Composition Of Zn Research Articles

Implications of incorporating CrFeNiTiZn high-entropy alloy on the tribomechanical and microstructure morphology behaviour of A356 composites processed by friction stir processing

Abstract This study investigated the impact of incorporating a CrFeNiTiZn High Entropy Alloy (HEA) into the A356 aluminum matrix through the friction stir processing (FSP) technique. The CrFeNiTiZn HEA, renowned for its compositional complexity and high-performance potential, was incorporated into the A356 alloy with different weight percent combinations to enhance its mechanical and tribological characteristics. The results revealed a refined microstructure characterized by solid solution phases and potential intermetallic compound formation due to the HEA addition for A356/2 %Cr2 %Fe2 %Ni2 %Ti2 %Zn composition. Strong interfacial bond strength was also observed among the matrix and reinforcement particles for the A356/2 %Cr2 %Fe2 %Ni2 %Ti2 %Zn composition. The number of grains was found to be about 1820.34 (average grain size is 686 µm) for A356/2 %Cr2 %Fe2 %Ni2 %Ti2 %Zn processed composite with FSP per square inch at 500 magnifications. The A356/2 %Cr2 %Fe2 %Ni2 %Ti2 %Zn composite exhibited improved tensile strength (35.70 %) and hardness (63.33 %) after the addition of 2 %Cr2 %Fe2 %Ni2 %Ti2 %Zn into A356 alloy, attributed to the strengthening effect of HEA particles. Furthermore, wear resistance is notably enhanced, likely due to the synergistic effects of the HEA’s inherent hardness and the modified microstructure.

Primitive asteroids as a major source of terrestrial volatiles.

The origins of Earth's volatiles are debated. Recent studies showed that meteorites display unique mass-independent isotopic signatures of the volatile element Zn, suggesting that Earth's Zn originated from materials derived from different regions of the Solar System. However, these studies largely omitted meteorites from the differentiated planetesimals thought to represent the Earth's building blocks, which underwent melting and substantial volatile loss. Here, we characterize the mass-independent Zn isotope compositions of meteorites from such planetesimals. We incorporate these results in mixing models that aim to reproduce Earth's abundance and isotope compositions of Zn and other elements. Our results suggest that, while differentiated planetesimals supplied ~70% of Earth's mass, they provided only ~10% of its Zn. The remaining Zn was supplied by primitive materials that did not experience melting and associated volatile loss. Combined with other findings, our results imply that an unmelted primitive material is likely required to establish the volatile budgets of the terrestrial planets.

Investigation of the concentration and isotopic composition of Cu, Fe and Zn in human biofluids in the context of Alzheimer’s disease via tandem and multi-collector inductively coupled plasma-mass spectrometry

Studies on essential trace elements in the context of Alzheimer’s disease (AD) concluded that Cu, Fe and Zn interact with amyloid-β, accelerating plaque formation in the brain. Additionally, Cu and Fe in the vicinity of plaques produce reactive oxygen species (ROS) resulting in oxidative stress, whereas Zn plays a role in the antioxidant defence as a co-factor for antioxidants. In this work, the Cu, Fe and Zn concentrations and isotope ratios were determined in whole blood, blood serum and cerebrospinal fluid of 10 patients diagnosed with AD and 8 control individuals, using tandem (ICP-MS/MS) and multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS), respectively. In whole blood and blood serum of AD patients, a heavier Cu isotopic composition was observed (significant for whole blood only) compared to controls. Albumin levels in cerebrospinal fluid tend to increase with age, which could indicate an increased leakiness of the blood-brain barrier. In cerebrospinal fluid, a large variability was observed for the Cu and Fe isotope ratios, potentially resulting from that leakiness at the blood-brain barrier. Therefore, potential effects of AD on the concentration and isotopic composition of essential elements in cerebrospinal fluid related to amyloid-β formation could be hidden. Finally, in blood serum, Zn, urea and creatinine concentrations showed an increase with age and showed a significant difference between sexes.

