Nano ZnO Research Articles

Nano ZnO modified amorphous carbon materials enabling long-cycle performance and high-capacity for lithium/sodium-ion batteries

Zinc-modified carbon materials exhibit high specific capacity, good safety, and low self-discharge, making them promising anode materials for lithium-ion and sodium-ion batteries. However, the high cost of raw materials, complex fabrication processes, and limited cycle life remain significant challenges to their further development. In this study, we elucidated a two-step process, simple in technique and suitable for large-scale production, for in-situ zinc modification of amorphous carbon. The synthesized carbon material exhibited superior reversible specific capacity (maintaining 780.27 mAh·g−1 capacity after 80 cycles at 50 mA·g−1 current density), high cycling stability (maintaining Coulombic efficiency at 100.06 % after 15,000 cycles at 10 A·g−1 current density), and good application value (achieving a capacity of 89.67 mAh·g−1 after 1000 cycles at 200 mA·g−1 current density for the assembled MFAC-Zn||NVP full cell). Through our investigation, we discovered that Nano ZnO not only directly participate in electrochemical reactions but also effectively improve the microstructure of amorphous carbon, increasing its three-dimensional axial stacking and providing more reaction sites. The enrichment of open pores significantly enhances the diffusion efficiency of ions within the carbon-based matrix. The superior diffusion ability of alkali metal-ion in the electrode is the reason for the excellent electrochemical performance of Zinc-modified amorphous carbon. Moreover, the incorporation of Nano ZnO aids in the formation of a robust and thin SEI layer. This significantly enhances the stability of the electrode materials during cycling and improves charge transfer efficiency during the charge-discharge process. Our study provides a new strategy for adjusting the internal microstructure of amorphous carbon materials to achieve high-performance lithium/sodium storage.

Hierarchical Bi2S3 nanothorn on ZnO core-branch photoelectrode: A promising heterostructure for enhanced photoelectrochemical water splitting

The zinc oxide semiconductor associated with defects and their recombination effect restricts the development of photoelectrode for hydrogen evolution. The combination of semiconductor hetero-junction and hierarchical interface of ZnO/Bi2S3 photoelectrode fabricated. In this study, heterostructure ZnO/Bi2S3 were studied as a photoanode with their impact of oxygen vacancy in ZnO nano rods. The trace of the Bi2S3 on the ZnO was studied and compared with pristine and oxygen annealed ZnO nano rods. The photon-luminescence studies reveal that shallow donor and acceptor defect in ZnO and restricted by Bi2S3 heterostructure. The less defect contemplations in the photoanodes accelerates up electron and hole migration leading to significant built-in potential and photocurrent generation. The appropriate method has been followed to architype less interfacial defect in ZnO(300)/Bi2S3 photoanode and boosted the photo-redox reactions for efficient hydrogen evolution. The photoanode exhibits substantial properties of photocurrent density 0.33 mA/cm2, charge transfer resistance of 700 Ω cm2 and higher inbuilt potential of −0.88V vs Ag/AgCl with 0.17 % applied bias photon to electron conversion efficiency and 0.11 % solar to hydrogen conversion efficiency.

Study on the composition and properties of EME-SBS-Nano ZnO high modulus asphalt material

