Applied Nanoscience最新文献

This research investigates the synthesis of sodium alginate–iron oxide nanocomposites (SAL-Fe₃O₄) through the co-precipitation method, with a focus on the impact of gelation time. SAL-Fe₃O₄ nanocomposites were precipitated from Fe₂(SO₄)₃ and FeSO₄ under an alkaline medium in the presence of sodium alginate, maintaining a stoichiometric balance using a molar ratio of 1:2 for iron (III) Fe³⁺ to iron (II) Fe²⁺ ions precursors. Two types of SAL-Fe₃O₄ nanocomposites were prepared by varying the gelation time of sodium alginate to 3 and 24 h. Extensive characterization was performed using UV, FTIR, XRD and SEM with EDX analysis techniques to evaluate the properties of the nanocomposites. Fourier-Transformed infrared Spectroscopy (FTIR) analysis provided insights into the presence of sodium alginate on the SAL-Fe₃O₄ nanocomposite surface and the bonding characteristics within the polymer. X-ray diffraction (XRD) analysis was employed to determine lattices, phases, and preferred crystal orientations (texture) of the nanocomposites. Scanning Electron Microscope (SEM) was utilized to examine morphology, microstructures, dimensions, and size of the prepared nanocomposites. Energy-Dispersive X-ray (EDX) was used for the analysis of the elemental composition of the nanocomposites. Additionally, the catalytic efficiency of SAL-Fe₃O₄ nanocomposites was evaluated through the catalytic degradation of organic dyes using hydrogen peroxide (H₂O₂) as the oxidizing agent. The degradation processes were monitored by UV-visible spectrophotometry and the apparent rate constant (k_app), degradation time, percentage (%) degradation, degradation concentration and half-life values of different organic dyes were studied and compared, highlighting the influence of gelation time on the degradation efficiency.

Nano-sized amorphous Iron (III) oxides have been a fascinating material for the scientific community owing to their widespread promising application in photocatalysis of water decontamination, due to high specific surface area and variable valency. Malachite green dye is a non-biodegradable organic pollutant known for its toxic effects on humans and aquatic organisms. In the present work, Fe₂O₃ was synthesized through Citrate–Nitrate Sol–Gel route and Syzygium cumini leaf extract mediated green method. The composition and physical nature of the synthesized iron oxides were confirmed using p-XRD, SEM-EDAX, XPS techniques. A comparative investigation of visible light degradation of malachite green dye was done using differently synthesized Fe₂O₃ at pH 8. The LCMS study exposed that the sol–gel Fe₂O₃ was highly efficient in transforming Malachite green (MG) into a no. of intermediates of low molecular weights, whereas green Fe₂O₃ revealed formation of both high and low molecular weight metabolites. In the light of the evidence derived from LCMS, a pathway has been proposed to highlight the absolute and sequential transformation of the dye to environmentally benign compounds. The study also disclosed the key role played by Iron oxide nanoparticles (IONPs), in the total mineralization of the dye to carbonates and nitrates that can be assimilated by plants and the decontaminated water can be engaged in agricultural practices.

The study successfully synthesized nano-SiO₂ and Nd₂O₃ materials applying as fertilizers for growth of the Paramignya trimera (Oliv.) Guill. (Rutaceae), a well-known medicinal plant in Vietnam and Thailand for treatment of numerous cancers. The cultivation results indicated that the individual uses of nano-SiO₂ and Nd₂O₃, respectively, induced stem and root growth of the P. trimera. Therefore, applications of nano-Nd₂O₃ and SiO₂ mixture exhibited synergic effects to greatly enhance stem and root growth of the P. trimera. The plant height, root length, stem and root weight of the mixture Nd₂O₃ and SiO₂ exposed plant were greatly higher than those of the individual nano-material exposed plants. The extraction experiments indicated that ostruthin, a valuable medicinal substance, accumulated in the roots of the P. trimera rather than in its stems. The ostruthin content in the root of the Nd₂O₃ exposed P. trimera was also greatly higher than those in the control and SiO₂-exposed plants. This indicated that the Nd₂O₃ nano-materials not only induced root growth but also aided the accumulation of ostruthin in the roots of the P. trimera. This open new era on combination application of nano-SiO₂ and Nd₂O₃ for growth of the P. Trimera as well as other medicinal plants.

