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The functionalization of ZnO nanoparticles has proven to be an effective alternative to avoid agglomeration and improve their physic-chemical properties. In this work, we studied the functionalization of ZnO nanoparticles using citric acid (CA) through two methods: in situ functionalization and sonochemical functionalization to compare the effects on the physicochemical and antimicrobial properties of functionalized commercial ZnO nanoparticles with those synthesized and functionalized at the same time. Both methods are considered environmentally friendly (green chemistry) since the use of chemical toxic agents was avoided and the reaction medium was water. The in situ method demonstrated the ability of CA to act as a reducing and stabilizing agent. Fourier transform infrared spectroscopy (FTIR) and RAMAN spectroscopy analyses confirmed the functionality of ZnO nanoparticles, through the formation of the COO−/ZnO complex. The wurtzite-type hexagonal crystalline structure of the ZnO nanoparticles was confirmed by X-ray diffraction (XRD). The thermogravimetric analysis (TGA) analysis showed that in situ functionalization was more favored than sonochemical functionalization since 46.66 % and 27.22 % of the organic ligand were obtained on the surface of the nanoparticles, respectively. X-ray photoelectron spectroscopy (XPS) results revealed the chemical and electronic state of the zinc which was 2+ and atomic percentages of carbon of 40.64 % and 38.35 %, as well as atomic percentages of oxygen of 38.67 and 36.78 % for ZnO-AC and ZnO-AC-R1 nanoparticles, respectively. The evaluation of the antibacterial efficiency of the nanoparticles functionalized by both methods demonstrated that they possess a superior antimicrobial activity when compared with non-fuctionalized nanoparticles. The ZnO nanoparticles synthesized and functionalized via in situ showed an efficiency of 99.99 % starting concentrations of 200 ppm. [ABSTRACT FROM AUTHOR]

The escalating environmental concerns associated with conventional plastic packaging have accelerated the development of sustainable alternatives, making food packaging a focus area for innovation. Bioplastics, particularly polyhydroxyalkanoates (PHAs), have emerged as potential candidates due to their biobased origin, biodegradability, and biocompatibility. PHAs stand out for their good mechanical and medium gas permeability properties, making them promising materials for food packaging applications. In parallel, zinc oxide (ZnO) nanoparticles (NPs) have gained attention for their antimicrobial properties and ability to enhance the mechanical and barrier properties of (bio)polymers. This review aims to provide a comprehensive introduction to the research on PHA/ZnO nanocomposites. It starts with the importance and current challenges of food packaging, followed by a discussion on the opportunities of bioplastics and PHAs. Next, the synthesis, properties, and application areas of ZnO NPs are discussed to introduce their potential use in (bio)plastic food packaging. Early research on PHA/ZnO nanocomposites has focused on solvent-assisted production methods, whereas novel technologies can offer additional possibilities with regard to industrial upscaling, safer or cheaper processing, or more specific incorporation of ZnO NPs in the matrix or on the surface of PHA films or fibers. Here, the use of solvent casting, melt processing, electrospinning, centrifugal fiber spinning, miniemulsion encapsulation, and ultrasonic spray coating to produce PHA/ZnO nanocomposites is explained. Finally, an overview is given of the reported effects of ZnO NP incorporation on thermal, mechanical, gas barrier, UV barrier, and antimicrobial properties in ZnO nanocomposites based on poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate). We conclude that the functionality of PHA materials can be improved by optimizing the ZnO incorporation process and the complex interplay between intrinsic ZnO NP properties, dispersion quality, matrix–filler interactions, and crystallinity. Further research regarding the antimicrobial efficiency and potential migration of ZnO NPs in food (simulants) and the End-of-Life will determine the market potential of PHA/ZnO nanocomposites as active packaging material. [ABSTRACT FROM AUTHOR]

The removal of persistent dye pollutants from wastewater streams has drawn a lot of interest by the scientific community and photocatalysis is the most widely accepted practical strategy for addressing environmental contamination. Transition metal oxides are proved to be the most prospective catalysts for efficient and environment-friendly wastewater treatment because of their significant photocatalytic activity, excellent solubility and durability. Here, we describe a simple, eco-sustainable and cost-effective strategy for the synthesis of ZnO nanoparticles using Morinda umbellata leaf extract. The phytochemicals such as polyphenols, flavonoids and tannins present in the leaf extract act as reducing and stabilising agents. We investigated the photocatalytic activity of synthesised ZnO nanoparticles to break down organic dyes like Congo red (CR) and Malachite green (MG) in aqueous media. In aqueous solution, at ambient temperature, ZnO nanoparticles showed outstanding photocatalytic degradation efficiency of 98.9% (20 ppm) for the MG dye and 92.8% (10 ppm) for the CR dye at pH values of 10 and 6 respectively, in a short period of time. The optimum catalyst dosage was observed to be 0.1 and 0.125 g for MG and CR respectively. From the scavenger studies using different scavengers, it is confirmed that the superoxide radical is the main reactive species involved in the photocatalytic degradation of MG and CR. The kinetics of photodegradation was also investigated and followed a pseudo-first-order mechanism, with rate constants of 0.0204 min−1 for MG and 0.0123 min−1 for CR in accordance with the Langmuir–Hinshelwood model. The ZnO nanoparticles displayed excellent recycling capability for both dyes and the combined effects of their high adsorption capacity and photodegradation ability of organic dyes make them versatile choice for future applications. [ABSTRACT FROM AUTHOR]

The current study was conducted to investigate the effect of Melia azedarach seed-mediated ZnO nanoparticles on growth performance, protein utilisation efficiency, haematology and nutritional status in pigs. A total of 48 pigs were allocated to the following six treatments replicated 8 times: Negative Control (NC, No antibiotic), Treatment 2: Positive control (PC) given a conventional antibiotic (Oxytetracycline, 40 mg/kg feed); Treatment 3: Nano-ZnO 300 mg/L (N300ZnO), Treatment 4: Group given 150 mg/L Melia azedarach seed mediated nano-ZnO (N150MA), Treatment 5: Group given 300 mg/L Melia azedarach seed mediated nano-ZnO (N300MA), Treatment 6: Group given 450 mg/L Melia azedarach seed mediated nano-ZnO (N450MA). The experiment was conducted over 7 weeks. Melia azedarach seed-mediated ZnO nanoparticles had no significant effect on growth performance apart from average daily feed intake (ADFI) with treatment 3 having the highest value. It significantly affected protein consumption and growth efficiency but not protein efficiency ratio and specific growth rate. Melia azedarach seed-mediated ZnO nanoparticles had no significant impact on nutritional parameters, serum minerals apart from phosphorus which can negatively affect renal functioning. [ABSTRACT FROM AUTHOR]

A novel Zn(II) complex with the composition [Zn((2-Cl)(5-NO2)C6H3CONHO)2] was synthesized by reacting anhydrous ZnSO4 with 2-chloro-5-nitrobenzohydroxamate [(2-Cl)(5-NO2)C6H3CONHOK] (KHL) in 1:2 molar ratio in methanol (MeOH) solvent under stirring conditions. Various physicochemical studies, including elemental analysis, molar conductivity measurements, and spectroscopic techniques such as Fourier-transform infrared spectroscopy (FTIR), UV–visible, proton nuclear magnetic resonance (1H NMR), and carbon-13 nuclear magnetic resonance (13C NMR), were conducted to characterize the complex. The bonding via carbonyl and hydroxamic oxygen atoms (O, O coordination), and a distorted tetrahedral geometry around zinc were cautiously proposed based on the experimental data. The zinc hydroxamate complex served as a precursor for the green synthesis of zinc oxide (ZnO) nanoparticles utilizing an extract of Bergera koenigii (curry tree), characterized by XRD, BET, SEM (pre and post degradation), TEM and EDS mapping. The synthesized ZnO nanoparticles demonstrated remarkable photocatalytic activity under UV light assistance, achieving 99.5% and 99.94% degradation of cationic dyes, Malachite green and Fuchsin basic, respectively, within 10 to 15 min. Additionally, ZnO nanoparticles exhibited 98.94% degradation of potassium permanganate (KMnO4) within 10 to 12 min, showcasing superior photocatalytic efficiency compared to other reported nano photocatalysts. Mineralization tests were conducted using COD (Chemical Oxygen Demand) and TOC (Total Organic Carbon) analyses to enhance the understanding of photodegradation. Furthermore, ZnO nanoparticles displayed efficient and selective sensing for Cr(VI) and Hg(II) ions in the presence of other cations. [ABSTRACT FROM AUTHOR]

In this study, we present a novel method for synthesising zinc oxide nanoparticles (ZnO NPs) from the dried Caesalpinia sappan seeds powder. Comprehensive characterisation using XRD, FTIR, SEM, and EDX techniques was employed to elucidate the surface and morphological properties of these ZnO NPs. We showcase the versatile application of ZnO NPs as heterogeneous catalyst in the synthesis of 5-arylmethylidene-pyrimidin-2,4,6-triones. Notably, this eco-friendly approach eliminates the need for organic solvents, offering a sustainable route to producing 5-arylmethylidene-pyrimidin-2,4,6-triones in high yields. Furthermore, we investigate the corrosion inhibition properties of ZnO NPs on mild steel in 5% sodium chloride solution. Our findings reveal the ZnO NPs’ significant inhibition efficiency against corrosion, promising potential for practical applications. In addition to their chemical applications, we delve into the biological activities of ZnO NPs, including their antibacterial effects against both Gram-positive and Gram-negative bacteria, anti-oncogenic activity against DU-145 cells, and scavenging activities against oxidative stress. [ABSTRACT FROM AUTHOR]

