• Journal of Powder Materials
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• v.28 no.6
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• pp.455-461
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• 2021

In this study, multilayered SnO nanoparticles are prepared using oleylamine as a surfactant at 165℃. The physical and chemical properties of the multilayered SnO nanoparticles are determined by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Interestingly, when the multilayered SnO nanoparticles are heated at 400℃ under argon for 2 h, they become more efficient anode materials, maintaining their morphology. Heat treatment of the multilayered SnO nanoparticles results in enhanced discharge capacities of up to 584 mAh/g in 70 cycles and cycle stability. These materials exhibit better coulombic efficiencies. Therefore, we believe that the heat treatment of multilayered SnO nanoparticles is a suitable approach to enable their application as anode materials for lithium-ion batteries.

• Journal of Electrochemical Science and Technology
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• v.12 no.2
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• pp.188-203
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• 2021

The specific benefits of the modified films formed on preliminary anodized aluminum, including the versatility of their potential applications impose the need for evaluation of the exploitation reliability of these films. In this aspect, the durability of Cu and Ni modified anodized aluminum oxide (AAO) films on the low-doped AA1050 alloy was assessed through extended exposure to a 3.5% NaCl model corrosive medium. The electrochemical measurements by means of electrochemical impedance spectroscopy (EIS) and potentiodynamic scanning (PDS) after 24 and 720 hours of exposure have revealed that the obtained films do not change their obvious barrier properties. In addition, supplemental analyses of the coatings were performed, in order to elucidate the impact of the AC-deposition of Cu and Ni inside the pores. The scanning electron microscopy (SEM) images have shown that the surface topology is not affected and resembles the typical surface of an etched metal. The subsequent energy dispersive X-ray spectroscopy (EDX) tests have revealed a predominance of Cu in the combined AAO-Cu/Ni layers, whereas additional X-ray photoelectron (XPS) analyses showed that both metals form oxides with different oxidation states due to alterations in the deposition conditions, promoted by the application of AC-polarization of the samples.

• Korean Journal of Materials Research
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• v.32 no.1
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• pp.1-8
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• 2022

In this investigation, Bi₂MoO₆ deposited graphene nanocomposite (BMG) was synthesized using a simple microwave assisted hydrothermal synthesis method. The synthesized BMG nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy with energy dispersive X-ray analysis, and photocurrent analysis. The study revealed that the catalysts prepared have high crystalline nature, enhanced light responsive property, high catalytic activity, and good stability. XRD results of BMG composite exhibit a koechlinite phase of Bi₂MoO₆. The surface property is shown by SEM and TEM, which confirmed a homogenous composition in the bulk particles of Bi₂MoO₆ and nanosheets of graphene. The catalytic behavior was investigated by the decomposition of Rhodamine B as a standard dye. The results exhibit excellent yields of product derivatives at mild conditions under ultrasonic/visible light-medium. Approximately 1.6-times-enhanced sono-photocatalytic activity was observed by introduction of Bi₂MoO₆ on graphene nanosheet compared with control sample P25 during 50 min test.

• Computers and Concrete
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• v.29 no.4
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• pp.237-246
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• 2022

The concrete quality relies on general factors like preparation technique, uniformity of the compaction, amount and appropriateness of the additives. The current article investigates the impact of a well knows amino acid, L-arginine as an additive on water requirements, setting durations and characterization of various cement samples. Compressive strength tests of reference and L-arginine added cements at age of 2, 7 and 28 days were carried out according to TS-EN 196-1. Samples were blended by incorporating various amounts of L-arginine (25 ppm, 50 ppm and 75 ppm) in the cement water mixture which were tested with Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TG), scanning electron microscopy (SEM) and the energy-dispersive X-ray spectroscopy (EDS) on the 28th day. Results revealed that L-arginine does not affect the setting time, volume expansion of cement and water demands negatively; rather it imparts enhanced sustainability to the samples. It was determined that the highest value belonged to the 75L mortar with an increase of 2.6% compared to the reference sample when the compressive strengths of all mortars were compared on the 28th day. Besides, it has been observed that the development of calcium silicate hydrate or C-S-H gel, calcium hydroxide or CH and other hydrated products are associated with each other. L-arginine definitely has a contribution in the consumption of CH formed in the hydration process.

• Journal of Surface Science and Engineering
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• v.55 no.3
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• pp.143-155
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• 2022

Ceramic oxide layers successfully were formed on the surface of cast Al alloys with high Si contents using plasma electrolytic oxidation (PEO) process in electrolytes containing Na₂SiO₃, NaOH, and additives. The microstructure of the oxide layers was systematically analyzed using scanning electron microscopy (SEM), cross-sectional transmission electron microscopy (TEM), X-ray diffraction patterns (XRD), and energy X-ray dispersive spectroscopy (EDS). XRD analysis indicated that the PEO untreated high-silicon Al alloys (i.e., 17.1 and 11.7 wt.% Si) consist of Al, Si and Al₂Cu phases whereas Al₂Cu phase selectively disappeared after PEO treatment. PEO process yielded an amorphous oxide layer with few second phases including γ-Al₂O₃ and Fe-rich phases. The corrosion behaviors of high-silicon Al alloys treated by PEO process were investigated using electrochemical impedance spectroscopy (EIS) and other electrochemical techniques (i.e., open circuit potential and polarization curve). Electroanalytical studies indicated that high-silicon Al alloys treated by PEO process have greater corrosion resistance than high-silicon alloys untreated by PEO process.

