Search Results (1,631)

Organic-type solar cells containing an active layer of block copolymer donor PTB7-Fx (x = 0, 20, and 100), based on benzo [1,2-b:4,5-b’]dithiophene and variably fluorinated thieno [3,4-b]thiophene units, and fullerene acceptor [6,6]phenyl-C₇₁-methylbutyrate, were constructed. The active layer thin film of the solar cells was obtained from a dichlorobenzene solution at an established concentration via spin-coating of the donor–acceptor mixture in the presence of solvent additives such as 3% diiodooctane and 1% triethyl phosphate. Organic photovoltaic elements with normal device architecture were prepared on glass substrates using an indium tin oxide anode, a spin-coated hole transporting layer of poly(ethylene dioxythiophene):polystyrenesulfonate, the aforementioned active layer, followed by an electron transporting layer of zinc oxide nanoparticles, and finally a magnetron sputtered silver (Ag) top-electrode. The optical properties, thin film morphology, and the thickness of the active layers were investigated. Additionally, current density–voltage characteristics and impedance spectra of photovoltaic devices were measured. It was found that PTB7-Fx:PC₇₁BM-based solar cells processed in the presence of two types of solvent additives, diiodooctane and triethyl phosphate, with a sputtered Ag top-electrode display similar absorption and quantum efficiency spectra, as well as comparable current density–voltage characteristics and efficiencies to the same devices fabricated without additives. The diiodooctane solvent additive preferably dissolves the fullerene component and has a positive effect on fill factor enhancement, impedance spectra improvement, and amelioration in charge carrier transport and collection, whereas the triethyl phosphate solvent additive preferentially dissolves the copolymer donor and has a more pronounced impact on the refined morphology of the thin film active layers. Full article

Two hemostatic bionanocomposite dressings were developed using natural, semi-natural (or semi-synthetic) and synthetic polymers. The first system consisted of chitosan (CS), polyvinyl alcohol (PVA), and carboxymethyl cellulose (CMC) (CS/PVA/CMC), while the second was based on CS, PVA, and starch (SR) (CS/PVA/SR). Zinc oxide (ZnO) nanoparticles and bicyclic monoterpene camphor (CP) ketone were incorporated as bioactive agents in order to enhance antimicrobial and hemostatic performance. FTIR spectroscopy confirmed the successful solvent casting synthesis of the dressings and the interactions between the biopolymers and additives. XRD analysis indicated a predominantly amorphous structure, while SEM images and EDS analysis revealed uniform dispersion of ZnO particles within the polymer matrices without aggregation. Furthermore, the CS/PVA/CMC-1ZnO/CP sample exhibited a water sorption of 12,666 ± 126%, while CS/PVA/SR-1ZnO/CP reached 7013 ± 215%. ZnO incorporation also improved mechanical performance, with CS/PVA/SR-2ZnO/CP displaying the highest tensile strength (39.18 ± 0.2 MPa) and elongation at break (9.54 ± 1.04%). ZnO incorporation also led to a concentration-dependent increase in antibacterial activity, with SR-based dressings achieving near-complete bacterial reduction at higher ZnO loadings. All the dressings demonstrated good biocompatibility, while CS/PVA/SR-1ZnOCP showed the fastest clotting time (420s ± 40), highlighting its potential for hemostatic applications. Full article

The aim of the study was to modify polylactide with zinc oxide nanoparticles (ZnO), raspberry leaf extract (E), and a combined ZnO/extract system (EZnO) in order to prepare novel packaging materials via a solvent-free method, namely cast extrusion. Physicochemical properties: Morphology (GPC, SEM, FTIR), mechanical (tensile tests, puncture), barrier (WVTR, OTR, UV-Vis) and water contact angle for PLA-based films with two thickness ranges were investigated. Additionally, antimicrobial (antibacterial, antifungal and antiviral) tests were performed. GPC results revealed that the presence of the extract counteracted biopolyester degradation during hot melt processing. The best mechanical properties (TS ca. 50 MPa, EB ca. 18%) were obtained for PLA modified with raspberry leaf extract (PLA/E). EZnO addition led to the highest increase in oxygen (with 25%) and water vapor (up to ca. 28%) barrier properties. The material with EZnO addition was also found to be the only one to demonstrate antibacterial effectiveness, although the activity was insignificant. However, the incorporation of EZnO into the biopolymer matrix enhanced its antiviral properties, resulting in the complete inactivation of Φ6 bacteriophage particles used as a surrogate of SARS-CoV-2 virus. Full article

