Next Nanotechnology最新文献

Europium (Eu³⁺) and Terbium (Tb³⁺) co-doped phosphors have garnered significant attention in recent years due to their photoluminescence properties and potential applications in various fields. Lanthanide co-doped phosphors are outstanding luminous substances that are implemented to solve the limitations of traditional lighting sources based on sulphide. Over the last decade, increased research emphasis on these phosphors has resulted in a dramatic improvement in their photoluminescence performances, as well as a wide range of luminescence hues that may be used in a number of applications. This review article discusses the evolution of lanthanide (Eu³⁺-Tb³⁺) co-doped phosphors, with an emphasis on the different production techniques, sustained illumination processes, and prospective implications for solid-state lighting innovation. To produce highly crystalline phosphors at low temperatures, the solution combustion approach has proven to be more effective than other techniques including solid state, sol-gel, and hydrothermal procedures, etc. The role of lanthanide ions in photoluminescence tunability has received special attention. In addition, a detailed explanation of the photoluminescent (PL) features of these co-doped luminescent compounds has been described. Along with their uses, their excitation wavelength, emission wavelength, and Commission Internationale de l′éclairage (CIE) coordinates are also mentioned for comparison studies. These co-doped luminescent materials have broad use in several displays and solid-state lighting device applications because of the numerous energy transitions of rare earth ions inside the host lattice. The perusal of this review will be relevant for researchers exploring phosphors.

This research introduces a simple method for synthesizing elongated bimetallic nanoparticles comprised of copper (Cu) and silver (Ag) using a co-reduction process involving Cu and Ag ions with hydrazine, alongside dopamine acting as a capping agent. Various characterization techniques were employed to analyze the prepared nanoparticles. The presence of copper and silver was confirmed through UV–vis analysis, while transmission electron microscopy confirmed their elongated morphology. Powder X-ray diffraction analysis indicated alloy formation rather than a mere mixture of the two metals, with both Cu and Ag exhibiting pure metallic properties and face-centered cubic crystal structures. The antimicrobial activity of the synthesized nanostructures against both gram-positive and gram-negative bacteria was evaluated, demonstrating significant antibacterial properties. Furthermore, the cytotoxicity of the nanoparticles was assessed using baby hamster fibroblasts (BHK-21) cells, revealing promising biocompatibility and low cytotoxicity.

Herein, we proposed a unique structural design for indium gallium nitride (InGaN) based blue resonant cavity micro-light-emitting diodes (RC-μ-LEDs), focusing on the design, fabrication, and the relevant performance analyses. The proposed RC-μ-LEDs possess a three-layer staggered InGaN/GaN multiple quantum wells (MQWs) within the nanoporous Distributed Bragg Reflectors (NP-DBRs) and the conventional DBRs, introducing light confinement within such a resonant cavity. A passivation layer using atomic layer deposition (ALD) is adopted to reduce the leakage current from sidewall defects as well. Consequently, for the resulting RC-μ-LEDs, the divergence angle (DA) can be achieved down to 39.04°. While the input current increases from 1.77 A/cm² to 54 A/cm², the peak wavelength will shift from 456.16 nm to 449.18 nm, a blue shift of only 6.98 nm. Finally, we also discuss the temperature-dependent characteristics and the corresponding behaviors of our RC-μ-LEDs. Our demonstrated RC-μ-LEDs exhibit great wavelength stability with a diminished divergence angle, thus enabling full-color and low-crosstalk micro-LED displays for on-demand high-resolution applications.

With the rapid progress of intelligent vision of the Internet of Things, the gap between the resultant high-level demands and conventional silicon-based hardware architectures is continuously widening. Biomimetic artificial neural networks (ANNs) have recently been proposed to solve this problem. However, they still face the predicaments in uniformity, heterogeneous integration, and hardware implementation, etc. Here we demonstrate an intelligent vision ANN with two-dimensional material (2DM)/molecular ferroelectric (MF) bilayer electronic/optoelectronic memristors. In contrast to conventional ferroelectric transistors, in-plane ferroelectric polarization was also found to enable a simpler two-terminal structure with a lateral p/n-type doping in the adjacent 2DM layer. After a demonstration of fabricated array and board-level driving circuits, an image recognition and classification task is proposed, reaching an accuracy of 85.2%, which implies great potential towards multi-modal artificial intelligent vision systems.

Copper (Cupric) oxide is a readily synthesized, non-toxic metal oxide with a wide range of uses, including the treatment of water, the manufacture of electronic devices, solar cells, cathodes for lithium-ion primary batteries, gas sensors, electrochromic devices, supercapacitors, and field effect transistors. The effects of Zn doping in CuO in three different concentrations (weights %) were investigated. The band gap and carrier concentration were altered due to the formation of defect energy states, lattice stresses, and the formation of ZnO, and Cu2O in addition to CuO. Temperature increases from room temperature resulted in the production of metal oxides with preferred crystal growth in specific orientations. An increase in temperature, from 300 °C to 500 °C, generated residual strain release and atomic diffusions, resulting in grain growth and a reduction in the band gap. The changes in UV and PL spectra predicted the growth kinetics involved

This review explores the integration of graphitic carbon nitride (g-C₃N₄) with model drugs and diverse formulations to obtain nanocomposites with potential for cancer therapy. Beyond the synthesis, the study also deals with cancer-affected organs, elucidates mechanisms of drug action and categorizes g-C₃N₄-based anti-cancer compositions. The responsive elements contributing to cancer inhibition under the chemotherapeutic influence include reactive oxygen species (ROS), mitochondrial potential, oxidative stress, magnetic responsiveness, profound thermal and photo energy penetration, metal retention toxicity, adenosine triphosphate (ATP) blockade in cancer cells, insulating microenvironments within tumours and immune-modulating antibodies. Notably, breast, prostate, lung, ovary and stomach cancers owe their genesis exclusively to abnormal cell proliferation. Our review reveals that the integration of model drugs (MD) with metal ions (MI) on g-C₃N₄ (g-C₃N₄/MDMI) shows enhanced biological activity, compared to metal ions and model drugs alone. The paper refers to several characterization techniques to decipher intricate data patterns and facilitate explanations of in vitro analyses focused on cancer cell viability and proliferation. Upon analysis of all data, g-C₃N₄ emerges as a compelling drug carrier, particularly within the anticancer drug delivery systems. This review not only emphasizes the immense potential of g-C₃N₄ nanocomposites but also paves the way for future advancements in effective cancer treatments.