Zinc oxide nanoparticles (ZnO-NPs) are commonly used in both commercial and agricultural sectors. As a result, ZnO-NPs are extensively discharged into soil ecosystems, creating a significant environmental issue. Therefore, it is crucial to assess their influence on the soil ecology to ensure its secure and enduring utilization in the future. The exact degree of toxicity associated with ZnO-NPs and their ionic form is still uncertain. To address the challenges, the study used the soil bioindicator earthworm species Eudrilus eugeniae as an experimental model to evaluate the effects of two zinc species (ZnO-NPs and ZnCl2) at 100, 250, 500, and 750 mg kg−1 and control (0 mg kg−1) in garden soil over 28 days. The investigation also examined the impact of exposure on survival, reproduction, neuro-biomarker, avoidance behavior, and accumulation. The highest avoidance rates were 27.5% for ZnO-NP and 37.5% for ZnCl2 at 750 mg kg−1. ZnCl2 treatment reduced juvenile production by 3.73 ± 1.73, while ZnO-NPs showed 4.67 ± 1.15. At 750 mg kg−1, soils with ZnCl2 (63.3%) demonstrated lower survival rates than those with ZnO-NPs (53.3%), likely because of higher Zn ion levels. After 28 days of exposure, ZnCl2 (536.32 ± 11 mol min−1) activated AChE enzymes more than ZnO-NPs (497.7 ± 59 mol min−1) at the same dose, compared to control (145.88 ± 28 to 149.41 ± 23 mol min−1). Nanoparticles and zinc ions bioaccumulated and reacted negatively with the neurotoxic marker AChE, affecting earthworm reproduction and behavior. However, earthworms exposed to ZnCl2 exhibited less intestinal Zn than those exposed to NPs. The present work contradicts the finding that ZnO-NPs have hazardous effects on soil organisms. The results indicate that earthworm E. eugeniae may significantly affect soil metal uptake from metallic nanoparticles (NPs). This may help design NP soil pollution mitigation strategies. The study offers valuable information for establishing a relationship between the environmental toxicity of ZnO-NPs and soil ecosystems. [ABSTRACT FROM AUTHOR]

Introduction: The potential of zinc oxide (ZnO) and iron oxide (Fe2O 3) nanoparticles (NPs) to induce toxic effects, especially genotoxicity, has been demonstrated in previous studies and is in part related to the ability of NPs to produce ROS. The use of antioxidants is an effective method to reduce NP-induced genotoxicity. The aim of this study was to determine the protective role of vitamin C as a potent antioxidant in ZnO-and Fe2O3 NP-induced genotoxicity in the HGF-1 cell line. Methods: Different concentrations of ZnO and Fe2O3 NPs (50 μ g, 100 μ g, and 150 μ g/mL) were used to achieve the best concentration for further evaluation. HGF-1 cells were incubated with different concentrations of vitamin C 24 h before the NPs. The cells were then exposed to ZnO and Fe2O3 NPs at a concentration of 100 μ g/mL for 1 h. The possible genoprotective effects of vitamin C were determined using a comet assay. Results: The results of this study showed that all concentrations of vitamin C could reduce the DNA damage induced by ZnO and Fe2O3 NPs. Discussion: In conclusion, vitamin C could be considered a potent genoprotective agent against ZnO- and Fe2O3 NP-induced genotoxicity. [ABSTRACT FROM AUTHOR]

Spin coating is a key method for thin film preparation due to its simplicity and cost-effectiveness, relying on the number of layers deposited. This study investigates the impact of sample thickness on polyvinyl chloride (PVC) nanocomposites doped with zinc oxide (ZnO) nanoparticles, focusing on structural, optical properties, and photocatalytic activity. Different numbers of layers (15, 20, 25, and 30) were synthesized via sol–gel spin coating using tetrahydrofuran as a solvent. X-ray diffraction revealed ZnO crystallites in 30-layer films, with a wurtzite structure and 32 nm crystallite size. Raman and infrared spectra confirmed ZnO incorporation. Optical transmittance ranged from 75 to 86%, with band gap energies between 3.45 and 3.94 eV. Photoluminescence spectra indicated ultraviolet and green luminescence attributed to ZnO defects. Photocatalytic efficiency, tested with methylene blue under UV irradiation, showed the 30-layer sample achieving 79% removal efficiency at 60 min, outperforming others. [ABSTRACT FROM AUTHOR]

Utilizing natural extract to prepare nanoparticles has grabbed the attention of researchers' worldwide due to its magnificent physicochemical properties. In the present work, zinc oxide nanoparticles (ZnO NPs) were produced with the assistance of phytochemicals found in two different natural extract: coconut milk and coconut water. The structure, optical, morphology, and biological performance of the prepared particles were examined and analyzed. X-ray diffraction pattern clearly infers the presence of crystalline natured ZnO NPs with hexagonal wurtzite structure. The average crystallite size is calculated as 25.5 and 11.3 nm for ZnO NPs using coconut milk and water respectively. Furthermore, Fourier transform infrared spectroscopy shows the characteristic peaks from 400 to 900 cm−1 corresponds to stretching band of ZnO. Photoluminescence spectroscopic techniques were employed to analyze the types of defects present in the synthesized nanoparticles. The optical property of the prepared NPs was examined from ultraviolet-visible spectrum and its bandgap obtained from Tauc plot found to reduce from 3.07 to 2.78 eV due to recombination of electron-hole pair. For both ZnO NPs, scanning electron microscopic analysis revealed the formation of spherical shape particles measures from 20 to 80 nm without any agglomeration. The formation of rod-shaped particles was identified from transmission electron microscopic images for coconut water mediated ZnO NPs. The presence of Zn and O revealed from XPS spectrum. Both ZnO NPs were tested for antibacterial activity against Staphylococcus aureus,Streptococcus pneumonia, Klebsiella pneumoniae, and Escherichia coli at different concentrations using disc diffusion method. The NPs produced using coconut water exhibit an IC50 of 47.99 over coconut milk (113.5) from the anti-inflammation investigation. According to these results, coconut water-derived ZnO NPs may be a promising nanomaterial with the potential to be used in cutting-edge medical procedures. [ABSTRACT FROM AUTHOR]

Commercial dyes from industrial sector contribute significantly to environmental contamination. This research work focuses on the elimination of synthetic anionic dye through batch investigation employing adsorption technique. Chemical Sol–gel synthesis approach was employed to synthesize the adsorbents. The novelty of this work involves the utilization of the following chemicals Ni(NO3)2, Cu(NO3)2, Fe(NO3)3, and Co(NO3)2 used as reducing metals to prepare metal-doped zinc oxide nanoparticles (Co/ZnO, Ni/ZnO, Fe/ZnO, and Cu/ZnO). The synthesized metal-doped ZnO nanoparticles were characterized by using FTIR, BET, SEM and XRD, zeta potential analysis. The optimum pH for direct orange (RDO) dye was detected in an acidic range which was 7 for Co/ZnO (87.40 mg/g), 3 for Ni/ZnO (83.13 mg/g), 5 for Fe/ZnO (79.31 mg/g), and 5 for Cu/ZnO (69.41 mg/g). The optimum dosage for all nanoparticle was found 0.05 g/50 mL and showed best adsorption for Co/ZnO 86.78 mg/g, Ni/ZnO 78.54 mg/g, Fe/ZnO 70/mg/g, and Cu/ZnO 59.64 mg/g. The initial concentration of dye from 25 to 250 mg/L was determined to be optimal for the maximum remediation of anionic dye using several adsorbents. The best removal was achieved at 100 ppm by Co/ZnO (84.61 mg/g) and (Ni/ZnO), while Fe/ZnO (72.51 mg/g), and Cu/ZnO (68.65 mgg/g) achieved maximum adsorption capacity at 150 ppm. The highest adsorption capacity was found by Co/ZnO (90.31 mg/g) at 43 min, Ni/ZnO (81.31 mg/g) at 49 min, Fe/ZnO (78.75 mg/g) at 75 min, and by Cu/ZnO (71.75 mg/g) at 90 min with optimal temperature at 37 °C. A decrease in temperature resulted in decline of adsorption capacity of the adsorbents. It demonstrated the release of heat in the complex during the adsorptive removal of negatively charged RDO dye molecules. The Langmuir adsorption isotherms revealed the highest correlation with the equilibrium data, while the pseudo 2nd order model demonstrated an acceptable fit with the adsorption kinetic data. Various thermodynamic factors like enthalpy free energy and entropy were investigated. Highlights: Use of Ni, Cu, Fe, Co metals doped-ZnO as adsorbents to remove anionic dyes. Optimal dye removal conditions found: pH, temperature, dosage, time explored. Co/ZnO nanoparticles showed highest dye adsorption capacity in experiments. Study confirms Langmuir isotherm and pseudo 2nd order model fit for adsorption. [ABSTRACT FROM AUTHOR]

The sol–gel process was applied to prepare ZnO-saponite nanocomposite for environmental remediation and investigation of photocatalysis mechanisms. The nanocomposite followed the photodegradation of Rhodamine B (RhB) as a model dye under irradiation with visible light. The materials were characterized by X-ray diffraction, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy, photoluminescence, Point of zero charges (Pcz), and Brunauer–Emmett–Teller (BET). Reuse, the effect of scavengers, and toxicity were also investigated. The results showed an effective incorporation of the semiconductor on the surface of the support, forming a hexagonal structure with the wurtzite phase of ZnO. The evaluation of texture and morphology showed the effective distribution of ZnO nanoparticles on the surface of the synthesized photocatalyst. The intensified adsorption/photocatalysis process using saponite-based nanocomposite achieved more than 85% RhB dye removal efficiency after 270 min. It followed presented pseudo-first-order kinetics with a constant equal to 6.627 × 10–1 min−1. Furthermore, the evaluation of the effect of scavengers indicated that alcohol played an important role in scavenging hydroxyl radicals. It was stable after evaluating the catalyst after successive cycles, maintaining its structure, as FTIR proved. Furthermore, the studied nanocomposites did not show evidence of toxicity, thus being promising candidates for application in the removal of polluting dye. [ABSTRACT FROM AUTHOR]

