Photocatalysis of Sulfadiazine by Graphene/TiO2 Composite Photocatalysts

• Main Authors: SU, SIN-YU, 蘇芯褕
• Other Authors: HUNG, CHUNG-HSUANG
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/rv5j7p

碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程系碩士班 === 105 === This study investigated liquid-phase photocatalysis of sulfadiazine(SDZ) by both titanium dioxide (TiO2) and graphene doped TiO2 (GR/TiO2) thin-film. The thin-film photocatalysts were prepared with an electrophoretic deposition (EPD) technique by immobilizing P-25 TiO2, with various amount of GR, onto pure titanium (Ti) metal plates. This study explored the effects of preparation recipes on the photocatalytic activities of prepared samples, which were determined by the degradation rate of SDZ assisted by the prepared samples irradiated with a near-UV light. Several preparation parameters including applied DC biases (15~35 V), and terminal calcination temperatures (250~450℃) for the samples were evaluated. The study also used SEM and XRD to identify surface morphology, and crystal phase of prepared samples. Selected photocatalysts with better activities were further used for conducting SDZ photocatalytic degradation tests in variation pH levels and light sources. The results showed the photocatalysis of SDZ following pseudo first-order reaction kinetics. A better photocatalytic activities of prepared samples were achieved when the they were prepared with calcined in a 450℃ oven. Among them, TG0.5 photocatalyst has the highest activity (k = 0.348 hr-1), which is 13.7 % higher than that of TiO2 photocatalyst. In addition, the effect of EPD of DC biases on the degradation rate of SDZ, the photocatalytic activity of TiO2 increases with the increase of EPD of DC biases, with the highest activity at 35 V. The TG series of photocatalyst, it will be in a EPD of DC biases, with the fastest response rate, which are: TG0.5 (25 V), TG1.0 (20 V), TG1.5 (20 V). Based on the above results, it can be found that the calcination temperature is 450 ℃ with the highest activity, and different series of photocatalyst also has the best EPD of DC biases, can be assembled with a high activity of the photocatalyst, in order: 450TiO2-35V, 450TG0.5-25V, 450TG1.0-20V, 450TG1.5-20V. Finally, the effects of different light sources and pH values on degradation rate of SDZ were investigated. According to the experimental results, it was found that the degradation rate was the fastest and the proportion of pollutants adsorbed by the catalyst at pH= 3. In addition, the TiO2 photocatalyst itself is very poor for the visible light absorption capacity. The experimental results show that the photocatalyst doping of graphene can not only increase the activity of the original TiO2 photocatalyst, but also increase the absorption of the visible light source. Finally, the photocatalyst prepared in this study has the highest activity in UV light and LED light with photocatalyst doped with 0.5% graphene.