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Photocatalytic Degradation of Methylene Blue using Biosynthesized Zinc Oxide Nanoparticles from Bark extract of Kalopanax septemlobus
摘要： In this study, we applied Kalopanax septemlobus-ZnO nanoparticles (Ks-ZnO NPs) with green approach one-pot synthesis. Further, the extracts were used as capping agent and Zn (OAc)2 as the metal precursor to synthesize ZnO nanoparticles. The formation of ZnO NPs, the surface plasmon resonance were observed at 372 nm in UV-Vis spectroscopy. The presence of functional groups which as a capping agent and formation of ZnO nanoparticles were confirmed in Fourier Transform Infrared Spectroscopy (FTIR) result. The crystallization, elemental mapping and morphology showed by X-ray diffraction (XRD), Field-Emission Transmission Electron Microscopy (FE-TEM), and Energy dispersive X-ray spectroscopy (EDX) respectively. The photocatalytic activity of Ks-ZnO nanoparticles, was determined using Methylene blue dye degradation percentage under UV light irradiation (365nm), which resulted rate constant (k) was found 0.1215 with 97.5% of degradation in 30 minutes. In summary, phytochemicals in K. septemlobus extract have a potential as a reducing agent to form Ks-ZnO nanoparticles. The Ks-ZnO NPs are capable to degrade Methylene blue in brief time due to its extract-capped zinc oxide nanoparticles. Accordingly, the use of K. septemlobus for biosynthesis of nanoparticles may have an advance for many applications as a cost-effective and eco-friendly photocatalyst.
关键词： methylene blue,Kalopanax septemlobus,photocatalysis,nanoparticles,zinc oxide
更新于2025-09-04 15:30:14
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Facile Functionalization of Gold Nanoparticles with PLGA Polymer Brushes and Efficient Encapsulation into PLGA Nanoparticles: Toward Spatially Precise Bioimaging of Polymeric Nanoparticles
摘要： Nanocarriers prepared from poly(lactide-co-glycolide) (PLGA) have broad biomedical applications. Understanding their cellular uptake and distribution requires appropriate visualization in complex biological compartments with high spatial resolution, which cannot be offered by traditional imaging techniques based on fluorescent or radioactive probes. Herein, the encapsulation of gold nanoparticles (GNPs) into PLGA nanoparticles is proposed, which should allow precise spatial visualization in cells using electron microscopy. Available protocols for encapsulating GNPs into polymeric matrices are limited and associated with colloidal instability and low encapsulation efficiency. In this report, the following are described: 1) a facile protocol to functionalize GNPs with PLGA polymer followed by 2) encapsulation of the prepared PLGA-capped GNPs into PLGA nanocarriers with 100% encapsulation efficiency. The remarkable encapsulation of PLGA-GNPs into PLGA matrix obeys the general rule in chemistry “like dissolves like” as evident from poor encapsulation of GNPs capped with other polymers. Moreover, it is shown that how the encapsulated gold nanoparticles serve as nanoprobes to visualize PLGA polymeric hosts inside cancer cells at the spatial resolution of the electron microscope. The described methods should be applicable to a wide range of inorganic nanoprobes and provide a new method of labeling pharmaceutical polymeric nanocarriers to understand their biological fate at high spatial resolution.
关键词： phase transfer,gold nanoparticles,encapsulation,PLGA
更新于2025-09-04 15:30:14
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Green synthesis, characterization and antifungal and photocatalytic activity of Pithecellobium dulce peel–mediated ZnO nanoparticles
摘要： Zinc oxide (ZnO) nanoparticles (NPs) were synthesized by a conventional method using Pithecellobium dulce peel extract. The phytochemicals present in the peel act as stabilizing agents. The ZnO NPs were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy. The XRD pattern confirmed the formation of crystals, which exactly matched with JCPDS card no.36-1451. The nondestructive XRD pattern showed a hexagonal crystalline nature, and scanning electron microscopy revealed a spherical shape. Further, the ZnO NPs exhibited excellent photodegradation efficiency with regard to the dye methyleneblue (MB), a major water pollutant released by the textile industry. A kinetic study of photodegradation of MB showed 63% degradation and a rate constant of 0.00812 min-1. The antifungal activity of the ZnO NPs resulted in 37.81% and 63.57% inhibition of the growth of Aspergillus flavus and 40.21% and 43.04% of growth inhibition of Aspergillus niger at 500 and 1000ppm of ZnO NPs, respectively.