Balancing the oceanic Zn isotope budget: The key role of deep-sea pelagic sediments

Abstract Oxygenated deep-sea pelagic sediments with Fe-Mn–oxide particles represent a key oceanic oxic sink for transition metals in the modern ocean. However, the isotopic composition of authigenic Zn in the pelagic zone remains poorly constrained, which hampers our understanding of the global budget of Zn isotopes. Here, we analyzed the Zn isotopic compositions of two deep-sea pelagic sediment columns collected from the Pacific Ocean. The results show that authigenic Zn in deep-sea sediments is primarily hosted by the Fe-Mn (oxyhydr)oxides. The light Zn isotopic signatures (δ66Zn: −0.02‰ to 0.34‰, n = 42; computed as the per mille deviation of the 66Zn/64Zn ratio from the JMC-Lyon standard) observed in deep-sea sediments are completely different from the previously assumed values of ~1.0‰ based on the Zn isotopic compositions of Fe-Mn crusts and nodules. Based on this observation (Zn flux of deep-sea sediments = 5.3 × 108 mol yr–1), we propose a new, balanced global budget for Zn isotopes.

Essential minerals and anti-nutritional compounds in plant-based burgers using the infogest in vitro digestion protocol

Plant-based burgers (PBB) are becoming a worldwide popular alternative to meat-based burgers (MBB). Still, their mineral composition can differ significantly depending on the ingredients used, the effect of the matrix, and the chemical form of the elements that influence solubility in the digestive tract. Thus, the study evaluated the total content and bioaccessibility of calcium (Ca), iron (Fe), magnesium (Mg), manganese (Mn), and zinc (Zn) in commercial samples of PBB and MBB. Tests used acid mineralization in an analytical microwave, following INMETRO for method validation. Results, in mg/100 g, of Ca (22.2–144), Fe (3.52–12.9), Mg (21.6–120), Mn (<LOQ-2.26), and Zn (0.91–3.47) observed for PBB indicated extensive variation; and for MBB composition of Ca (<LOQ-8.15), Fe (1.79–2.06), Mg (18.2–20.1), Mn (<LOQ), and Zn (5.42–6.86) presented low variation. The percentage of bioaccessibility, was significant in chickpea PBB for Ca (31.5 %), Fe (51.2 %), Mg (81.0 %), Mn (61.7 %), and Zn (48.0 %). MBB also showed bioaccessibility for Ca (92.4 %), Fe (60.0 %), and Mg (83.6 %). Anti-nutritional compounds such as myo-inositol phosphates and total dietary fiber did not affect negatively mineral bioaccessibility in PBB evaluated. To date, this study is the first to carry out in vitro digestion simulation assays using the INFOGEST 2.0 protocol to evaluate the bioaccessibility of essential minerals in PBB and anti-nutritional compounds. In addition, the data presented can help manufacturing companies develop more nutritious and competitive plant-based meat analogs (PBMA) as PBB. They can also influence dietary recommendations and public health policies by identifying foods nutritionally more suitable, which has a positive impact on public health. With this information, consumers can make more informed and responsible food choices, based on nutritional needs.

Structure- and Morphology-Controlled Synthesis of Hexagonal Ni2-x Zn x P Nanocrystals and Their Composition-Dependent Electrocatalytic Activity for Hydrogen Evolution Reaction.

Nickel phosphides are an emerging class of earth-abundant catalysts for hydrogen generation through water electrolysis. However, the hydrogen evolution reaction (HER) activity of Ni2P is lower than that of benchmark Pt group catalysts. To address this limitation, an integrated theoretical and experimental study was performed to enhance the HER activity and stability of hexagonal Ni2P through doping with synergistic transition metals. Among the nine dopants computationally studied, zinc emerged as an ideal candidate due to its ability to modulate the hydrogen binding free energy (ΔG H) closer to a thermoneutral value. Consequently, phase pure hexagonal Ni2-x Zn x P nanocrystals (NCs) with a solid spherical morphology, variable compositions (x = 0-17.14%), and size in the range of 6.8 ± 1.1-9.1 ± 1.1 nm were colloidally synthesized to investigate the HER activity and stability in alkaline electrolytes. As predicted, the HER performance was observed to be composition-dependent with Zn compositions (x) of 0.03, 0.07, and 0.15 demonstrating superior activity with overpotentials (η-10) of 188.67, 170.01, and 135.35 mV, respectively at a current density of -10 mA/cm2, in comparison to Ni2P NCs (216.2 ± 4.4 mV). Conversely, Ni2-x Zn x P NCs with x = 0.01, 0.38, 0.44, and 0.50 compositions showed a notable decrease in HER activity, with corresponding η-10 of 225.3 ± 3.2, 269.9 ± 4.3, 276.4 ± 3.7 and 263.9 ± 4.9 mV, respectively. The highest HER active catalyst was determined to be Ni1.85Zn0.15P NCs, featuring a Zn concentration of 5.24%, consistent with composition-dependent ΔG H calculations. The highest performing Ni1.85Zn0.15P NCs displayed a Heyrovsky HER mechanism, enhanced kinetics and electrochemically active surface area (ECSA), and superior corrosion tolerance with a negligible increase of η-10 after 10 h of continuous HER. This study provides critical insights into enhancing the performance of metal phosphides through doping-induced electronic structure variation, paving the way for the design of high-efficiency and durable nanostructures for heterogeneous catalytic studies.

