticle producer based on its ability to reduce silver ions to nanoparticles. The formation of silver nanoparticles was confirmed by characteristic colour changes and further confirmed by UV–visible spectroscopy with SPR around 415 nm. The synthesized silver nanoparticles were characterized using various techniques, including TEM, SEM and DLS. DLS confirmed the nano-size, homogeneity and good stability of the fabricated particles TEM analysis revealed the spherical morphology of the nanoparticles, with an average size of 50 nm. SEM analysis also confirmed and supported the data. The antioxidant activity of the green-synthesized silver nanoparticles was evaluated using standard assays, and results demonstrated significant antioxidant potential, indicating the ability of the nanoparticles to neutralize free radicals and protect against oxidative stress. The bio-synthesised silver nanoparticles were also tested for their antifungal properties against two clinically relevant fungal strains. Resazurin-based micro-dilution viability assays, agar well diffusion, and spread plate assay methods were employed to determine the MIC and MBC of the nanoparticles, assessing their inhibitory effects on fungal growth. The results revealed potent antifungal activity, with varying degrees of efficacy against the tested fungal pathogens. Besides bioactivity, the cytotoxicity of the nanoparticles was also evaluated using primary cell cultures of peripheral blood cells. The bio-fabricated structures exhibited minimal toxicity and mortality, indicating their benign and eco-friendly nature in biological systems. This study highlights the successful green synthesis of silver nanoparticles using bacteria and elucidates their antioxidant, cytotoxicity, and antifungal activities. These findings contribute to the development of eco-friendly nanoparticle synthesis methods and suggest potential applications in the fields of medicine, agriculture, and environmental remediation.