The objective of this research is to address the rut problems in asphalt pavements and to resist the permanent plastic deformation with the increasing heavy traffic loads. In this paper, a new type materials of high modulus asphalt was developed by incorporating styrene–butadiene–styrene (SBS) and zinc oxide nanoparticles (nano ZnO) with an (EME)-type high modulus modifier, guided by the synergistic effects and the preparation methods of High-speed shear. The basic road performance, mechanical response and thermal stability of the new high modulus asphalt materials were analysed through basic physical indicator tests, dynamic shear rheometer tests, thermogravimetric analysis (TGA), the time–temperature superposition principle, the Refutas model, and the Christensen-Andersen-Marasteanu model. The optimal results demonstrate that the optimal blend ratio of the developed asphalt is 12% EME/8% SBS/1.5% ZnO. Under this composition, the road performance indicator values of softening point, penetration and ductility of the modified asphalt met the standard requirements. The dynamic shear rheometer tests demonstrates that the inclusion of SBS and nano ZnO considerably enhanced the shear resistance and recovery deformation capacity of EME, effectively improving the high-temperature deformation resistance of asphalt. Furthermore,the Refutas and the Christensen-Andersen-Marasteanu model fitting results showed that adding SBS and nano ZnO considerably improved the temperature sensitivity of the EME types high modulus modified asphalt and exhibiting low frequency sensitivity. Compared to PR Module-type high modulus modifier(PRM),TGA reveals that the maximum thermal weight loss of EME-SBS-ZnO decreased by 3.5441%, indicating better thermal stability and the major character of SBS,EME and asphalt is physical reaction. Moreover, EME-nano ZnO-SBS high modulus asphalt at 64 °C shows Jnr-diff = 9.5% and passes the "E" extreme traffic grade. Additionally, its cost is 4.67% lower than that of the PRM high modulus modified asphalt, presenting considerable economic benefits.

Nano-sized ZnO enhances photosynthetic parameters, yield and Zn content in rice (Oryza sativa)

A pot culture experiment was conducted during rainy (kharif) season of 2021 at ICAR-Indian Institute of Rice Research, Hyderabad, Telangana to study the influence of the foliar application of various Zn sources such as nano ZnO, bulk ZnO, and ZnSO4 on rice crop. The experiment was laid out in a completely randomized design (CRD) with the following treatments, containing 3 concentrations of bulk ZnO (500 mg/litre, 1000 mg/litre, and 1500 mg/ litre), 3 concentrations of nano ZnO (50 mg/litre, 100 mg/ litre, and 150 mg/litre), 0.5% ZnSO4 and control with 3 replications. The findings revealed that ZnO nanoparticles (NPs) positively impacted rice grain yield, dry matter accumulation, and Zn content. Compared to the control (no zinc), ZnO NPs (150 mg/litre) and standard ZnSO4 treatments exhibited the highest plant height (83.3 cm and 73.7 cm, respectively), grain yield (5.97 g/pot and 6.03 g/pot), and straw yield (7.82 g/pot and 7.94 g/pot). The increased photosynthetic substances and higher dry matter accumulation throughout the rice growth stage contributed to the enhanced grain yield. Furthermore, supplementing Zn via nano ZnO (150 mg/litre) and 0.5% ZnSO4 resulted in significant Zn enrichment: 33,35; 77,87 and 21, 28% in straw, grain and soil, respectively over control plants. This study effectively demonstrates that ZnO nanoparticles have the potential to serve as high-performance fertilizers, benefiting both rice yield and quality.

Quercus ballot as an innovative feedstock for biodiesel production using ZnO nanocatalyst

Selecting non-edible plant seed oil remains the best choice for biodiesel production using an effective nanocatalyst. In this study, the ZnO was prepared as a nanocatalyst using an aqueous extract from the Alhaji marorum plant. Nano ZnO has shown high catalytic activity, is cost-effective, environmentally friendly and converts triglycerides into fatty acid methyl esters. The results indicate that ZnO nanocatalyst exhibit a high specific surface area (146.82 m2 g-1), large pore volume (0.35 cm3 g-1), and an average crystallite size of 42.3 nm. The FESEM analysis shows that the particle size of ZnO lies in the range of 30–50 nm with a rod shape and densely packed morphology. The biodiesel is produced using a transesterification process from novel non-edible Quercus ballot plant seeds. The resulting biodiesel has a 98.06 % yield under a methanol/oil ratio of 6:1 with 0.5 wt% ZnO nanocatalyst at 65 °C for 80 min. It is established that the methanol-to-oil ratio and the catalyst concentration significantly affect the transesterification reaction. The biodiesel produced is characterized by GC–MS to determine its exact composition and FTIR is used to confirm functional groups and is evaluated according to ASTM D6751.

Unveiling the effects of ZnO nanoparticle incorporated chitosan coating on postharvest quality of eggplant (Solanum melongena L.)