关键词： Photocatalytic activity,Methylene blue,Antifungal,Pithecellobium dulce,ZnO nanoparticles
更新于2025-09-04 15:30:14
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Photocatalytic activities using a nanocomposite of mesoporous SiO2 and CdInSe-graphene nanoparticles under visible light irradiation
摘要： The new novel ternary mesoporous SiO2/CdInSe-graphene composites with diameters of approximately 8.08 nm have been fabricated through a self-assembly method. All physical tests demonstrated that the CdInSe-graphene was successfully uniformly distributed onto the surface of the ordered mesoporous silica particles. The obtained mesoporous SiO2/CdInSe-graphene composites exhibited good photocatalytic activity for degradation of both cationic-anionic organic dye groups, as well as the decomposition of the representative phenol group of the compound under visible light irradiation. Moreover, the photocatalytic evolution of hydrogen was studied for establishing a wider application of the as-fabricated SiO2/CdInSe-graphene catalyst in the case of energy conversion. This work indicated that the combination of the mesoporous silica and CdInSe-graphene enables achievements such as an enhancement photocatalytic performance, which has potential in industrial waste management and energy conversion.
关键词： Dye decomposition,CdInSe nanoparticles,Graphene-based nanocomposite,Gallic acid degradation,Mesoporous silica,Hydrogen production
更新于2025-09-04 15:30:14
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Spin–Lattice Relaxation and Diffusion Processes in Aqueous Solutions of Gadolinium-Based Upconverting Nanoparticles at Different Magnetic Fields
摘要： We investigated the influence of gadolinium (Gd)-based upconverting nanoparticles (UCNPs) on water spin–lattice relaxation (T1) and diffusion at different magnetic field strengths (0.4 T and 9.4 T). Our findings show that smaller NPs (12 nm compared to 19 nm) were more favourable for proton relaxivity. We also demonstrate that using simplified Solomon–Bloembergen–Morgan (SBM) model we can associate two measured diffusion coefficients with processes occurring near the surface of UCNPs and in bulk water. Using the relationship between relaxation and diffusion, we can estimate not only the total impact of NPs on relaxation of water molecules, but also the impact on relaxation of local water molecules, directly connected to paramagnetic Gd3+ ions in NPs. Different magnetic field strengths did not alter the spin–lattice relaxivity of NPs. This suggests that Gd-based UCNPs could be developed into high-performance multimodal magnetic resonance imaging contrast agents working over a broad range of imaging field strengths used in clinical routine.
关键词： Magnetic fields,MRI contrast agents,Gadolinium-based upconverting nanoparticles,Diffusion processes,Spin–lattice relaxation
更新于2025-09-04 15:30:14
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Synthesis of Si-based KH560/RGO@Fe3O4 composite for improving electromagnetic properties in 2–18?GHz frequency range
摘要： Silicon coupling reagent is regarded as a common additive on surface treatment of polymer due to its high bonding strength and low cost. In this paper, a series of γ-(2, 3-epoxypropoxy) propyltrimethoxysilane (KH560)-based reduced graphene oxide (RGO)@Fe3O4 (KH560/RGO@Fe3O4) composites with different ratio of Fe3O4 nanoparticles (NPs) are synthesized by a facile hydrothermal method. It is confirmed that the silicon reagent KH560, as a hopeful candidate for increasing the RGO lattice defects, is favorable to improve the electromagnetic wave absorption. Meanwhile, the microwave attenuation mechanism of KH560/RGO@Fe3O4 composite suggests that the dielectric loss mainly causes by multiple Debye dipolar relaxation and its magnetic loss comes from the eddy-current effect of Fe3O4 NPs over the high frequency range. In consequence, the KH560/RGO@Fe3O4 composite endows the excellent absorption performance, the reflection loss (RL) value is optimized to ? 25 dB at 14.1 GHz with a thickness of 3 mm and the maximum frequency bandwidth for RL < ? 10 dB is 4.1 GHz with a thickness of 4 mm.
关键词： Electromagnetic wave absorption,Fe3O4 nanoparticles,Reduced graphene oxide,Hydrothermal method,Silicon coupling reagent
更新于2025-09-04 15:30:14
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Preparation of Si-SiOx nanoparticles from volatile residue produced by refining of silicon
摘要： Residual Si was produced on a furnace wall when upgraded metallurgical grade Si was re?ned by electron beam melting. It was then recycled to prepare Si-SiOx nanoparticles with an average size of 100 nm by planetary ball milling. The obtained Si-SiOx nanoparticles mainly consist of amorphous Si, crystalline Si and amorphous SiOx, which was con?rmed by XRD, FTIR, XPS and TEM. SiOx is mainly composed of SiO2 and SiO1.35. Distilled water used as a grinding aid not only enhances milling ef?ciency, but also plays a key role in obtaining SiOx. During re?ning of upgraded metallurgical grade Si, the deposition pattern of residual Si on furnace wall agrees with model of three-dimension growth. Growth of Si-SiOx nanoparticles is the mutual effect of distilled water and ball milling. Si-SiOx nanoparticles were doped into phenolic resin pyrolysis carbon as anode materials for lithium ion batteries, and 10% doping was observed to improve the speci?c capacity. After 500 cycles, speci?c capacity of delithiation remained around 550 mA h/g. It suggests the residual Si is a value-added by-product, and it can be recycled as anode materials for lithium ion batteries.
