Synthesis Of Ag@AgCl/Fe-S Plasmonic Catalyst For Heterogeneous Photo-fenton Degradation Of BPA

The photo-Fenton process is one of the Advanced Oxidation Processes applied in the degradation of organic pollutants in water,and has attracted much attention because of its fast reaction rate,low toxicity,and mild conditions.However,traditional photo-Fenton system also suffered from the major drawbacks of low visible light utilization and the recovery difficulty,in order to overcome this problem,a inexpensive,natural,strong adsorptive sepiolite was used as a support to synthesize a heterogeneous potential plasmonic catalyst based on the remarkable photocatalytic performance of Ag@AgCl in harnessing visible light because of their surface plasmon resonance?Ag@AgCl/Fe-S?,and the morphology,properties and photocatalytic mechanism of the synthesized photo-Fenton catalyst was discussed in this study.The followings were the main contents:?1?Ag@AgCl/Fe-S was synthesized successfully by ion exchange and photo-reduction methods,and the catalyst was characterized by XRD,UV-vis,SEM,BET,PL and XPS analyses.The XRD,SEM analyses showed that the Ag@AgCl was successfully loaded on the Fe pillared sepiolite,and XPS results showed that the iron oxides in sepiolite was FeOOH and Fe2O3.The UV-vis and PL spectra illustrated that the Ag@AgCl/Fe-S had better ability of absorbing visible light and separating electron-hole pairs.?2?The activity of the catalyst was investigated using BPA as target pollutants,and the results showed the Ag@AgCl/Fe-S exhibited higher photocatalytic activity than raw Ag@AgCl and Fe pillared sepiolite,nearly complete degradation was achieved in 60 min in the conditions of H₂O₂: 6 mM;BPA: 10 mg/L;catalyst dosage: 1.0 g/L;pH=4;Light intensity: 500 W.Under the same conditions,61.2% TOC removal was attained in 180 min.As for Ag@AgCl and Fe pillared sepiolite catalysts,the mineralization were only 46.61% and 28.85%,respectively.After that,the effects of H₂O₂ concentration,pH,illumination intensity,catalyst dosages and initial BPA concentrations on the rate of degradation were also discussed in detail.?3?Kinetic experiments,active species capture experiments and GC-MS measurements were carried out to explore the regularity and mechanism of the plasmonic catalyst in heterogeneous photo-Fenton process.The active species capture experiment revealed that hydroxyl radicals?HO·?and holes?h+?exhibit synergistic effect in this system to accelerate the BPA degradation reaction,and the possible mechanism of this system was also proposed based on the results.Moreover,the intermediate products of BPA degradation were detected by GC-MS,and the degradation pathway was also proposed in this study.