Browsing by Author "Kaya, Murat"
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Item PREPARATION OF SILVER NANOPARTICLES LOADED POLYANILINE TITANIUM DIOXIDE NANOCOMPOSITE MATERIAL AND USAGE IN ENVIRONMENTAL REMEDIATION(2022-01-24) Elbuzedi, Mohamed; Kaya, Murat; Tirkeş, SehaIn recent decades, environmental pollution due to toxic and carcinogenic organic dyes in the wastewater of many textile industries is a serious problem for human health. Therefore, the removal of these dyes in wastes is the way of resolving this environmental issue. The possible methods to achieve degradation of these toxic molecules into non-toxic components are adsorption, reverse osmosis, precipitation, and coagulation-flocculation. However, these techniques need further treatments and are not cost-effective. Among the several methods to solve this problem, Advanced Oxidation Processes (AOPs), which include extremely reactive anions (O2 − ) and radicals (•OH), have attracted great attention because of their potential utilization for wastewater treatment. These reactive oxygen species are released by the semiconductor photocatalysts after exposure by the UV or visible light. Numerous semiconducting catalysts such as ZnO, Fe2O3, SnO2, CdS, TiO2, etc. were used to remove organic dyes from the wastewater because of their unique properties in photocatalysis. The solar light-based photocatalytic activity has a prominent capability for the usage in environmental remediation. However, the insufficient activity of the semiconductor photocatalysts due to their large band gaps under visible irradiation is still preventing their applications. Many researchers have tackled to reduce band gaps of semiconductor photocatalysts to obtain maximum efficiency from the visible part of the solar spectrum by doping or co-doping with metal and nonmetal ions. Besides the metal oxide semiconductors, conjugated polymer-based photocatalysts are emerging candidates, which use visible light for photocatalysis. In addition to its low toxicity, better stability, and low cost, polyaniline (PANI) has a high absorption coefficient in the visible range of light and high mobility of charge carriers. Moreover, under photo illumination, PANI is both a strong electron donor and a superb hole acceptor material. In order to increase the photocatalytic activity, noble metal modification, like gold, and silver, can be applied. The noble metal modification causes the formation of surface plasmon resonance effect on the surface of the polymer. The electronic field, which is generated on the photocatalytic material surface, can enhance the efficiency of charge (electron-hole) separation which is known as the key factor of the increase in photocatalytic efficiency. When the metal nanoparticles like Ag, Au, and Pt added to photocatalytic materials, the lifetime of e- -h + pairs increase due to their surface plasmon resonance effect resulted from the collective oscillations of surface electrons. In addition to this, noble metals deposited on the polymer can serve as centers for recombination of the photogenerated charge carriers, which causes a decrease in recombination rates of these charges in the photocatalyst. Among the metal nanoparticles, silver-based one has widely preferred due to high surface plasmons at a wavelength between 320 and 450 nm, which affects the reduction in the recombination rates of e- -h + pairs. In this study, polyaniline-titanium dioxide nanoparticles composite material with the magnetic property which was decorated with silver nanoparticles polyaniline (MNP PANI-TiO2-AgNPs) were prepared through the chemical polymerization followed by the liquid impregnation method with additional reduction process to achieve an effective catalyst working under solar light. In order to reveal the effect of each component founded in the MNP-PANI-TiO2- AgNPs composite material on catalytic activity, bare PANI, magnetic nanoparticles added PANI (MNP-PANI) and TiO2 and magnetic nanoparticles added PANI (MNP PANI-TiO2) were prepared by applying the same procedure. After that, they were decorated with silver nanoparticles to form PANI-AgNPs, MNP-PANI-AgNPs, and TiO2-AgNPs. The characterization of prepared catalysts was performed by using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDX), X-ray Photoelectron Spectroscopy (XPS) and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The photocatalytic activities of the TiO2 nanoparticles (P25), bare