This study describes the development of an electrochemical sensor for quantitatively measuring acetaminophen (ACOP) in drug tablets. The sensor design is based on the modification of glassy carbon electrode (GCE) using zinc oxide nanoparticles (ZnONPs) embedded in a naturally occurring clay matrix (Sa) functionalized with phenylalanine (Phe). To ensure that the ZnONPs are homogeneously dispersed on the clay surface, the nanocomposite was synthesized using an impregnation approach and low-temperature heat treatment. The amino acid promotes specific interactions with ACOP through hydrogen bonding and π-π stacking, acting as both a stabilizing agent and a molecular recognition moiety. FTIR, UV-Vis, XRD, and FESEM/EDX mapping were employed to fully characterize the developed material (ZnONPs-Sa/Phe). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used for the electrochemical determination of ACOP using the modified electrode GCE/ZnONPs-Sa/Phe. Parameters susceptible to affecting the sensitivity of the developed sensor were optimized, revealing that 5 µL of the suspension ZnONPs-Sa/Phe immobilized on GCE was ideal for the sensing of ACOP in a phosphate buffer solution at pH 2.0. The calibration curve obtained by plotting peak current intensity against ACOP concentration exhibited linear behavior within the concentration range between 0.02 µM and 0.28 µM, enabling determination of the limits of detection (LOD) and quantitation (LOQ) at 8.54 × 10⁻⁹ M and 2.84 × 10⁻⁸ M, respectively. The reproducibility, stability, and selectivity of the sensor were evaluated, followed by its application to the nano-sensing of ACOP in Africure and Doliprane tablets, yielding satisfactory results. The simplicity, affordability, and high analytical sensitivity of the developed sensor make this sensing platform a promising tool for pharmaceutical quality control applications. Full article

Licania tomentosa leaf extract was used to synthesize zinc oxide nanoparticles (ZnO NPs) which were systematically analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Visible (UV-Vis) and Fourier transform infrared (FT-IR) spectroscopies and energy-dispersion X-ray spectroscopy (EDS) methods. Based on XRD scans, the green NPs have an average crystallite size of 15.9 nm as estimated using the Scherrer equation and have a roughly spherical shape with an average diameter of 25.15 ± 1.2 nm as calculated from SEM data. As estimated from the Tauc plot based on UV-Vis absorption spectra, ZnO NPs have a small band gap of 3.0 eV. The biosynthesized ZnO NPs were effectively utilized for the photodegradation of methylene blue (MB) and crystal violet (CV) dyes under UV illumination with resulting MB and CV degradation efficiencies of ~94% and ~81% after 60 min and 70 min, with pH = 12 and pH = 10, respectively. Different experimental parameters such as NPs quantity, experimental pH, light intensity and initial concentration of dyes were varied to test the performance of the catalyst. Furthermore, efficient recycling of the catalyst was demonstrated. We also undertook antimicrobial studies of the green ZnO NPs. The ZnO NPs demonstrated broad-spectrum antimicrobial efficacy against Escherichia coli ATCC 35218, Enterococcus faecalis ATCC 29737, Klebsiella pneumoniae ATCC 700603, Pseudomonas aeruginosa ATCC 27853, P. aeruginosa B3, Staphylococcus aureus ATCC 29213, and S. aureus SA01, with the minimum inhibitory concentration (MIC) and the inhibitory concentrations associated with 50% effect (IC50) values ranging from 250 to 2000 µg/mL and 7.74 to 283.14 µg/mL, respectively. The nanoparticles also significantly inhibited biofilm formation by E. faecalis ATCC 29737, P. aeruginosa ATCC 27856, and S. aureus SA03. The antimicrobial efficiency of the ZnO NPs against Escherichia coli ATCC 25922 and Staphylococcus aureus SA03 isolates was also assessed using the disk diffusion assays. Taken together, our results reveal that the biosynthesized ZnO NPs are promising multifunctional materials with potential applications in antimicrobial treatments, biofilm control, and photocatalytic remediation. Full article

