Sharif Digital Repository

In this research we focus on synthesis and analysis of metal and metal oxide nanoparticles and their photocatalytic activity. At the beginning a high current DC power supply and a reactor for the electrical arc discharge process designed and implemented. Several nanoparticles such as tungsten oxide, zinc oxide, silver and gold have synthesized by this method in deionized water, deionized water including surfactants and stabilizers and analyzed. Several characterization techniques such as X-ray diffraction (XRD), dynamic light scattering (DLS) X-ray photoelectron spectroscopy (XPS), BET, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis spectroscopy have... 

The aim of this project is investigation on synthesis and characterization of the TiO2-CNT nanocomposite films on aluminum substrate by sol-gel dip coating method. The pure TiO2 and TiO2-CNT nanocomposite layers were coated on aluminum substrate and heat treated in 400 C. In this work Ti-tetra isopropxide and different amounts of CNTs (5,10,15 %wt), were used for obtain the composites. The coatings were characterized by X-Ray diffraction (XRD) and the crystallite size of TiO2 was calculated by Scherrer formula. The corrosion properties of coating were examined by polarization test, and corrosion resistance of pure TiO2 was compared with TiO2-CNT coatings, and It showed that the composite... 

TiO2, Ag/TiO2 and AgBr/TiO2 synthesized by sol – gel method. Synthesized samples were characterized by X- Ray diffraction (XRD) , Fourier transformed infrared ( FT – IR) , Scanning electron microscopy ( SEM) techniques. The results of XRD showed that the particle size is in the nanorange and anatase form of titania is present in all of the photocatalysts. Kinetics of photocatalytic degradation of an azo dye (Acid Orange 7) on photocatalysts was studied. The effect of various parameters such as dye concentration, amount of photocatalyst( AgBr/TiO2) and pH of solution on the rate and efficiency of degradation of Acid Orange 7 was studied. The optimized conditions ( [AgBr/TiO2]= 100 ppm,... 

In this research, the synthesis of the electrospum nano fiber doped zinc oxide and its photocatalyst usage was investigated. The band gap of the zinc oxide in the area of UV leads to deactivation of this material at the visible light. With due the attention to sunny weather in Iran and the fact that about 50 percentage of sunlight is visible light, producing and usage of catalyst materials actived at visible light is economical. Doping is one of the ways of activating ZnO at visible light, so in this research thiourea is used as the source of ZnO doping. The results of the expriments done at visible light and also spectrums of DRS, XPS and XRD prove that the doping is happened. Also, in this... 

Removing pollutants of water and, in general, wastewater treatment is one of the most important issues in the world. In this research, we synthesized a nanophotocatalyst based on znic-iron in the form of a magnetic core-shell Fe3O4@ZIF-8, and used to degrade the malachite green toxic color of wastewater. SEM, XRD and FT-IR analyzes have been taken and analyzed fore all three core, shell and core-shell composite catalysts.Due to the band gap of core-shell nanocomposite and the performance of the malachite green dye, a photocatalytic process under the visible light was obtained, which at an optimum amount of photocatalyst 0.003g, we reach 99.2% dye degradation at the 30ppm concentration. This... 

Different nanocomposites were prepared based on the carbon nitride, structures and metal organic framework. The photocatalytic activities of a group of metal-organic metal frameworks were evaluted. Next step, the combination of binary and ternary composites based on carbon nitride/metal-organic frameworks structures with other semiconductors such as oxyacid, bismuth oxy halide and ferrite spinel was used. In addition, synthesis of varius type of metal oxides structures with metal organic framework precursors has also been another perpuse of this thesis.The catalytic and photocatalytic activities of designed nanocomposites were performed for a redox process (4-nitrophenol (4-Nip) to... 

Synthesis, characterization and photocatalytic applications of core-shell like ZnO@CdS nanorods have been studied in this research. The synthesis of core-shell like ZnO@CdS nanorods was carried out in three different steps. At first, ZnO seed layer was formed on glass substrate via sol-gel process under optimum conditions using absolute ethanol solution containing zinc acetate and a stabilizer ( either Monoethanolamine (MEA) or diethanolamine (DEA)). When MEA used as stabilizer, the optimum concentration of sol was found 0.2 M, while increasing the sol concentration caused the seed layer to be grown in a string-like structure. The RMS surface roughness of seed layer prepared by 0.2 M sol... 

These days, technological advances and industrial expansion cause to increase environmental pollution. Using different kinds of chemicals in textile industries, agriculture, ... led to enter huge amount of pollutant to natural ecosystems, especially in aquatic ecosystems. Advanced oxidation processes (AOPs) based on the generation of very reactive species such as hydroxyl radicals (•OH) oxidize a broad range of pollutants quickly and non selectively. Among AOPs, heterogeneous photocatalysis using TiO2 as photo-catalyst appears as the most emerging destructive technology. In this project, TiO2 nanostructured hybrid materials were synthesized as photocatalysts by various methods including... 

Photocatalytic degradation is one of the developing modern and effective methods for decontamination of hazardous pollutants of chemical industrial wastewater. For this purpose, in this research, the efficiency of the photocatalytic process in degradation of Cortisone Acetate is investigated under solar light irradiation, and the effect of two useful oxidants, potassium persulfate (PDS) and potassium proxy mono sulfate (PMS), on the degradation efficiency is examined. At first, the single effect of these two oxidants, and then their interaction effects with the photocatalyst (TiO2-P25) and solution pH by analytical analysis and with the help of Response Surface Methodology (RSM) and... 

This thesis is concerned with the synthesis and characterization of high porous Ti based on thin films and the effect of polymer agents on their photocatalytic properties. Ti films can demonstrate different properties like self -cleaning and treatment of broad range of aqueous pollutants when it is exposed to light of wavelength less than 400 nm. This is due to photocatalytic reaction occurring on film surface which results in film superhydrophilicity and the active oxygen species production. This active sites and radicals will cause oxidize organic pollutants and microbe adherent to the material surface.
In this study Ti thin films have been prepared by the sol-gel method from... 

In recent decades, desulfurization processes have become necessary to reduce environmental pollution due to fuel sulfur emissions. In this research, in order to photocatalytic oxidation desulfurization of liquid fuel, a model fuel (normal octane) under visible light irradiation of 250 W sodium lamp, using H2O2 oxidant and methanol solvent in the presence of BMO/Fe@MIL(x%) composite. BMO and Fe@MIL were investigated. From the tests, X-ray diffraction, scanning and transmission electron microscope imaging, absorption and desorption of nitrogen gas, infrared spectrometer-Fourier transform, visible-ultraviolet reflection spectroscopy, optical radiation spectroscopy and vibration magnetometer in... 

Azo dyes that are the most common dyes in textile industries, are toxic and stable complex compounds. Release of this dyes in environment disturb the ecosystem and endanger human health. So selection of an appropriate method for treatment of them is a sensitive work. photocatalytic degradation is one of the best promising methods because of its perfect mineralization, middle condition and lack of creating the secondary pollutant. In this research CuO/CNT nanocomposite was synthesized and used as a photocatalyst. The surface features of CuO/CNT were surveyed by using Fourier transform infrared(FTIR), X-ray diffraction (XRD) and Scanning electron microscopy (SEM). Photocatalytic efficiency of...