Due to rapid moisture loss, eggplant (Solanum melongena L.), a significant economic product, has a short postharvest shelf life. This study examined at 4 °C for 20 days at the effects of chitosan (CH) 1% and CH with micro ZnO (0.25 g/L) on eggplant quality. After 0, 5, 10, 15, and 20 days, coating effects on parameters (weight loss, pH, respiration rate, total acidity, soluble solids, firmness, total anthocyanin, antioxidant, phenolic, antioxidant enzymes superoxide dismutase, peroxidase and malondialdehyde activity), as well as microbiological count (total bacteria and yeast), were examined. When compared to the control, the coatings significantly affected the quality parameters, eggplant fruit coatings with CH (1 %) + nano ZnO (0.25 g/L) had the significantly least respiratory rate, weight loss, firmness, TAC, TPC, TAA and enzyme activity (P < 0.05). The microbial load during fruit preservation was suppressed by nano ZnO treatments (total bacterial and fungal count in control and eggplant treated with nano ZnO were 4.46, 4.33 and 3.96, 3.17 log CFU g−1 respectively). Treatments had little effect on fruit's flavour or aroma, but ZnO-treated fruit had improved texture, colour, and acceptance overall compared to control fruit. Finally, nano ZnO may offer a chance to preserve quality and limit deterioration during extended storage.

Difference in the toxic effects of micro and nano ZnO particles on L. minor - an integrative approach.

The toxicity of nano-sized ZnO particles (nZnO) was evaluated and compared to that of their micro-sized counterparts (mZnO) using an integrative approach to investigate the mechanism of toxicity, utilizing duckweed (Lemna minor) as plant model. Following 7days of exposure to nZnO or mZnO (2.5, 5, 25, and 50mg L-1) growth rate, photosynthesis, oxidative stress, and genotoxicity parameters have been determined in duckweed. Phytotoxicity of both ZnO forms at relatively low concentrations was due to the release of free Zn ions into the nutrient media. However, the accumulation of Zn in plants treated with nZnO was significantly higher than in those treated with mZnO. Both mZnO and nZnO significantly reduced growth rate and impaired the functionality of the photosynthetic apparatus as evidenced by structural changes of chloroplasts, a decline in the efficiency of photosystem II, and chlorophyll a content. Additionally, exposure to mZnO and nZnO resulted in the accumulation of reactive oxygen species (ROS), increased lipid peroxidation, the formation of carbonylated proteins, DNA damage, and alterations in antioxidant defense mechanisms. Overall, nZnO caused significantly stronger toxic effects than mZnO. The mechanism of nZnO toxicity to L. minor, as determined by multivariate statistical analysis, involved the disruption of primary photosynthetic reactions due to a redox imbalance in the cell caused by the enhanced absorption of Zn into plant tissues.

Efficient photocatalytic degradation of crystal violet dye using time-dependent ZnO nano spindle

Photocatalysis, utilizing metal–semiconductor oxides, has emerged as a promising technique for the oxidation of organic molecules due to its efficiency, cost-effectiveness, and eco-friendly nature. This study presents the synthesis and application of time-dependent ZnO nano spindles for the efficient photocatalytic degradation of crystal violet dye. ZnO nanostructures, known for their high photocatalytic activity, were synthesized using a simple and low-cost coprecipitation method, with the spindle morphology being fine-tuned by varying reaction times. The resulting nano spindles were characterized using X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and UV–vis spectroscopy to confirm their structural, morphological, and optical properties. XRD analysis revealed that the ZnO samples possess a hexagonal wurtzite crystal structure with a space group of P63mc. SEM analysis confirmed the formation of spindle-like morphologies, with the synthesized samples measuring just a few nanometers in size. The surface area and porosity of the ZnO samples have been observed by using the Brunauer–Emmett–Teller (BET) analysis. The obtained surface area of all ZnO samples is in the range of 15 to 30 m2g−1. Photocatalytic performance was evaluated under UV light irradiation, demonstrating that the degradation efficiency of CV dye significantly depends on the exposure duration and the morphological attributes of the ZnO nano spindles. The degradation kinetics followed a pseudo-first-order model, with the optimized ZnO nano spindles achieving up to 99 % degradation efficiency within 150 min. This study highlights the potential of time-dependent morphological control in ZnO nanostructures to enhance photocatalytic processes, presenting a viable solution for the treatment of dye-laden wastewater.