Corrosion Behavior and Mechanical Properties of Zn–Ti Alloys as Biodegradable Materials

The influence of the chemical composition and structural state of Zn–Ti alloys on corrosion behaviour and mechanical properties was studied. Zn-based alloys were investigated, more precisely, pure technical Zn and Zn with 0.10, 0.25 and 1.00 wt.% Ti. The microstructure and chemical composition of these materials were analysed using light optical microscopy (LOM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The chemical composition of the alloys and the surface after immersion were analysed using an EDS detector from Bruker. The alloys’ electro-chemical corrosion resistance was further investigated through linear (LP) and cyclic (CP) potentiometry and open-circuit potential (OCP) analysis. A tensile/compression equipment (Instron 34SC-5) was used to determine the compression behaviour. UMT testing equipment was used to determine microhardness (by Rockwell indentation) and COF vs. length. For percentages higher than 0.25 wt.% Ti, the formation of a primary TiZn16 intermetallic compound in the (α-Zn + TiZn16) eutectic matrix was observed, a slight influence of TiZn16 on the Zn corrosion resistance results, and a greater influence on the mechanical properties was confirmed.

Copper-doped zinc tartrate (Cu-ZnT) nanocrystals: Exploring their physical and antimicrobial properties

This study investigates the growth and properties of pure zinc tartrate (ZnT) and copper-doped zinc tartrate (Cu-ZnT) nanocrystals synthesized via a sol-gel technique using double-distilled water, sodium metasilicate, and tartaric acid. Controlled pH gels were prepared with the subsequent addition of zinc chloride and copper chloride solutions to facilitate nanocrystal formation. The synthesized nanocrystals were characterized using various techniques, including Energy-Dispersive X-ray analysis, Fourier Transform Infrared Spectroscopy, Thermogravimetric analysis, UV–visible-near infrared spectral analysis, X-ray diffraction (XRD), and Field Emission Scanning Electron Microscopy. EDAX confirmed the elemental composition of Zn, Cu, C, and O in the crystals. FTIR spectra revealed the presence of functional groups corresponding to water of crystallization, tartaric acid moieties, and potentially other compounds. TGA analysis indicated a two-stage decomposition process for ZnT and the formation of zinc copper oxide in Cu-ZnT. UV–vis-NIR analysis yielded a low cut-off wavelength of 285 nm for both crystals, suggesting electronic transitions below 350 nm. Both ZnT and Cu-ZnT nanocrystals are transparent in visible and near-infrared light, absorbing strongly in the ultraviolet. Copper doping enhances Cu-ZnT light absorption. While both act as insulators, Cu-ZnT exhibits significantly higher conductivity due to copper doping. XRD analysis estimated an average crystalline size of 42 nm, while FE-SEM images revealed a quasi-spherical morphology. Refractive index, extinction coefficient, and optical bandgap were further determined, highlighting the potential suitability of these nanocrystals for optoelectronic applications. Antibacterial and antifungal assays demonstrated moderate effectiveness against tested microorganisms compared to standard drugs.

Assessment of particulate Zn and Pb sources in the Orne watershed (Northeast France) using geochemical tools.

