Search Results (6,796)

Green peppers (Capsicum annuum L.) are a fruit vegetable with great culinary versatility and present important nutritional properties for human health. Water deficit negatively affects the nutritional quality of green peppers’ fruits. This study aimed to investigate the influence of zinc oxide nanoparticles (ZnONPs), associated with plant growth-promoting bacteria (PGPB), on the post-harvest nutritional quality of green peppers subjected to water deficit. In an open-field experiment, two irrigation levels (50 and 100% of crop evapotranspiration (Etc)), four treatments composed of a combination of ZnONPs, zinc sulfate (ZnSO₄), and PGPB (T1 = ZnSO₄ via leaves, T2 = ZnONPs via leaves, T3 = ZnONPs via leaves + PGPB via soil, T4 = ZnSO₄ via soil + PGPB via soil), and a control treatment (Control) were tested. Water deficit or water deficit mitigation treatments did not interfere with the physical–chemical parameters (except vitamin C content) and physical color parameters (except the lightness) of green peppers. On average, the water deficit reduced the levels of Ca (−13.2%), Mg (−8.5%), P (−8.5%), K (−8.6%), Mn (−10.5%), Fe (−12.2%), B (−12.0%), and Zn (−11.5%) in the fruits. Under the water deficit condition, ZnONPs or ZnSO₄ via foliar, associated or not with PGPB, increased the levels of Ca (+57% in the T2 and +69.0% in the T2), P, Mg, and Fe in the fruits. At 50% Etc, the foliar application of ZnONPs in association with PGPB increases vitamin C and mineral nutrients’ contents and nutritional quality index (+12.0%) of green peppers. Applying Zn via foliar as ZnONPs or ZnSO₄ mitigated the negative effects of water deficit on the quality of pepper fruits that were enhanced by the Bacillus subtilis and B. amyloliquefaciens inoculation. The ZnONPs source was more efficient than the ZnSO₄ source. The water deficit alleviating effect of both zinc sources was enhanced by the PGPB. Full article

Zn–air batteries (ZABs) are a promising technology; however, their commercialization is limited by challenges, including those occurring in the electrolyte, and thus, gel polymer electrolytes (GPEs) and hydrogels have emerged as substitutes for traditional aqueous electrolytes. In this work, PVA/PAA membranes were synthesized by the solvent casting method and soaked in 6 M KOH to act as GPEs. The thickness of the membrane was modified (50, 100, and 150 μm), and after determining the best thickness, the membrane was modified with synthesized SiO₂ nanospheres and multi-walled carbon nanotubes (CNTs). SEM micrographs revealed that the CNTs displayed lengths of tens of micrometers, having a narrow diameter (95 ± 7 nm). In addition, SEM revealed that the SiO₂ nanospheres had homogeneous shapes with sizes of 110 ± 10 nm. Physicochemical experiments revealed that SiO₂ incorporation at 5 wt.% increased the water uptake of the PVA/PAA membrane from 465% to 525% and the ionic conductivity to 170 mS cm⁻¹. The further addition of 0.5 wt.% CNTs did not impact the water uptake but it promoted a porous structure, increasing the power density and the stability, showing three-times-higher rechargeability than the ZAB operated with the PVA/PAA GPE. Full article

Herein, motivated by the excellent redox properties of rod-shaped ceria (CeO₂-NR), a series of TM/CeO₂ catalysts, employing the first-row 3d transition metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) as active metal phases, were comparatively assessed under identical synthesis and reaction conditions to decipher the role of active metal in the CO₂ hydrogenation process. Notably, a volcano-type dependence of CO₂ hydrogenation activity/selectivity was disclosed as a function of metal entity revealing a maximum for the Ni-based sample. Ni/CeO₂ is extremely active and fully selective to methane (Y_CH4 = 90.8% at 350 °C), followed by Co/CeO₂ (Y_CH4 = 45.2%), whereas the rest of the metals present an inferior performance. No straightforward relationship was disclosed between the CO₂ hydrogenation performance and the textural, structural, and redox properties, whereas, on the other hand, a volcano-shaped trend was established with the relative concentration of oxygen vacancies and partially reduced Ce³⁺ species. The observed trend is also perfectly aligned with the previously reported volcano-type dependence of atomic hydrogen adsorption energy and CO₂ activation as a function of 3d-orbital electron number, revealing the key role of intrinsic electronic features of each metal in conjunction to metal–support interactions. Full article

