Journal of Nanoanalysis
Volume:9 Issue: 1, Sep 2022

In this study, simple ionic liquid-assisted preparation of SnO microflowers with nanosheet subunits under reflux condition without calcination were described. Samples were synthesized using 1-pentyl-3-methylimidazolium bromide, [pmim]Br, as an ionic liquid in different molar ratio, sodium hydroxide and Tin(II) chloride. The results show that SnO with high purity and uniform size distribution was obtained using 1:4:4 molar ratios of SnCl2/NaOH/IL by simple reflux method and the ionic liquid only act as a suitable template. The characterization of the products were carried out by FT-IR, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDXS) and DRS techniques. Photodegradation of Remazol Black B (RBB) from the aqueous solution was investigated by SnO nanosheets (93.48% dye removal). The rate of degradation of RBB in the presence of SnO is distinctive by the pseudo-first-order kinetic model (R2 > 0.79).Keywords: SnO, Nanosheet, Microflower, 1-Pentyl-3-methylimidazolium bromide, Ionic liquid, Photodegradation, Remazol Black B.

Mercury is one of the environmental toxic pollutants required to be removed. Mercury can interfere with the vital functions of the cells by binding to the sulfhydryl groups in enzymes and proteins. The purpose of this study was to investigate the adsorption of mercury ions from aqueous solutions using a novel adsorbent prepared by the nano-gel of Descurainia Sophia plant stem. Adsorption of mercury was performed in a discontinuous system. Detection of the adsorbent structure before and after the adsorption process was performed by SEM, TEM and FTIR analysis. The optimal mercury adsorption conditions were determined as 0.6 g/100 ml of mercury solution, the contact time of 100 min, and pH of 8. Under such conditions, the adsorption efficiency of 87.3% was obtained. Three parameters including Morris-Weber, pseudo-first-order, and pseudo-second-order kinetics were investigated to understand the kinetics of the removal process. Langmuir, Freundlich, and Dubinin-Radushkevich isotherms were also used to calculate adsorption capacity. The results showed that the nano-gel of Descurainia stem has a high ability to remove mercuric ions from aqueous solutions at different concentrations. Moreover, the temperature increase has a positive effect on the removal efficiency. The thermodynamic investigations indicate that the adsorption of mercury on the nano-gel of Descurainia stem is spontaneous and endothermic.

Y-type zeolite can be considered among the most applied zeolites at industrial scale especially for catalytic transformations among various zeolites. Various synthesis techniques are employed to produce zeolite Y among which hydrothermal technique is considered as the most prevalent. In this study, synthesis of Y-type nano-zeolite was investigated through template-free hydrothermal technique. At various temperatures and aging times, zeolite Y was synthesized in the 10-30 nm size range with a first stage temperature of 25 °C and 87 °C as the second stage temperature. The as-synthesized zeolite was characterized using X-ray diffraction (XRD), Fourier-Transform Infrared (FTIR) spectroscopy, Field-Emission scanning electron microscopy (FE-SEM), Nitrogen adsorption–desorption, Transmission electron microscopy (TEM), and NH3-TPD and utilized as the nano-catalyst in methanol to dimethyl ether (DME) conversion process. Based on the results, at 400 °C, 53.7 % conversion to DME was obtained with 100% purity using hydrogen form of zeolite Y (H-Y) nano-catalyst. Natural zeolite is also considered as a proper additive to economize the product.

The aim of this study was to evaluate the efficiency of Ag/WO3 photocatalytic process for degradation of Flumequine (FL) antibiotic from aqueous solutions. In this study, WO3 and Ag/WO3 particles were synthesized and characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy dispersive X-ray spectrometry (EDS)/Map, Brunauer, Emmett, Teller (BET)/Barrett, Joyner, Halenda (BJH) and UV–vis diffuse reflectance spectroscopy (DRS) techniques. The photocatalytic degradation of FL from aqueous solutions was studied by Ag/WO3 photocatalyst under sunlight irradiation. The response surface methodology (RSM) with Central Composite Design (CCD) with 4 variables was used to investigate the relationship between the obtained responses and process variables and optimize with Design Expert software. In this study, the effect of pH, time (min), photocatalyst mass (g) and FL concentration (mg/L) were evaluated at 5 levels. Finally, the software is the best point to achieve the highest degradation efficiency of FL 99.54%, in optimal conditions at pH 3.07, time 101.14 (min), photocatalyst mass 0.13 (g) and FL concentration 41.3 (mg/L).

