جستجوی مقالات مرتبط با کلیدواژه « nio » در نشریات گروه « شیمی »

Spray pyrolysis has been used to fabricate different mixed TiO2/NiO/In2O3 nanostructures. TiO2/NiO/In2O3 has been structurally and optically explored using X-ray diffraction, field emission scanning electron microscopy, and UV-Vis spectroscopy. The particles analysis using X-ray diffraction had a polycrystalline structure and all of the observed peaks can be assigned to the samples with nanostructure, while FESEM reveals that they are very small, spherical, and range in size from 14 to 100 nm. The UV-Vis observed the edge of absorbance at about 335-305 nm; the energy band gap was calculated to be 3.3-3.58 eV. The absorbance in this area is caused by the creation of TiO2/NiO/In2O3 nanoparticles. The synthesis of thin films was tested in gas sensor applications. The gas response of the tested samples to hydrogen sulfide gas at different operating temperatures was analysed. The thin film demonstrates that when the operating temperature got higher, sensitivity increased as well. With an increase in operational temperature, recovery and response times are slowed down.

We designed a facial and novel CeO2/NiO/NiAl2O4 nanocomposite prepared by recalcination of the cerium impregnated product of the primary calcined production of NiAl-NO3 layered double hydroxide (LDH) through the structural memory effect. The materialization of as-prepared nanocomposite was confirmed by Fourier-transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetry (TG), dynamic light scattering (DLS) and transmission electron microscopy (TEM). Morphologic studies revealed that the size of the nanocomposite was below 100 nm. The resulting mixed metal oxide nanocomposite was employed as an efficient adsorbent for the removal of Direct Red 23 (DR23) as a model pollutant from textile wastewater. The dye removal study showed >98% efficiency for the removal of dye which revealed the superiority of material for decontamination of waste water, while the maximum adsorption capacity determined from isotherm data was 588.24 mg of dye per g of the adsorbent. In addition, the reusability was also performed up to three cycles with 89, 85 and 88% efficiency for DR23. Also, thermodynamics, isotherm and kinetic studies were investigated. Overall, we offer a facile method for synthesizing CeO2/NiO/NiAl2O4 nanocomposite, efficiently decontaminating DR23 from water with good recyclability.

NiO/WO3 nanocomposites has been successfully synthesized by a precipitation deposition method with different mole ratios were synthesized and characterized by Fourier transform infrared Spectra (FT-IR), X-ray diffraction (XRD), Energy dispersive X-ray spectroscopy (EDX), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) techniques.Absorption range and band gap energy, which are responsible for the observed photocatalyst behavior, were investigated by UV-vis diffuse reflectance spectroscopy (UV-vis-DRS). The formation of cubic structured NiO and orthorhombic structured WO3 was confirmed by powder X-ray diffraction analysis. The photocatalytic activity was tested for the degradation of Crystal Violet (CV) under visible-light irradiation. It was found that 0.5-0.5 mole NiO-WO3 displayed excellent photocatalytic activity than that of 0.6-0.4 mole NiO-WO3, 0.4-0.6 mole NiO-WO3. The effect of operation parameters such as initial dye concentration, pH and catalyst concentration has been investigated in detail.The mechanisms of the enhancement of photocatalytic activity of the nanocomposite photocatalyst will be discussed by the p-n heterojunction principle and the valence band theory.The pure nanocomposite systems have been also reported for a comparative purpose.

he electro-oxidation of venlafaxine (VEN) was investigated at a carbon paste electrode, the modified electrode by NiO/Graphene Reduce (GR) nanocomposite. The structure and morphological aspects of the nanocomposite were approved using FE-SEM, EDAX, and FT-IR. The electrode reaction process was a diffusion-controlled one and the electrochemical oxidation involved two electrons transferring and two protons participating. Under the optimized conditions, the electro-oxidation peak currents were linearly dependent on the concentration of VEN in the concentration range from 1.0- 40.0 μM with the limit of detection (S/N=3) as 0.05 μM. The proposed method has been successfully applied in the electrochemical quantitative determination of VEN content in real samples and the determination, results could meet the requirement of the quantitative determination.

It is seen that metal nanoparticles are used in many areas due to their antimicrobialeffects. For this reason, our study focused on the production of a-Fe2O3, NiOand CoO NPs of golden nanoparticles, which are easily obtained with the use ofErzincan grape extract, safe to use, environmentally friendly and cost-effective.Metal ions synthesized by the green synthesis method were characterized usingthe Scanning Electron Microscope (SEM) analysis. From the SEM diagrams ofthe synthesized nanoparticles, it was determined that the nanoparticles wereapproximately 5 to 65 nm in size. Both antimicrobial, genotoxicity and cytotoxicity effects were investigated to determine the rates at which nanoparticles can be used as biosafe. Synthesized a-Fe2O3, NiO and CoO NPs showed excellent antibacterial properties on pathogen bacteria against human. In addition, it was determined that a-Fe2O3, NiO and CoO M-NPs showed genotoxic properties in parallel with increasing concentrations. This study, as far as we know, is the first report on microbial a-Fe2O3, NiO and CoO NPs and their biological properties synthesized by this statistical approach.