Significant research accomplishments have been made so far for the development and application of ZnO nanomaterials in enhanced optical biodetection. The unparalleled optical properties of ZnO nanomaterials and their reduced dimensionality have been successfully exploited to push the limits of conventional optical biosensors and optical biodetection platforms for a wide range of bioanalytes. ZnO nanomaterial-enabled advancements in optical biosensors have been demonstrated to improve key sensor performance characteristics such as the limit of detection and dynamic range. In addition, all nanomaterial forms of ZnO, ranging from 0-dimensional (0D) and 1D to 2D nanostructures, have been proven to be useful, ensuring their versatile fabrication into functional biosensors. The employment of ZnO as an essential biosensing element has been assessed not only for ensembles but also for individual nanomaterials, which is advantageous for the realization of high miniaturization and minimal invasiveness in biosensors and biodevices. Moreover, the nanomaterials' incorporations into biosensors have been shown to be useful and functional for a variety of optical detection modes, such as absorption, colorimetry, fluorescence, near-band-edge emission, deep-level emission, chemiluminescence, surface evanescent wave, whispering gallery mode, lossy-mode resonance, surface plasmon resonance, and surface-enhanced Raman scattering. The detection capabilities of these ZnO nanomaterial-based optical biosensors demonstrated so far are highly encouraging and, in some cases, permit quantitative analyses of ultra-trace level bioanalytes that cannot be measured by other means. Hence, steady research endeavors are expected in this burgeoning field, whose scientific and technological impacts will grow immensely in the future. This review provides a timely and much needed review of the research efforts made in the field of ZnO nanomaterial-based optical biosensors in a comprehensive and systematic manner. The topical discussions in this review are organized by the different modes of optical detection listed above and further grouped by the dimensionality of the ZnO nanostructures used in biosensors. Following an overview of a given optical detection mode, the unique properties of ZnO nanomaterials critical to enhanced biodetection are presented in detail. Subsequently, specific biosensing applications of ZnO nanomaterials are discussed for ~40 different bioanalytes, and the important roles that the ZnO nanomaterials play in bioanalyte detection are also identified. [ABSTRACT FROM AUTHOR]

Bryophyllum pinnatum is used to cure infections worldwide. Although the flavonoids of this plant are well known, it is still unknown how much of the plant’s Ag and ZnO nanoparticles are beneficial. In the current research work, silver and zinc oxide nanoparticles were prepared using Bryophyllum pinnatum extract. The synthesized particles were characterized by UV-visible spectroscopy, SEM, EDS, XRD and FTIR. Synthesized particles were subjected to evaluation of their bactericidal and antifungal activity at various doses. Uv vis spectra at 400 nm corresponding to AgNPs confirmed their synthesis. Strong peaks in the EDS spectra of Ag and ZnO indicate the purity of the sample. The scanning electron microscopic images of ZnONPs showed a size of about 60 nm ± 3 nm, which demonstrated the presence of triangular-shaped ZnO nanoparticles. Green synthesized nanoparticles showed bactericidal activity against both Gram-positive (Micrococcus luteus, Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Agrobacterium tumifaciens, Salmonella setubal, Enterobacter aerogenes) strains. AgNPs proved to be more effective against Gram-negative bacterial strains compared to Gram-positive owing to MIC values (10 ppm and 20 ppm respectively). Whereas, ZnONPs were found more effective against Gram-positive bacteria with lower MIC values (10 ppm) as compared to Gram-negative ones (20 ppm). Also, the synthesized nanoparticles exhibited moderate dose-dependent antifungal activity against tested fungal strains ranging from 10 to 70%. Cytotoxicity of nanoparticles was found significant using Brine shrimp’s lethality assay with IC50 values of 4.09 ppm for AgNPs, 13.72 ppm for ZnONPs, and 24.83 ppm for plant extract. Conclusively, Ag and ZnO nanoparticles were more effective than plant extract and AgNPs had higher activities than those of ZnONPs. Further research is warranted to explore the precise mechanism of action and the potential applications of these nanoparticles in the medical field. [ABSTRACT FROM AUTHOR]

Nitroaromatic compounds represent a class of highly toxic pollutants discharged into aquatic environments by various industrial activities, posing significant threats to ecological integrity and human health due to their persistent and hazardous nature. In this study, Pd-doped ZnO nanoparticles were investigated as a potential solution for the degradation of nitro organics, offering heightened photocatalytic efficacy and prolonged stability. The synthesis of Pd-doped ZnO NPs was achieved via the hydrothermal method, with subsequent analysis through XRD spectra and XPS confirming successful Pd doping within the ZnO matrix. Characterization through FESEM and HRTEM unveiled the heterogeneous morphologies of both undoped and Pd-doped ZnO nanoparticles. Additionally, UV–vis and PL spectroscopy provided insights into the optical properties, chemical bonding, and defect structures of the synthesized Pd-doped ZnO NPs. Pd doping induces a redshift in ZnO's absorption spectra, reducing the bandgap from 3.12 to 2.94 eV as Pd concentration rises from 0 to 0.2 wt.%. The photocatalytic degradation, following pseudo-first-order kinetics, achieved 90% nitrobenzene abatement (200 µg/L, pH 7) under visible light within 320 min with a catalyst loading of 16 µg/mL. The photocatalytic efficacy of 0.08 wt% Pd-doped ZnO (k = 0.058 min⁻1) exhibited a 25-fold enhancement compared to bare ZnO (k = 3.1 × 10–4 min-1). Subsequent quenching and ESR experiments identified hydroxyl radicals (OH•) as the predominant active species in the degradation mechanism. Mass spectrometry analysis unveiled potential breakdown intermediates, illuminating a plausible degradation pathway. The investigated Pd-doped ZnO nanoparticles demonstrated reusability for up to five successive treatment cycles, offering a sustainable solution to nitro organics contamination challenges. [ABSTRACT FROM AUTHOR]

Cinnamaldehyde (CIN), a harmless bioactive chemical, is used in bio-based packaging films for its antibacterial and antioxidant properties. However, high amounts can change food flavor and odor. Thus, ZnO nanoparticles (NPs) as a supplementary antimicrobial agent are added to gelatin film with CIN. The CIN/ZnO interactions are the main topic of this investigation. FTIR-Attenuated Total Reflection (ATR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were utilized to investigate CIN/ZnO@gelatin films. Transmission electron microscope (TEM) images revealed nanospheres morphology of ZnO NPs, with particle sizes ranging from 12 to 22 nm. ZnO NPs integration increased the overall activation energy of CIN/ZnO@gelatin by 11.94%. The incorporation of ZnO NPs into the CIN@gelatin film significantly reduced water vapour permeability (WVP) of the CIN/ZnO@gelatin film by 12.07% and the oxygen permeability (OP) by 86.86%. The water sorption isotherms of CIN/ZnO@gelatin were described using Guggenheim-Anderson-de Boer (GAB) model. The incorporation of ZnO NPs into the CIN@gelatin film reduced monolayer moisture content (M0) by 35.79% and significantly decreased the solubility of CIN/ZnO@gelatin by 15.15%. The inclusion of ZnO into CIN@gelatin film significantly decreased tensile strength of CIN/ZnO@gelatin by 13.32% and Young's modulus by 18.33% and enhanced elongation at break by 11.27%. The incorporation of ZnO NPs into the CIN@gelatin film caused a significant decrease of antioxidant activity of CIN/ZnO@gelatin film by 9.09%. The most susceptible organisms to the CIN/ZnO@gelatin film included Candida albicans, Helicobacter pylori, and Micrococcus leutus. The inhibition zone produced by the CIN/ZnO@gelatin film versus Micrococcus leutus was 25.0 mm, which was comparable to the inhibition zone created by antibacterial gentamicin (23.33 mm) and cell viability assessment revealed that ZnO/CIN@gelatin (96.8 ± 0.1%) showed great performance as potent biocompatible active packaging material. [ABSTRACT FROM AUTHOR]

This study aims to comparatively investigate the morphological and optical characteristics of zinc oxide nanoparticles as a function of the preparation conditions. A series of ZnO nanoparticles were synthesized by facile precipitation method at constant temperature, by varying the zinc sources (zinc acetate, zinc nitrate and zinc chloride) or the precipitant nature (hexamethylenetetramine, urea). The structural, morphological and optical attributes of the prepared ZnO samples were assessed by SEM, XRD, FTIR, UV–Vis and photoluminescence analyses. The morphology of the achieved samples varies from spiky sticks to hexagons or foils with irregular shapes, observing that urea favour the development of two- or three-dimensional ZnO nanostructures, while hexamethylenetetramine predominantly triggered the formation of highly organized one-dimensional structures. The XRD patterns of all ZnO samples matches zincite crystalline hexagonal phase and the evaluation of crystallite size revealed higher values for the samples prepared in the presence of hexamethylenetetramine (HMTA). The optical band gap of ZnO NPs, as estimated from the UV–Vis absorption spectra, varied slightly from 3.13 to 3.21 eV, while fluorescence investigation proves that samples prepared with urea precipitant have a lower rate of charge recombination. Tests on the photocatalytic degradation of malachite green dye under UV light irradiation demonstrated that the dynamics of photogenerated charge carriers play a significant role in the photocatalytic performance of ZnO samples. [ABSTRACT FROM AUTHOR]

This article discusses the potential of zinc oxide nanoparticles (ZnO NPs) in mitigating salt stress in common beans. The study found that the application of ZnO NPs through foliar application, nano priming, and soil application promoted plant growth and reduced salt stress. Nano priming was found to be the most effective approach. The study provides evidence of the potential of ZnO NPs in addressing salinity-induced growth inhibition in crops. [Extracted from the article]