The Orne River, a tributary of the Moselle River, was highly impacted by industrial activities for more than one century. Land use along the Orne River is highly contrasted, with local specificity from its source to its junction with the Moselle River. The intense industrial activity left behind tons of steelmaking wastes (SMW) on the land surface and within the Orne riverbed. To assess the sources of particulate Zn and Pb transported as suspended sediment in the Orne River, different sets of samples from likely Zn- and Pb-bearing particle sources within the Orne watershed were collected. Three sets of samples were taken from potential sources representing detrital, urban, and inherited industrial particles. Mineralogy, element contents, and Zn and Pb isotope compositions were obtained to characterize and reveal the fingerprint of each set of samples. Soil samples were collected on distinct geomorphological areas characterized by different soil types and land uses. They all display detrital minerals assigned to the geological background. Urban dusts and steelmaking residues display specific mineral phases (sulfates and iron oxides, respectively). Element compositions present strong discrepancies between the distinct sets of samples. SMWs are particularly enriched in Fe, Zn, and Pb. Concerning isotopic composition, SMWs exhibit δ66Zn values ranging from - 0.67 to 1.66‰. Urban samples display δ66Zn values between - 0.11 and 0.13‰, and soils present δ66Zn values between - 0.24 and 0.47‰. The 206Pb/204Pb ratio was estimated to range from 17.550 to 18.807 for soils, from 17.973 to 18.219 for urban samples, and from 18.313 to 18.826 for SMWs. For each of the three sets of samples (soils, urban, industrial), variations of geochemical fingerprint were observed. For soils, the relatively large variations of Zn and Pb isotopic compositions were attributed to distinct land use and the contribution of atmospheric deposition. For industrial samples, the variations were more intense and may be attributed either to distinct industrial processes in the production of pig iron or to distinct furnace-flume treatment modes. The three sets of samples (urban, industrial, and detrital) could be distinguished based on Zn and Pb contents and isotopes. Finally, this study not only highlighted the sources that released particulate Zn and Pb into the Orne River system, it also demonstrated that urban particles are well defined in terms of Zn and Pb isotopic signatures, and those isotopic signatures could be extrapolated to other case studies.

Copper and zinc isotopic variations in Ni-Cu-PGE ores of the Noril’sk Province (Russia)

Research subject. Mineral assemblages of sulfides from massive and disseminated sulfide nickel-copper-platinum-group element (Ni-Cu-PGE) and low-sulfide PGE ores of the Noril’sk Province, which hosts the richest complex deposits of platinum-group metals, nickel, and copper. Aim. In order to identify sources of ore material and explore new forecasting approaches for Ni-Cu-PGE deposits, we study the Cu- and Zn isotopic compositions of sulfides from economic Kharaelakh and Noril’sk-1 intrusions containing unique and large sulphide Ni-Cu-PGE deposits (Oktyabr’sk and Noril’sk-1, respectively), subeconmic Zub-Marksheider and Vologochan intrusions containing small- to medium-size Ni-Cu-PGE deposits, and non-economic Nizhny Talnakh and Nizhny Noril’sk intrusions containing low grade disseminated Ni-Cu mineralization. Results. The analyzed samples are characterized by sulfide mineral assemblages, which contain mainly chalcopyrite, pyrrhotite, pentlandite, troilite, cubanite, and galena. Sulfide Ni-Cu-PGE ores of the Oktyabr’sk and Noril’sk-1 deposits, associated with economic intrusions (i.e., Kharaelakh and Noril’sk-1), demonstrate distinct δ65Cu values from –2.42 to –1.40‰ and from –0.33 to 0.60‰, respectively, which differ from the δ65Cu values for sulfides from other Ni-Cu-PGE deposits and ore occurrences of the Noril’sk Province (data comprise 36 analyses). We note that the Cu-isotopic composition for sulfide minerals of massive and disseminated ores from the Kharaelakh intrusion has similar “isotope-light” characteristics. The most pronounced shift towards “isotope-heavy” copper was found in the horizon of low-sulfide PGE ores of the Noril’sk-1 intrusion (δ65Cu = 0.51–0.60‰). The isotopic composition of Zn (δ66Zn) for the studied sulfide samples from economic, subeconomic, and non-economic intrusions, with the exception of one sample (0.73 ± 0.14‰), is characterized by similar “isotope-light” values (from –0.65 to –0.03‰). Conclusions. The revealed variations in the Cu- and Zn-isotopic composition in the studied sulfide assemblages from all types of ores reflect their primary characteristics; however, for the unique Oktyabr’sk Ni-Cu-PGE deposit, characterized by the most “isotopically light” composition of copper (δ65Cu = –1.9 ± 0.34‰), the possibility of assimilation of an external source of Cu during the formation of sulfide Ni-Cu-PGE ores cannot be excluded. The combined use of Cu and Zn isotopic parameters proved to be a weakly informative predictive indicator for the detection of high-grade sulfide ores, primarily due to the similarity of the Zn isotopic composition of the ore material in all investigated intrusions of the Noril’sk Province.