Water pollution caused by harmful organic pollutants discharged from various industries, such as textiles, pharmaceuticals, papermaking, and printing, is resulting in serious health complications and adversely impacting aquatic life. Numerous strategies/methods have been employed to remove these pollutants from water streams. Amongst them, photocatalysts have proven effective in tackling these issues. Zinc oxide (ZnO) and titanium Dioxide (TiO₂) photocatalysts are at the forefront due to their exceptional properties, which render them ideal for wastewater treatment. However, their full capacity as photocatalysts is limited by the wide band gap and faster electron-hole recombination rates. Metal decoration on the surface of these semiconductors is one of the fascinating strategies to address these limitations. In this brief review, the synthesis, morphology, and photocatalytic activity of ZnO and TiO₂ decorated with metal nanoparticles (NPs) towards the degradation of harmful organic pollutants from various industries are presented. Metal decoration of the surface of ZnO and TiO₂ is a viable method to enhance the photocatalytic activity of these semiconductors, particularly under visible light. Full article

Surface discharge-induced degradation poses a significant threat to the operational reliability of high-voltage insulation systems. This research investigates the dielectric endurance of polyester-based nanocomposites reinforced with seven distinct nano-additives: iron oxide (Fe₃O₄), copper oxide (CuO), titanium oxide (TiO₂), aluminum oxide (Al₂O₃), silicon dioxide (SiO₂), zinc borate (ZnB) and graphene oxide (GO). Specimens were fabricated at 0.5% and 0.75% weight concentrations and subjected to constant AC electrical stress of 4.5 kV at 50 Hz until failure using the first-plane tracking method. To accurately monitor the aging process, a sophisticated signal processing framework involving Hankel-matrix-enhanced Robust Principal Component Analysis (RPCA) was developed to extract high-frequency discharge features from captured leakage current signals. The degradation characteristics were quantified using various statistical metrics, including Kurtosis, RMS and Burst Discharge Index (BDI). Experimental findings demonstrate that the incorporation of nanoparticles significantly extends the time-to-failure compared to neat polyester, although the effectiveness is highly dependent on both additive type and concentration. At 0.5 wt.%, ZnB exhibited the superior performance in delaying carbonized track formation. However, at 0.75 wt.%, Al₂O₃ emerged as the most effective additive, achieving a maximum endurance time of 31.61 min. In contrast, certain additives like TiO₂ showed a performance decline at higher loadings, likely due to nanoparticle agglomeration. The Hankel-RPCA methodology successfully isolated discharge-specific signatures from background noise, establishing a strong correlation between signal features and material failure stages. This study confirms that the synergy between advanced nanomaterial modification and robust signal processing provides an effective diagnostic tool for monitoring insulation health, offering a vital pathway for the designing of high-performance dielectrics for real-world power system applications. Full article

Zinc oxide (ZnO) is a semiconductor with photocatalytic activity, although it presents limitations due to its band gap and the rapid recombination of the electron–hole pair; therefore, strategies such as doping have been explored. In this work, ZnO nanoparticles doped with 3% and 5% silver (Ag) were synthesized using a Cylindropuntia cholla root extract as a reducing and stabilizing agent. The structural, chemical, and optical properties of the synthesized nanoparticles were investigated using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Cathodoluminescence (CL), X-ray Photoelectron Spectroscopy (XPS), and Energy-Dispersive X-ray Spectroscopy (EDS). FT-IR shows that the nanoparticles have peaks between 400 cm⁻¹ and 406 cm⁻¹, attributed to the Zn–O bond. XRD characterization confirmed the formation of the wurtzite crystalline phase of ZnO, as well as the cubic phase of Ag. CL reveals two peaks: one attributed to the ultraviolet (UV) region and another in the visible region, which is associated with defects in the lattice. XPS and EDS confirm the presence of Zn, O, and Ag in the samples. The degradation of methylene blue was 90.9%, 96.4%, and 97.0% for ZnO, 3AgZnO, and 5AgZnO, respectively, demonstrating an improvement in dye degradation efficiency when doping ZnO nanoparticles with Ag. Full article