In this work, zinc nanoparticles were prepared using the low-temperature plasma method at different times 3 min, 5 min, 7 min, 9 min, where the initial reactions of zinc lead to the formation of nanoparticles. The metal interacts with the ionized plasma under different conditions and may turn into an oxide such as exposing the sample to air and raising the temperature of the solution a few degrees as a result of high voltage and within a certain range. The atmospheric pressure plasma system acts as the cathode, while the zinc metal strip acts as the anode. A series of techniques were used, including the use of X-ray diffraction (XRD), ultraviolet-visible spectroscopy and scanning electron microscopy (FESEM). The X-ray diffraction results showed that the samples have polycrystalline structures with hexagonal and cubic structures with a time difference, and the X-ray diffraction results showed the conversion of zinc particles into zinc oxides. FESEM images reveal particle size and shape. The ZnO nanoparticles prepared by the mentioned method seem to form different nanoshapes such as starfish and mushroom nanoparticles. The UV-visible results showed that the samples had an energy gap of about 3.4 eV at a time of 3 min, and this value decreases with increasing reaction time. The appearance of zinc oxides increases gradually with the passage of time. These results provide credibility for the fabrication of ZnO nanostructures for use in future gas sensing applications, despite the inhomogeneity of particle size among ZnO particles, the sensor was also fabricated to detect nitrogen gas (NH3) with different concentrations (17.25 ppm, 46.38 ppm, 78.58 ppm). at room temperature. The ZnO sample showed the highest sensitivity (88.1%) at 7 min. The sensitivity showed different results and increased with reaction time and gas concentration. However, response and recovery time are moderate and decrease as reaction time increases. [ABSTRACT FROM AUTHOR]

This study addresses the critical need for efficient and sustainable methods to tackle organic pollutants and microbial contamination in water. The present work aim was to investigate the potential of multi-structured zinc oxide nanoparticles (ZnO NPs) for the combined photocatalytic degradation of organic pollutants and antimicrobial activity. A unique fusion of precipitation-cum-hydrothermal approaches was precisely employed to synthesize the ZnO NPs, resulting in remarkable outcomes. The synthesized CTAB/ZnO NPs demonstrated exceptional properties: they were multi-structured and crystalline with a size of 40 nm and possessed a narrow band gap energy of 2.82 eV, enhancing light absorption for photocatalysis. These nanoparticles achieved an impressive degradation efficiency of 91.75% for Reactive Blue-81 dye within 105 min under UV irradiation. Furthermore, their photocatalytic performance metrics were outstanding, including a quantum yield of 1.73 × 10–4 Φ, a kinetic reaction rate of 3.89 × 102 µmol g–1 h–1, a space–time yield of 8.64 × 10–6 molecules photon–1 mg–1, and a figure-of-merit of 1.03 × 10–9 mol L J–1 g–1 h–1. Notably, the energy consumption was low at 1.73 × 10–4 J mol–1, compared to other systems. Additionally, the ZnO NPs exhibited effective antimicrobial activity against S. aureus and P. aeruginosa. This research underscores the potential of tailored ZnO NPs as a versatile solution for addressing both organic pollution and microbial contamination in water treatment processes. The low energy consumption further enhances its attractiveness as a sustainable solution. [ABSTRACT FROM AUTHOR]

The action-to-reaction dynamics of next-generation nanofertilizers (NFs) towards field crops are currently being addressed in precision and sustainable agriculture. Therefore, our aim was to evaluate the effects of foliar application of ZnO nanoparticles (ZnO-NPs) or their combination with hybrid nanoporous biosilica mixed with yeast (ZnSi-bio) for soybean plants' selected production and physiological indices in comparison to an NF-free control. The experiment was conducted at eco-friendly concentrations in Veľký Krtíš, Slovakia, a location within the Central European agronomical region. The ZnSi-bio variant had an improved number of pods, seed count, and yield, while the ZnO-NPs variant had an enhanced seed bulk density compared to the NF-free control, which had a greater effect on thousand-seed weight (TSW). Significant differences were found in the final quality components of soybeans with respect to phosphorus content without ZnO-NP biofortification. In the case of the ZnSi-bio variant, soybeans were biofortified with zinc. Both leaf-applied NFs markedly improved nutritional and energetic values for soybeans. NFs continued to positively affect seasonal physiology, such as the stomatal conductance (Ig) and crop water stress index (CWSI), compared to the control. The results suggest that the ZnO-NPs, especially when combined with hybrid biosilica and yeast, open new avenues for interdisciplinary research in agro-food science. [ABSTRACT FROM AUTHOR]

Synthesis, structural and photoluminescence studies of p-(n-heptyl) benzoic acid (7ba) liquid crystalline (LC) compound with the homogeneous dispersion of ZnO nanoparticles (NPs) in different weight concentrations (i.e., 1–2.5 wt.%) were undertaken. The synthesized samples were subsequently characterized by different characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible (UV-Vis) spectroscopy, differential scanning calorimetry (DSC), optical polarising microscopy (POM), Fourier transform infrared spectroscopy (FT-IR), and photoluminescence (PL) spectroscopy. From the XRD studies, the diff raction peaks observed were well resolved indicating the presence of ZnO NPs. The particle size was found to be 60 nm. SEM studies revealed the uniform dispersion and the presence of ZnO NPs in the LC samples. From the DSC analysis, the temperatures at which the phase changes take place and the corresponding enthalpy values were estimated. FTIR spectra gave information about the various functional groups present in the samples. PL studies showed the peak at 663 nm due to the presence of point defects within the bandgap-like vacancies and interstitials known as deep-level emission. [ABSTRACT FROM AUTHOR]

This study reports a micromachined parylene-C-coated integrated electrode (IDE) sensor fabricated on a polyimide film. Glucose and uric acid within the human sweat concentration range were tested using hydrothermally grown ZnO nanoparticles (NPs) immobilized on the IDE regions of sensors and modified with urate oxidase and glucose oxidase enzymes. Four important sensing parameters, including capacitance, impedance, resistance, and phase, were simultaneously investigated during the dynamic test. The sensor fabrication and characterization of ZnO NPs and ZnO NP formed sensing film were described in detail. The experimental results show that the amount of capacitance change and phase change vs. the concentration variation of glucose and uric acid exhibits an excellent linear regression relationship. On the other hand, the amount of impedance change vs. concentration variation of glucose and uric acid exhibits a power regression relationship. Sensitivities of uric acid and glucose detection based on capacitance changes were 0.1131 pF/µM and 0.7875 pF/µM, respectively. Limits of detection of uric acid and glucose were 1.23 µM and 0.311 µM, respectively. Thus, the developed sensor can be applied to wearable devices for the quantitative analysis of sweat composition in the future. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanoparticles are widely recognized for their distinctive properties and versatile applications across diverse technological domains. However, traditional methods of synthesizing ZnO nanoparticles are characterized by environmental incompatibility, high costs, and the necessity for precise process control to attain the intended particle dimensions and morphology. The present study utilized a chives extract as a sustainable and eco-friendly fuel in the solution combustion synthesized (SCS) process to produce ZnO nanoparticles. The investigation encompassed an analysis of the impact of the fuel-to-oxidizer (F/O) ratio on the synthesized ZnO nanoparticles' size, morphology, and crystallinity. X-ray diffraction (XRD) results showed that the particle's crystallite size increased significantly from 12 nm to 42 nm after decreasing the F/O ratio. Furthermore, electron microscopic imagery and FTIR spectroscopy outcomes indicated that modifications in the F/O ratio significantly influenced the SCS process parameters, forming particles with diverse morphologies, including spherical, pyramid-like, hexagonal, and hexagonal plate-like shapes. This research presents a straightforward, cost-efficient, and environmentally sustainable approach for producing ZnO nanoparticles with diverse morphologies, presenting a broad potential for various applications. [ABSTRACT FROM AUTHOR]

Magnetically separable Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@ZnO, and Fe3O4@SiO2@ZnO–Ag composites are synthesized using hydrothermal and wet chemistry methods. The samples obtained are characterized in terms of morphology, composition, optical, and magnetic properties using TEM, SEM‐EDS, XRD, FTIR, VSM, XPS, and UV–vis, and the photodegradation of Acid Blue 161 dye under UV irradiation is investigated. As a result of SEM and TEM analyses, the diameters of Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@ZnO, and Fe3O4@SiO2@ZnO–Ag composites are determined as 210, 220, 230 and 235 nm, respectively. The magnetic properties of the samples are determined by VSM analysis. In VSM analyses, magnetization saturation values of Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@ZnO, and Fe3O4@SiO2@ZnO–Ag composites are determined as 81, 64, 41 and 20 emus × g−1, respectively. In XRD analysis, the face‐centered cubic structure of Fe3O4 particles and the hexagonal wurtzite structure of ZnO are determined and it is determined that they are compatible with standard diffraction cards. According to UV–Vis analysis, Eg values for Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2@ZnO, and Fe3O4@SiO2@ZnO–Ag composites are found as 1.3, 1.68, 2.21, and 2.15 eV, respectively. Among the photocatalysts prepared, Fe3O4@SiO2@ZnO–Ag composite Acid Blue 161 shows superior removal and recyclability against photodegradation of the dyestuff. [ABSTRACT FROM AUTHOR]

The synthesis of zinc oxide nanoparticles (ZnO NPs) through the use of plant extracts is a remarkably simple, cost-effective, efficient, and environmentally friendly approach. In recent years, there has been a surge in the exploration of eco-friendly methods for synthesizing ZnO NPs, with researchers addressing the potential of extracts derived from various plant components, including leaves, stems, roots, and fruits. This comprehensive review aims to encapsulate and delve into the extensive research surrounding the green synthesis of ZnO NPs, emphasizing their diverse antimicrobial applications while encompassing the latest advancements documented in the literature. Furthermore, this review meticulously examines the sizes and morphological characteristics of the synthesized nanoparticles, offering valuable insights into their structural properties. Finally, a thorough exploration of the potential interaction mechanisms between ZnO NPs and bacterial cell walls was conducted, elucidating how such interactions may induce cell death and highlighting the consequential antimicrobial activity exhibited by these nanoparticles. [ABSTRACT FROM AUTHOR]

