title: Effects of doping amounts of potassium ferricyanide with titanium dioxide and calcination durations on visible-light degradation of pharmaceuticals.
abstract: Acetaminophen (ACT) is one of the most frequently detected pharmaceuticals in aqueous environments, and treatment of ACT were generally carried out by photocatalytic degradations under high energy UV irradiation. In this study, potassium ferricyanide was utilized as a quadruple-elemental dopant in a TiO2photocatalyst in order to enhance its visible-light activity. Two critical parameters (amounts of dopants and durations of calcination) of the synthesis of the photocatalyst by a sol-gel method were systematically evaluated. Crystal structure of the doping TiO2was examined by X-ray diffraction while the effects of the two parameters on the photocatalytic activity were elucidated by various characterizations. Increasing the amount of dopant or the duration of calcination red-shifted the UV-vis DRS of the doped TiO2. The estimated band gap energy of the doped TiO2decreased slightly as the amount of dopant increased, but it increased as the duration of calcination increased. The FT-IR yielded characteristic peaks that revealed the effects of the two parameters, whereas the SEM images revealed the morphological evolutions of each effect. The photocatalyst, synthesized at optimum conditions was able to remove 99.1 % acetaminophen with rate constant of 7.9 × 10-3min-1, which was 4.88 times greater than virgin TiO2. In general, this study not only optimized synthetic conditions of the new visible-light active photocatalyst for ACT degradation but also presented characterizations conducted by SEM, XRD, UV-vis DRS, and FTIR to elucidate the relationship between modified structure and the photocatalytic activity. Graphical abstract Effects of doping amounts of K3[Fe(CN)6] and calcunation duration on visible light absorbance of TiO2photocatalysts.
authors: Department of Environmental Engineering and Science, Feng Chia University, Taichung, 407, Taiwan.
authors: Justin Chun-Te
authors: JC
authors: Lin
authors: Department of Chemical Engineering, University of the Philippines, Diliman, Quezon City, 1101, Philippines.
authors: Mark Daniel G
authors: MD
authors: de Luna
authors: Department of Chemical Engineering, University of the Philippines, Diliman, Quezon City, 1101, Philippines.
authors: Mary Jane N
authors: MJ
authors: Gotostos
authors: Department of Environmental Resources Management, Chia Nan University of Pharmacy and Science, Tainan, 717, Taiwan. mmclu@mail.cnu.edu.tw.
authors: Ming-Chun
authors: MC
authors: Lu
mesh_terms: D000082:Acetaminophen / Q000737:chemistry*; D002384:Catalysis; D005292:Ferricyanides; D008027:Light; D010782:Photolysis; D017550:Spectroscopy, Fourier Transform Infrared; D014025:Titanium; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D005292:Ferricyanides; C009495:titanium dioxide; D000082:Acetaminophen; D014025:Titanium; C028033:potassium ferricyanide
keywords: Calcination duration; Doping amounts; Surface characterizations; TiO2; Visible-light photocatalysis