Synthesis of triple ZnO-SnO2-Zn2SnO4 nanocomposides and determination of their photocatalytic activities

In recent years, especially in semi-arid and arid regions, due to rapid population growth, unplanned urbanization and rapid development of industrialization, in addition to the increase in the demand for clean water resources, the degree of pollution of water resources is also increasing. Nowadays, low cost cleaning processes are needed in the treatment/cleaning processes applied to industrial wastewater containing organic dyestuffs. Photocatalytic method is one of the options that can offer an effective solution for this purpose. With the photocatalytic method, semiconductor materials are used that allow the organic dyestuffs in water waste to be directly destroyed by making use of ultraviolet (UV) and/or sunlight. Two-component zinc oxide (ZnO), tin oxide (SnO2) and three-component zinc tin oxide (Zn2SnO4, ZTO) n-type semiconductor metal oxides and the synthesis and examination of photocatalytic activity of binary - ternary nanocomposite structures (ZTO:ZnO, ZTO:SnO2, ZTO:SnO2:ZnO) formed with these components has been an important research topic. Production of desired shapes and sizes in photocatalyst synthesis may vary depending on the synthesis method chosen. In this thesis, the electro-spinning method, which can produce nanocomposites in the desired size and morphology and does not require a complex experimental setup, has been chosen as the synthesis method. In this thesis, firstly, ternary ZTO:SnO2:ZnO nanocomposite structures were synthesized by electro-spinning method. In order to optimize the optical properties of nanofibers, the effects of heat treatment temperature on the photocatalytic properties of nanofibers were investigated by applying heat treatment at different temperatures ranging from 400°C to 1200°C in order to remove the polymeric material from the fiber structure. According to the XRD results, it was understood that the most suitable heat treatment temperature for the synthesis of high crystallinity ZTO:SnO2:ZnO is 1150 ℃. Then, the behavior of Rhodamine B (RhB) organic dyestuff under UV light was investigated in order to determine the photocatalytic activity of ZTO:SnO2:ZnO nanocomposite structures. In order for nanocomposites to have the best photocatalytic activity, studies were carried out to examine the concentrations of the fibers applied at different heat treatment temperatures in the dye solution, the pH value of the dye solution, and the exposure time of the dye solution to light. As a result, within the scope of the thesis study, the synthesis of ZTO:SnO2:ZnO nanocomposite structures by electro-spinning method and their photocatalytic activities under UV/visible light were examined in detail and the most suitable synthesis/photocatalytic parameters were determined. According to the results obtained from the studies carried out within the scope of the thesis, it was observed that the ternary ZTO:SnO2:ZnO nanocomposite fibers produced by heat treatment at 1150 °C were added to a In recent years, especially in semi-arid and arid regions, due to rapid population growth, unplanned urbanization and rapid development of industrialization, in addition to the increase in the demand for clean water resources, the degree of pollution of water resources is also increasing. Nowadays, low cost cleaning processes are needed in the treatment/cleaning processes applied to industrial wastewater containing organic dyestuffs. Photocatalytic method is one of the options that can offer an effective solution for this purpose. With the photocatalytic method, semiconductor materials are used that allow the organic dyestuffs in water waste to be directly destroyed by making use of ultraviolet (UV) and/or sunlight. Two-component zinc oxide (ZnO), tin oxide (SnO2) and three-component zinc tin oxide (Zn2SnO4, ZTO) n-type semiconductor metal oxides and the synthesis and examination of photocatalytic activity of binary - ternary nanocomposite structures (ZTO:ZnO, ZTO:SnO2, ZTO:SnO2:ZnO) formed with these components has been an important research topic. Production of desired shapes and sizes in photocatalyst synthesis may vary depending on the synthesis method chosen. In this thesis, the electro-spinning method, which can produce nanocomposites in the desired size and morphology and does not require a complex experimental setup, has been chosen as the synthesis method. In this thesis, firstly, ternary ZTO:SnO2:ZnO nanocomposite structures were synthesized by electro-spinning method. In order to optimize the optical properties of nanofibers, the effects of heat treatment temperature on the photocatalytic properties of nanofibers were investigated by applying heat treatment at different temperatures