Abstract Nitroaromatic compounds represent a class of highly toxic pollutants discharged into aquatic environments by various industrial activities, posing significant threats to ecological integrity and human health due to their persistent and hazardous nature. In this study, Pd-doped ZnO nanoparticles were investigated as a potential solution for the degradation of nitro organics, offering heightened photocatalytic efficacy and prolonged stability. The synthesis of Pd-doped ZnO NPs was achieved via the hydrothermal method, with subsequent analysis through XRD spectra and XPS confirming successful Pd doping within the ZnO matrix. Characterization through FESEM and HRTEM unveiled the heterogeneous morphologies of both undoped and Pd-doped ZnO nanoparticles. Additionally, UV–vis and PL spectroscopy provided insights into the optical properties, chemical bonding, and defect structures of the synthesized Pd-doped ZnO NPs. Pd doping induces a redshift in ZnO’s absorption spectra, reducing the bandgap from 3.12 to 2.94 eV as Pd concentration rises from 0 to 0.2 wt.%. The photocatalytic degradation, following pseudo-first-order kinetics, achieved 90% nitrobenzene abatement (200 µg/L, pH 7) under visible light within 320 min with a catalyst loading of 16 µg/mL. The photocatalytic efficacy of 0.08 wt% Pd-doped ZnO (k = 0.058 min⁻1) exhibited a 25-fold enhancement compared to bare ZnO (k = 3.1 × 10–4 min-1). Subsequent quenching and ESR experiments identified hydroxyl radicals (OH•) as the predominant active species in the degradation mechanism. Mass spectrometry analysis unveiled potential breakdown intermediates, illuminating a plausible degradation pathway. The investigated Pd-doped ZnO nanoparticles demonstrated reusability for up to five successive treatment cycles, offering a sustainable solution to nitro organics contamination challenges.

Abstract Bryophyllum pinnatum is used to cure infections worldwide. Although the flavonoids of this plant are well known, it is still unknown how much of the plant’s Ag and ZnO nanoparticles are beneficial. In the current research work, silver and zinc oxide nanoparticles were prepared using Bryophyllum pinnatum extract. The synthesized particles were characterized by UV-visible spectroscopy, SEM, EDS, XRD and FTIR. Synthesized particles were subjected to evaluation of their bactericidal and antifungal activity at various doses. Uv vis spectra at 400 nm corresponding to AgNPs confirmed their synthesis. Strong peaks in the EDS spectra of Ag and ZnO indicate the purity of the sample. The scanning electron microscopic images of ZnONPs showed a size of about 60 nm ± 3 nm, which demonstrated the presence of triangular-shaped ZnO nanoparticles. Green synthesized nanoparticles showed bactericidal activity against both Gram-positive (Micrococcus luteus, Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Agrobacterium tumifaciens, Salmonella setubal, Enterobacter aerogenes) strains. AgNPs proved to be more effective against Gram-negative bacterial strains compared to Gram-positive owing to MIC values (10 ppm and 20 ppm respectively). Whereas, ZnONPs were found more effective against Gram-positive bacteria with lower MIC values (10 ppm) as compared to Gram-negative ones (20 ppm). Also, the synthesized nanoparticles exhibited moderate dose-dependent antifungal activity against tested fungal strains ranging from 10 to 70%. Cytotoxicity of nanoparticles was found significant using Brine shrimp’s lethality assay with IC50 values of 4.09 ppm for AgNPs, 13.72 ppm for ZnONPs, and 24.83 ppm for plant extract. Conclusively, Ag and ZnO nanoparticles were more effective than plant extract and AgNPs had higher activities than those of ZnONPs. Further research is warranted to explore the precise mechanism of action and the potential applications of these nanoparticles in the medical field.

Abstract Cinnamaldehyde (CIN), a harmless bioactive chemical, is used in bio-based packaging films for its antibacterial and antioxidant properties. However, high amounts can change food flavor and odor. Thus, ZnO nanoparticles (NPs) as a supplementary antimicrobial agent are added to gelatin film with CIN. The CIN/ZnO interactions are the main topic of this investigation. FTIR-Attenuated Total Reflection (ATR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were utilized to investigate CIN/ZnO@gelatin films. Transmission electron microscope (TEM) images revealed nanospheres morphology of ZnO NPs, with particle sizes ranging from 12 to 22 nm. ZnO NPs integration increased the overall activation energy of CIN/ZnO@gelatin by 11.94%. The incorporation of ZnO NPs into the CIN@gelatin film significantly reduced water vapour permeability (WVP) of the CIN/ZnO@gelatin film by 12.07% and the oxygen permeability (OP) by 86.86%. The water sorption isotherms of CIN/ZnO@gelatin were described using Guggenheim-Anderson-de Boer (GAB) model. The incorporation of ZnO NPs into the CIN@gelatin film reduced monolayer moisture content (M 0) by 35.79% and significantly decreased the solubility of CIN/ZnO@gelatin by 15.15%. The inclusion of ZnO into CIN@gelatin film significantly decreased tensile strength of CIN/ZnO@gelatin by 13.32% and Young`s modulus by 18.33% and enhanced elongation at break by 11.27%. The incorporation of ZnO NPs into the CIN@gelatin film caused a significant decrease of antioxidant activity of CIN/ZnO@gelatin film by 9.09%. The most susceptible organisms to the CIN/ZnO@gelatin film included Candida albicans, Helicobacter pylori, and Micrococcus leutus. The inhibition zone produced by the CIN/ZnO@gelatin film versus Micrococcus leutus was 25.0 mm, which was comparable to the inhibition zone created by antibacterial gentamicin (23.33 mm) and cell viability assessment revealed that ZnO/CIN@gelatin (96.8 ± 0.1%) showed great performance as potent biocompatible active packaging material.

Abstract This study addresses the critical need for efficient and sustainable methods to tackle organic pollutants and microbial contamination in water. The present work aim was to investigate the potential of multi-structured zinc oxide nanoparticles (ZnO NPs) for the combined photocatalytic degradation of organic pollutants and antimicrobial activity. A unique fusion of precipitation-cum-hydrothermal approaches was precisely employed to synthesize the ZnO NPs, resulting in remarkable outcomes. The synthesized CTAB/ZnO NPs demonstrated exceptional properties: they were multi-structured and crystalline with a size of 40 nm and possessed a narrow band gap energy of 2.82 eV, enhancing light absorption for photocatalysis. These nanoparticles achieved an impressive degradation efficiency of 91.75% for Reactive Blue-81 dye within 105 min under UV irradiation. Furthermore, their photocatalytic performance metrics were outstanding, including a quantum yield of 1.73 × 10–4 Φ, a kinetic reaction rate of 3.89 × 102 µmol g–1 h–1, a space–time yield of 8.64 × 10–6 molecules photon–1 mg–1, and a figure-of-merit of 1.03 × 10–9 mol L J–1 g–1 h–1. Notably, the energy consumption was low at 1.73 × 10–4 J mol–1, compared to other systems. Additionally, the ZnO NPs exhibited effective antimicrobial activity against S. aureus and P. aeruginosa. This research underscores the potential of tailored ZnO NPs as a versatile solution for addressing both organic pollution and microbial contamination in water treatment processes. The low energy consumption further enhances its attractiveness as a sustainable solution.

Staphylococcus aureus (S. aureus) has long been acknowledged as being one of the most harmful bacteria for human civilization. It is the main contributor to skin and soft tissue infections. The gram positive pathogen also contributes to bloodstream infections, pneumonia, or bone and joint infections. Hence, developing an efficient and targeted treatment for these illnesses is greatly desired. Recently, studies on nanocomposites (NCs) have significantly increased due to their potent antibacterial and antibiofilm properties. These NCs provide an intriguing way to control the growth of bacteria without causing the development of resistance strains that come from improper or excessive use of the conventional antibiotics. In this context, we have demonstrated the synthesis of a NC system by precipitation of ZnO nanoparticles (NPs) on Gypsum followed by encapsulation with Gelatine, in the present study. Fourier transform infrared (FTIR) spectroscopy was used to validate the presence of ZnO NPs and Gypsum. The film was characterized by X-ray diffraction (XRD) spectroscopy and scanning electron microscopy (SEM). The system exhibited promising antibiofilm action and was effective in combating S. aureus and MRSA in concentrations between 10 and 50 ug/ml. The bactericidal mechanism by release of reactive oxygen species (ROS) was anticipated to be induced by the NC system. Studies on cell survival and in-vitro infection support the film's notable biocompatibility and its potential for treating Staphylococcus infections in the future. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanoparticles are widely recognized for their distinctive properties and versatile applications across diverse technological domains. However, traditional methods of synthesizing ZnO nanoparticles are characterized by environmental incompatibility, high costs, and the necessity for precise process control to attain the intended particle dimensions and morphology. The present study utilized a chives extract as a sustainable and eco-friendly fuel in the solution combustion synthesized (SCS) process to produce ZnO nanoparticles. The investigation encompassed an analysis of the impact of the fuel-to-oxidizer (F/O) ratio on the synthesized ZnO nanoparticles’ size, morphology, and crystallinity. X-ray diffraction (XRD) results showed that the particle’s crystallite size increased significantly from 12 nm to 42 nm after decreasing the F/O ratio. Furthermore, electron microscopic imagery and FTIR spectroscopy outcomes indicated that modifications in the F/O ratio significantly influenced the SCS process parameters, forming particles with diverse morphologies, including spherical, pyramid-like, hexagonal, and hexagonal plate-like shapes. This research presents a straightforward, cost-efficient, and environmentally sustainable approach for producing ZnO nanoparticles with diverse morphologies, presenting a broad potential for various applications.