Recent research has focused on zinc oxide nanoparticles (ZnO NPs) in culture and in vivo cell lines due to their cytotoxic potential. In addition, ZnO has garnered considerable interest in cancer therapy. Our objective was to assess the cytotoxicity of ZnO NPs on cell lines from the ovary, prostate, and bone (SK-OV-3, PC3, and Saos-2). ZnO nanoparticles were used to culture SK-OV-3, PC3, and Saos-2 cancer cells at concentrations of 0, 20, 40, 80, 160, and 320 ppm. Cancer cells were subsequently incubated for 24 and 48 h. Using the MTT assay, the apoptosis and cytotoxicity of cells were quantified. ZnO NPs of both diameters exhibited cytotoxic properties. Regardless of the lowest concentration, the extent of the cytotoxic effect on apoptosis is 32.55 nm. A rise in ZnO NP concentration was associated with an increase in apoptosis and a decrease in viability. The findings of this study suggest that the examined cancer types exhibited cytotoxic effects upon exposure to ZnO NPs, as compared to the control group that was not exposed. Furthermore, the maximum cytotoxic effects were observed at higher concentrations. It seems that the observed increase in cytotoxicity may not be significantly altered.

The growing demand for alternative energy sources has driven significant developments in novel device designs that generate energy through light conversion. Among the different types of solar cells, dye-sensitized solar cells (DSSCs) have emerged as one of the most promising options due to their potential to approach theoretical efficiencies of up to 46%. Although current real-world efficiencies typically range from 10 to 14% that generates numerous opportunity areas for DSSC improvement through different strategies, including the development of innovative solar cell structures, new growth or synthesis processes, and the integration of novel oxide materials. Titanium dioxide is one of the most significant oxide semiconductors and its interest has notably increased in recent years due to its unique optoelectronic properties and its applications in dye-sensitized solar cells (DSSCs). In DSSCs, photoelectrodes play a vital role in photoconversion. Photoelectrodes for DSSCs require blocking and porous oxide semiconductor layers to prevent electron leakage and enhance efficiency. Typically, these layers are produced through various techniques and steps, complicating the fabrication process and extending processing times. Therefore, in this work, we propose a one-step method to simultaneously grow TiO₂-blocking and porous layers for DSSC photoelectrodes at relatively low temperatures. Characterization results using FESEM/EDS, XRD, and UV–visible spectroscopy confirm the growth of both compact and porous layers. These layers are composed of the anatase particulate deposits (100–200 nm) with acceptable grain sizes (17.3–84.1 nm) and exhibit a suitable band gap (3.14 eV). Finally, TiO₂ films were applied in DSSCs as photoelectrodes and showed promising performance in solar cell prototypes.

A sustainable approach for the manufacture of palladium (Pd) nanoparticles utilizing Morinda citrifolia leaf extract was established. The topological, crystallographic, and composition and structure of a UV–Vis spectrophotometer have been utilized to evaluate the generated nanoparticles, TEM, XRD, and FTIR investigations. The created nanoparticles underwent additional testing to see how well they removed the dyes rhodamine 6G (Rh-6 G), methyl orange, and Congo red. The generated Pd nanorods fully decolored nearly 99.9% of the Rh-6G dye in about 10 min. Greener fabrication for metallic nanoparticles has regularly been established, and cleaner and more effective nanorods for pollutant remediation have also been created. This study reveals the environmentally friendly synthesis of Pd NRs and its uses in environmental remediation.