Detection of Al, Mg, Ca, and Zn in copper slag by LIBS combined with calibration curve and PLSR methods

The precise measurement of Al, Mg, Ca, and Zn composition in copper slag is crucial for effective process control of copper pyrometallurgy. In this study, a remote laser-induced breakdown spectroscopy (LIBS) system was utilized for the spectral analysis of copper slag samples at a distance of 2.5 m. The composition of copper slag was then analyzed using both the calibration curve (CC) method and the partial least squares regression (PLSR) analysis method based on the characteristic spectral intensity ratio. The performance of the two analysis methods was gauged through the determination coefficient (R 2), average relative error (ARE), root mean square error of calibration (RMSEC), and root mean square error of prediction (RMSEP). The results demonstrate that the PLSR method significantly improved both R 2 for the calibration and test sets while reducing ARE, RMSEC, and RMSEP by 50% compared to the CC method. The results suggest that the combination of LIBS and PLSR is a viable approach for effectively detecting the elemental concentration in copper slag and holds potential for online detection of the elemental composition of high-temperature molten copper slag.

Purification and characterization of a novel zinc chelating peptides from Holothuria scabra and its ex vivo absorption activity in the small intestine

Zinc supplements currently marketed in Indonesia are second-generation zinc supplements, which must be improved for the effectiveness caused by their low absorption rate and side effects on the gastrointestinal tract. Third-generation zinc supplements are currently being investigated to improve the effectiveness of the previous generation of supplements. The present study aimed to discover a new alternative source of zinc-chelating peptide (ZCP) from Holothuria scabra. In addition, the research investigates the ZCP characteristics and absorption abilities in an ex vivo evaluation using the everted gut sac model method. The results obtained were six zinc peptides: Asp-Asp-Ala- Phe-Gln-Ala-Phe-Cys; Thr-Asp-Asn-Leu; Leu-Gly-Cys; Pro-Gly-Thr; Ser-Cys; and Pro-Tyr. The characterization showed that the resulting peptides comprised two to eight amino acids with molecular weights between 208 and 915 Da. The highest zinc binding capacity of the peptides was 92.11 mg/100 g at 30 kDa for molecular weight. Fourier-transform infrared spectra indicate that zinc ions (Zn2+) bind to carboxyl groups and interact with nitrogen atoms in amino acids and amides. The scanning electron microscope-energy dispersion spectroscopy results stated that, topographically and morphologically, ZCP has a different surface with peptides with Zn composition in the sample. Furthermore, we evaluated the peptide fractions for ex vivo absorption in the small intestine using the everted gut sac method. We found that zinc-binding peptides transported and enhanced zinc absorption in the duodenum segment at 60 minutes, resulting in a 40% increase in absorption rate. The potency of ZCPs from H. scabra as an alternative to third-generation zinc supplements with higher absorption than previous-generation supplements.

Stable isotope composition and concentration systematics of Ca and trace elements (Zn, Sr) in single aliquots of fossil bone and enamel