This study evaluates the preparation of novel ternary functional adsorbents based on polyaniline, zinc oxide nanoparticles, and moringa oleifera gum to produce zinc oxide/Moringa oleifera gum-grafted L-methionine-functionalized polyaniline bionanocomposites (ZM-g-Pani) and employed to sequestrate divalent metal ions (Cd²⁺, Hg²⁺ and Pb²⁺) from wastewater samples. The morphological and structural properties of ZM-g-Pani were exploited using FT-IR, FE-SEM/EDS, TEM, and XRD. FT-IR and FE-SEM studies show that the as prepared nanocomposite has an abundant number of reactive groups and a porous structure, thus demonstrating outstanding divalent metal cation removal. FT-IR study confirms that the attachment of L-methionine to polyaniline is facilitated by the C-S linkage. Both TEM and FE-SEM techniques confirmed the clustered granules of ZnO over the surface of polyaniline, which ultimately provided more surface area to adsorb metal ions. The study demonstrated that Cd²⁺, Hg²⁺ and Pb²⁺ ions could undergo physical sorption and chemisorption simultaneously during the adsorption process. The maximum adsorption capacity was 840.33, 497.51, and 497.51 mg/g for Cd²⁺, Hg²⁺, and Pb²⁺, respectively. The impact of co-existing ions, including NO₃⁻, PO₄³⁻, SO₄²⁻, Cl⁻, Na⁺, Cu²⁺, and Al³⁺, showed that there were no notable alterations in the adsorption of the selected metal ions with ZM-g-Pani. ZM-g-Pani showed eight successive regeneration cycles for Cd²⁺, Hg²⁺, and Pb²⁺ with more than 85% removal efficiency. Full article

This study investigates a hybrid microelectromechanical system (MEMS) acoustic resonator through a hybrid approach to combine capacitive and piezoelectric transduction mechanisms, thus harnessing the advantages of both transducer technologies within a single device. By seamlessly integrating both piezoelectric and capacitive transducers, the newly designed hybrid resonators mitigate the limitations of capacitive and piezoelectric resonators. The unique hybrid configuration holds promise to significantly enhance overall device performance, particularly in terms of quality factor (Q-factor), insertion loss, and motional impedance. Moreover, the dual-transduction approach improves the signal-to-noise ratio and reduces feedthrough noise levels at higher frequencies. In this paper, the detailed design, complex fabrication processes, and thorough experimental validation are presented, demonstrating substantial performance enhancement potentials. A hybrid disk resonator with a single side-supporting anchor achieved an outstanding loaded Q-factor higher than 28,000 when operating under a capacitive drive and piezoelectric sense configuration. This is comparably higher than the measured Q-factor of 7600 for another disk resonator with two side-supporting anchors. The hybrid resonator exhibits a high Q-factor at its resonance frequency at 20 MHz, representing 2-fold improvement over the highest reported Q-factor for similar MEMS resonators in the literature. Also, the dual-transduction approach resulted in a more than 30 dB improvement in feedthrough suppression for devices with a 500 nm-thick ZnO layer, while hybrid resonators with a thicker piezoelectric layer of 1300 nm realized an even greater feedthrough suppression of more than 50 dB. The hybrid resonator integration strategy discussed offers an innovative solution for current and future advanced RF front-end applications, providing a versatile platform for future innovations in on-chip resonator technology. This work has the potential to lead to advancements in MEMS resonator technology, facilitating some significant improvements in multi-frequency and frequency agile RF applications through the original designs equipped with integrated capacitive and piezoelectric transduction mechanisms. The hybrid design also results in remarkable performance metrics, making it an ideal candidate for integrating next-generation wireless communication devices where size, cost, and energy efficiency are critical. Full article

Vanadium-based materials have the advantages of abundant valence states and stable structures, having great application potential as cathode materials in metal-ion batteries. However, their low voltage and vanadium dissolution in traditional water-based electrolytes greatly limit their application and development in aqueous zinc metal batteries (AZMBs). Herein, phosphate- and vanadium-based cathode materials (MnVOPO₄·2H₂O) with stacked layers and few defects were prepared via a condensation reflux method and then combined with a high-concentration electrolyte (21 m LiTFSI + 1 M Zn(CF₃SO₃)₂) to address these limitations. The specific capacity and cycle stability accompanying the stable high voltage of 1.39 V were significantly enhanced compared with those for the traditional electrolyte of 3 M Zn(CF₃SO₃)₂, benefiting from the suppressed vanadium dissolution. The cathode materials of MnVOPO₄·2H₂O achieved a high specific capacity of 152 mAh g⁻¹ at 0.2 A g⁻¹, with a retention rate of 86% after 100 cycles for AZMBs. A high energy density of 211.78 Wh kg⁻¹ was also achieved. This strategy could illuminate the significance of electrolyte modification and provide potential high-voltage cathode materials for AZMBs and other rechargeable batteries. Full article

