Aqueous Cr(VI) photo-reduction catalyzed by TiO2 and sulfated TiO2.
TiO(2) and sulfated TiO(2) (SO(4)(2-)/TiO(2)) catalysts with different textural properties were prepared under different calcination temperatures and the photo-reduction of Cr(VI) to Cr(III) catalyzed by these catalysts was investigated. For the photocatalytic reduction of Cr(VI), the photocatalytic activities of the TiO(2) samples were found to be strongly dependent of the calcination temperature and TiO(2) calcined at 400 degrees C showed a higher catalytic activity compared to other TiO(2) catalysts. In contrast, sulfation of TiO(2) stabilized the catalytic activities of SO(4)(2-)/TiO(2) catalysts. At low calcination temperature, SO(4)(2-)/TiO(2) catalysts exhibited catalytic activities almost comparable with that of TiO(2) and the catalytic activities of SO(4)(2-)/TiO(2) catalysts were markedly higher than TiO(2) under high calcination temperature. In addition, the removal of surface SO(4)(2-) of SO(4)(2-)/TiO(2) catalyst led to a marked decrease of the catalytic activity for Cr(VI) photo-reduction, suggesting that the presence of surface SO(4)(2-) provided an acid environment over the catalyst surface and favored the photo-reduction of Cr(VI).
Jiang
Fang
F
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
Zheng
Zheng
Z
Xu
Zhaoyi
Z
Zheng
Shourong
S
Guo
Zhaobing
Z
Chen
Liqiang
L
D002384:Catalysis; D002857:Chromium / Q000737:chemistry*; D010084:Oxidation-Reduction; D010777:Photochemistry; D013055:Spectrophotometry, Infrared; D013431:Sulfates / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
D013431:Sulfates; D002857:Chromium; C009495:titanium dioxide; D014025:Titanium