Nano-Structures & Nano-Objects最新文献

The possibility of detecting and discriminating drug molecules is of utmost importance for several areas, including such important fields as security, public health and industry. The adequate detection of this type of substances then affects key sectors of society and is the subject of several studies and works that attempt to improve such detection and discrimination. Among the new devices used to detect drug molecules, the development, both experimental and theoretical, of nanosensors plays an increasingly important role and is expected to significantly increase the pace of progress in this field. In this work we have calculated the electronic and transport properties of a series of nanoscale devices based on carbon nanotubes and metallic heteronanotubes with hBN strips. These devices are specifically designed to sense drug molecules of a certain size and discriminate between three of them, namely cocaine, heroin, and morphine. We have found that the devices can effectively feel the presence of the drug molecules and distinguish between them through changes in the transmission, the conductance and the current. We have also found that such quantities depend on the angle of orientation, which shows that these systems have also the potential to determine the angle at which the molecule passes through it, i.e. to angularly discriminate between them. Furthermore, we have computed the Seebeck coefficient and found that such quantity can also be utilized to distinguish between the compounds. We have in addition found that the compounds behave as acceptors (they acquire charge) when the walls of the device are nanotubes and as donors (they lose charge) when the nanotube walls are heteronanotubes. Finally, we calculated the binding energies and found that the systems are exothermic. Such energies are not, however, big enough to promote the stick of the molecules to the walls of the devices, which shows the suitability of them for sensing the compounds.

In the current era of industrial advancement, pollution resulting from industrial activities has escalated into a critical issue that demands resolution. Within this spectrum of pollutants, the issue of dye contamination stands out as particularly pressing and in need of immediate attention. Within the field of surface engineering, incorporating nanoparticles into plasma electrolytic oxidation (PEO) solutions is gaining recognition as an effective method to boost the photocatalytic characteristics of the coatings applied to titanium bases. The composition of the PEO electrolyte plays a crucial role in determining the composition, microstructure, and morphology of PEO coatings. Consequently, the addition of particles to the electrolyte leads to modifications in the coatings, affecting factors such as phase composition, pore characteristics, layer thickness, and compactness. A novel strategy involves introducing particles into the electrolyte, aiming for their in-situ integration into PEO coatings during growth. Researchers have successfully produced multifunctional coatings with diverse properties by leveraging particle addition. The properties of the particles themselves, along with the electrical and electrolyte parameters during the PEO process, influence how efficiently the particles are taken up and incorporated into the coatings. This review paper explores the complex interactions between particulate additives in PEO mixtures and their subsequent effects on the photocatalytic efficacy of titanium-based coatings. This thorough investigation acts as an all-encompassing guide to demystifying the intricate association between nanoparticle integration and the photocatalytic effectiveness of titanium coatings, setting the stage for groundbreaking progress in functional surface engineering methods.

Synthetic dyes pose a formidable challenge in wastewater treatment, resisting conventional oxidation and reduction reactions and posing risks to human health and the environment. This study introduces the innovative nanocomposite MgO-Y₂O₃@gC₃N₄ (MYCN) as a highly effective adsorbent for eliminating methylene blue (MB) dye. The MYCN nanocomposite was synthesized by dispersing Magnesium oxide and Y₂O₃ nanoparticles in isopropanol using an ultrasonic bath for 0.40 hours at 500 rpm, followed by the addition of g-C₃N₄ nanosheets. The resulting mixture underwent heating, grinding, and annealing processes for 1.5 hours at 145 °C. Through structural analysis using XRD, characteristic peaks corresponding to individual components were confirmed, while TEM, EDX, and BET techniques revealed the successful integration of MgO and Y₂O₃ with g-C₃N₄ nanosheets. The adsorption efficiency of the MYCN nanocomposite was extensively evaluated under varying experimental conditions, including contact time, initial MB concentration, and solution pH. With its impressive surface area of 90.2 m².g⁻¹, the nanocomposite exhibited remarkable adsorption capacity, leading to significant removal of MB dye from aqueous solutions. Although pH had a minimal influence on dye removal, the highest adsorption rate (94.34 %) was achieved at pH 7. Optimal adsorption conditions were determined as a contact time of 120 minutes, an initial MB concentration of 5 mg/L, and a pH of 7. To characterize the adsorption behavior and determine equilibrium concentrations, Freundlich and Langmuir's isotherm models were employed. The Langmuir model displayed an excellent fit to the experimental data, supported by a high regression coefficient (R² > 0.95), indicating a monolayer adsorption process.

