Enhancement for Photocatalytic Activity of TiO₂ Combined with Activated Carbon under Surface Fluorination (F-TiO₂/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 TiO_2, 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.

• Periodical: Key Engineering Materials (Volumes 675-676)
• Pages: 560-563
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.675-676.560
• Online since: January 2016
• Authors: Janjira Sivapatarnkun, K. Hathaisamit, S. Pudwat
• Keywords: Activated Carbon, Photocatalysis, Sol-Gel Method, Surface Fluorination, TiO₂

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