نشریه شیمی کاربردی روز
پیاپی 41 (زمستان 1395)

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 900 ºC 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 900 ºC for 1h. The average diameter of micro- spheres of about ~2.7 µm 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 180 °C 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 (ΔG°, ΔH°, and ΔS°) show that the adsorption process is feasible, spontaneous and endothermic at 20-50°C. 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.

This study aimed to investigate the efficiency of 3A zeolite as an adsorbent for removal of rhodamine B (RhB) dye from water samples. For increasing in removal efficiency of RhB by 3A zeolite, the effect of pH, amount of adsorbent, different dye concentrations and contact time on efficiency of adsorption process were investigated and optimized in the batch system. In addition, correspondence rate of data to isotherms and kinetics of the adsorption processes were determined. Maximum adsorption capacity was obtained 0.740247 mg g-1 at pH=6, amount of adsorbent 0.5 g, dye concentrations 8 mg L-1 and contact time 20 minutes. According to obtained results, Langmuir isotherm exhibited best fit with the experimental data. Kinetic models indicated a correlation between the adsorption processes with the pseudo second kinetic model. According to obtained results, it was found that 3A zeolite has a good capacity to remove RhB dye from water samples.

The mesoporous titanium dioxide nanoparticles were successfully prepared via a sol–gel method using cetyltrimethyl ammonium bromide (CTAB) as a soft template. The obtained samples were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), N2 adsorption/desorption analysis, FTIR and UV–visible spectroscopies. The obtained results reveal that the all samples have anatase phase, spherical morphology and the mean size value less than 50 nm. With increasing the molar ratio of CTAB/titanates up to 1:5, the particle size decreases and the specific surface area increases. The performance of the synthesized nano-photocatalysts was measured by photocatalytic removal of phenazopyridine using UV irradiation light by 15 W (UV–C) mercury lamp emitted around 254 nm. The findings confirm that the photocatalytic activity of TiO2 nanoparticles strongly is depends on the physical properties such as size and specific surface area. When the particle size is about 28 nm, the highest photocatalytic activity is observed.

Solid-phase extraction combined with dispersive liquid–liquid microextraction has been developed as a new approach for the extraction of enrofloxacin in chicken meat prior to high performance liquid chromatography with UV detection. In the SPE-DLLME, enrofloxacin was first extracted from chicken meat into the mixture of 10 mL acetonitrile acidified with formic acid buffer (pH=4) and 10 mL EDTEA-McIlvaine buffer (0.1 M) and 20 mL n-hexane as an extracting phase by using ultrasound-assisted extraction. Then, the extract by ultrasound-assisted extraction was used for solid-phase extraction. After clean-up, enrofloxacin was preconcentrated by using DLLME technique. Thus, 1.5 mL methanol extract (disperser solvent) and 200 µL chloroform (extraction solvent) were added to 5.0 mL ultrapure water and a DLLME technique was applied. Under the optimum conditions, the linearity of the method was in the range from 10 to 500 µg kg-1 with the correlation coefficient (r2) of 0.9972. The method detection limit was 5.0 µg kg-1. The proposed method has been successfully applied to the analysis of the enrofloxacin in chicken meat, and a satisfactory result was obtained.

Nano perlite sulfuric acid (n-PeSA) as an inexpensive powerful solid acid nanocatalyst has been successfully applied for the efficient and green synthesis of 1,8-dioxo-octahydroxanthenes and tetrahydrobenzoxanthenes under solvent free condition in excellent yield. These new procedures offer many advantages including ease of preparation and handling, low cost and low toxicity of catalyst, environmental friendliness reaction conditions, short reaction time and absence of any tedious workup or purification .Furthermore, the catalyst could be recycled and reused at least five times without appreciable deterioration in catalytic activity, confirming the stability of the covalent bonding of acidic centers.

Dioxomolybdenum(VI) and copper(II) complexes were synthesized using H2L1 and H2L2 tridentate Schiff base ligands. The ligands were derived from the condensation 2-hydroxy-4-methoxysalicylaldehyde or 2-hydroxy-4-methoxyacetophenone with 2-aminopropanol, respectively. Both complexes were characterized by physico-chemical and spectroscopic methods. Dimeric nature of the Mo(VI) complexes was revealed by IR spectroscopy. Furthermore, MoO2L2(VI) nanoparticles were synthesized by Ultrasonic irradiation.. Elemental analysis, scanning electron microscopy, and FT-IR spectroscopy were used to characterize the nanoparticles. The Schiff base ligands and their complexes have been studied for antibacterial activity against Gram positive and Gram negative bacteria. The results indicated that the Mo(VI) and Cu(II) complexes were effective against all of studied bacteria and its effectiveness was higher for, Escherichia coli.

Graphene nano sheets (GNS) supported cobalt catalyst, is introduced for Fischer-Tropsch synthesis (FTS). The catalyst was prepared using wet impregnation method with cobalt loading of 15.0 wt%. The physico-chemical properties of the catalyst is investigated by TPR, TPD, BET, XRD, TEM and H2 chemisorption methods. The performance of the catalyst was assessed in a fixed bed micro-reactor at 220oC, 18 bars and H2/CO ratio of 2. The results were compared with those of Co/ γ-alumina. Using GNS as cobalt catalyst support decreased the average cobalt particles size from 16 to 9 nm, increased cobalt dispersion from 6 to 21% and improved the catalyst reducibility by a factor of 2.25. The activity of Co/GNS catalyst in FTS enhanced in comparison with that obtained for Co/γ-Al2O3. The products selectivity showed a slight shift to lower molecular weight hydrocarbons. Using GNS as catalyst support increased the catalyst lifetime.

Ni/RuO2 electrode was fabricated by electrochemical deposition from an acidic RuCl3 solution at room temperature, then annealing at 120oC for 150 min. Morphology characterization revealed a mud-crack structure and electrochemical investigations of Ni/RuO2 and Ni bare substrate indicated more activity of Ni/RuO2 toward hydrogen evolution reaction. Afterward, RuO2-TiO2 (20-80), RuO2-TiO2-IrO2 (20-60-20) and RuO2-TiO2-Ta2O5 (20-60-20) mol. % were constructed by sol gel and thermal decomposition at 450oC on previously prepared Ni/RuO2 substrates. SEM micrographs showed the most roughness for RuO2-TiO2-IrO2 coating. XRD analysis revealed the formation of solid solution structures between RuO2 by IrO2 and Ta2O5. Electrochemical studies, including activity and stability studies also revealed the excellent performance for RuO2-TiO2-IrO2 due to its more surface roughness and also stabilizing effect of IrO2 and RuO2 on each other.

Two mononuclear complexes [ZnII(MAA)(phen)(Cl)] (A) and [CuII(TTA)2] (B) (TTA = 4,4,4-Trifluoro-1-(2-furyl)-1,3-butanedione), (MAA = methyl acetoacetate and phen = 1,10-phenanthroline) were synthesized and fully characterized by UV–Vis and FTIR spectroscopy. In this study, the MKN-45 cell line used for MTT assay. Two complexes exhibited lethal effects against MKN-45 cell lines compared to the untreated control. The IC50 is observed about 1 µg/mL for both complexes. Besides, the migration studies revealed that complex (B) is more active than complex (A) against the MKN-45 cancer cell lines. In morphology assay, it was also found that many of the cells showed cytoplasmic shrinkage and loss of normal nuclear architecture.