Photodetectors and gas sensors are vital in modern technology, spanning from environmental monitoring to biomedical diagnostics. This paper explores the UV detection and gas sensing properties of a zinc oxide (ZnO) nanorod array (ZNA) grown on silver nanowire mesh (AgNM) using a hydrothermal method. We examined the impact of different zinc acetate precursor concentrations on their properties. Results show the AgNM forms a network with high transparency (79%) and low sheet resistance (7.23 Ω/□). A sol–gel ZnO thin film was coated on this mesh, providing a seed layer with a hexagonal wurtzite structure. Increasing the precursor concentration alters the diameter, length, and area density of ZNAs, affecting their performance. The ZNA-AgNM-based photodetector shows enhanced dark current and photocurrent with increasing precursor concentration, achieving a maximum photoresponsivity of 114 A/W at 374 nm and a detectivity of 6.37 × 10¹⁴ Jones at 0.05 M zinc acetate. For gas sensing, the resistance of ZNA-AgNM-based sensors decreases with temperature, with the best hydrogen response (2.71) at 300 °C and 0.04 M precursor concentration. These findings highlight the potential of ZNA-AgNM for high-performance UV photodetectors and hydrogen gas sensors, offering an alternative way for the development of future sensing devices with enhanced performance and functionality. Full article

Toxic metal wastewater is a challenge for exposed terrestrial and aquatic environments, as well as the recyclability of the water, prompting inputs for the development of promising treatment methods. Consequently, the rGO/ZnONP nanocomposite was synthesized at room temperature for four hours and was tested for the adsorption of cadmium and lead in wastewater. The optimized nanocomposite had the lowest band gap energy (2.69 eV), and functional group interactions were at 516, 1220, 1732, 3009, and 3460 cm⁻¹. The nanocomposite showed good ZnO nanoparticle size distribution and separation on rGO surfaces. The nanocomposite’s D and G band intensities were almost the same, constituting the ZnO presence on rGO from the Raman spectrum. The adsorption equilibrium time for cadmium and lead was reached within 10 and 90 min with efficiencies of ~100%. Sips and Freundlich best fitted the cadmium and lead adsorption data (R² ~ 1); therefore, the adsorption was a multilayer coverage for lead and a mixture of heterogenous and homogenous coverage for cadmium adsorption. Both adsorptions were best fitted by the pseudo-first-order model, suggesting the multilayer coverage dominance. The adsorbent was reused for three and seven times for cadmium and lead. The nanocomposite showed selectivity towards lead (95%) and cadmium (100%) in the interfering wastewater matrix. Conclusively, the nanocomposite may be embedded within upcoming lab-scale treatment plants, which could lead to further upscaling and it serving as an industrial wastewater treatment material. Full article

In this research, we developed a novel slow-release biofertilizer by utilizing an environmentally friendly method to synthesize ZnO-NPs using sodium hydroxide, zinc acetate salt, and Lepidium sativum seed extract. The commercial fertilizer urea 46% was encapsulated in the nano-ZnO/alginate beads. The structural and morphological characteristics of the nanocomposites were confirmed using X-ray diffraction (XRD) and scanning electron microscopy, which confirmed the successful creation of nanocomposite alginate beads. The results indicated that the ZnO/alginate/urea beads exhibited a steady and continuous release of urea for up to one hour and extended nutrient availability over time. This research demonstrates the potential of ZnO-NP/alginate composites as a promising platform for developing slow-release biofertilizers, combining the beneficial properties of ZnO nanoparticles with the controlled-release capabilities of alginate matrices. This research highlights the potential of ZnO-NP/alginate composites as a sustainable and efficient solution for agricultural applications, providing a controlled release of nutrients that could minimize their environmental impact and enhance crop productivity. Full article

