Fabrication of a Narrow-Band-Gap Ag6Si2O7/BiOBr Composite with High Stability and Enhanced Visible-Light Photocatalytic Activity

• Published in: Catalysis letters Vol. 148; no. 9; pp. 2777 - 2788
• Main Authors: Qin, Jibo, Chen, Nan, Feng, Chuanping, Chen, Huiping, Li, Miao, Gao, Yu
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-09-2018; Springer Nature B.V
• Subjects: Bismuth; Catalysis; Catalytic activity; Chemistry; Chemistry and Materials Science; Crystal structure; Dyes; Electron microscopes; Field emission microscopy; Heterojunctions; Industrial Chemistry/Chemical Engineering; Light; Morphology; Optical properties; Organometallic Chemistry; Photocatalysis; Photoelectrons; Physical Chemistry; Reflectance; Scanning electron microscopy; Spectrum analysis; Stability; Transmission electron microscopy; Photocatalytic; BiOBr composite; Ag; Si; Photocatalytic stability; Visible light; O
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-018-2498-x

In this study, a facile and economical method was reported to enhance the photocatalytic activity of bismuth oxybromide (BiOBr) semiconductor through the fabrication of heterojunction with Ag
6
Si
2
O
7
. Field emission scanning electron microscopy, the transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV–Vis diffuse reflectance spectra were utilized to characterize the crystal structures, morphologies and optical properties of the as-prepared samples. Photocatalytic experiments showed that the Ag
6
Si
2
O
7
/BiOBr composite had a higher rate and efficiency for degradation of methyl orange and phenol than the pure Ag
6
Si
2
O
7
and BiOBr under visible light illumination. The optimal Ag/Bi molar ratio in Ag
6
Si
2
O
7
/BiOBr composite was found to be 2:1. The enhanced photocatalytic performance could be attributed to the high separation efficiency of the photogenerated electron–hole pairs. The trapping experiments of radicals showed that the photogenerated holes (h
+
) and superoxide ions (·O
2
−
) were the main active species. Moreover, the synthesized samples exhibited almost no activity loss even after four recycling runs, indicating their high photocatalytic stability. Considering the facile and environment friendly route for the synthesis of Ag
6
Si
2
O
7
/BiOBr hybrids with enhanced visible-light-induced photocatalytic activity, it is possible to widely apply these hybrids in arious fields.
Graphical Abstract