Facile synthesis of magnetic Fe3O4@BiOI@AgI for water decontamination with visible light irradiation: Different mechanisms for different organic pollutants degradation and bacterial disinfection. (15th June 2018)

• Record Type: Journal Article
• Authors: Liang, Jialiang; Liu, Fuyang; Li, Mian; Liu, Wen; Tong, Meiping
• Is Part Of: Water research. Volume 137(2018)
• Page Start: 120
• Page End: 129
• Publication Date: 2018-06-15
• Subjects: Fe3O4@BiOI@AgI -- Photocatalytic activity -- Degradation kinetics of RhB and BPA -- Bacterial disinfection -- Active species -- Reusability; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2018.03.027
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Magnetic Fe3 O4 @BiOI@AgI (FBA) spheres were synthesized through a multi-step process. The fabricated photocatalysts were characterized by different techniques. To testify the visible light driven photocatalytic activity of FBA, Rhodamine B and Bisphenol A were chosen as model common and emerging organic contaminants, respectively. While, gram-negative strain Escherichia coli was selected as model waterborne bacteria. The results showed that under visible light irradiation, FBA contained strong photocatalytic degradation capacity towards both RhB and BPA. Moreover, FBA was also found to exhibit excellent disinfection activity towards E. coli . The photocatalytic mechanisms for different pollutants by FBA were determined and found to vary for different pollutants. Specifically, scavenger experiments, degradation intermediates determination, as well as theoretical density functional theory (DFT) analysis showed that RhB and BPA were degraded via photosensitization (dominated by e - and ·O2 − ) and direct photocatalytic oxidation (contributed by h +, e - and ·O2 − ), respectively. Whereas, E. coli cells yet were found to be inactivated by the generation of e - and ·O2 − rather than by the released Ag + . Since it contained superparamagnetic property, FBA could be easily separated from the reaction suspension after use. Due to the excellent photo stability, FBA exhibited strong photocatalytic activity in the fourth reused recycle. Therefore, FBA could serve as a promising alternative for water purification. Graphical abstract: Highlights: Facile synthesis of Fe3 O4 @BiOI@AgI hybrid photocatalyst. Excellent visible light driven activity towards RhB, BPA and E. coli cells. Different photocatalytic mechanisms for different pollutants. Magnetic recycle and good photo stability. DFT calculation elucidates the degradation pathways of RhB and BPA.