Measurements of modern bone and tooth enamel show that calcium stable isotopes (δ44Ca), zinc (δ66Zn), and strontium (δ88Sr) have great potential as ecological and dietary tracers for studies on fossil material. Despite the fact that these three elements can be recovered using sequential chromatographic extraction from a single aliquot, a multi-proxy study has not been attempted yet, which would allow a less destructive analysis of precious fossil material. The present study consists of analyzing δ44Ca, δ66Zn, δ88Sr, and 87Sr/86Sr values in fossil bone and tooth enamel of carnivore and herbivore mammals from the Camiac cave (Upper Pleistocene, Gironde, France). Our study aims at (1) developing a protocol for Ca, Zn, and Sr stable isotope analyses from a single fossil bone or enamel aliquot; (2) testing the respective preservation of biological isotopic signatures in bone and tooth enamel; and (3) comparing the patterning of the different isotopic systems in a fossil mammal community. In the present study, fossil enamel samples have not been leached, as it has been done so far for Zn isotope analyses, but fossil bone samples have been leached using diluted acetic acid or were left unleached. Using inclusive statistical analyses, we identify the effect of leaching on bone chemical compositions, and the concentration and isotope composition of Ca, Zn, and Sr in leached bone and unleached enamel show no sizeable diagenetic overprint. We report for the first time δ66Zn values in fossil bone. The results show that bone δ66Zn values mirror the pattern already observed in enamel, e.g., a significant trophic 66Zn depletion between herbivores and carnivores. Bone δ44Ca and δ88Sr values also mirror those in enamel, and the results highlight a clear distinction between ruminants and non-ruminants, the latter being 44Ca-enriched. The present study focuses on the importance of analyzing several isotopic systems in a single fossil bone or enamel aliquot and shows encouraging results for the preservation of biological isotopic signatures in fossil bone, despite the longstanding dread of a so-called associated pervasive diagenesis. The present study will therefore be useful to consider any precious fossil material with limited destructive sampling possibilities.

Insight into the role of Mg/B and Mg/Cu dual dopant on the properties of ZnO nanoparticles prepared by facile one-step combustion route for photocatalytic and antibacterial application

ZnO semiconductors are widely known to have benefits in photocatalytic and antibacterial applications. In this study, (Mg/B)–ZnO and (Mg/Cu)–ZnO were synthesized using the combustion method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), UV–Vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The XRD results confirmed a decrease in the crystal size and an increase in the crystallinity of the doped ZnO samples. SEM analysis confirmed the morphological changes in the structure from rod-shaped to spherical, and the particle size decreased in the doped ZnO samples. EDS analysis validated the nanoparticle composition of Zn, O, Mg, B, and Cu without impurities. Raman spectra confirmed the formation of defects due to the substitution of dopants in the ZnO lattice. All samples for FTIR analysis showed functional chemical group vibrations from Zn–O, C–H, and O–H stretching. The existence of dopant bonds with oxygen was also validated from this analysis. The change in band gap energy was observed from 3.13 to 3.10 eV in Mg/Cu–ZnO and 3.12 eV in Mg/B–ZnO sample due to the influence of the addition of dopant ions. The XPS spectra show the chemical composition of the nanoparticle samples and the oxidation numbers that correlate with the results of EDS and XRD analyses. A decrease in the emission intensity in the PL measurement was observed in the green emission region in the Mg/B–ZnO sample, which correlated with the decrease in electron recombination. The Photocatalytic application was performed by measuring its ability to degrade methyl violet dye under visible-light irradiation. The maximum deterioration after 120 min of irradiation was obtained for the Mg/Cu–ZnO, Mg/B–ZnO, and ZnO samples at 92.62 %, 92.20 %, and 80.89 %, respectively. Antibacterial activity increased against S. aureus bacteria in co-doped ZnO samples with inhibition zones of 12.15 mm, 8.15 mm, and 6.45 mm for Mg/B–ZnO, Mg/Cu–ZnO, and ZnO samples, respectively.

Zn‐doped MnOx nanowires displaying plentiful crystalline defects and tunable small cross-sections for an optimized volcano-type performance towards supercapacitors

MnOx-based nanomaterials are promising large-scale electrochemical energy storage devices due to their high specific capacity, low toxicity, and low cost. However, their slow diffusion kinetics is still challenging, restricting practical applications. Here, a one-pot and straightforward method was reported to produce Zn-doped MnOx nanowires with abundant defects and tunable small cross-sections, exhibiting an outstanding specific capacitance. More specifically, based on a facile hydrothermal strategy, zinc sites could be uniformly dispersed in the α-MnOx nanowires structure as a function of composition (0.3, 2.1, 4.3, and 7.6 wt.% Zn). Such a process avoided the formation of different crystalline phases during the synthesis. The reproducible method afforded uniform nanowires, in which the size of cross-sections decreased with the increase of Zn composition. Surprisingly, we found a volcano-type relationship between the storage performance and the Zn loading. In this case, we demonstrated that the highest performance material could be achieved by incorporating 2.1 wt.% Zn, exhibiting a remarkable specific capacitance of 1082.2 F.g−1 at a charge/discharge current density of 1.0 A g−1 in a 2.0 mol L−1 KOH electrolyte. The optimized material also afforded improved results for hybrid supercapacitors. Thus, the results presented herein shed new insights into preparing defective and controlled nanomaterials by a simple one-step method for energy storage applications.

