Preparation of Multifunctional Photocatalytic Nanocomposit Materials and, Usage in Hydrogen Output and Environmental Remediation/Çok Fonksiyonlu Fotokatalitik Nanokompozit Malzemelerin Hazırlanması, Hidrojen Eldesinde ve Çevre Islahında Kullanımı

Due to the increasingly polluted environment and the limited energy reserves, the development of high efficiency renewable technologies, green energy sources and eco-friendly methods for environmental remediation and energy production is highly important. Hydrogen (H2), as a clean and carbonless energy source, is of great potential in solving the environmental pollution and energy shortage. Turkey is a country that clued-in textile production. But widespread discharge of wastewaters from the textile industries, which contain large amounts of dyes, has become a great concern to the environment and ecosystem due to their non-biodegradability, toxicity, and potential carcinogenicity. Therefore finding effective treatment methods and extending the treatment units which use them is necessary. The need to meet stringent international regulations and standards for wastewater discharge has motivated the development of efficient, non-toxic and low-cost photocatalytic materials for the photodegradation of organic pollutants with solar energy in wastewater. Besides mild operating conditions photocatalytic process can be powered by sunlight which significantly reducing the energy required and therefore the operating costs. Thus, semiconductor photocatalysis has attracted widespread attention in scientific community due to its potential application in environmental remediation and hydrogen production. Owing to the strong oxidizability, nontoxicity, and long-term photostability, nanostructured titanium dioxide (nano-TiO2) has many advantages when compared with other photocatalysts. However, there are still some shortcomings, such as the lack of a visible light response, a low quantum yield, and lower photocatalytic activity. To overcome these problems, studies have been focused on some strategies, including noble metal deposition, doping of metal or nonmetal ions, blending with another metal oxide, surface photosensitizing with dye, and compositing with polymer. In particular, organic/inorganic nanocomposite materials, where the organic major component is based on polymers, are a fast-growing area of research. Catalyst recovery and reuse are the two most important features for many catalytic processes. Most heterogeneous systems require a filtration or centrifugation step to recover the catalyst. However, magnetically supported catalysts can be recovered with an external magnet due to the paramagnetic character of the support thus remarkable catalyst recovery can be provided without the need for a filtration step and the catalysts can be subsequently reused in another cycle. In this study, it is planned to develop multifunctional organic-inorganic nanocomposite photocatalysts for H2 production from harmful volatile organic compounds (VOC) founded in industry based waste waters and provide environmental remediation with the removal of organic dyes founded in waste waters from industry simultaneously with photocatalytic degradation by using sunlight. For this purpose, novel magnetically recyclable, Poly (3, 4-ethylenedioxythiophene (PEDOT) and noble metal modified TiO2 based (CoFe2O4-PEDOT-TiO2/M, (M=Ag, Au, Pd)) nanocomposites with high photocatalytic activity and well-separation property will be produced. The photocatalytic properties (enhanced light absorption and charge-transfer kinetics) of the nanocomposites aimed to be enhanced by the synergetic effects of TiO2 nanoparticles, noble metal nanoparticles and PEDOT loading. Besides, with the addition of magnetic silica coated cobalt ferrite (CoFe2O4@SiO2) nanoparticles into the nanocomposite structure, their separation from the liquid phase and reuse process can be done via application of an external magnetic field is the another aim of this study. The composition, structure, morphology, and optical properties of the prepared nanocomposites will be investigated by TEM, HR-TEM, STEM, FE-SEM, XPS, XRD, ICP-OES, N2-Ads.-Des., FTIR, Raman and UV-Vis. The comparative photocatalytic activity of the prepared catalysts will be investigated under different light sources (UV, Vis, sunlight). The ethanol which is an easily evaporable organic compound with a relatively low toxicity to study the photocatalytic degradation of VOC’s is chosen as model pollutant. To evaluate the photocatalytic activity of the produced catalysts in the degradation of organic dye, methyl orange (MO) and methylene blue (MB), typical pollutants in the textile industry which have the relatively high toxicity and complex structures make them difficult to be treated by physical and biological methods, will be investigated under UV and Vis light irradiation. Finally the efficiency of the prepared multifunctional advanced materials on the mixture of model compounds and real samples will be investigated