The study of wide-bandgap nanomaterials has gained considerable attention in recent years, especially in the case of semiconductor oxides that exhibit full or partial optical transparency in fundamental research and technological applications. These include optoelectronic devices, gas sensors and photovoltaic cells, among others. The activation or adjustment of optical and structural properties, especially the bandgap and the parameters of unit cell lattice, can be achieved by varying the dopant concentration during the synthesis of semiconductor thin films in these applications. In this context, copper oxide has emerged as a valuable material, owing to its thoroughly analyzed structural behavior and its broad potential across multiple technological fields. The present work focuses on the synthesis of zinc-doped copper oxide (Zn_xCu_1−xO) thin films on silicon and quartz substrates through ultrasonic spray pyrolysis. The effects of varying the zinc doping concentration (0.0, 5.0, 10.0 and 20.0 at. %) on the morphological, structural, and optical characteristics of the Zn_xCu_1−xO films were analyzed. Scanning electron microscopy (SEM) analysis indicated a gradual increase in nanoparticle size, rising from 221 nm for CuO to approximately 322 nm for the Zn_0.2Cu_0.8O samples as the zinc content increased. Structural characterization via X-ray diffraction (XRD) confirmed a monoclinic crystal arrangement belonging to the $C_{2h}^6$ (c2/c) space group. As the percentage of zinc increased, the XRD peaks shifted to lower angles, consequently increasing the volume and crystal lattice parameters of the Zn_xCu_1−xO structure; this finding was additionally supported by a redshift observed in the Raman analysis. The transmittance spectra of the films showed low transmittance between 40 and 44%. The optical bandgap of the Zn_xCu_1−xO thin films was estimated from the transmittance data by applying the Tauc plot method. A decrease in the band gap was observed at higher doping concentrations. It can be confirmed that no secondary phases are observed at a doping level of 20.0 at. % of zinc, indicating good solubility of zinc in CuO. The analysis and discussion of these findings are included throughout this work to elucidate the controversies noted in the literature. Full article

Zinc oxide (ZnO), silver (Ag) and titanium dioxide (TiO₂) nanoparticles (NPs), are three of the most widely manufactured NPs, while composite NPs have gained popularity due to their enhanced properties. NP release in environmental matrices increases chances of bioavailability and subsequent impact on human health. The current study focuses on manufacturing, characterization and cyto-genotoxic assessment of Ag, ZnO/Ag, TiO₂ and TiO₂/Ag NPs with and without humic acids (HAs), aiming for a holistic approach that leads to a comprehensive profile of said NPs. It entails (a) the synthesis of the aforementioned NPs via single-nozzle Flame Spray Pyrolysis (SN-FSP); (b) the characterization of NPs (in powder form and in dispersion media) using Powder X-ray Diffraction (PXRD), Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS); and (c) the assessment of their genotoxicity and cytotoxicity against human lymphocytes in presence of two HAs, thus simulating actual environmental conditions, and without HAs, through the cytokinesis block micronucleus assay (CBMN) with cytochalasin-B. No genotoxicity was observed in any case, whereas cytotoxicity induction varied depending on the NP and the presence or absence of the two HAs. Therefore, it is indispensable to evaluate the toxic profile of NPs considering different environmental scenarios, while conducting an integrated characterization of NPs. Full article

Naked oat (Avena nuda L.) is an important dual-purpose crop for grain and forage in cold regions; however, its high fatty acid content renders seeds prone to deterioration during storage. This study aimed to investigate the protective effects of zinc oxide nanoparticles (ZnO NPs) on artificially aged naked oat seeds and elucidate the underlying molecular mechanisms. Non-aged seeds (Naged) were subjected to artificial aging at 45 °C and 100% relative humidity for 24 h (Aged), followed by priming with 30 mg L⁻¹ ZnO NPs for 6 h (Daged). Antioxidant enzyme activities were determined spectrophotometrically, and transcriptome sequencing was performed on an Illumina platform to identify differentially expressed genes (DEGs) and enriched pathways. We found that ZnO NPs increased catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) activities by 3–4-fold, restored germination rate from 75% to 98%, and enhanced seed vigor index. A total of 21,403 DEGs were detected, with 15,841 stably expressed in response to nano-priming. Reactive oxygen species (ROS) burst rapidly induced up-regulation of AP2/EREBP transcription factor family members, which subsequently activated antioxidant enzyme genes to maintain cellular redox homeostasis. Metabolic pathway analysis demonstrated that the phenylpropanoid pathway was reprogrammed, characterized by down-regulated lignin biosynthesis and up-regulated flavonoid production, thereby enhancing ROS scavenging capacity. Additionally, the pentose phosphate pathway was activated to provide additional NADPH for antioxidant defense, and up-regulated ADP-glucose pyrophosphorylase (AGPase) facilitated starch accumulation. Notably, the 40S ribosomal protein S13 exhibited the highest connectivity in protein–protein interaction networks, was up-regulated 2.1-fold, and was enriched in post-translational modification processes. These findings suggest that nano-priming with ZnO NPs represents a promising biotechnological strategy for enhancing seed vigor and storability in naked oat, with potential applications in sustainable agriculture and the seed industry. Full article