It is important to improve the separation ability of photogenerated electrons and the adsorption capacity of carbon dioxide (CO₂) for efficient photoreduction of CO₂. Here, we synthesized ZnCdS quantum dots (ZCS-QDs) and cerium dioxide nanosheets (CeO₂) using the solvothermal method and calcination method. We combined CeO₂ and ZCS-QDs to effectively enhance the charge separation efficiency, and the lifetime of photogenerated electrons was increased 4.5 times. The CO evolution rate of the optimized composite (ZCS-QDs/CeO₂) was up to 495.8 μmol g⁻¹ h⁻¹, and it had 100% product selectivity. In addition, the stability remained high after five cycles. The CO₂ adsorption capacity of the catalyst surface was observed by in situ FTIR. The test results showed that improving CO₂ capture ability and promoting photogenic electron separation had positive effects on enhancing photoreduction of CO₂. This study provides a reference for constructing a zero-dimensional–two-dimensional (0D–2D) heterojunction and explores potential CO₂ reduction reaction mechanisms. Full article

The salinity and alkalinity of soils are two fundamental factors that limit plant growth and productivity. For that reason, a field study conducted at Sakha Agric. Res. Station in Egypt during the 2022–2023 winter season aimed to assess the impact of gypsum (G), compost (C), and zinc foliar application in two images, traditional (Z₁ as ZnSO₄) and nanoform (Z₂ as N-ZnO), on alleviating the saline–sodic conditions of the soil and its impact on wheat productivity. The results showed that the combination of gypsum, compost, and N-ZnO foliar spray (G + C + Z₂) decreased the soil electrical conductivity (EC), sodium adsorption ratio (SAR), and exchangeable sodium percentage (ESP) by 14.81%, 40.60%, and 35.10%, respectively. Additionally, compared to the control, the G + C + Z₂ treatment showed improved nutrient content and uptake as well as superior wheat biomass parameters, such as the highest grain yield (7.07 Mg ha⁻¹), plant height (98.0 cm), 1000-grain weight (57.03 g), and straw yield (9.93 Mg ha⁻¹). Interestingly, foliar application of N-ZnO was more effective than ZnSO₄ in promoting wheat productivity. Principal component analysis highlighted a negative correlation between increased grain yield and the soil EC and SAR, whereas the soil organic matter (OM), infiltration rate (IR), and plant nutrient content were found to be positively correlated. Furthermore, employing the k-nearest neighbors technique, it was predicted that the wheat grain yield would rise to 7.25 t ha⁻¹ under certain soil parameters, such as EC (5.54 dS m⁻¹), ESP (10.02%), OM (1.41%), bulk density (1.30 g cm⁻³), infiltration rate (1.15 cm h⁻¹), and SAR (7.80%). These results demonstrate how adding compost and gypsum to foliar N-ZnO can improve the soil quality, increase the wheat yield, and improve the nutrient uptake, all of which can support sustainable agriculture. Full article

Research on tribocatalysis, which involves the triboelectric effect, is based on the concept that friction between dissimilar materials can generate charges capable of initiating catalytic reactions. This phenomenon holds significant potential for the degradation of wastewater contaminants in the environment. In this study, pure and Ce-modified (2 mol%) ZnO powders were investigated as tribocatalysts for the degradation of doxycycline (DC), a tetracycline antibiotic, in the absence of light. The research demonstrates that friction between the catalyst, the beaker, and the polytetrafluoroethylene (PTFE) magnetic rod induces charge transfer at their interfaces, leading to the breakdown of pollutants. Additionally, doxycycline degradation was observed at three different stirring speeds (100, 300, and 500 rpm). The results confirmed the tribocatalytic effect, showing that DC degradation increases with higher stirring speeds. Using ZnO and ZnO/Ce powders, maximum degradations of 80% and 55%, respectively, were achieved in 24 h at a stirring speed of 500 rpm. The findings of this study suggest that these samples can effectively degrade contaminants in water through the application of mechanical energy. Full article

