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

In this study, ZnWO4:Er3+ nanocrystals were synthesized using a simple co-precipitation method. The structural properties of the prepared powders were characterized through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM). The synthesized nanopowders exhibited a monoclinic wolframite crystal structure. Using the Williamson-Hall method, the lattice strain and crystal size of the synthesized powders were estimated. ZWO nanopowders with a 1 at.% concentration of Er dopant showed the lowest strain and crystallite size. FE-SEM results revealed that the prepared nanoparticles have a spherical morphology with an average size of 140 nm. The FTIR analysis confirmed the presence of Zn-O, Zn-O-W, and W-O vibrations in the synthesized structure. The transmittance percentage in the doped sample changed concerning the pure one, indicating that interstitial Er3+ ions affected the number of W-O, Zn-O, and Zn-O-W bonds. The facilely synthesized Erbium-doped ZnWO4 nanocrystals showed promise for a range of practical applications.

Zn based composite coatings reinforced with TiO2 nanoparticles were fabricated via electrodeposition with 5, 10, and 15 g/L TiO2 concentration under variant current densities of 0.08, 0.1 and 0.12 A/cm2. Field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), x-ray diffraction analysis (XRD), weight loss measurements, salt spray technique, anodic polarization, and eventually potentiodynamic polarization tests were conducted and the corresponding findings were discussed. Rising the electrodeposition current density from 0.08 to 0.12 A/cm2 for both pure Zn and Zn-TiO2 coatings led to deposit more and smaller crystals and with incorporation of TiO2 nanoparticles, the morphology changed from hexagonal crystals to flake type grains. Increasing the TiO2 concentration from 5 to 15 g/L, steadily lowered the TiO2 incorporate rate (vol.%). Accordingly, the same smoothness and even more uniformity with smaller crystallites was observed at 15 g/L compared to that of 5 g/L. Weight loss measurements, salt spray tests and anodic polarization test showed remarkable superior corrosion resistance of Zn-TiO2 (5 g/L) than that of pure Zn coating. An increas in icorr (µA/cm2) from 0.08 to 0.1 A/cm2 occurred, followed by a decrease from 0.1 to 0.12 A/cm2 for pure zinc coating. By increasing the current density from 0.08 to 0.12 A/cm2 for Zn-TiO2 coating, a steadily decrease of icorr was observed. Furthermore, by rise of TiO2 (%C) from 5 to 15 g/L, icorr experienced a significance increase that could be ascribed to the remarkable reduction in TiO2 vol.%. Ultimately, the optimum corrosion resistance belonged to the electrodeposited Zn-TiO2 (5 g/L) coating deposited 0.12 A/cm2 exhibiting the lowest amount of icorr of 2.7 µA/cm2 equal to 1.6 mpy.

Electrospun NanoFibers (ENFs) were fabricated from the mixture of Cellulose Acetate (CA), chitosan (CHI), and poly (ethylene oxide) using an acetic acid solution. The impact of CA/CHI ratio (0.5, 1, 1.5 wt %), CHI/PEO ratio (1, 1.5, 2 wt%), Sodium Dodecyl Sulfate (SDS) (0, 1.5, 3% w/w) and ammonium oxalate (3%, w/w) on the diameter, tensile strength, elongation, and porosity of the ENFs were optimized using Response Surface Methodology-Central Composite Rotatable Design (RSM-CCRD). The results revealed that ENFs were formed of non-woven fibers with a maximum diameter of 113 nm. Second-order polynomial models with high R2 values (0.996–0.99) were developed using Cubic analysis. The optimum condition was identified to be at the compounded level of CA/CHI 1.5 wt%, CHI/PEO 1 wt%, and SDS 3% (w/v). At the best point, the diameter, surface tension, elongation, and porosity of the fabricated ENFs were 96.07 nm, 0.054 N/mm2, 13.09 mm, and 52.29 respectively.

A wide range of hard adulterants in waste water are generated from different industries as a by-product of the organic compound. In this review, the cationic dye Malachite Green removal from wastewater by photocatalytic route by using various metal oxide nanoparticles is analysed. The effect of some specific parameters like the method of preparing the catalyst, the initial concentration of dye, the amount of nanocatalyst required for degradation, the initial pH of dye solution, type of light source used, and time of light exposure required for removal of dye were specially incorporated. Some general conclusions were made based on the pivotal analysis of literature available. With a view to reach higher removal efficiency, in an economical manner, some optimal testing conditions on degradation of these hard dyes should be carried out.

India presently comprises 23 species of Chlorophytum which are commercially utilized as ‘White gold’ or ‘Divya aushadhi’. There are pressing demands on the biodiversity and bioresources of Western Ghats and Chlorophytum is one of the highly demanded medicinal entities, as Chlorophytum has export value and there is a vast demand for its roots under the trade name ‘Safed Musali’. The roots of various species are collected from nature. Even all the species of Chlorophytum are not studied properly for taxonomy, morphology, medicinal value and antioxidant contents. The present review proposes a comprehensive impression of phytogeographical survey, morphological, genetic and phytochemical diversity, medicinal properties and uses, field studies and breeding practices of genus Chlorophytum. Conclusively, the anticipated article is an endeavour to provide a complete update of several studies led by members of the genus Chlorophytum that will possibly be utilized systematically and appropriately in different conservation strategies and sustainable development.

Different antibiotic drugs are widely present in the environment for the treatment of bacterial infections. Overuse of antibiotics leads to the accumulation of these drugs in water systems. Removing antibiotics-based pollutants from water is essential. Nanoscience and nanotechnology can be very helpful in this field. In this work, CuO/ZrO2 nanocomposites was prepared via the simple and facile method. The prepared samples were analyzed X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR) analysis, and UV-Vis analysis. The results indicate the high potential of synthesized nanocomposites made in photocatalytic degradation. The prepared CuO/ZrO2 Nanocomposites degrades 96.4% of Tetracycline antibiotic under ultraviolet light irradiation after 120 min. The effect of CuO/ZrO2 nanocomposites dosage and solution pH was studied. It was found that the photocatalytic performance of CuO/ZrO2 nanocomposites can be improved via increasing concentration until optimal dosage (0.8 g/L) and in a higher dosage than 0.8 g/L no significant improvement was observed. Also, the results confirmed that the photodegradation of tetracycline can be elevated via increasing pH.

The present research aimed to evaluate the effects of synthesis parameters on morphology and photocatalytic activity of TiO2 nanotube aligned arrays (TNAs) via a low cost anodization process. The impact of electrolyte composition, anodization time, as well as applied voltage on morphological and architecture properties of TNAs including; length, inner diameter, and wall thickness were accurately investigated. We further studied effect of heat treatment on crystalline and phase transformation of the samples at different annealing temperatures. Photocatalytic properties of the fabricated samples were studied for degradation of p-nitrophenol under UV light irradiation. Physical/chemical characteristics of the photo-anodes were observed using several techniques including field emission scanning electron microscopy (FE-SEM) , Energy Dispersive X-Ray Spectroscopy (EDX) and XRD . Moreover, the maximum photocatalytic performance for p-nitrophenol degradation was obtained as about 80%.