Functionalized SBA - 15 (Immobilization of Pd on the modified SBA - 15) has been utilized as an efficient catalyst for the preparation of chromenes by multi-component reactions of aromatic aldehydes, malononitrile and 4-hydroxycoumarin under reflux in ethanol. The catalyst has been characterized by X - ray diffraction spectroscopy ( XRD ), Field emission scanning electron microscopy ( FE - SEM ), Transmission electron microscopy (TEM), Energy-dispersive X - ray spectroscopy ( EDX ), X - Ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT - IR), N2 adsorption analysis, Temperature Programmed Desorption (TPD), and Differential thermal analysis (TGA - DTA). The structures of the products were deduced from their 1 H NMR, 13 C NMR, FT - IR, and elemental analyses. The advantages of this method include the reusability of the catalyst, low catalyst loading, excellent yields in short reaction times and easy separation of products, with no recrystallization required.

One of the most important problems in the oil industry is the presence of sulfur and sulfur compounds in crude oil. Sulfur compounds in crude oil can have detrimental effects on the environment, equipment, catalysts, and end products. One of the most important goals of researchers in recent years is to sweeten petroleum products from these compounds. This study aims to use NiWO4/W5O14/WO3 composite nanostructure to solve this problem using the photocatalytic oxidative desulfurization method. This composite nanostructure has been synthesized by Pechini sol-gel method with high purity at low temperature and examined by XRD, EDS, FESEM, and FT-IR analysis. Due to the presence of WO3 in the composition, the bandgap was greatly reduced and the efficiency was increased. As a result, the nanostructure could degrade more than 73% of the sulfur in thiophene in 180 min under visible light. By optimizing the amount of photocatalyst and irradiation time, the efficiency can be improved.

Corrosive environment can significantly effect on the mechanical behavior of composite structures which can improve by using hydrophobic nanoparticles. The aim of this study is to investigate the improvement of the mechanical properties of incorporated glass fiber reinforced polymer (GFRP) composite specimens with 3 wt. % of nanoclay and nanosilica in a corrosive environment. Filled GFRP composites were fabricated using the mechanical stirrer following by sonication method, and the hand layup method. After preparing the neat and incorporated GFRP according to ASTM standards, all the samples were immersed in 5% sulfuric acid solution for 0, 1, and 3 months. As the immersion time increased, the samples containing nanosilica absorbed more water than the other samples. The tensile and compressive tests were performed at different immersion times to obtain the ultimate tensile and compressive strength and tensile modulus. The results showed that by adding nanoparticles, the mechanical properties were increased, which GFRP containing nanoclay showed a better behavior in the corrosive environment. By adding 3 wt. % of nanoclay, the ultimate tensile and compressive strength and the tensile modulus decreased after one month of immersion by only 0.34%, 1.81% and 2.95%, respectively, and after three months of immersion only decreased by 0.43%, 10.88% and 6.95%, respectively. Finally, SEM images of all specimens were examined to investigate the fracture mechanisms and the corrosion behavior of fabricated nanocomposites.

Transition metal ions have been extensively studied for the removal of heavy metal ions as efficient adsorbent from aqueous solution. In this work, Fe2O3 nanoparticles were synthesized by thermal decomposition route of FeSO4.4H2O at the presence of urea (1:1 molar ratio) at two different temperatures (500 °C and 600 °C) and characterized by XRD and TEM. The XRD result show that single-phase of α-Fe2O3 was prepared by increasing of calcination temperature from 500 °C to 600 °C. TEM images confirmed that the as-prepared products have a different shapes and that particle sizes are in the range of tens nanometers. The average crystallite size of pure α-Fe2O3 calculated from XRD pattern was 53.1 nm and 41 nm, respectively, depending on the method employed. In addition, Pb(II) adsorption has been studied and considered as a function of pH solution, contact time, initial Pb(II) concentration and also adsorbent dosage. The adsorption results show that the iron oxides were able to high percentage remove Pb(II) by increasing of contact time, adsorbent dosage and initial Pb(II) ion. The pH solution of 6 proved to be the most suitable for the removal of Pb(II).