ranging from 400°C to 1200°C in order to remove the polymeric material from the fiber structure. According to the XRD results, it was understood that the most suitable heat treatment temperature for the synthesis of high crystallinity ZTO:SnO2:ZnO is 1150 ℃. Then, the behavior of Rhodamine B (RhB) organic dyestuff under UV light was investigated in order to determine the photocatalytic activity of ZTO:SnO2:ZnO nanocomposite structures. In order for nanocomposites to have the best photocatalytic activity, studies were carried out to examine the concentrations of the fibers applied at different heat treatment temperatures in the dye solution, the pH value of the dye solution, and the exposure time of the dye solution to light. As a result, within the scope of the thesis study, the synthesis of ZTO:SnO2:ZnO nanocomposite structures by electro-spinning method and their photocatalytic activities under UV/visible light were examined in detail and the most suitable synthesis/photocatalytic parameters were determined. According to the results obtained from the studies carried out within the scope of the thesis, it was observed that the ternary ZTO:SnO2:ZnO nanocomposite fibers produced by heat treatment at 1150 °C were added to a In recent years, especially in semi-arid and arid regions, due to rapid population growth, unplanned urbanization and rapid development of industrialization, in addition to the increase in the demand for clean water resources, the degree of pollution of water resources is also increasing. Nowadays, low cost cleaning processes are needed in the treatment/cleaning processes applied to industrial wastewater containing organic dyestuffs. Photocatalytic method is one of the options that can offer an effective solution for this purpose. With the photocatalytic method, semiconductor materials are used that allow the organic dyestuffs in water waste to be directly destroyed by making use of ultraviolet (UV) and/or sunlight. Two-component zinc oxide (ZnO), tin oxide (SnO2) and three-component zinc tin oxide (Zn2SnO4, ZTO) n-type semiconductor metal oxides and the synthesis and examination of photocatalytic activity of binary - ternary nanocomposite structures (ZTO:ZnO, ZTO:SnO2, ZTO:SnO2:ZnO) formed with these components has been an important research topic. Production of desired shapes and sizes in photocatalyst synthesis may vary depending on the synthesis method chosen. In this thesis, the electro-spinning method, which can produce nanocomposites in the desired size and morphology and does not require a complex experimental setup, has been chosen as the synthesis method. In this thesis, firstly, ternary ZTO:SnO2:ZnO nanocomposite structures were synthesized by electro-spinning method. In order to optimize the optical properties of nanofibers, the effects of heat treatment temperature on the photocatalytic properties of nanofibers were investigated by applying heat treatment at different temperatures ranging from 400°C to 1200°C in order to remove the polymeric material from the fiber structure. According to the XRD results, it was understood that the most suitable heat treatment temperature for the synthesis of high crystallinity ZTO:SnO2:ZnO is 1150 ℃. Then, the behavior of Rhodamine B (RhB) organic dyestuff under UV light was investigated in order to determine the photocatalytic activity of ZTO:SnO2:ZnO nanocomposite structures. In order for nanocomposites to have the best photocatalytic activity, studies were carried out to examine the concentrations of the fibers applied at different heat treatment temperatures in the dye solution, the pH value of the dye solution, and the exposure time of the dye solution to light. As a result, within the scope of the thesis study, the synthesis of ZTO:SnO2:ZnO nanocomposite structures by electro-spinning method and their photocatalytic activities under UV/visible light were examined in detail and the most suitable synthesis/photocatalytic parameters were determined. According to the results obtained from the studies carried out within the scope of the thesis, it was observed that the ternary ZTO:SnO2:ZnO nanocomposite fibers produced by heat treatment at 1150 °C were added to a 100 mL RhB dye solution with a pH value of 2.03 and reached a decomposition value of 97.8% in 180 minutes under UV light. According to the results obtained from the studies carried out within the scope of the thesis, it was observed that the ternary ZTO:SnO2:ZnO nanocomposite fibers produced by heat treatment at 1150 °C were added to a 100 mL RhB dye solution with a pH value of 2.03 and reached a decomposition value of 97.8% in 180 minutes under UV light. According to this result, the ternary nanocomposite fiber structure produced exhibits very effective photocatalytic properties.