Enhancement for Photocatalytic Activity of TiO<sub>2 </sub> Combined with Activated Carbon under Surface Fluorination (F-TiO<sub>2</sub>/AC)

Abstract

The prepared TiO2 and commercial grade of TiO2 with anatase and rutile phase combined with bulk and powder of activated carbon (TiO2/AC) observed the photocatalytic activity under weak UV. The surface fluorination was applied for all photocatalysts (F-TiO2/AC) to enhance photocatalytic activity. The decolorization of methylene blue (MB) was used to indicate the efficiency of adsorption and degradation of the samples. The prepared TiO2 was prepared by Sol-Gel method under condition of the titanium tetraisopropoxide (TTIP) to 2-propanol (2-PP) ratio of 1:30 and adjusts pH of 2 by HCl acid. Under surface fluorination, the samples of TiO2/AC were immersed of 2 hours under NaF solution of 30 mmol. Surface morphology was observed by field-emission scanning electron microscopy (FE-SEM). MB absorption was recorded by UV-VIS spectrophotometer to indicate MB decolorization. The results showed that, MB were under photocatalytic test of the rich porosities of AC and prepared TiO2/AC were the highest decolorization due to AC showed high adsorption and prepared TiO2/AC showed high decomposition of MB. Both of TiO2/AC and F-TiO2/AC, pure anatase phase showed higher photocatalytic activity than pure rutile phase. Under the same crystalline phase, F-TiO2/AC showed higher photocatalytic activity than TiO2/AC. Prepared TiO2 showed higher photocatalytic activity than TiO2 of commercial grade. Moreover, under the same TiO2, AC powder showed higher adsorption than AC bulk due to AC powder has surface area greater than AC bulk. The best sample for MB-decolorization was F-prepared TiO2/AC powder. Under the sample to MB solution (0.05 mmol) ratio of 0.15g: 400 ml, the MB solution changed to be the colorless solution after treatment of 5 min.