In this study, magnetic Fe3O4 nanoparticles were synthesized by co-precipitation method and then Au shell was extended over these nanoparticles via chemical reduction of chloroauric acid with sodiumborohydride under ultrasound irradiation. The obtained Au/Fe3O4 nanoparticles were characterized by using X-ray diffraction technique and Fourier transform infrared spectroscopy and their physical properties was studied by scanning electron microscopy and transmission electron microscopy. The characterized nanoparticles were used as efficient catalyst in the degradation of Rhodamine 6G dye in aqueous solution. UV-Vis spectroscopy was used to determine the dye concentration during optimization of the reaction conditions, and effect of various parameters such as pH, catalyst loading, temperature, and amount of the oxidant was investigated. It was found that Au/Fe3O4 catalyst at 80 oC in the pH of 12 can effectively degrade Rhodamine 6G dye molecules in the presence of hydrogen peroxide as an inexpensive and available oxidant. The catalyst after recycling was also, able to perform its role in successive runs.

In this work, core (SiO2) – shell (CuS) nanostructures have beendeveloped using a simple wet chemical route. X-ray diffraction analysis (XRD), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), EDS and fourier transform infrared (FT-IR) were used to characterize the products. The morphological studies revealed theuniformity in size distribution with core size of 250 nm andshell thickness of 7. 5-17 nm. The structural studies indicate hexagonal structure of covellite (CuS) shell with no other trace for impurities in the crystalstructure. This CuS layer exhibit the band gap energy of3. 1 eV, due to quantum confinement and numerousdefects presence. Photocatalytic activity of nanocomposites was studied for degradation of Methylene Blue (MB) under visible light. Several parameters were examined, catalyst amount (0. 1– 1 g L-1 ), pH (1– 13) and initial concentration of MB (0. 96– 10 ppm). The extent of degradation was estimated from the residual concentration by spectrophotometrically.

In this paper, Fe3O4@SiO2 core/shell magnetic nanostructure has been synthesized and modified by N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (AEAPTMS). Fe3O4@SiO2 was used as a novel adsorbent for separation of hexachloroplatinic acid. X-ray diffraction (XRD), scanning electron microscopy (SEM), and FT-IR technique were used to characterize morphologies and surface texturing of these adsorbents. The effective factors on adsorption, such as pH, contact time; salt effect and temperature were studied systematically. The optimal conditions of Platinum adsorption were obtained at temperature of about 25oC, pH about 2.5 and the equilibrium time of 30-40 minutes. The maximum adsorption capacity (qmax) in the optimal conditions was equal to 74 mg/g. The magnetic separation of the absorbent was achieved by a magnet and finally the absorbent was compared with other absorbents. Inductive coupled plasma optical emission spectrometer (ICP-OES) was used for determination of metal ion concentrations in the aqueous solution.

In this paper, Fe3O4@SiO2 core/shell magnetic nanostructure has been synthesized and modified by N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (AEAPTMS). Fe3O4@SiO2 was used as a novel adsorbent for separation of hexachloroplatinic acid.X-ray diffraction (XRD), scanning electron microscopy (SEM), and FT-IR technique were used to characterize morphologies and surface texturing of this adsorbents. The effective factors on adsorption, such as pH, contact time; salt effect and temperature were studied systematically. The optimal conditions of Platinum adsorption were obtained at temperature of about 25oC, pH about 2.5 and the equilibrium time of 30-40 minutes. The maximum adsorption capacity (qmax) in the optimal conditions was equal to 74mg/g. The magnetic separation of the absorbent was achieved by a magnet and finally the absorbent was compared with other absorbents. Inductive coupled plasma optical emission spectrometer (ICP-OES) was used for determination of metal ion concentrations in the aqueous solution.

Background & Objective: Antibiotics are considered among the pollutants in water environments with stable effects. This study aimed to investigate the efficiency of photocatalytic process using core– shell TiO2 under ultraviolet radiation for the removal of Cefixime antibiotic from aqueous solutions. Materials and methods: This study was conducted in an experimental-laboratory scale. The effect of factors such as pH (5, 6, 7, 8 and 9), initial concentrations of Cefixime (2-10 mg/L) and concentrations of catalyst (0. 5-5 g/L) was surveyed. Sample volume for every step of the experiments was 1000 ml. A batch stainless steel 3L photo catalytic reactor was designed. The synthesized catalyst was characterized by SEM، XRD and VSM Methods. Results: Physical characteristics of the Fe3O4/SiO2/TiO2 revealed that the catalyst particles had the average size of 10 nm. The photocatalytic degradation of Cefixime with UV+ Fe3O4/SiO2/TiO2 in the optimal condition was 100% (pH =6, retention time= 25 min, Cefixime concenteration= 2 mg/L catalyst dosage= 4 g/L). Synthetic models showed that the process of photocatalytic removal of Cefixime followed the first-order model. Conclusion: The results of this study suggested that UV+ Fe3O4/SiO2/TiO2 process is very effective method for the complete removal of Cefixime antibiotic from aqueous solutions.