Abstract Using the renewable energy, especially solar energy, is an environmental-friendly approach for seawater desalination. Solar evaporation is a promising freshwater harvesting strategy rich in energy, including solar and water energy. Herein, we propose a solar evaporation hybrid hydrogel including polyvinyl alcohol (PVA) and glutaraldehyde (GA) as a polymer network, semiconductor oxide nanoparticles (ZnO, CuO) and activated carbon as a photothermal material. Structural properties of hybrid hydrogel were characterized by X-ray diffraction (XRD) analysis, surface morphology by field emission scanning electron microscope (FE-SEM), chemical bonding by Fourier transform infrared spectroscopy (FTIR) and optical absorption and absorption coefficient (α) of components by UV–Vis spectroscopy. The result showed in visible region, PVA:ZnO:AC hydrogel nanocomposite has a strong absorption (55%) compare of the PVA:CuO:AC hydrogel nanocomposite (35%). In addition, by distillation measurements, the evaporator system demonstrated for PVA:CuO:AC and PVA:ZnO:AC Hydrogel an evaporation rate of 2.29 kg m−2 h−1 and 5.19 kg m−2 h−1 with the evaporation efficiency of 30.66% and 70.80%, respectively, under 0.1 sun irradiation. For PVA:CuO:AC hydrogel, the hardness of Caspian seawater decreased from 6648 to 115 ppm and ion conductance from 8641 (μS) to 244 (μS) and for the PVA:ZnO:AC Hydrogel decreased to 97 ppm and ion conductance to 206 (μS). Experiments showed that with changing type of the ZnO or CuO semiconductor oxide nanoparticles can effectively on regulate the optical properties of the evaporator. Eventually, this work begins a new point of synthesizing cost-effective photothermal absorbers based on metal oxides material and activated carbon nanocomposite.

In this study, a series of submicron‐sized functional polymer particles poly(Sty‐co‐MAA) with variable methacrylic acid (MAA) content were prepared by soap‐free emulsion polymerization of styrene (Sty), methacrylic acid (MAA), and ethylene glycol dimethacrylate (EGDMA). The number‐average diameters of polymer particles (Dn) were in the range of 0.11 to 0.19 μm. A decrease in particle size was observed with increasing the molar ratio of MAA comonomer in the recipe. ZnO/poly(Sty‐co‐MAA) hybrid polymer particles were prepared by seeded emulsion copolymerization in presence of zinc oxide nanoparticles (ZnO NPs) as seed particles synthesized using Citrus lemon aqueous leaf extract. Scanning electron microscopy (SEM), transmission electron microsphere (TEM), X‐Ray Diffraction (XRD), and Fourier transformed infra‐red (FT‐IR) analysis were performed to characterize polymer particles. The crystalline size of ZnO NPs and ZnO/poly(Sty‐co‐MAA) hybrid polymer particles calculated from XRD analysis were 20.75 and 29.85 nm, respectively. These hybrid polymer particles were applied as photocatalyst in the photodegradation of methylene blue (MB) dye under UV irradiation, which showed high catalytic activity with degradation efficiency of 85.70 % at room temperature compared to bare ZnO NPs. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate dental adhesives containing different concentrations of zinc oxide nanoparticles (ZnO‐NPs) for their use in the treatment of dental fluorosis, observe the interaction of the adhesive on healthy enamel surfaces and with mild and moderate fluorosis, measure the adhesive strength and fluorosis, and determine the phosphorus (P) and calcium (Ca) content on these surfaces, as a reference for the potential use of this adhesive with ZnO‐NPs for dental fluorosis treatment.Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) were used to characterise the ZnO‐NPs and analyse the weight percentages of P and Ca in the enamel using X‐ray energy dispersive spectroscopy (EDS) and the adhesive strength using a universal mechanical testing machine.FESEM characterisation revealed that the ZnO‐NPs were less than 100 nm in size, with quasi‐spherical and hexagonal prism shapes. The synthesis of the ZnO‐NPs was confirmed by TEM, revealing their hexagonal crystalline structure. The adhesive strength by the universal mechanical testing machine showed that the adhesive with a 3% wt. concentration of ZnO‐NPs was better in the three groups of teeth, showing higher adhesive strength in teeth with mild (15.15 MPa) and moderate (12.76 MPa) fluorosis surfaces, and was even higher than that in healthy teeth (9.65 MPa).EDS analysis showed that teeth with mild and moderate fluorosis had the highest weight percentages of P and Ca, but there were no statistically significant differences compared to healthy teeth and teeth treated with adhesives.Lay description: This study focused on testing a new dental adhesive containing small particles called ZnO nanoparticles (ZnO‐NPs). This study aimed to demonstrate whether this adhesive with ZnO‐NPs could be useful for treating dental fluorosis by improving its adhesion to teeth.One of the first objectives was to determine whether the dental adhesive could adhere better to teeth affected by mild or moderate fluorosis than to healthy teeth by measuring whether the levels of two important elements for healthy teeth, calcium (Ca) and phosphorus (P), were affected by the adhesive.The size and shape of the small particles and teeth with mild or moderate fluorosis were observed using scanning electron microscopy. The nanoparticles were small (< 100 nm) and had specific quasi‐spherical and hexagonal prismatic shapes. More damage to the enamel was observed in teeth with mild or moderate fluorosis than in healthy teeth.The adhesive strength test demonstrated that the dental adhesive with 3% ZnO‐NPs had the best adhesion on all healthy conditions of teeth. It was particularly effective in teeth with mild or moderate fluorosis.Finally, the evaluation of the levels of P and Ca on the enamel showed that teeth with fluorosis had higher levels of these elements, but using the dental adhesive with ZnO‐NPs did not change the levels of these elements significantly because the adhesive avoided greater detachment because of greater adhesion to these surfaces.In conclusion, adding these small particles to dental adhesives could be an option for treating teeth affected by fluorosis. It stuck well and did not affect the levels of the important elements in the teeth. [ABSTRACT FROM AUTHOR]

Mung bean (Vigna radiata (L.) R. Wilczek) seeds, recognized for their significant nutritional content, but limited by the presence of anti-nutritional phytate, display potential in terms of sprouting and biofortification with ZnO nanoparticles. This study aimed to investigate how ZnO NPs affect the nutritional aspects of mung bean seedlings, going beyond growth parameters, to examine soluble carbohydrates, free amino acids, and fatty acid levels, with the objective of advancing our understanding of NP-plant interactions and their nutritional consequences. Accordingly, the effect of ZnO NPs on mung bean seedlings was studied by germinating and growing the seeds in a growth medium with varying concentrations of ZnO NPs ranging from 10 to 160 ppm. Analysis of the nutritional composition of the seedlings revealed a significant increase in free amino acid and soluble sugar levels under ZnO NP treatments, with a peak at 160 ppm ZnO NPs concentration. The fatty acid composition also exhibited significant changes in response to ZnO NPs, with different fatty acids showing distinct responses. ZnO NPs generally had a positive influence on the production of nutritionally valuable omega-6 fatty acids, leading to the highest levels of linoleic acid and arachidonic acid in samples treated with 10 and 20 ppm of ZnO NPs. In conclusion, the findings of this study highlight the potential of ZnO nanoparticles to positively influence the nutritional composition of mung bean seedlings. These results contribute to our understanding of the intricate interactions between nanoparticles and plants, emphasizing the importance of further research in this area to fully understand the implications for agricultural and nutritional practices. [ABSTRACT FROM AUTHOR]

In this study, zinc oxide nanoparticles (ZnO‐NPs) are synthesized and combined with chitosan (Cs) to create Cs/ZnO‐NPs nanomicelles, aiming to investigate their potential as a novel cancer treatment. The ZnO‐NPs are produced through a sintering process at temperatures ranging from 300 to 700 °C. The most effective nanoparticles are obtained at 600 °C, as determined by X‐ray diffraction (XRD) and Fourier‐transform infrared spectroscopy (FTIR) analyses, which confirmed their crystallinity and purity. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are employed to characterize the size and shape of the nanoparticles, revealing predominantly spherical and hexagonal structures with stable dimensions. The cytotoxic effects of the Cs/ZnO‐NPs are evaluated against various cancer cell types. The results show that at a concentration of 125 µg mL−1, the Cs/ZnO‐NPs demonstrate significantly higher cancer cell toxicity compared to ZnO‐NPs alone, while remaining non‐toxic to normal cells. This indicates that Cs/ZnO‐NPs have a superior ability to selectively target cancer cells. These findings suggest that Cs/ZnO‐NPs nanomicelles hold promise as an effective and safe nanotherapeutic approach in the realm of cancer treatment, meriting further exploration for clinical applications. [ABSTRACT FROM AUTHOR]

