In this study, TiO2-Activated carbon (AC) complex fibers were prepared by electrospinning for the synergetic effect of adsorption and degradation of organic pollutant. The average diameter of these fibers increased with increasing the amount of AC added, except for 1AC-TOF (AC/TiO2 =1/40 mass ratio). After calcinations at 500℃, long as-spun fibers were broken and their average diameter was slightly decreased. The resultant fibers after calcination had rough surface and sphere shapes like a peanut. From XRD results, it was confirmed that as-spun fibers were changed to anatase TiO2 fiber after calcinations at 500℃. The prepared TiO2-AC complex fibers could remove procian blue dyes by solar light irradiation with high removal property of 94~99%. The PB dye was rapidly removed by adsorption during the initial 5 minutes. But after 5 minutes, dye removal was occurred by photodegradation. In this study, the most efficient AC/TiO2 ratio of TiO2-AC complex fibers was 5/40, showing the synergetic effect of adsorption and photodegradation. It is expected that the TiO2-AC complex fibers can be used to remove of organic pollutants in water system.

In order to investigate the effect of doping C, N, B and F elements on TiO2 for reducing the band gap, the heat treatment of TiO2 was carried out with tetraethylammonium tetrafluoroborate. Through XRD and XPS analysis, the C, N, B and F doped anatase TiO2 was confirmed. According to the increase of temperature during treatment, the particle size was increased due to aggregation of TiO2 with elements (B, C, N and F). To investigate the capacity of photocatalyst for degradation of dye under solar light, the degradation of acridine orange and methylene blue was conducted. The degradation of dyes was carried out successfully under solar light indicating the effect of doping elements (B, C, N and F) on TiO2 for reducing the band gap effectively.

Naphtha cracking bottom oil was reformed with heat treatment and then spun at 310℃. These pitch-based carbon fibers were carbonized at 1000℃ after oxidation at 280℃, for 90 min. These fibers were chemically activated with molar ratio of KOH/CF (1 : 1) at different temperatures (250~900℃) for 1 hr. The process of activation was characterized with DTA, TGA, BET surface area and pore size distribution. The activation of fibers by KOH was performed by several process. One is the reduction process that carbon fiber was reacted with K2O produced from dehydration process above 400℃. The other is the process that K2CO3 was directly reacted with carbon fiber. At 800℃, the activation was performed by catalyzed mechanism that K2O was obtained from the reaction of metal potassium with CO2, then was changed to K2CO3. At 870℃, the activation was also observed that activation mechanism was promoted by metal catalyst with CO2 from decomposition of K2CO3. The specific surface area of prepared activated carbon fibers was dependent on the activation mechanism. The specific surface area was in the range of 1519~2000 cm3/g and was the largest prepared at 870℃. The pores developed were mostly micropores which was very narrow and uniform. The total pore volume was 0.58~0.77 cm3/g.