Fotokatalitik özellikte seramik nanofiber üretimi ve karakterizasyonu

In recent years, attention has been directed towards transition metal ion doping on TiO2 in order to improve its photocatalytic activity. However, there are several disadvantages in using TiO2. Firstly, the wide band gap of TiO2 inhibits the utilization of solar energy in photocatalytic processes. Secondly, the fixation and recovery of TiO2 nanoparticles are very difficult and tortuous. To overcome this shortcoming, photocatalysts have re- cently been developed, in which TiO2 was coated on appropriate substrates such as on a ceramic, glass or metal plate, by the sol–gel process. However, in these applications, the coated TiO2 easily peels off from the substrate. To solve this problem TiO2 can be in- corporated in a glass-ceramic system. One of the significant characteristics of glass-ceramics is the excellent formability. In recent years, novel TiO2 doped glass-ceramic nanofibers with photocatalytic ability have been prepared by sol-gel/electrospining techniques. As these glass-ceramics contain TiO2 in composition, it prevents peeling of the TiO2 from the substrate. It is known that the electrospinning technique presently offers a simple and cost-effective approach to nanofibers. The fibers fabricated by combined sol-gel/electrospinning techniques have such favorable characteristics as exceptional length, uniform diameter, diverse composi- tion, and high surface area, and can be applied in many fields. This study was the first study that ceramic nanofibers were fabricated by a facile method of electrospinning and sol-gel synthesis in the systems of SiO2-CaO-Al2O3-TiO2. Precur- sor solution has been prepared with different TiO2 contents. As polymer solution, 10% Polyacrylonitrile (PAN) solution in DMF has been used. Ceramic nanofibers were ex- posed to calcination process at different temperatures between 600-800°C. The charac- teristics of the ceramic nanofibers were investigated in detail by using SEM, FTIR, XRD, BET, DTA and photocatalytic activity measurement. Results showed that the ce- ramic nanofibers with 65% and 75% TiO2 content, which calcined at 700°C and 800°C have anatase phase. They may be feasible candidates for industrial applications to clean wastewater.