关键词： Residual Si,Si-carbon anode,Si-SiOx nanoparticles,Planetary ball milling,Electron beam melting
更新于2025-09-04 15:30:14
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Facile Synthesis of Ag/ZnO Photocatalysts on the Degradation of Diuron Herbicide Under Simulated Solar Light and the Investigation of Its Antibacterial Activity for Waste-Water Treatment
摘要： Nanocrystalline Ag/ZnO powders have been successfully prepared by a modified polyol process using triethylene-glycol (TEG) as solvent, reducing and stabilizing agent. The synthesis procedure has been conducted without any post-synthesis thermal treatment. The structural and optical properties have been characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption study, inductively coupled plasma optical emission spectroscopy and UV–Vis diffuse reflectance spectroscopy. The photocatalytic activity of Ag/ZnO materials has been studied by analyzing the degradation of an herbicide, diuron, under solar light. Ag/ZnO photocatalysts with optimized x = 0.7% Ag content showed 14 times higher rate of degradation than that of unmodified ZnO. We attribute these observations to the addition of silver nanoparticles allowing interfacial oxide-to-metal electron transfer within the hybrid Ag/ZnO photocatalyst. The inhibitory and bactericidal activities of samples have been tested against Gram-negative bacteria; Escherichia coli, Salmonella typhimurium and gram-positive bacteria; Staphylococcus aureus, Enterococcus faecium and Candida albicans. The results showed that the Ag/ZnO can be used as photocatalysts and antibacterial agents for potential practical applications in the wastewater treatment.
关键词： Nanoparticles,Photocatalysis,Antibacterial,ZnO,Wastewater treatment,Ag
更新于2025-09-04 15:30:14
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Light-Induced Assembly of Metal Nanoparticles on ZnO Enhances the Generation of Charge Carriers, Reactive Oxygen Species and Antibacterial Activity
摘要： Increasing the photocatalytic activity of semiconductors by forming heterojunctions with metal improves their energy transfer efficiency and environmental remediation capabilities. However, our knowledge regarding the structure-activity relationship of semiconductor/metal hybrid nanostructures is lacking due to poor control over their physicochemical properties. Here, we report a facile way to make ZnO/metal heteronanoparticles by mixing/irradiation process of ZnO and metal nanoparticles. The resultant products provide an expedient model to explore the effects of various metal NPs on light-induced electron/hole separation, reactive oxygen species (ROS) production and antibacterial activities of ZnO NPs. Electron spin resonance spectroscopy was used to compare the effect of mixing Pt, Au, or Ag NPs at different size and concentration with ZnO NPs on light-induced electron-hole separation and ROS production. The enhancing effect of metal NPs depends on particle size, composition, and mass ratio of the metal NPs to the ZnO NPs. Smaller-sized Pt NPs are more efficient in promoting charge carrier generation and ROS production. At 5 nm, Ag NPs promoted charge carrier generation more efficiently than Pt and Au NPs, but Pt NPs promoted ROS generation more efficiently than Au and Ag NPs. These results provide valuable strategy to design the synthesis of semiconductor/metal hybrid nanostructures and easy tailoring of ROS and charge carrier production.
关键词： reactive oxygen species,photocatalytic activity,metal nanoparticles,antibacterial activity,ZnO
更新于2025-09-04 15:30:14
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AIEgen Nanoparticles of Arylamino Fumaronitrile Derivative with High Near-infrared emission for Two-photon Imaging and in vivo Cell Tracking
摘要： Developing of two-photon materials for live-cell imaging and in vivo analysis in-deep have been received great attention, and it is still urgent so that such microscopy technique could be promoted and advanced into new progress using the powerful probs. Herein, a new arylamino fumaronitrile derivative NPAPF was synthesized and transferred as aggregation-induced emission luminogen (AIEgen) fluorescent nanoparticles (AF-NPs) via assembly technique. This AF-NPs exhibited two-photon absorption cross-section at 2.6×106 GM with 19.5% of fluorescence quantum yield. Moreover, utilizing the great potential of AF-NPs, two-photon imaging of live cells with good cytocompatibility is realized upon two-photon microscopy. By in vivo long-term tracing studies of mesenchymal stem cells, we demonstrated the tremendous advantage of AF-NPs tracer in monitoring the stem cells transplant. Therefore, our unique AF-NPs provided an efficient two-photon-absorbing probe for investigating biological mechanism and behavior, and also opened a new avenue for spatiotemporal visualization of transplanted stem cells.
关键词： organic nanoparticles,aggregation-induced emission,two-photon,in vivo imaging,mesenchymal stem cell
更新于2025-09-04 15:30:14