Zinc oxide-based nanomaterials (ZONMs) are of significant scientific and industrial interest due to their unique properties, versatility, and cost-effectiveness. This review comprehensively summarizes the potential applications of ZONMs across numerous fields, including dye-sensitized solar cells, the concrete and rubber industries, optoelectronics, gas sensing, the cosmetic industry, the textile industry, antibacterial activity, drug delivery, anticancer activity, antidiabetic activity, immunotherapy, anti-inflammatory activity, agriculture, and photodegradation. The review begins with an overview of ZONMs, highlighting their physical and structural properties. Subsequently, it discusses the applications of ZONMs in the aforementioned fields, emphasizing their outstanding performance and potential for commercialization. Additionally, the review explores the literature where ZONMs have been synthesized using various methods. It provides insights into the fabrication processes employed for ZONMs and discusses the advancements in synthesis techniques. Through an exploration of relevant studies, the review sheds light on the innovative approaches and methodologies utilized for the production of ZONMs across various research endeavours. Overall, this review provides valuable insights into the progressive advances and diversified applications of ZONMs, shedding light on their promising role in addressing various challenges in technology, healthcare, and environmental preservation.

A sol-gel approach was used to create magnetite nanoparticles (Fe₃O₄ NPs) as a core and silver (Ag) as a shell. Ag-Fe₃O₄ NPs were identified by x-ray diffraction (XRD) and energy dispersive x-ray (EDX), scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, and vibrating sample magnetometer (VSM) techniques. The capabilities of Ag-Fe₃O₄ NPs to induce apoptosis were investigated utilizing the Acridine orange/Ethidium bromide stain. The activity of NPs against (HT-29) cancer cells was further evaluated in and out of the existence of near-infrared (NIR) laser beam and alternating magnetic field (AMF). The exposed laser enhanced the cytotoxicity effect against (HT-29) cells. However, greatly elevated cytotoxic activity was seen with using the AMF.

Metal oxide-biochar nanoparticles have emerged as promising materials for the removal of dyes from aqueous solutions due to their unique properties and environmental compatibility. In this mini-review, we provide a comprehensive overview of recent advancements in the applications of metal oxide-biochar nanoparticles for dye removal. We begin by discussing the synthesis methods employed for the fabrication of metal oxide-biochar nanoparticles, including hydrothermal synthesis, co-precipitation, and sol-gel methods. The synergistic effects of combining metal oxides with biochar are explored, highlighting the enhanced adsorption capacities and photocatalytic activities of the resulting nanocomposites. Furthermore, we delve into the mechanisms underlying the adsorption and photocatalytic degradation of dyes by metal oxide-biochar nanoparticles. The role of surface functional groups, pore structures, and electron transfer processes in dye adsorption and degradation processes is elucidated. Additionally, we review recent studies investigating the application of metal oxide-biochar nanoparticles in real-world scenarios, including wastewater treatment and environmental remediation. Case studies demonstrating the efficacy of these nanomaterials in removing various dye pollutants from aqueous solutions are presented, emphasizing their potential for large-scale implementation. Finally, we discuss future perspectives and challenges in the field, including the need for standardized synthesis protocols, comprehensive characterization techniques, and further exploration of the environmental implications of metal oxide-biochar nanoparticles. Overall, this mini-review provides valuable insights into the recent advancements and potential applications of metal oxide-biochar nanoparticles for dye removal, highlighting their importance in addressing water pollution challenges.

This study investigates the electrical conductivity of NiFe₂O₄ nanofluids in water and ethylene glycol (EG) as base fluids, aiming to understand how varying volume fractions (φ= 0 %, 0.1 %, 0.25 %, 0.45 %, 0.7 %, and 1 %) and temperatures (20–70°C) influence electrical conductivity. NiFe₂O₄ nanoparticles were synthesized using the chemical co-precipitation method and characterized through X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive Spectroscopy (EDS). The results revealed that at 70°C, the electrical conductivity of NiFe₂O₄-water nanofluid increased by 1100 % within the volume fraction range of 0–1 %. For NiFe₂O₄-EG nanofluid, the increase in electrical conductivity was even more significant, reaching 1235 % within the same volume fraction range. Similarly, at a 1 % volume fraction within the temperature range of 20–70°C, the electrical conductivity of NiFe₂O₄-water nanofluid increased by 136 %, while for NiFe₂O₄-EG nanofluid, it was 370 %. These findings indicate that both temperature and volume fraction significantly enhance the electrical conductivity of the nanofluids, with a more pronounced effect observed in the NiFe₂O₄-EG nanofluid compared to the NiFe₂O₄-water nanofluid. The study validated Shen et al.'s model for electrical conductivity in nanofluids, contrasting with Maxwell's model. The novelty of this work lies in the comprehensive analysis of the electrical conductivity behavior of these nanofluids, which has not been extensively reported in the literature. These findings have potential applications in heat transfer enhancement and magnetic-targeted drug delivery.