Dodonea viscosa-zinc oxide (DV-ZnO) nanocomposite was synthesized and characterized using Fourier transform infrared (FTIR), thermal gravimetric method (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The most abundant compounds in the plant extract were explored using gas chromatography-mass spectrometry (GC-MS). FTIR indicated the existence of the different functional groups, XRD showed that the nanocomposite has the hexagonal wurtzite shape of ZnO nanoparticles, SEM-EDS showed a size of 50 nm, and elemental analysis depicts the existence of the different elements in the extract, which confirms, along with TGA results, the formation of DV-ZnO nanocomposite. The nanocomposite synergistic effect was examined for anticorrosion capabilities using gravimetric, electrochemical, and surface analysis methods. Both the plant extract and the nanocomposite exhibited corrosion inhibition abilities. However, the incorporation of the plant extract with ZnO increased the inhibition efficiency by 20 %. Weight loss and electrochemical methods concluded an inhibition efficiency of 80 % for DV-ZnO nanocomposite. The inhibition of the nanocomposite is due to the adsorption of the inhibitor on the carbon steel surface, which was verified using X-ray photoelectron spectroscopy and scanning electron microscopy (SEM). The adsorption was found to follow both Langmuir and Temkin isotherms. Surface examination using atomic force microscopy (AFM) found that the carbon steel surface roughness was decreased from the sample submerged in an uninhibited medium (Sa = 121.20 nm) when adding DV-ZnO nanocomposite (Sa = 22.95 nm) and DV plant extract inhibitor (Sa = 54.73 nm). [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanoparticles, as a non-toxic, harmless, and low-cost photocatalytic material, have attracted much attention from the scientific and industrial communities. However, due to their small particle size and high surface energy, ZnO nanoparticles are prone to agglomeration. In addition, ZnO nanoparticles only have catalytic activity and electron–hole pairing under ultraviolet light. Therefore, Copper(I) oxide (Cu2O)-ZnO/cellulose composites with excellent photocatalytic performance were fabricated by loading Cu2O crystals and using cellulose fiber substrate in this work. Cu2O can increase the light absorption range (including ultraviolet light and visible light) of ZnO/cellulose composites. Moreover, Cellulose fibers can improve the contact area to pollution and photostability of the Cu2O/ZnO nanoparticles, thereby enhancing the photocatalytic activity. The Cu2O-ZnO/cellulose composite showed the highest photocatalytic activity for Methyl orange (MO) degradation, which was approximately 40% and 10% times higher than those of the ZnO/cellulose and Cu2O/ZnO composites, respectively. Moreover, the degradation rate of phenol reached 100% within 80 min. The highly enhanced activity of the Cu2O-ZnO/cellulose composite is attributed to the enlargement of the light absorption range and the formation of heterojunctions between the counterparts, which effectively suppress the recombination of the photogenerated charge carriers. Overall, this work aims to improve the photocatalytic activities of ZnO/cellulose composites by loading Cu2O crystals, hoping to provide a novel and efficient photocatalyst for wastewater treatment. [ABSTRACT FROM AUTHOR]

The decomposition of returned straw is increasing facing the negative impacts by metal nanoparticles (NPs), however, which may be modulated by soil fauna and this modulation effect is unclear. Here, the interactive effects of ZnO NPs with soil fauna on wheat straw decomposition were investigated in a potted rice cropping system. The results showed that ZnO NP below middle concentrations did not significantly influence straw decomposition, and mass loss was mainly driven by microfauna and microbes. High concentrations of ZnO NPs significantly impeded decomposition, mainly by reducing the complexity of fungal communities. This negative effect was ascribed to the promotion of Zn solubilization by bacterial taxa such as unclassified Acidobacteria, Bacteroidetes and Gemmatimonadetes. ZnO NPs had a greater impact on soil microorganisms than on fauna, reduced microbial activity, promoted the released straw nutrients entering into the soil by damaging nutrient transferring microorganisms and dominated the effects on soil stoichiometry. However, soil fauna significantly increased the activities of C- and N-releasing enzymes, decreased the activity of P-releasing enzymes, regardless of ZnO NP concentration, and promoted straw C decomposition. ZnO NPs altered soil microbial community composition, but these changes were modulated by soil fauna. Nonetheless, nutrient transport by fungi such as Ascomycota and Zygomycota and grazing by fauna were the predominant modulators on straw stoichiometry. The results of this study revealed that rational control of soil fauna will be helpful for promoting straw decomposition and efficient recycling of straw nutrients by crops under ZnO NP contamination.Article Highlights: High ZnO NP concentrations inhibit straw decomposition mainly by reducing diversity of fungal community. The negative effects of ZnO NPs are ascribed to Zn solubilization by bacterial taxa such as unclassified Acidobacteria, Bacteroidetes and Gemmatimonadetes. ZnO NPs have greater impact on soil microorganisms than on fauna, reduce microbial activity, promote the released nutrients into soil and dominate the effects on soil stoichiometry. Fungal transport (e.g., Ascomycota and Zygomycota) and fauna grazing are the predominant modulators on straw stoichiometry. [ABSTRACT FROM AUTHOR]

The initial healing stages of bone fracture is a complex physiological process involving a series of spatially and temporally overlapping events, including pathogen clearance, immunological modulation, and osteogenesis. In this study, we have developed a piezoelectric and aligned nanofibrous scaffold composed of ZnO@PCL/PVDF with multiple antibacterial, immunomodulatory, and osteogenic effects using electrospinning technology. This scaffold's piezoelectric signal output under ultrasound (US) control can be similar to the physiological electrical signals of healthy bone tissue, creating a truly biomimetic electrical microenvironment in the bone defect. In vitro studies have shown that ZnO@PCL/PVDF scaffold significantly enhances the proliferation, migration, and osteogenic differentiation of MC3T3-E1 cells under piezoelectric drive provided by ultrasound. Furthermore, the scaffold exhibits inhibitory effects on the growth of E. coli and S. aureus, as well as the ability to induce M2 macrophage polarization, indicating potent antibacterial and immunomodulatory properties. In vivo experiments demonstrated that the ZnO@PCL/PVDF scaffold can accelerate the repair of mandibular defects in rats, effectively inhibit bacterial colonization, and reduce inflammatory responses. Altogether, this study confirms that the newly developed ZnO@PCL/PVDF scaffold effectively promotes bone repair by truly mimicking the endogenous electrical microenvironment and precisely regulating the temporospatial disorders of initial bone healing, thus providing a simple and effective solution for bone defects. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) is a natural substance produced by microorganisms and offers numerous benefits. It can be produced by utilizing biomass waste which is abundantly available through fermentation process. This study investigates the utilization of pineapple peel waste for BC synthesis and observes their properties as nanocomposite membranes after the addition of ZnO nanoparticles (ZnO-NPs) as candidate biomaterials for water filtration membranes. The experimental methods were conducted by synthesizing BC using pineapple peel extract using fermentation process. Subsequently, BNC was produced using a high-pressure homogenizer, and ZnO-NPs nanoparticles were added as reinforcement at concentrations of 2.5 wt%, 5.0 wt%, and 7.5wt.%. The mixture was sonicated and subsequently dried in an oven at 60°C for 20 h. BNC/ZnO-NPs membranes were characterized using XRD, FTIR, tensile test, BET, antibacterial test, and SEM analysis. The results indicate that the membrane structure of BNC/ZnO-NPs nanocomposite has peaks at diffraction angles of 14.4°, 15.2°, 16.9°, 22.8°, 31.6°, 34.1° and 36.8°. The addition of ZnO-NPs enhances the crystalline index of BNC by 81.37% at 2.5wt.% ZnO-NPs but reduces the membrane strength due to increasing pore diameter and rougher surface morphology of membrane. Incorporation of ZnO-NPs results in membrane chemical bonding, proved by raising a new peak at wavenumber of 715 cm− 1 and reduces the transmittance of hydroxyl group. This showed antibacterial activity against gram-positive bacteria like S.aureus, but they have no effect on gram-negative bacteria like E. coli. This antibacterial activity is good for resisting biofouling and the membrane can be further developed to meet the requirements for field water filtration applications like desalination. [ABSTRACT FROM AUTHOR]

This study explores the enhancement of silicon-based solar cell performance and durability through the application of zinc oxide (ZnO) nanocomposite film coatings. Utilizing the sol–gel method, ZnO nanorods were synthesized and dispersed within a polyvinyl butyral (PVB) matrix, resulting in uniform nanocomposite films. Comprehensive characterization using X-ray Diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), UV-Visible spectroscopy, and contact angle measurements confirmed the effective integration and desirable properties of ZnO within the PVB matrix. The ZnO coatings demonstrated superior UV absorptivity, significantly blocking UV radiation at 355 nm while maintaining high transparency in the visible range. This led to improvements in key photovoltaic parameters, including short circuit current (Jsc), open-circuit voltage (Voc), efficiency (η), and fill factor (FF). Although a minor reduction in Isc was observed due to the ZnO layer's influence on the light absorption spectrum, the overall efficiency and fill factor experienced notable enhancements. Furthermore, the thermal load on the solar cells was effectively reduced, mitigating UV-induced degradation and thereby prolonging the operational lifespan of the solar panels. Under damp heat conditions, the coated solar panels exhibited remarkable durability compared to their uncoated counterparts, underscoring the protective advantages of ZnO films. These findings highlight the potential of ZnO nanocomposite coatings to significantly boost the efficiency, reliability, and longevity of silicon-based solar panels, making them more viable for long-term deployment in diverse environmental conditions. [ABSTRACT FROM AUTHOR]

The facile in situ synthesis of graphene-coated metal-oxide nanoparticles and their potential applications in optoelectronic devices are highly anticipated. In this study, we prepared three-dimensional graphene flakes decorated with ZnO nanoparticles (LIG/ZnO) using femtosecond laser-induced zinc salt-containing cork. The LIG/ZnO heterojunction was formed by carbonizing the cork and decomposing the zinc salt in situ to coat LIG during laser irradiation. The correlation between the zinc salt concentration and the morphology, structure, and field-emission characteristics of LIG/ZnO was systematically investigated. The optimized LIG/ZnO-5 emitters demonstrate a decreased threshold electric field (E th) of 1.07 V/μm, an enhanced field enhancement factor (β) value of 20,559, and a maximum current density of 18.07 mA/cm2 at 1.96 V/μm, representing the most superior performance reported to date. The enhanced field-emission performance of LIG/ZnO can be attributed to the larger number of effective emission sites from ZnO nanoparticles and LIG edges, as well as to the energy band variation induced by the heterostructures. Density functional theory (DFT) calculations show the migration of electrons from the LIG to the ZnO after the formation of the heterojunction, which elevates the Fermi level of emitters. In addition, the accumulation of electrons on the surface of ZnO nanoparticles in the presence of a strong electric field results in a downward shift of the energy band, thereby enhancing the likelihood of electron-vacuum tunneling. • LIG/ZnO heterojunctions were prepared by ultrafast laser direct writing. • The morphology of LIG/ZnO synthesized by laser irradiation and the density of coated ZnO nanoparticles are controllable. • The relationship between the concentration of zinc salt, and field emission characteristics of LIG/ZnO was systematically studied. • The optimized LIG/ZnO-5 emitters have a low E th ∼1.07 V/μm and stable electron emission properties. [ABSTRACT FROM AUTHOR]