Anelosimuseximius bioinspired ZnO nano cobwebs for environmental remediation of drugs and endocrine disruptors from water

The pollution of wastewater with pharmaceuticals and endocrine-disrupting chemicals (EDCs) in populated areas poses a growing threat to humans and ecosystems. To address this serious problem, various one-dimensional (1D) hierarchical ZnO-based nanostructures inspired by Anelosimus eximius cobwebs were developed and successfully grown on a glass substrate through simple hydrothermal synthesis. The nanorods (nr) obtained during primary growth were chemically etched with KOH (ZnOnr-KOH), followed by the secondary growth of nano cobweb-like (ncw) structures using polyethyleneimine (ZnOnr/ncw). These structures were further decorated by the photoreduction of Ag nanoparticles (ZnOnr/ncw/Ag). The feasibility of ZnO-based 1D nanostructures to remove pollutants was demonstrated by degrading commonly prescribed pharmaceutical drugs (diclofenac and carbamazepine) in a miniature cuvette reactor. The photocatalytic activities for drug degradation generally decreased in the order ZnOnr/ncw/Ag > ZnOnr/ncw > ZnOnr-KOH. Additionally, the suitability of the samples for scaling up and practical application was demonstrated by photocatalytic degradation of the hormone estriol (E3) in a flow-through photoreactor. The photocatalytic degradation efficiency of E3 followed the same trend observed for drug degradation, with the complete elimination of the endocrine disruptor achieved by the best-performing ZnOnr/ncw/Ag within 4 h, due to optimized charge transfer and separation at the heterostructure interface.

Study on the UV aging resistance of ZnO‐modified epoxy resin by experiments and MD simulation

AbstractThis study investigates the impact of zinc oxide nanoparticles on epoxy resin systems and the ultraviolet (UV) aging resistance of modified epoxy resin composites using molecular dynamics (MD) simulations and experimental methods. Initially, various epoxy resin cross‐linking models are established through MD simulations to understand the influence of different nano ZnO contents on resin modification, further validated by experiments. Subsequently, the UV radiation resistance of nano ZnO–epoxy resin composites is assessed by subjecting them to high‐intensity UV radiation equivalent to 3 years of natural environmental conditions, analyzing changes in tensile properties, impact performance, hardness, and glass transition temperature of epoxy resin before and after UV radiation exposure. The findings suggest that the addition of nano zinc oxide reduces the impact of UV radiation on epoxy resin, with optimal UV radiation resistance observed at a nano zinc oxide mass fraction of 0.3 wt%.

Green Synthesis of Nanomaterials with Phytochemicals for Treating Multidrug Resistant Bacteria

The Bacteria with Multidrug resistance and Extreme drug resistance are increasing at a rapid rate. Various methods have been employed to combat drug resistant bacteria. Major classes of antibiotics aren’t effective against these bacteria. Alternative methods have been studied in recent years. Nanoparticles are used against multidrug resistant bacteria; The green synthesized nanoparticles are more reliable due to more shelf life and lesser toxicity relative to chemically synthesized nanoparticles. Multi drug resistant E. coli and Staphylococcus aureus was isolated from sewage samples. Green synthesized nanoparticles from various plants samples have been prepared with Zinc and Copper forming respective oxides with Neem, Nakara, Jatropha, Mango, Clove, Ginger, Cardamom, Cinnamon and Betel against multidrug resistant Escherichia coli and Staphylococcus aureus. Isolated E. coli was susceptible to Fluoroquinolone and Augmentin whereas S. aureus was susceptible to vancomycin. Green synthesized nanoparticles had more antimicrobial activity against E. coli and S. aureus than chemically synthesized nanoparticles and plant extracts. Green synthesized Nakara CuO nano particles had inhibition zone of 31 ±0.6mm and 30 ±0.7mm for E. coli and S. aureus respectively, ZnO nano particles of Nakara had 25 ±0.6mm inhibition zone for E. coli and S. aureus. Green synthesized Jatropha CuO nano particles had inhibition zone of 26 ±0.5 and 26 ±0.4mm for E. coli and S. aureus. ZnO nano particles of Jatropha had 31±0.7mm and 30±0.7mm inhibition zone for E. coli and S. aureus respectively. The Scanning electron microscopy studies revealed 26nm Jatropha ZnO and 25nm Nakara CuO nanoparticles. Nano materials were found to be non-toxic in cell line studies. The present study concludes to study the impact of green synthesized nanoparticles as an alternative to antibiotics to combat multidrug resistant bacteria.