Bio‐inspired synthesis of bio‐hydroxyapatite/synthetic hydroxyapatite hybrid nanosystems

AbstractThe current study focuses on the synthesizing of novel hybrid nanosystems of bio‐hydroxyapatite (BioHAp)/synthetic‐hydroxyapatite (HAp‐Syn). Bio‐HAp was defatted, deproteinized, and then sonicated to obtain nanoparticles (nBioHAp). Hybrid nanosystems (HNS) were synthesized by wet chemical precipitation using nBioHAp as nucleation sites and applying four different precipitation times of 45, 90, 135, and 180 min. X‐ray diffraction (XRD) showed that the patterns of the nBioHAp and HAp‐Syn samples have broadened diffraction peaks due to simultaneous elastic and inelastic scattering. Their crystallite size is about 25 nm, while the hybrid nanosystems have a size between 35 and 40 nm. Fourier‐transform infrared spectroscopy (FT‐IR) revealed the main groups associated with hydroxyapatite (PO32−, OH−, and CO32−), and the nanometer character of the crystals was demonstrated by studying the full width at half maximum (FWHM) of the spectra. Scanning electron microscopy (SEM) revealed the differences between the morphologies of nBioHAp and HAp‐Syn. The shape of HNS resembled that of biogenic HAp, which was confirmed by transmission electron microscopy (TEM). Inductively coupled plasma spectroscopy (ICP‐OES) and energy dispersive X‐ray spectroscopy (EDS) were used to confirm the elemental composition of Mg, Na, K, and Zn as minority ions.

Tailoring the *CO and *H Coverage for Selective CO2 Electroreduction to CH4 or C2H4.

In the electrochemical CO2 reduction reaction (CO2RR), the coverages of *CO and *H intermediates on a catalyst surface are critical for the selective generation of C1 or C2 products. In this work, we havesynthesized several CuxZnyMnz ternary alloy electrocatalysts, including Cu8ZnMn, Cu8Zn6Mn, and Cu8ZnMn2, by varying the doping compositions of Zn and Mn, which are efficient in binding *CO and *H adsorbates in the CO2 electroreduction process, respectively. The increase of *H coverage allows to promotion of the CH4 and H2 formation, while the increase of the *CO coverage facilitates the production of C2H4 and CO. As a result, the Cu8ZnMn catalyst presented a high CO2-to-CH4 partial current density (-418±22mAcm-2) with a Faradaic efficiency of 55±2.8%, while the Cu8Zn6Mn catalyst exhibited a CO2-to-C2H4 partial current density (-440±41mAcm-2) with a Faradaic efficiency of 58±4.5%. The study suggests a useful strategy for rational design and fabrication of Cu electrocatalysts with different doping for tailoring the reduction products.

Influence of Al contents on the long-term corrosion behaviors of cold-sprayed Zn-xAl coatings

ZnAl coating is considered one of the most economic candidates for marine static immersive corrosion protecting technology, in which the Al/Zn ratio is quite crucial to achieve a certain aggressive ions concentration corrosion. In this study, different Al contents Zn-xAl composite coatings were prepared using low-pressure dynamic cold spraying, potentiodynamic polarization and electrochemical impedance spectroscopy techniques were implied to reveal the long-term corrosion behaviors in 3.5 wt% NaCl solution and experimentally optimize the Al and Zn composition of the composite coating for marine static immersion corrosive resistance. The results showed that the weight loss kinetics curve of Zn-xAl composite coatings conforms well to a linear equation over time after logarithms, an increase in Al content leads to enhanced corrosion resistance of Zn-xAl composite coatings. After 1440 h immersion, the optimum Zn95Al composite coating, with high ECorr (−1.522 V) and low ICorr ((4.881 ± 0.98) × 10−5 A/cm2), presented the best corrosion resistance, due to the compact network passive film composing of Al(OH)3 and Al2(OH)5Cl∙2H2O, which slowed down mass-transfer step of Zn/Al elements.

