Photocatalytic debromination of preloaded decabromodiphenyl ether on the TiO(2) surface in aqueous system.
There have been serious concerns about polybromodiphenyl ethers (PBDEs) in the environment because of their global distribution and bioaccumulation. Owing to strong hydrophobicity of PBDEs, the regular photocatalytic system, in which the substrate is solvated in the bulk solution, is not applicable to the removal of the PBDEs in water. In this work, the photocatalytic reduction degradation of decabromodiphenyl ether (BDE209), the most-used PBDEs, was investigated in aqueous system, by pre-adsorbing it on the surface of photocatalyst. It was found that the preloaded BDE209 underwent efficient reductive debromination in aqueous system under irradiation with wavelength larger than 360 nm in the presence of electron donors such as methanol. Our experiments further show that such a preloaded system exhibits different characteristics from that in the organic solution. The meta-debrominated intermediate is predominant in the present system, while the ortho-debrominated one is the main nona-BDE products in the organic solution. In addition, different from other photocatalytic system, the pH has little effect on the photocatalytic reaction. We propose that these differences are originated from the formation of overlayer of hydrophobic BDE209 to limit the motion of BDE209 and the access of water and H(+)/OH(-) to the TiO(2) surface.
Department of Chemistry, Shaoxing University, Zhejiang Shaoxing 312000, China.
Chunyan
C
Sun
Jincai
J
Zhao
Hongwei
H
Ji
Wanhong
W
Ma
Chuncheng
C
Chen
D004785:Environmental Pollutants / Q000737:chemistry / Q000528:radiation effects*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005411:Flame Retardants / Q000528:radiation effects*; D055768:Halogenated Diphenyl Ethers / Q000737:chemistry / Q000528:radiation effects*; D057927:Hydrophobic and Hydrophilic Interactions / Q000528:radiation effects; D010782:Photolysis / Q000528:radiation effects; D014025:Titanium / Q000737:chemistry / Q000528:radiation effects*; D014867:Water / Q000737:chemistry
D004785:Environmental Pollutants; D005411:Flame Retardants; D055768:Halogenated Diphenyl Ethers; D014867:Water; C009495:titanium dioxide; D014025:Titanium; C010902:decabromobiphenyl ether