Effect of ZnO particle size on the radiation shielding efficiency of B2O3–BaO–ZnO glass system

Abstract This study analyzes the ZnO particle size’s effect on glass samples’ radiation shielding ability. Four glass samples with differing micro and nanoparticle ZnO content were investigated at four energies, 0.060, 0.662, 1.173, and 1.333 MeV. The investigated glasses are a B2O3–BaO–ZnO glass system and are composed of 30 % micro ZnO (30 M), 20 % micro ZnO and 10 % nano ZnO (20 M−10 N), 10 % micro ZnO and 20 % nano ZnO (10 M−20 N), and lastly 30 % nano ZnO (30 N). The theoretical XCOM software was employed to validate the experimental LAC values of the glasses, revealing that for at all energies, the values obtained from the two methods agreed with each other well. The glasses’ HVL, MFP, and RSE were then compared. The HVL values at all energies decreased as more nano ZnO was introduced into the glass system, reaching a minimum of 1.947 cm at 0.662 MeV for the 30 N sample. This sample also had the lowest MFP at all energies, while the 30 M glass had the highest, such as 0.088 and 0.070 for 30 M and 30 N respectively at 0.060 MeV. The RSE of a 1 cm thick sample of each of the glasses was tested and found that the 30 N sample exhibited the greatest RSE. The relative percent deviation between the 30 N and 30 M glasses was also analyzed, which highlighted the difference between 30 N’s greater LAC values compared to 30 M at all energies.

Synthesis and characterization of novel water hyacinth (Eichhornia Crassipes) biodegradable mulch films

In this paper, carboxymethyl cellulose (CMC) and hemicellulose derived from water hyacinth were used to prepare hemicellulose-based biodegradable mulch film by covalent cross-linking and ionic cross-linking in order to expand its application in agricultural production practice. The esterification reaction between hemicellulose, CMC and citric acid resulted in an increase in tensile strength and elongation at break of the membranes. When citric acid was not used as cross-linking agent and the pH was lowered, the sodium carboxylate group was protonated into carboxylic acid group, which provided abundant active sites for chemical cross-linking of hydroxyl group on hemicellulose and hydroxyl group on CMC. Furthermore Zn2+ could cross-link with carboxylic acid group through hydrogen bonding, and when the DS of carboxymethyl group was high, the cross-linking of Zn2+ with Zn2+ was higher, and the conversion into nano ZnO was lower, which was conducive to the uniform distribution and reduction of agglomeration phenomenon in the films. It is favorable for its uniform distribution in the film and reduces the agglomeration phenomenon. The mulch films made from water hyacinth has excellent mechanical properties, light transmittance, water absorption, soil moisture retention and heat preservation, and is biodegradable. This study will provide new ideas for water pollution control and farmland pollution for sustainable agricultural production.

Enhancing wheat tolerance to salinity using nanomaterials, proline, and biochar-inoculated with Bacillussubtilis

Salinity negatively impacts crop production by affecting physiological and biochemical processes in plants. This study investigates the effectiveness of Nano-ZnO (NZn), proline (PA), Nano-TiO2 (NTi), Nano-SiO2 (NSi)), and biochar inoculated with Bacillus subtilis (OSBS) in enhancing wheat tolerance to salinity stress. Pot experiments were conducted under saline conditions with varying rates of biochar and foliar applications. Results indicated that 2 % OSBS with NZn and NSi significantly improved wheat growth, leaf area, and nutrient level, reducing the negative impacts of salinity.