PANI, MNP-PANI, MNP-PANI-TiO2, TiO2-AgNPs, PANI-AgNPs, MNP-PANI-AgNPs and MNP-PANI TiO2-AgNPs were revealed in methylene blue (MB) degradation by using solar light exposure, respectively. According to the results, among them, MNP-PANI-TiO2- AgNPs composite material showed enhanced catalytic activity which provided 99 % degradation of dye in 40 min. So, highly efficient and stable photocatalyst which can be active in visible light was produced by adding AgNPs, MNP and TiO2 nanoparticles onto conducting polymer PANI by using green and fast methods.thesis.listelement.badge PREPARATION OF TITANIUM DIOXIDE NANOPARTICLES ADDED PANI AND THEIR ANTIBACTERIAL RESPONSE ANALYSIS(2022-03-01) ALTMARI, MAHA MUNADHIL SALMAN; İşgör, Belgin; Kaya, MuratBecause of an increase the bacterial attack in different sectors of our life, it become necessary to search about a new antibacterial material. The aim of this research is to produce an anti-bacterial and environmentally friendly material used as a surface coating to reduce diseases caused by bacterial infection. In this work, we prepared polyaniline (PANI) by using the chemical polymerization of aniline with ammonium persulfate (APS), after that we used commercially available titanium dioxide nanopowder for preparation (PANI-TiO2) nanocomposite material by chemical polymerization. The morphologies, structures, and elemental composition of the nanocomposite material are characterized by using TEM, SEM and EDX. After that, study the antibacterial activity ofTiO2, PANI and (PANI-TiO2) nanocomposite was investigated by using E. coli and S. aureus. The results of this study show that no antibacterial effectof TiO2 and PANINPs for each type of bacteria, but the antibacterial effect for (PANI- TiO2) was very weak on S. aureus and very strong on E. coli.Article Synthesis, Characterization and Application of High Sulfur Content Polymeric Materials from Fatty Acids(Reactive and Functional Polymers, 2023-06) Berk, Hasan; Kaya, Murat; Topçuoğlu, Mert; Türkten, Nazlı; Karataş, Yunus; Cihaner, AtillaA new series of high sulfur content polymers containing various amounts of fatty acids (oleic acid (OA), linoleic acid (LA) and linolenic acid (LnA)) was synthesized via inverse vulcanization method and characterized successfully. In particular, the effect of double bonds and free alkyl chains on polysulfur copolymers has been investigated systematically by using OA with one double bond, LA with two double bonds and LnA with three double bonds. The copolymers with functional carboxylic acid groups are soluble in common organic solvents, processable and electroactive. Also, the usage of the copolymers was tested in the removal of methylene blue and as a cathode material in Li-S battery. Results showed that the polymers can be a potential material for use in dye removal.thesis.listelement.badge SYNTHESIZE AND PHOTOCATALYTIC APPLICATIONS OF TITANIUM DIOXIDE AND MAGNETIC NANOPARTICLES CONTAINING HIGH SULFUR CONTENT POLYMERIC COMPOSITES(2022-03-01) Topcuoğlu, Mert; Kaya, Murat; Cihaner, AtillaSulfur is one of the most abundant elements in nature. It is not toxic but is a flammable solid even though it is stored outdoors. Approximately 70 million tons of sulfur is obtained as a by-product from oil refineries every year but the use of this huge amount of sulfur is very limited. Therefore, it is very important to convert elemental sulfur into valuable products like polymers and ensure the use of large quantities in industry. In this study, the synthesis of new high sulfur polymeric materials using vegetable fatty acid and their usage as a support material in the preparation of photocatalyst for methylene blue removal is aimed. For this purpose, copolymerization of elemental sulfur and fatty acid, linolenic acid (LnA), was carried out by reverse vulcanization method. The photocatalytic activities of the prepared polysulfur copolymers were tested in the degradation of methylene blue under a solar simulator for comparison study. Then, polysulfur copolymer was prepared again by adding magnetic nanoparticles and titanium dioxide nanoparticles. The photocatalytic activity of the resulting composite material, poly(S-r-FA)-TiO2-MNP, was examined in the same reaction. Also, stability of the composite material was carried out. The characterization of the prepared materials was carried out using SEM, TEM, EDX, FTIR, and NMR. The decrease in dye concentration was followed by UV-Vis spectrometry.