Functional nanoferrites are attracting interest in photocatalytic applications due to their intriguing and excellent optical and magnetic properties. In that order, as suitable adsorbents for wastewater treatment, graphene-based nanoferrites can be tuned. In this article, ZnFe₂O₄/GO nanocomposites have been prepared to study the structural, optical, magnetic, and photocatalytic properties through investigational (experimental) results and theoretical insights. Further, the synthesized nanocomposites fall under the mesoporous range with an average crystalline size of around 15–18 nm with good colloidal stability. Spherically agglomerated morphology has been observed by FE-SEM analysis. Magnetic characterizations were done by vibrating sample magnetometer (VSM) with superparamagnetic behavior at room temperature (RT). Optical insights reveal that the samples exhibit good photocatalytic properties with a degradation rate of 85.8% with methylene blue (MB) organic pollutant. Hence, this article aims to study the properties of prepared ZnFe₂O₄/GO nanocomposites through a detailed theoretical discussion of density functional theory (DFT).

Titanium dioxide nanoparticles (TiO₂ NPs) have garnered considerable attention due to their diverse applications. Introducing niobium (Nb) and nitrogen (N) doping, followed by functionalization with Mucuna pruriens beans methanolic extracts, offers a novel avenue to harness their antioxidant potential. This functionalization enables Nb-N doped TiO₂ NPs to engage with the bioactive compounds inherent to M. pruriens beans methanolic extracts, thereby fostering a synergistic enhancement of antioxidant activity. This study focuses on the functionalization of doped Nb-N-TiO₂ NPs and evaluates the antioxidative capabilities of those functionalized NPs to pure doped Nb-N-TiO₂ NPs. These functionalized NPs (FNb-N-TiO₂) underwent characterization through ultraviolet–visible spectroscopy (UV–Vis), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning electron microscopy (SEM) analysis. Subsequently, their antioxidant capabilities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power Assay (FRAP) assays. Functionalized Nb-N-TiO₂ NPs FTIR peaks exhibited at 2430 and 2010 cm⁻¹; unrelated peak vibrations are associated with the (Nb-N) doping, and the increased transmittance signifies successful functionalization and potential bonding between M. pruriens extract phytochemicals. A distinctive triangular aggregation pattern in SEM ranging in size from 5 µm to 500 nm was seen in FNb-N-TiO₂. At a concentration of 500 μL⁻¹, FNb-N-TiO₂ exhibited exceptionally high antioxidant activity, reaching an impressive 70% compared with pure Nb-N-TiO₂ NPs at 51%. The results demonstrated that FNb-N-TiO₂ NPs exhibit significant antioxidant properties compared to their non-functionalized, pure Nb-N-TiO₂ NPs. In conclusion, this study substantiates the considerable antioxidant potential of doped Nb-N-TiO₂ NPs mediated by M. pruriens methanolic extract, thereby emphasizing their potential for diverse applications in both biomedical and environmental sciences.

Nanostructured materials have significantly influenced numerous scientific and technological areas, mainly due to the tuneability of their optical and electrical properties. When working with quantum dots (QDs)-based thin films, the high prevalence of trap states and low conductivity has been a remarkable challenge, which has been addressed by the fabrication of hybrid materials. However, on the road to improving their properties, fabrication of nanostructured hybrid materials, especially when involving 2D nanomaterials, still poses a challenging task, particularly when solution-processed approaches are considered. In the current work, the fabrication of a solution-processed QDs-2D nanomaterial hybrid, comprising PbS QDs and thermally reduced graphene oxide (rGO) is discussed. This study explores the nanostructured hybrid material's behavior when varying the weight percent ratio between the constituents, revealing a substantial impact of this parameter on the optoelectronic properties of the resulting hybrid material; particularly affecting the photogenerated charge carrier transfer, charge carrier mobility, charge carrier concentration and resistivity. Physical characterization of the hybrid material revealed a dramatic change in the interaction between the PbS QDs and the rGO as the weight percent of rGO increased in the hybrid material, showing a clear reduction of PbS QDs coverage on rGO’s surface, which also produced an increment in the signals related to the oxidation of PbS QDs and rGO. The sample with 5% wt. of rGO showed optimal optoelectronic properties for possible applications in photodetector technologies or solar cells, displaying a high photogenerated current with a charge carrier mobility, charge carrier concentration, and resistivity of approximately 2.26 cm²/V-s, 1.27 × 10¹⁴ cm⁻³ and 2.18 × 10⁴ Ω-cm, respectively. These findings serve as a foundational basis for the development of efficient optoelectronic devices based on this type of nanostructured hybrid material.