In this work, a polymeric blend of polypropylene (PP) and high-density polyethylene (HDPE) was prepared with different weight percentages. Zinc oxide nanoparticles (ZnO) were added to the 90/10 and 80/20 blends with different weight ratios (1%, 2%, and 3%) to study their effect on both the mechanical and thermal properties of the PP/HDPE blends. A twin-screw extruder was used for the preparation of polymeric blends and their composites. Mechanical properties (tensile properties and hardness) were studied. Thermal properties using Differential Scanning Calorimetry (DSC) were investigated. Fourier transform infrared (FTIR) was used to predict the change in chemical structure. Results for PP/HDPE blends show that both tensile strength and hardness decrease as the amount of HDPE increases due to immiscibility, and these properties are improved by the addition of ZnO nanoparticles. Thermal properties from DSC show that the melting temperature Tm, crystallization temperature Tc were improved by the ZnO addition, and the degree of crystallinity improved only for the90/10 blend. FTIR shows that there is only a physical interaction, not a chemical one. [ABSTRACT FROM AUTHOR]

The widespread application of conventional chemical fertilizers has led to various environmental issues, including reduced food quality, soil degradation, and harm to beneficial soil organisms. Conversely, the use of Nano-fertilizers holds promise as a potential solution to address these challenges. Therefore, the present study was conducted to evaluate the effectiveness of supplementing small quantities of Nano-fertilizers in conjunction with conventional NPK fertilizers to reduce the overall volume of traditional fertilizers when cultivating spinach plants. Moreover, the performance of micro Nano fertilizers (Fe, Zn) with spinach plants was assessed in comparison to the performance of chelated fertilizers. A split-plot experimental design was utilized, consisting of twenty treatments with three replicates, which were the simple possible combination between four NPK additions as main plots and five foliar applications of Fe and Zn as sub main factor. Main factor treatments were T1: 100% recommended dose of NPK as traditional bulk form,T2: 75% recommended dose of NPK as traditional bulk form + 15% recommended dose of NPK as Nano form,T3: 50% recommended dose of NPK as traditional bulk form + 15% recommended dose of NPK as Nano form andT4: 25% recommended dose of NPK as Nano form. While, the sub main factor treatments were F1: Control (without foliar),F2: Fe- Nano (10mg L-1, Fe2O3 Nanoparticles), F3: Zn- Nano (10mg L-1, ZnO Nanoparticles), F4: Fe- EDTA (100mg L-1 using Fe -EDTA 6% Fe) and F5: Zn- EDTA (100mg L-1 using Zn -EDTA 6%Zn). The T2 treatment emerged as the most effective in achieving the highest values for all the all the measured parameters such as plant height (cm), fresh and dry weights (g plant-1), leaf area (cm2 plant-1) and yield (ton ha-1) of spinach plants at the harvest stage. It was followed closely by the T3 treatment . In contrast, the T1 treatment ranked third after both T3 and T2. Lastly, the T4 treatment was found to have the least impact on these growth parameters and yield. Fe treatments exhibited greater effectiveness when compared to the Zn treatments. Furthermore, the data demonstrate that the Nano form exhibited greater effectiveness when compared to the chelated form in the context of both Fe and Zn treatments. Generally, it can be noticed that the F2 treatment was the superior for obtaining the maximum values for the most of studied traits. Therefore, it is recommended that farmers and agricultural practitioners consider adopting this approach to optimize crop performance while minimizing the environmental impact of conventional chemical fertilizers. [ABSTRACT FROM AUTHOR]

The enhancement of seed germination by using nanoparticles (NPs) holds the potential to elicit the synthesis of more desired compounds with important biomedical applications, such as preventing protein glycation, which occurs in diabetes. Here, we used 7 nm and 100 nm ZnO and 4.5 nm and 16.7 nm Fe2O3 NPs to treat sunflower seeds. We evaluated the effects on germination, total phenolic content, and the anti-glycation potential of extracted polyphenols. Sunflower seeds were allowed to germinate in vitro after soaking in NP solutions of different concentrations. Polyphenols were extracted, dosed, and used in serum albumin glycation experiments. The germination speed of seeds was significantly increased by the 100 nm ZnO NPs and significantly decreased by the 4.5 nm Fe2O3 NPs. The total phenolic content (TPC) of seeds was influenced by the type of NP, as ZnO NPs enhanced TPC, and the size of the NPs, as smaller NPs led to improved parameters. The polyphenols extracted from seeds inhibited protein glycation, especially those extracted from seeds treated with 7 nm ZnO. The usage of NPs impacted the germination speed and total polyphenol content of sunflower seeds, highlighting the importance of NP type and size in the germination process. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanoparticles with diverse morphologies were synthesized using an economical and environmentally friendly co-precipitation method. The samples underwent characterization through X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, and energy-dispersive spectra analysis. The photocatalytic degradation capabilities of the synthesized samples were assessed using organic dyes and antibiotics as model pollutants. SEM images revealed nanospheres, nanorods, and nanotubes structures of ZnO under three distinct conditions. The average crystallite sizes of hexagonal wurtzite ZnO samples were determined using Debye–Scherrer's formula from the full width at half maximum of XRD peaks, resulting in sizes of 52.80, 57.23, and 78.02 nm for ZnO nanospheres (ZnO-S), ZnO nanotubes (ZnO-T), and ZnO nanorods (ZnO-R), respectively. The optical band gap energies were measured at 3.25, 3.26, and 3.28 eV for ZnO-S, ZnO-T, and ZnO-R, respectively, demonstrating lower values compared to bulk ZnO (3.37 eV). Photocatalytic efficiency assessment using methylene blue indicated that ZnO-S exhibited the highest degradation efficiency (98.64%), followed by ZnO-T (97.63%) and ZnO-R (59.94%) under optimized conditions of 0.05 g/L catalyst dose, 90-min irradiation time, 130-W light intensity, and 1-mg/L methylene blue concentration. ZnO-S demonstrated effective photocatalysis in the ofloxacin degradation with a rate constant of 0.0112 min−1. According to a study on photocatalytic mechanisms, hydroxyl radicals play an important role in the degradation of pollutants. The photocatalyst maintains high photocatalytic efficiency even after five uses. Collectively, ZnO with different morphologies holds promise as a potential catalyst for environmental protection. [ABSTRACT FROM AUTHOR]

The fruit extract of Buchanania obovata and the eutectic-based ionic liquid were utilized, in an eco-friendly, inexpensive, simple method, for synthesizing zinc oxide nanoparticles (ZnO NPs). The influence of the reducing, capping and stabilizing agents, in both mediums, on the structure, optical, and morphological properties of ZnO NPs was extensively investigated. The surface plasmon resonance peaks were observed at 340 nm and 320 nm for the fruit-based and the eutectic-based ionic liquid mediums, respectively, indicating the formation of ZnO NPs. XRD results confirmed the wurtzite structure of the ZnO NPs, exhibiting hexagonal phases in the diffraction patterns. The SEM and TEM images display that the biosynthesized ZnO NPs exhibit crystalline and hexagonal shape, with an average size of 40 nm for the fruit-based and 25 nm for the eutectic-based ionic liquid. The Brunauer–Emmett–Teller (BET) surface area analysis, revealed a value ∼13 m2 g−1 for ZnO NPs synthesized using the fruit extract and ∼29 m2 g−1 for those synthesized using the eutectic-based ionic liquid. The antibacterial activity of the biosynthesized ZnO NPs was assessed against clinically isolated Gram-negative (E. coli) and Gram-positive (S. aureus) bacterial strains using the inhibition zone method. The ZnO NPs produced from the eutectic-based ionic liquids confirmed superior antibacterial activity against both S. aureus and E. coli compared to those mediated by the utilized fruit extract. At a concentration of 1000, the eutectic-based ionic liquid mediated ZnO NPs displayed a maximum inhibition zone of 16 mm against S. aureus, while against E. coli, a maximum inhibition zone of 15 mm was observed using the fruit extract mediated ZnO NPs. The results of this study showed that the biosynthesized ZnO NPs can be utilized as an efficient substitute to the frequently used chemical drugs and covering drug resistance matters resulted from continual usage of chemical drugs by users. [ABSTRACT FROM AUTHOR]

This study has been aimed to synthesise the self-assembled, flower-shaped zinc oxide nanoparticles (ZnO NFs) by using a green synthesis method using the aqueous extract from the peels of Citrus reticulata. Both HR-TEM and Fe-SEM analyses have confirmed the flower-like morphology for the synthesised nanoparticles. The observed zeta potential value of −48.0 mV further indicated its highly stable structure. The X-ray diffractogram of the ZnO NFs showed the characteristic diffraction peaks for the crystalline ZnO without any impurity peak, indicating the complete reduction into nanoparticles and thereby, the formation of pure crystalline ZnO NFs. The antibacterial activity of ZnO NFs was then studied using the standard well diffusion method and demonstrated significant bactericidal effects against Staphylococcus aureus and Escherichia coli, with a minimum inhibitory concentration (MIC) of 0.048 mg mL−1. Additionally, the ZnO NFs were evaluated for their potential to enhance the shelf life of Gerbera jamesonii flowers when treated with different concentrations in a chitosan-based solution. The ZnO NFs supplemented solution here was found to preserve the freshness of the cut flowers for up to 9.3 ± 0.3 days compared to the 3-day shelf life of the control group. These findings suggest ZnO NFs to have significant antibacterial properties and can effectively extend the shelf life of cut flowers. [ABSTRACT FROM AUTHOR]