Antifungal and Antioxidant Properties of Some Artificial Antioxidants, Generally Recognized as Safe Compounds and Nano-Oxides

In this study, the usage potential of some artificial antioxidants, generally recognized as safe (GRAS) compounds and nano-oxides solutions in wood preservation industry, was investigated. For this purpose, antifungal and antioxidant properties of solutions were determined. Erythorbic acid, ethoxyquin, potassium disulfide, sodium ascorbate, sodium erythorbate and Enginerring and Nature Sciences Faculty (TBHQ) were selected as artificial antioxidants; dehydroacetic acid, sorbic acid and sodium benzoate were used as GRAS compounds and nano MgO, nano CeO, nano ZnO, nano SiO2 and TiO2 were investigated as nano-oxides in this study. Three different concentrations (0.5%, 1.0% and 1.5% ) were prepared, and anti-fungal test were carried out. The brown rot fungus Coniophora puteana (Schumach.) P. Karst. (BAM Ebw. 15) was used for the anti-fungal test. Then antioxidant activity of the solutions were determined. Iron (III) ion reducing antioxidant power method (FRAP) was used to determine the antioxidant activity of solutions. All solutions at 1.5% concentration completely inhibited the growth of C. puteana fungus. The antioxidant activity of solutions was sorted as artificial antioxidants&gt;GRAS compounds&gt;nano-oxides, respectively. It was concluded that the tested substances can be used as impregnating agents in wood preservation.

Phytochemical fabrication of ZnO nanoparticles and their antibacterial and anti-biofilm activity

The synthesis of metal nanoparticles through bio-reduction is environmentally benign and devoid of impurities, which is very important for biological applications. This method aims to improve ZnO nanoparticle's antibacterial and anti-biofilm activity while reducing the amount of hazardous chemicals used in nanoparticle production. The assembly of zinc oxide nanoparticles (ZnO NPs) is presented via bio-reduction of an aqueous zinc nitrate solution using Echinochloacolona (E. colona) plant aqueous leaf extract comprising various phytochemical components such as phenols, flavonoids, proteins, and sugars. The synthesized nano ZnO NPs are characterized by UV–visible spectrophotometer (UV–vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (X-RD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elemental composition by energy-dispersive x-ray spectroscopy (EDX). The formation of biosynthesized ZnO nanoparticles was confirmed by the absorbance at 360–370 nm in the UV–vis spectrum. The average crystal size of the particles was found to be 15.8 nm, as calculated from XRD. SEM and TEM analysis of prepared ZnO NPs confirmed the spherical and hexagonal shaped nanoparticles. ZnO NPs showed antibacterial activity against Escherichia coli and Klebsiella pneumoniae with the largest zone of inhibition (ZOI) of 17 and 18 mm, respectively, from the disc diffusion method. Furthermore, ZnO NPs exhibited significant anti-biofilm activity in a dose-dependent manner against selected bacterial strains, thus suggesting that ZnO NPs can be deployed in the prevention of infectious diseases and also used in food preservation.

Ruthenium-doped ZnO nanostructures: Growth, characterization, and applications in waveguides and light-emitting devices

ZnO based materials are gaining importance due to its potential applications. In many of these applications, the size, shape and dopability of the structures grown play a determinant role. In the present work, ZnO nano- and microstructures doped with Ru have been grown using the Vapour-Solid (VS) method. Among the different growth parameters, gas flux and initial dopant content seem to play the major role to determine both shape and size of the structures. The main morphologies obtained are self-arranged triangular grids and elongated structures. Based on microscopic observations a simplified growth model is proposed for the grids. An exhaustive characterization has been performed. X-Ray diffraction (XRD) investigations demonstrate good crystallinity and texturing related to preferential growth direction changes due to doping. Luminescence characterization through photo- and cathodoluminescence (PL and CL) techniques reveals typical ZnO near band edge and deep level emission bands at 3.2 and 2.3 eV, respectively. The potential use of elongated structures as waveguides and optical cavities, Fabry-Pèrot resonators, is explored.

