Details

Autor(en) / Beteiligte

• Wang, Xiang-Ming
• Wu, Song-Hai
• Ren, Hai-Tao
• Zhu, Peng-Yue
• Wang, Cong
• Liu, Yong
• Sun, Shi-Wei
• Zhang, Xiao-Cong
• Lin, Yi-Ying
• Meng, Zi-He
• Jia, Shao-Yi
• Han, Xu

Titel

Formation of hydroperoxo (-OOH) species on the surface of self-doped BiWO: reactivity towards As() oxidation

Ist Teil von

• Physical chemistry chemical physics : PCCP, 2020-06, Vol.22 (22), p.12456-12464

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Bi 2+ x WO 6 is a cost-effective and environmentally friendly photocatalyst that shows high reactivity in the oxidation of various contaminants under visible light. However, under alkaline conditions, the reactive oxidative species in the Bi 2+ x WO 6 system are still not clear yet. In this study, it is observed that the oxidation rates of As( iii ) increase with increasing pH values in the Bi 2.15 WO 6 system. Photoluminescence and the Mott-Schottky analyses confirm that OH − promotes the separation and transfer of photogenerated electron-hole pairs over Bi 2.15 WO 6 , thus facilitating the oxidation of As( iii ). Electron spin resonance spectra analysis and quenching experiments rule out contributions of *OH, O 2 &z.rad; − , 1 O 2 and superoxo species to As( iii ) oxidation and indicate that surface -OOH and/or H 2 O 2 are indeed the predominant species under alkaline conditions. The improved production of H 2 O 2 by H-donors such as glucose and phenol, as well as the UV-vis diffuse reflectance and Raman analyses, further confirms the formation of surface -OOH on Bi 2.15 WO 6 under alkaline conditions. In the dark, the significant higher oxidation rate of As( iii ) by H 2 O 2 -Bi 2.15 WO 6 than that by H 2 O 2 alone reveals that surface −OOH, instead of H 2 O 2 , plays an important role in As( iii ) oxidation. This study enriches our understanding of the diversity of reactive oxygen species (ROS) in the Bi 2.15 WO 6 system and gives new insight into the mechanism involved in the oxidation of As( iii ) under alkaline conditions. The formation of -OOH groups and their high reactivity for As( iii ) oxidation under visible light and alkaline conditions are demonstrated.