• Corrosion Science and Technology
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• v.22 no.1
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• pp.1-9
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• 2023

This work studied the inhibitory effect of the combination of benzoate-intercalated hydrotalcite (HT-BZ) and Ce³⁺-loaded clay (Clay-Ce) on carbon steel (CS). HT-BZ was prepared by the co-precipitation method and Clay-Ce was fabricated by a cation exchange reaction. HT-BZ and Clay-Ce were assessed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) coupled with zeta potential measurement. Electrochemical measurements coupled with scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) were used for studying the inhibitory action of the mixture of HT-BZ and Clay-Ce on steel electrodes immersed in 0.1 M NaCl. For comparison, the inhibitory effect of HT-BZ or Clay-Ce alone was also evaluated. The results showed that HT-BZ combined with Clay-Ce provided synergistic inhibition of the CS substrate. The mixture of 0.5 g/L HT-BZ + 0.5 g/L Clay-Ce provided 93.5% inhibition efficiency. The protective mechanism of the HT-BZ + Clay-Ce mixture consisted of the reaction of released BZ and Ce³⁺ and the deposition of HT-BZ and Clay-Ce structures on the CS substrate.

• Membrane and Water Treatment
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• v.13 no.2
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• pp.73-83
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• 2022

In the present study, we compared the adsorption capacity of Pb (II) from contaminated water of used cardboard (UC) and a commercial powdered activated carbon (PAC), the latter has been characterized by different techniques, namely X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), wavelength dispersion x-ray fluorescence (WDXRF), infrared spectroscopy (IR) and surface area B.E.T analyzer. The effect of various parameters, such as the pH, the contact time, the amount of adsorbent, and the temperature on the adsorption of Pb (II) on both materials was investigated. The Pb (II) adsorptions are perfectly described by a pseudo-second-order model, while the intraparticle diffusion is a decisive step after the first minutes of contact. The fit to the Langmuir and Redlich-Peterson models seems perfect for these adsorption reactions. (PAC) showed a greater affinity for Pb (II) compared to (UC) and the adsorption of Pb (II) ions is strongly pH-dependent, on the other hand, the increase in temperature doesn't have much influence on the two solids. This study showed that the capacity of (UC) to adsorb Pb (II) from an aqueous solution is greater than two-thirds of that of (PAC).

• Advances in nano research
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• v.14 no.6
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• pp.557-573
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• 2023

The rapid growth of zinc-oxide (ZnO) nanostructures (NSs) on woven carbon fiber (WCF) is reported in this study employing a microwave-aided chemical bath deposition process. The effects of different process parameters such as molar concentration, microwave duration and microwave power on morphologies and growth rate of the ZnO on WCF were studied. Furthermore, an attempt has been taken to study influence of different type of growth solutions on ZnO morphologies and growth rates. The surface functionalization of WCF fabrics is achieved by successful growth of crystalline ZnO on fiber surface in a very short duration through one-step microwave synthesis. The morphological, structural and compositional studies of ZnO-modified WCF are evaluated using field-emission scanning electron microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy respectively. Good amount of zinc and oxygen has been seen in the surface of WCF. The presence of the wurtzite phase of ZnO having crystallite size 30-40 nm calculated using the Debye Scherrer method enhances the surface characteristics of WCF fabrics. The UV-VIS spectroscopy is used to investigate optical properties of ZnO-modified WCF samples by absorbance, transmittance and reflectance spectra. The variation of different parameters such as dielectric constants, optical conductivity, refractive index and extinction coefficient are examined that revealed the enhancement of optical characteristics of carbon fiber for wide applications in optoelectronic devices, carbon fiber composites and photonics.

• Journal of Powder Materials
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• v.30 no.3
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• pp.233-241
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• 2023

In this study, we evaluated the effects of acid leaching on the properties of Cr powder synthesized using self-propagating high-temperature synthesis (SHS). Cr powder was synthesized from a mixture of Cr2O3 and magnesium (Mg) powders using the SHS Process, and the byproducts after the reaction were removed using acid leaching. The properties of the recovered Cr powder were analyzed via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), particle size analysis (PSA), and oxygen content analysis. The results show that perfect selective leaching of Cr is challenging because of various factors such as incomplete reaction, reaction kinetics, the presence of impurities, and incompatibility between the acid and metal mixture. Therefore, this study provides essential information on the properties under acidic conditions during the production of high-quality Cr powder using a self-propagating high-temperature synthesis method.

• Analytical Science and Technology
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• v.21 no.6
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• pp.553-561
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• 2008

$CNT/TiO_2$ composites were prepared by using multiwall carbon nanotubes (MWCNT) and various titanium alkoxide precursors. The composites were comprehensively characterized by scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and UV-vis absorption spectroscopy. The photoactivity of the prepared materials under UV irradiation, was tested using the conversion of MB from model aqueous solution. Finally, according to the results of methylene blue (MB) removal experiment, we could see that sample CTOS have better MB removal effect than samples CTIP and CTPP.