JOURNAL OF APPLIED CHEMISTRY
Year:2017 | Volume:11 | Issue:41|Papers Count:9

In the present work, a new micro- spherical SnO2/Zn2SnO4 via a refluxing method has been synthesized. The heat treatment of the product was carried out at 500 and 900oC for 1 h. The sample was characterized by X-ray diffraction (XRD), UV-Vis spectrophotometer and field emission scanning electron microscopy (FE-SEM). The SnO2/Zn2SnO4 sample was formed after heat treatment at 900oC for 1h. The average diameter of micro- spheres of about ~2.7 mm were obtained. The photocatalytic activity of the sample by decolorization of two dye mixture- methylene blue (M.B.) and methyl orange (M.O.) was evaluated under UV-Vis. irradiation. The result showed that the SnO2/Zn2SnO4 sample is capable to decolorize (M.B.) and (M.O.) in dye mixture solution.

In this study, we grew nanopyramidal SnO2 hydrothermally at low temperature on both bare and nanotextured silicon substrates. Plasma etching of silicon is accomplished for the evolution of nanotextures on silicon substrate which are called silicon nanograsses. Comparing Scanning Electron Microscope (SEM) images of the synthesized SnO2 nanopyramids on two bare and nanotextured silicon substrates, reveals that there are considerable differences between growth on these substrates such as better uniformity. Therefore, application of silicon nanograss substrates in the synthesis of SnO2 nanostructures can improve growth process and this promotes various applications of this material in the different science fields. We also survey the effect of seed layer on growth of SnO2 nanopyramid.

Bi2O3 nanomaterials doped with Eu3+ and Nd3+ ions have been synthesized by a simple hydrothermal process at 180oC for 48 h. Bi(NO3)3.5H2O and KOH were used as raw materials. The as-prepared materials were characterized by X-ray diffraction (XRD). The data showed that the doped Bi2O3 materials were crystalized in a monoclinic crystal structure with space group of P21/c and cell parameters of a=5.8499 Å, b=8.1698 Å and c=7.5123 Å. The morphology of the obtained nanomaterials was investigated by field emission scanning electron microscope (FESEM). The morphology was remained unchanged after doping the rare elements into Bi2O3. However, different morphology of the compounds was achieved. The FESEM images showed that the materials were composed of micro-nano rods, nanoparticles and flower structures. Elemental analyses of the doped nanomaterials were performed by energy-dispersive X-ray spectrometry (EDS). Also cell parameter refinements and interplanar spacing (d) of the obtained materials were investigated.

An efficient and eco-friendly method is introduced for the synthesis of 4,4'-(arylmethylene)-bis-(1H-pyrazol-5-ols) by the condensation reaction of two equivalents of 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one with various aromatic aldehydes, catalyzed by the boehmite nanoparticles (BNPs). This heterogeneous catalyst was recycled and used in four runs for the reaction between benzaldehyde and 3-methyl-l-phenyl-5-pyrazolone without any loss of its catalytic activity.

The aim of the present study is to investigate the removal of nickel ions from aqueous solutions using natural zeolite. Batch experimental studies were conducted to evaluate by changing relevant parameters such as initial pH of solution, dosage of adsorbent, contact time, initial nickel ion concentration and temperature. The experimental isotherm data are analyzed using Langmuir and Freundlich equations. The Langmuir model fits the equilibrium data better than the Freundlich model. According to the Langmuir equation, the maximum uptake for nickel ions is 18.09 (mg/g). Pseudo-first-order and pseudo-second-order models are used to represent the kinetics of the process. The results indicate that the pseudo-second-order model is the one that best describes the kinetics of the adsorption of metal ions. The calculated thermodynamic parameters (ΔGo, ΔHo, and ΔSo) show that the adsorption process is feasible, spontaneous and endothermic at 20-50oC. Based on the experimental results, it can be concluded that natural zeolite has the potential of application as an efficient adsorbent for the removal of heavy metals from aqueous solutions.

The present study was focused on the simultaneous removal of Ni (II) and Co (II) ions from aqueous solutions by ultrasound-assisted adsorption onto carboxylated nanoporous graphene (G-COOH). Nanoporous graphene was synthesized by chemical vapor deposition method then functionalized by carboxyl groups and finally characterized using SEM, XRD, EDX, BET and FT-IR techniques. The effects of variables such as pH, sonication time, adsorbent dosage, and temperature on simultaneous removal of Ni (II) and Co (II) ions were studied and optimized. The kinetic and isotherm experiment data could be well described with the pseudo-second order kinetic model and the Langmuir isotherm model. The maximum adsorption capacity of G-COOH for Ni (II) and Co (II) ions was 94.34 mg g-1 and 87.72 mg g-1, respectively. Thermodynamic studies indicated that the adsorption process was spontaneous and endothermic in nature.

In this study, a simple and efficient method for removal of Cr (VI) from water samples was developed using modified nanoclay. A facile one-step method was employed to produce Dithizone-Montmorillonite (Dz-MMT) composite. The synthesized composite was characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The effectiveness of the composite in Cr (VI) removal from aqueous solutions at different adsorbent dose, solution pH, contact time, and agitation rate were examined. The composite had a high uptake capacity in room temperature and removed Cr (VI) (10 mg/L) of about 98% from aqueous solutions by 3 g/L of adsorbent in 90 min. The equilibrium adsorption isotherm data are tested by applying both Langmuir and Freundlich isotherm models. The composite effectively removed Cr (VI) from water, and the maximum adsorption capacity obtained from the Langmuir equation was 76.9 mg/g. Adsorption kinetics of Cr (VI) on the composite followed the pseudo-second-order kinetic model. The method was applied to the removal of Cr (VI) in tap water, river water, and industrial wastewater samples from different parts of Khouzestan, Iran.

The use of temporary corrosion protective is one of the best ways against the corrosion of steels that can be easily removed from the metal surface after treatment. In this research, N,N'-(3,3',4,4'-Benzophenonetetracarboxylic)-3,3',4,4'-diimido-bis-(aminonaphthalene-4-sulfonicacid) (BTDIAS) was synthesized as a new organic corrosion inhibitor. This sulfonated compound added to the base oil with a concentration of (2-100) ppm. The efficiency of sulfonated compound as organic corrosion inhibitor is evaluated by weight loss method and surface photography. The solutions of sulfonated compound (BTDIAS) (2-100) ppm in base oil were used on the low carbon steel surfaces, as a temporary corrosion protector. The samples were tested in a humidity chamber based on standard method (ASTM D-2247). The samples containing (5-30) ppm sulfonated compound showed the best corrosion resistance.

In this study, MnO2 nanowire adsorbent was synthesized by low cost preparation method that was capable of extracting gold form diluted jewellery waste water solutions. Different adsorption parameters like number of treatment, hold time, pH and agitation speed of mixing on the gold adsorption were studied. Adsorption experiments was designed by Taguchi method and effectiveness of parameters as well as optimum operating conditions were determined. The manganese oxide adsorbent, prepared by low-temperature synthesis followed by acid treatments, exhibits a nanowire like morphology. The results showed that under the optimum operating condition, gold adsorption efficiency was more than 77.2% during 2h.