Nickel oxide (NiO) nano-size powder is synthesized using nickel (II) acetate tetrahydrate, sodium lauryl sulfate (SLS) and ammonia as precursors. Applied surfactant is anionic surfactant. The sample was characterized by FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM). The results obtained confirm the presence of nickel oxide nano-powders produced during chemical precipitation. Evaluation of the catalytic activity of developed nano-NiO particles were carried out using ultraviolet visible spectra. The uv-vis spectra obtained after ultraviolet irradiation in the presence of nickel oxide can indicate the degradation of tetracycline (TC) and dye Acid red -18 (ponceau 4R). The prepared NiO exhibits that 75% of Acid red -18 has been eliminated after 10 min.The results indicate that optimum concentration of NiO catalyst and the best pH for the degradation of AR were 0.5 g L-1 and pH 7, respectively. The best TC degradation results were obtained with 2 g L−1of the photocatalyst at pH 11.

Up to now, researchers have proposed several synthesis methods for the preparation of β-nickel(II) hydroxide nanostructures. Most of these approaches contain harsh synthetic conditions such as multi-step processes, high temperatures and long reaction time. In this work, a novel, facile and low cost method is introduced to produce of β-Ni(OH)2 nanostructures using the gas-solution precipitation from nickel(II) sulfate solution in the presence of anionic or cationic surfactant upon exposure to ammonia gas at room temperature. Herein, no other additive is needed and the method is suited for large-scale preparation. The structural characterizations were carefully investigated by the powder X-ray diffraction technique and Fourier transformation infrared spectroscopy. Further, the scanning electron microscopy results showed the important roles of the sodium dodecylsulfate and cetyltrimethylammonium bromide on the morphology and size of the products. The calcination process of hydroxide samples was also conducted to synthesize nickel(II) oxide nanostructures.

A novel carbon paste electrode modified with NiO/CNTs nanocomposite and an ionic liquid (n-hexyl-3-methylimidazolium hexafluoro phosphate) was fabricated. The electrochemical study of the modified electrode, as well as its efficiency for voltammetric oxidation of naproxen, is described. The electrode was also employed to study the electrochemical oxidation of naproxen, using cyclic voltammetry, chronoamperometry and square wave voltammetry as diagnostic techniques. Square wave voltammetry exhibits a linear dynamic range from 7.5×10−7 to 8.0×10−4 M and a detection limit of 1.2×10−7 M for naproxen.

Graphene-based nanocomposites are newly emerged materials with a wide range of applications such as in supercapacitors electrode. The high conductivity and ability for passing electric current, makes Graphene an appropriate new item to be used in cells. Electroactive transition metal oxides, owing fast reversible redox pairs, are used to store electrical charge. Furthermore, the Graphene/NiO nanocomposites can be used to improve the electrochemical properties of NiO. Here we report a new and facile route for synthesizing Graphene/NiO nanorods composite (GNC). High-quality few-layer Graphene/NiO nanorod composite (GNC) is synthesized via solvothermal method. Solution phase exfoliation of graphite is investigated in N-Methyl-Pyrrolidone (NMP). The existence of few-layer graphene is confirmed by Raman spectroscopy while presence of NiO is demonstrated by UV-Vis spectroscopy (UV) and X-ray diffraction (XRD) pattern. The Field Emission Scanning Electron Microscopy (FESEM) and X-ray diffraction (XRD) pattern also provide proof of GNC on graphene. Images indicate NiO nanorods with average diameter of 35 nm and 100 nm lengths, deposited on graphene.

Some issues; leakage, tunneling currents, boron diffusion are threatening SiO2 to be used as a good gate dielectric for the future of the CMOS (complementary metal- oxide- semiconductor) transistors. For finding an alternative and novel gate dielectric, the NiO (Nickel oxide) and PVA (polyvinyl alcohol) nano powders were synthesized with the sol-gel method and their nano structural properties were studied using the X-ray diffraction (XRD), Atomic force microscopy (AFM), Scanning electron microscopy (SEM), UV-Vis spectrophotometer and GPS 132 techniques. The obtained results indicated that the sample (5 g NiO and 0.02g PVA prepared at 30˚C, annealed in an oven at a temperature of 80˚C) can fill this gap due to its higher dielectric constant, better morphology, less rough surface and less leakage current.

We report on the synthesis, morphology, chemically and structurally of TiO2-NiO-SiO2 nanostructure. The TiO2-NiO-SiO2 nanostructure was synthesized by a method based on the sol-gel method, by the simultaneous gelation of all cations. The coatings were deposited on dried soda-lime glass slides by spin coating. Composite powders and coating on glass have been characterized by XRD, SEM, EDAX, and FTIR. X-ray diffraction showed the formation of nano crystalline, anatase, TiO, NiO and NiTiO3 phases. Scanning electron microscopy revealed that nanostructure formed by increasing the calcinations temperatures. EDX spectroscopy confirmed the composition of the ternary powders and coating, which were formed during the gelation process. The effects of chemical compositions and calcinations temperature on the surface topography and the crystallization of phases were studied. The activation energy (E) of nanoparticles formation during thermal treatment was calculated.