Sustainable Green Synthesis and Molecular Docking Study of a Bis-Fused System Incorporating Pyrido[2,3-d]pyrimidine using Nanocatalyst under Microwave Condition

Aims: This study aimed to employ sustainable green methods in the synthesis of bisfused cycles incorporating pyrido[2,3-d]pyrimidine moiety using a green catalyst nano ZnO catalyst by one-pot, multicomponent reaction among 2,2'-(propane-1,3-diylbis(sulfanediyl)) bis(6-aminopyrimidin-4(3H)-one) 3, 1H-indene-1,3(2H)-dione 4, and aromatic aldehydes 5. Method: The reactions proceeded with both conventional and microwave (MW) irradiation methods. Result:: The microwave-assisted method carried out the reaction in 10 min and had high yields (89-95%). Conclusion: A molecular docking simulation study was conducted using human serum albumin (PDB: ID (2XVQ)). The study revealed that compounds strongly fit into the active sites of the target protein.

Synthesis of ZnO and NiO nano ceramics composite high-performance supercapacitor and its catalytic capabilities

NiO and ZnO mixed nanocomposites were manufactured using the solution combustion process. As-prepared samples were analyzed using XRD. The XRD shows an average crystallite size of 35–40 nm. The elemental composition determined by EDS indicates a nearly equal proportion of Ni and Zn, with an atomic ratio of Ni/Zn = 0.96. The specific capacitances of NiO is 295.5 Fg-1, ZnO is 117.3 Fg-1 and ZnO/NiO nanocomposites is 561.75 Fg-1 which are more than NiO and ZnO alone. This study shows that constructing binary oxide nanocomposites is an approach for developing high-performance supercapacitor electrode materials. Experimental observations on catalytic activity revealed that NiO/ZnO increased catalytic activity. Furthermore, adding NiO to ZnO in the composite increased the overall amount of oxygen vacancies in the samples. Our research lays the door for a simple, inexpensive, nontoxic, and quick technique to synthesize binary transition metal oxide-based electrode materials for high-performance supercapacitors.

Evaluation of the teratogenic potency of bulk zinc oxide and its nanoparticles on embryos of the freshwater snail, Helisoma duryi

Bulk zinc oxide (ZnO-BPs) and its nanoparticles (ZnO-NPs) are frequently used in various products for humans. Helisoma duryi embryos can serve as effective model organisms for studying the toxicity of NPs. This study aimed to compare the teratogenic potency of ZnO-BPs and ZnO NPs in the embryonic stages of H. duryi to evaluate the utility of this snail as a bioindicator for ZnO-NPs in the aquatic environment. The mechanisms of teratogenesis were evaluated by determination of the LC50, studying the effect of sub-lethal concentrations of both ZnO forms on the embryos, and studying their enzyme activity, oxidative stress, and biochemical analysis. The SDS-PAGE electrophoresis was undertaken to assess the effect of ZnO-BPs and ZnO NPs on protein synthesis. The results revealed that the veliger stage of H. duryi is the specific stage for bulk and nano ZnO. ZnO-NPs proved to be more toxic to snails’ embryos than ZnO-BPs. Exposure to ZnO influences specific types of defects in development, which in the case of BPs are far less drastic than those caused by NPs. Thus, the toxicity of ZnO-NPs in embryonic development is due to their unique physicochemical properties. The observed malformations include mainly hydropic malformation, exogastrulation, monophthalmia, shell misshapen, and cell lyses. Almost all tested oxidative biomarkers significantly changed, revealing that ZnONPs display more oxidative stress than ZnO-BPs. Also, the low concentration of ZnO induces many disturbances in the organic substances of veliger larvae, such as a decrease in the total protein and total lipid levels and an increase in the glycogen level. The results indicated that ZnO-BPs increase the number of protein bands. Conversely, ZnO-NPs concealed one band from treated egg masses, which was found in the control group. Embryos of snail are an appropriate model to control freshwater snails. This study demonstrates that H. duryi embryos can serve as effective model organisms to study the toxicity of ZnO-NPs.