Mechanism and experimental study on the photocatalytic performance of Ag/AgCl @ chiral TiO2 nanofibers photocatalyst: The impact of wastewater components

JOURNAL OF HAZARDOUS MATERIALS

卷:285

Article

Wang, Dawei¹  Li, Yi¹  Puma, Gianluca Li²  Wang, Chao¹  Wang, Peifang¹  Zhang, Wenlong¹  Wang, Qing¹ 

[1] Hohai Univ, Coll Environm, Key Lab Integrated Regulat & Resource Dev Shallow, Minist Educ, Nanjing 210098, Jiangsu, Peoples R China

[2] Univ Loughborough, Dept Chem Engn, Loughborough LE11 3TU, Leics, England

关键词: Wastewater components;    Ag;    AgCl;    Photocatalytic performance;    Transformation;   

DOI  :  10.1016/j.jhazmat.2014.10.060

来源: Elsevier

【 摘 要 】

The effect of the water matrix components of a secondary effluent of a urban wastewater treatment plant on the photocatalytic activity of Ag/AgCl @ chiral TiO2 nanofibers and the undergoing reaction mechanisms were investigated. These effects were evaluated through the water components-induced changes on the net rate of hydroxyl radical ((OH)-O-center dot) generation and modeled using a relative rate technique. Dissolved organic matter DOM (k = -2.8 x 10(8) M-1 s(-1)) scavenged reactive oxygen species, Cl- (k = 5.3 x 10(8) M-1 s(-1)) accelerated the transformation from Ag to AgCl (which is not photocatalytically active under visible-light irradiation), while Ca2+ at concentrations higher than 50 mM (k = -1.3 x 10(9) M-1 s(-1)) induced aggregation of Ag/AgCl and thus all of them revealed inhibitory effects. In contrast, NO3- (k = 6.9 x 10(8) M-1 s(-1)) and CO32- (k = 3.7 x 10(8) M-1 s(-1)) improved the photocatalytic activity of Ag/AgCl slightly by improving the rate of HO center dot generation. Other ubiquitous secondary effluent components including SO42- (k = 3.9 x 10(5) M-1 s(-1)), NH3+ (k = 3.5 x 10(5) M-1 s(-1)) and Na+ (k = 2.6 x 10(4) M-1 s(-1)) had negligible effects. 90% of 17-alpha-ethynylestradiol (EE2) spiked in the secondary effluent was removed within 12 min, while the structure and size of Ag/AgCl @ chiral TiO2 nanofibers remained stable. This work may be helpful not only to uncover the photocatalytic mechanism of Ag/AgCI based photocatalyst but also to elucidate the transformation and transportation of Ag and AgCl in natural water. (C) 2014 Elsevier B.V. All rights reserved.

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