To better understand the effects of agronomic practices on yield–nutrition relationships in wheat (Triticum aestivum L.) grains for Zn biofortification while improving yields simultaneously, effects of different soil fertilization and different drone-based foliar spraying treatments were investigated in calcareous soils. For soil fertilization, the incorporation of Zn or increasing the N/P ratio in compound fertilizers proved to be effective in enhancing grain Zn concentrations and yields. However, the overall effects of soil fertilization are limited, with a maximal yield increase of only 7.0% and a maximal increase of the grain Zn concentration from 19.4 to 27.0 mg/kg, which is far below the target biofortification value of 40–50 mg/kg. Unfortunately, there was a negative side effect, which decreased Fe and Mn concentrations and the Fe bioavailability. Notably, drone-based foliar Zn sprayings increased grain yields from the control 7.5 t/ha to 8.6 t/ha at ZnO treatment by 12.0% and 8.8 t/ha at ZnSO₄·7H₂O treatment by 17.3%. Meanwhile, grain Zn concentrations were increased from the control 33.5 mg/kg to 41.9 mg/kg at ZnO treatment by 25.1% and 43.6 mg/kg at ZnSO₄·7H₂O treatment by 30.1%. Treatments with ZnSO₄·7H₂O increased grain Zn concentrations and accumulation more so than ZnO, indicating the importance of chemical Zn forms in determining the effectiveness of foliar spraying. Moreover, foliar Zn sprayings simultaneously increased grain concentrations and accumulation of Fe, Mn and Cu, demonstrating multiple benefits. There were positive correlations between Zn and Fe, Mn or Cu, indicating synergistic interactions. Compared to micronutrients, concentrations of grain macronutrients (N, P, K, Ca and Mg) were less affected. Thus, a dual-benefit in both grain yields and micronutrient (particularly for Zn) nutrition could be effectively achieved through appropriate soil fertilization and foliar Zn spraying. These findings provide a better understanding of the yield–nutrition relationship among wheat grain yields, Zn and other nutrient elements for a better integrated manipulation to achieve a win–win situation in yield and nutrition. Full article

Polyvinylidene fluoride (PVDF)-coated ZnO nanorod piezoelectric sensors were prepared on silicone-based polymer polydimethylsiloxane (PDMS) substrates using a hydrothermal method. The effects of catalysts (sodium hydroxide, ammonium hydroxide, and hexamethylenetetramine) on the lattice microstructure and piezoelectric properties of ZnO nanorods were analyzed. The piezoelectric properties of polyvinylidene fluoride-coated ZnO nanorods’ tactile sensors with different catalysts were measured under different forces. ZnO nanorods with hexamethylenetetramine have a high c-axis (002)-preferred orientation hexagonal wurtzite crystal structure with a maximum length of 5800 nm and an aspect ratio of 72.5. The Polyvinylidene fluoride/ZnO nanorod sensor with hexamethylenetetramine showed an excellent linear response to external pressure in the range of 0.1~1.2 N, and the best sensitivity is 61.1 mV/N. Full article

This study aimed to assess the effects of substituting zinc oxide with terminalia chebula extract (TCE) on growth performance, antioxidant capacity, immune function, and intestinal health in weaned pigs. Initially, 72 weaned Duroc × Landrace × Large White piglets, 28 days old with an initial weight of 7.43 ± 0.14 kg, equally divided by gender, were randomly assigned into three groups, with six replicates and four piglets per replicate. They were fed a basal diet (CON group), a diet containing 2 g/kg zinc oxide (ZnO group), or 2 g/kg TCE (TCE group) for a duration of 28 days. Subsequently, to further confirm the most appropriate levels of TCE in piglets, 96 piglets of the same breeds and age, with an initial weight of 7.42 ± 0.12 kg, also equally divided by gender, were randomly assigned into four groups, each with six replicates and four piglets per replicate, and fed a basal diet (CON group), or diets supplemented with 1 g/kg TCE (LTCE group), 2 g/kg TCE (MTCE group), or 4 g/kg TCE (HTCE group) for a duration of 28 days. The results demonstrated that both TCE and ZnO reduced diarrhea rates (p = 0.001) and enhanced average daily gain (ADG) (p = 0.014) compared to the control group. TCE at 1 g/kg and 4 g/kg reduced the feed to gain ratio (p = 0.050). Dietary supplementing with TCE and ZnO increased serum total antioxidant capacity (T-AOC) (p = 0.020). Various doses of TCE also increased jejunal IgA (p = 0.000) levels and IL-10 expression (p = 0.004), and decreased the levels of TNF-α in both serum (p = 0.043) and jejunal mucosa (p = 0.000). Notably, TCE reduced the crypt depth (CD) of the duodenal (p = 0.007) and increased the villus height (VH) of the ileal (p = 0.045), and with increased dosage, there was a rise in the villus height to crypt depth ratio (VH:CD) in the duodenum (p = 0.000) and jejunum (p = 0.001). Higher abundances of Lactobacillaceae (p = 0.000) and lower levels of Streptococcaceae (p = 0.000) and Peptostreptococcaceae (p = 0.035) in cecal contents were fed the ZnO and TCE pigs compared with CON pigs. Therefore, TCE was firstly presented as being able to replace zinc oxide, improve intestinal morphology, and enhance antioxidant and immune functions, thus safeguarding intestinal mucosal health and promoting piglet growth. Full article