The Mg(OH)₂ and MgO nanomaterials were synthesized by precipitation followed by calcination from the industrial waste MgCl₂·6H₂O originated from the magnesiothermic reaction of solar-grade silicon (P-waste). A similar synthesis process was carried out in parallel with the commercial precursor MgCl₂·6H₂O (P-com) to compare the products obtained with precursors. For the synthesis of Mg(OH)₂ (1st step), aqueous solutions were prepared (low pH for P-waste and natural pH for P-com). NaOH was used as a precipitating agent, and different synthesis temperatures were evaluated (25, 50, 75, and 90 °C). MgO (2nd step) was obtained through calcination at 500 °C for 30 min of previously synthesized Mg(OH)_2. The P-waste and the two synthesis products (Mg(OH)₂ and MgO) were chemically, thermally, structurally, and morphologically characterized. The results showed that the P-waste is more soluble in an acidic environment, and both precursors present similar thermal behavior and structural profiles. The Mg(OH)₂ obtained in the 1st step of synthesis by both precursors presented the crystalline phases Brucite with lamellar morphology and Halite (NaCl) remained of the precursors. The powders obtained from both precursors in the 2nd step presented the same crystalline phase Periclase (MgO), but different morphologies such as fragmented lamellar for the P-com and cubic for the P-waste. However, the particle size distribution narrows, and the D50 of MgO decreases as a function of increasing the synthesis temperature employed in the 1st step for the P-com. In contrast, the D50 of MgO decreases in the P-waste as a function of low pH. Furthermore, surprisingly, it was observed that the morphology of MgO nanocubes can be obtained from residues and commercial precursors at low calcination temperature and short time (500 °C/30 min) when the Halite remaining from the purification washes is above 4.0% by weight.

Flexible nanocomposite materials were prepared by introducing Zinc Oxide (ZnO) and Carbon Black (CB) as nano-fillers separately into vulcanized natural rubber (NR). The impact of curing agents and filler integration on the structure and electrical characteristics of NR was thoroughly examined. Electrical properties such as dielectric constant, dielectric loss, and ac conductivity were assessed. Pure NR exhibited higher dielectric properties and ac conductivity compared to NR cured with pentane-1,5-deylidenediamine (PDD), which gradually decreased up to a certain threshold due to the immobilization of non-rubber constituents. Dielectric Constant of pure NR decreases from 148.81 to 6.87 upon the addition of 2 ml crosslinking agent into NR. Furthermore, NR composites filled with CB demonstrated lower dielectric properties compared to those filled with ZnO, likely attributed to the polar nature of ZnO. Dielectric Constant of cured NR was increased and exhibited 20.7 for the NR composite with 0.06 % ZnO. The surface roughness of the resulting nanocomposites was analyzed using optical profilometry, and its correlation with dielectric and ac conductivity was investigated.

The antibacterial property of silver nanofluid was investigated on Pseudomonas aeruginosa and Klebsiella pneumoniae. Silver nanoparticles were synthesized using Nigella sativa (black seeds), green tea, ginger, and garlic as reductant agents through hydrothermal and microwave methods. The physical characteristics of nanoparticles were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Energy-dispersive X-ray spectroscopy (EDX), and visible ultraviolet spectroscopy (UV–vis). The crystal size measured from SEM analysis on average was about 60 nm and calculated from Debey-Scherer equation was around 43 nm. The nanofluid was prepared by solving the nanoparticles in deionized water. The effect of prepared nanofluid was examined on the growth of two kinds of bacteria that is Pseudomonas aeruginosa and Klebsiella pneumoniae by an antibacterial sensitivity test using the pour plate method. The nanofluids showed a considerable antibacterial effect on Pseudomonas aeruginosa and a moderate effect on Klebsiella pneumoniae on agar plates.

The need for alternative treatment of infections caused by vancomycin-resistant Enterococci (VRE) is of global concern. This study used Azanza garckeana (AG) seeds to synthesize silver nanoparticles (AgNPs) with anti-VRE activity. The nanoparticles were characterized using UV-Vis, FTIR, SEM, and EDXRF. Antimicrobial activities, MIC, and MBC were evaluated by agar well and microtiter dilution, respectively. UV-spectroscopy confirmed the presence of peaks at 435 nm for spherical AgNPs. FTIR spectrum showed sharp peaks at 3441, 2936, 2859, 1640, and 1385 cm⁻¹, indicating the presence of hydroxyl, methyl, methylene, alkenyl, and alkyl groups in the AgNPs. SEM and EDXRF results revealed particles with clustered crystalline patterns and silver as the highest element present, with nickel also present in very minute amounts. The AgNPs exhibited inhibitory activity against the VRE species at both 50 and 100 µg/ml. Also, MIC values varied between 12.5 µg/ml and 25 µg/ml, while MBC values were 50 µg/ml and 25 µg/ml respectively. Conclusively, A. garckeana AgNPs demonstrated potent antimicrobial activity, suggesting their antimicrobial properties could be utilized in a variety of biomedical applications.