Investigation on the influence of Zn content on the structural, optical, morphological and electrical properties of ternary compound Cd1−xZnxS window layer for CdTe solar cell

Ternary compound Cd[Formula: see text]Zn[Formula: see text]S thin films with different zinc compositions were deposited by the chemical bath deposition method, as a window layer for CdTe solar cells. The influence of Zn content on the structural, optical, morphological and electrical properties of Cd[Formula: see text]Zn[Formula: see text]S was studied from X-ray diffraction (XRD), SEM and UV-vis spectroscopy. We have considered the transformation of the crystal phase, change in the crystallite size and lattice parameters of Cd[Formula: see text]Zn[Formula: see text]S thin film with the change of Zn content through XRD studies. SEM measurement revealed that the size of Cd[Formula: see text]Zn[Formula: see text]S particles and surface roughness of thin film decreases with the increase of Zn composition. It was found that the band gap value obtained from transmittance spectrum became wider with the increase of Zn contents, which indicates the increase of film transmittance. The electrical resistivity of Cd[Formula: see text]Zn[Formula: see text]S thin films increased as Zn content [Formula: see text] increases. Finally, we measured the performances of CdTe solar cells using Cd[Formula: see text]Zn[Formula: see text]S thin films as a window layer and confirmed that desirable Zn content was in the range [Formula: see text] = 0.5-0.6.

Study of biocompatibility and antitumor cytotoxic activity &lt;i&gt;in vitro&lt;/i&gt; of Zn – 1 %Mg and Zn – 1 %Mg – 0.1 %Ca alloys strengthened by equal angular pressing

Introduction. The biological activity of potential biodegradable zinc-based alloys that are promising for oncoorthopedics was studied in this work. The alloys were processed by equal-channel angular pressing, which made it possible to increase their strength due to microstructure refinement and the ability to provide the functionality of osteosynthesis, fixed due to the metal structure developed on their basis.Aim. Investigation of effect of equal-channel angular pressing (ECAP) treatment on strength, ductility, degradation rate, biocompatibility in vitro and cytotoxicity against SKOV-3 tumor cells of the Zn – 1 %Mg and Zn – 1 %Mg – 0.1 %Ca alloys.Materials and methods. The Zn – 1 %Mg and Zn – 1 %Mg – 0.1 %Ca alloys in the initial state and after ECAP were used as objects of study, and blood cells of CBA mice were used as model systems. To assess the hemolytic activity, the samples were incubated with red blood cells for 4 and 24 hours at 37 °C, assessing the relative increase in the level of extracellular hemoglobin compared to the intact control. The cytotoxicity of the alloys was assessed by the change in the level of extracellular lactate dehydrogenase (LDH) activity after 24 hours of incubation with mononuclear white blood cells. The study of antitumor cytotoxic activity was carried out on human ovarian cancer cells of the SKOV-3 line in vitro, assessing their survival after 48 hours of incubation with alloy samples using the LDH test.Results. As a result of the studies, it was concluded that the studied alloys after ECAP treatment retained their biocompatibility, since there were no signs of hemolysis and cytotoxicity with respect to blood cells. However, contact with samples of all studied alloys in vitro induced a significant inhibition of the metabolic activity of the ovarian cancer cell culture in comparison with the control. Incubation with alloys samples leads to a decrease in cellular activity by an average of 49 % and 59 % for Zn – 1 %Mg and Zn – 1 %Mg – 0.1 %Ca alloys, respectively. The addition of calcium to the composition of the alloy Zn – 1 %Mg contributed to the growth of antitumor cytotoxic activity.Conclusion. Thus, based on the results of assessing the hemolytic activity and cytotoxicity of the samples, we can conclude that the studied alloys are biocompatible. It was also found that Zn – 1 %Mg and Zn – 1 %Mg – 0.1 %Ca alloys had a pronounced cytotoxic effect on SKOV-3 tumor cells. The obtained data indicate the prospects for the development of a new type of medical devices based on the studied alloys, promising, in particular, for oncoorthopedics: a metal structure developed on their basis can ensure the strength of osteosynthesis, reduce the risk of local recurrence of oncological disease and does not require a second operation to remove the device.