The use of nanoparticles (NPs) synthesized from plant extracts is an alternative to conventional pesticides for the control of agricultural pests. This study aimed to optimize the conditions of synthesis of silver–zinc nanoparticles (Ag-ZnNPs) using extracts of Ocimum basilicum L. and Crotalaria longirostrata Hook. & Arn. and to evaluate their phytotoxic impact on maize seedlings. The Ag-ZnNPs (Ag-Zn nanoparticles) were synthesized by redox reaction between metal ions and reducing metabolites present in the extracts. A response surface methodology (RSM) with three factors (extract concentration, heating time and pressure) was applied to determine the optimal synthesis conditions. The phytotoxicity of nanoparticles (NPs) on maize seedlings was subsequently evaluated on root growth, oxidative stress enzymes (CAT, POD, and APX), and physiology of seedlings. Nanoparticles synthesized from C. longirostrata extract demonstrated superior properties, with an optimization of synthesis (R² = 95.3%) where the extract concentration (1:4 v/v; p < 0.01) was the critical factor influencing the reduction of metallic ions to nanoparticles. These NPs exhibited superior stability, smaller size (<100 nm), and zeta potential greater than 30 mV compared with O. basilicum extracts. Their NPs exhibited poorer optimization of synthesis (R² = 43.8%) without the effect of any of the variables evaluated. Essentially, C. longirostrata NPs showed no phytotoxic effects on maize seedlings’ physiological parameters and enhanced root growth (117.2 mm) without negatively affecting photosynthesis (PSII 70-81 FvFm). Ag-ZnNPs synthesized with C. longirostrata exhibited optimal stability and size, along with no observed possible phytotoxicity effects, unlike O. basilicum NPs, which cause stress on maize seedlings. Therefore, Crotalaria longirostrata NPs could represent a promising material for agricultural pest control, with no apparent adverse effect on maize crops. Full article

Fungal growth and insufficient thermal comfort degrade building durability and indoor quality, especially in humid and high-radiation regions. Zinc oxide (ZnO) stands out for its strong antifungal activity and radiative cooling potential. In this study, a commercial coating was modified with ZnO nanoparticles synthesized via a green chemistry route using Cymbopogon citratus (lemongrass) leaf extract as a reducing agent. Structural and morphological characterization by XRD, SEM, and EDS confirmed the formation of hexagonal wurtzite-phase nanoparticles with hemispherical and ellipsoidal morphologies, presenting average sizes of 50.27 ± 19.84 nm and 128.25 ± 33.43 nm, respectively, and an average crystallite size of 20.32 nm. Antifungal activity, evaluated using the poisoned food technique against Aspergillus niger and Penicillium spp., showed significant growth inhibition, reaching up to 94.63% for A. niger and 72.64% for Penicillium at a concentration of 3 mg/mL after 120 h of incubation. Thermal comfort performance was assessed to direct sunlight, in which coatings modified with 5% w/w ZnO nanoparticles achieved an average internal temperature reduction of 0.6 °C and a maximum reduction of 2.4 °C compared to uncoated surfaces. These results demonstrate that ZnO nanoparticles synthesized through environmentally friendly methods can effectively enhance both antifungal resistance and passive cooling performance. Full article

Hybrid material-derived adsorbents have demonstrated exceptional efficacy in a variety of fields, including environmental cleanup and manufacturing operations. In this study, zinc oxide nanoparticles modified with carbon (ZnO-C) as hybrid adsorbent materials were synthesized using both expired zinc chloride and corncob extract. Hybrid ZnO-C adsorbents were employed for the removal of heavy metals, Co(II), and Ni(II) ions, from wastewater via adsorption. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and energy dispersive spectroscopy (EDS) were among the methods used to fully characterize the structural and morphological properties. To maximize the adsorption process for every metal ion, kinetic and equilibrium studies were carried out. Results revealed that the ZnO-C material formed crystalline, spherical granules with nanoparticle sizes ranging from 25 nm, embedded within a carbon matrix. Additionally, these spherical zinc oxide particles tended to aggregate into clusters. FTIR analysis indicated that the surface of ZnO-C was rich in hydroxyl (OH) groups and zinc oxide, which play a crucial role in the adsorption mechanism. The capacity of ZnO/CC-NPs to adsorb cobalt and nickel ions from aqueous solutions was investigated, examining the influences of initial ion concentration, pH levels, contact duration, and temperature. The findings highlight the high efficiency of ZnO/CC-NPs as an adsorbent, promoting the reuse of waste materials and supporting environmental sustainability efforts. Full article