title: Roles of TaON and Ta(3)N(5) in the visible-Fenton-like degradation of atrazine.
abstract: In this study, the roles of TaON and Ta3N5 in the degradation of atrazine by the visible-Fenton-like system were examined in detail. The TaON and Ta3N5 samples prepared by the nitridation of Ta2O5 and characterized by XRD, DRS, BET and PL analyses. The results showed that the TaON sample had weaker absorption in the visible region but higher specific surface area than the Ta3N5 sample. The degradation rate of atrazine in visible-TaON-Fenton-like system was 2.64 times than that in visible-Ta3N5-Fenton-like system. Both Fe(2+) and H2O2 could be reduced by eCB (electrons in the conduction band) in TaON or Ta3N5, while atrazine could not be oxidized by hVB (holes in the valance band). OH is the active species for the degradation of atrazine in visible-TaON/Ta3N5-Fenton-like systems. Majority of OH originated from Fenton reaction. After Fe(3+) was reduced by eCB to Fe(2+), Fe(2+) reacted quickly with H2O2 to generate OH. In addition, by capturing eCB, a little of H2O2 was reduced to yield OH, which contributed a small fraction of atrazine degradation. Based on the experimental results, the roles of TaON and Ta3N5 in the visible-Fenton-like system were proposed. And the higher photocatalytic activity of TaON than Ta3N5 was suggested to be due to the higher separation efficiency of electrons and holes, which may be related to the larger specific surface area.
authors.affiliation: Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: yxdu@niglas.ac.cn.
authors.forename: Yingxun
authors.initials: Y
authors.lastname: Du
authors.affiliation: Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Nanjing Institute of Geography and Limnology, State Key Laboratory of Lake Science and Environment, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D001280:Atrazine / Q000737:chemistry*; D002384:Catalysis; D004785:Environmental Pollutants / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007202:Indicators and Reagents; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D008027:Light; D009573:Nitrites / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010777:Photochemistry; D013056:Spectrophotometry, Ultraviolet; D013635:Tantalum / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004785:Environmental Pollutants; C045076:Fenton's reagent; D006540:Herbicides; D007202:Indicators and Reagents; D009573:Nitrites; D013635:Tantalum; D006861:Hydrogen Peroxide; D007501:Iron; D001280:Atrazine; D010100:Oxygen
keywords: Mechanism; Photo-Fenton-like; Ta(3)N(5); TaON; Visible light