In this work, Bi₂S₃ nanoparticles (NPs) have been synthesized by the green combustion method at 500 °C for 10 min using C.argentae. The structure, optical, and morphological studies of the synthesized material were analysed using PXRD, FTIR, UV, PL, and SEM spectroscopy techniques. The PXRD pattern of the material demonstrates that the obtained particles are of bismuth sulphide with an orthorhombic structure. The FTIR spectrum of it shows a characteristic peak at 606.8 cm⁻¹. In the UV–visible spectrum, on extrapolating the linear portion of the curve, the band gap on the X-axis is found to be 3.17 eV. PL intensity peaks show excitation and emission ranges of 384 nm and 532 nm respectively. SEM studies of the material show that the nanoparticles are in granular shape. Further, by using synthesized nanomaterials, photocatalytic degradation is carried out for methylene blue dye with different variations, and scavenger activity is carried out using K₂Cr₂O₇, EDTA, ascorbic acid, and TBA. Seed germination activity is also carried out for fenugreek seeds with synthesized material and dye, with dye, and with a mixture of dye and nanoparticles, along with the simultaneous study of dye degradation.

Anion-modified carbon nanomaterials (CNMs) represent a diverse class of functional nanomaterials that have attracted considerable interest due to their tunable properties and diverse applications. These materials are obtained by covalent attachment of negatively charged groups such as carboxylate, sulfonate/sulfate, and phosphonate to various CNMs, including carbon nanotubes, graphene, and carbon dots. The synthesis, characterization, and performance of these materials are affected by the type and quantity of anionic groups as well as the nature and morphology of the CNMs. This review provides a comprehensive overview of recent advances in anionic CNMs, including preparation methods, structural and surface analysis techniques, and applications in catalysis, ion exchange, membrane fabrication, electrochemical energy storage, and chemical sensing. Additionally, challenges and perspectives for future research in this emerging field will be discussed. While there are reviews on specific aspects of anionic CNMs, there is a lack of a comprehensive review on various negatively charged CNMs. The present review aims to address this gap by providing an overview of covalent modifications using carboxylate, sulfonate/sulfate, and phosphonate groups. The focus is on low molecular weight anionic fragments.

Two approaches were used to produce chromium oxide nanoparticles (Cr₂O₃ NPs) from corn plant leaf extract: the sol-gel (S-G) method and the simple chemical (S-C) method. These techniques were inexpensive and kind to the environment. Cr₂O₃ NPs were found to have an average crystallite size via XRD examination of 21 nm at 200 °C, 14–94 nm at 600 °C using the S-C approach, and, the via S-G method, 13–93 nm at 200 °C and 13–92 nm at 600 °C, respectively. Using the S-G approach and the S-C process at 200 and 600 °C, respectively, Cr₂O₃ NPs with particle sizes of 28–48 nm, 26–36 nm, 25–31 nm, and 78–200 nm were revealed by FE-SEM analysis. The optical band gap values of Cr₂O₃ NPs were determined via UV-Vis analysis to be 2.5 and 2.8 eV using a S-C technique at 200 and 600 °C, respectively, while the optical band gap values of Cr₂O₃ NPs were found to be 3 and 3.3 eV using a S-G method at 200 and 600 °C, respectively. The EDX spectra with their picture revealed Cr-O purity with Cr and O occurrences. FT-IR spectroscopy shows the significance of determining the chemical band strength, which was found to be 977 cm⁻¹ of Cr₂O₃ NPs by the S-C method. While the chemical band strength of Cr₂O₃ NPs by the S-G method was found to be 642 cm⁻¹. The width of the inhibition zone in the study demonstrated that Cr₂O₃ NPs made from corn extract exhibited potent antibacterial effects on the test isolates. It varied from 12 to 14 mm for gram-negative bacteria (E. coli and Klbesia) and from 15 to 20 mm for gram-positive bacteria (S. aureus and S. epidermidis) using a S-C method at 200 °C. It ranged from 15 to 17 mm for gram-negative bacteria (E. coli and Klbesia) to 19–22 mm for gram-positive bacteria (S. aureus and S. epidermidis) at 200 °C utilizing a S-G technique. The difference was 16 mm for antifungal (C. albicans) using Cr₂O₃ NPs via S-G at 200 °C and 15 mm for C. albicans using Cr₂O₃ NPs via a S-C technique at 200 °C. Using a S-G method, the bacterial suspension varied in diameter at 200, 400, and 600 °C, respectively, for gram-negative (E. coli and Klbesia) and gram-positive (S. aureus and Staphylococcus epidermidis) strains. The gram-negative strains varied in diameter from 20 to 22 mm, 20–21 mm, and 19–21 mm. An antifungal (C. albicans) inhibition zone was created utilizing Cr₂O₃ NPs in a S-G method at 200, 400, and 600 °C to be 23, 22, and 22 mm wide, respectively. The high degradation efficiency for MB, MO, and (RdB) dye was found from 97 % to 99 % of Cr₂O₃ NPs synthesis via the simple chemical method, respectively, while the degradation efficiency for MB, MO, and RdB dye was found from 97 % to 99 % of Cr₂O₃ NPs synthesis via the sol-gel meth