Design of a photocatalyst for bromate decomposition: surface modification of TiO2 by pseudo-boehmite.
The rate of BrO3- reduction by a commercial TiO2 photocatalyst under UV illumination in an aqueous solution was increased by lowering the pH from 7 to 5. The effect is attributable to an enhancement of the electrical interaction between BrO3- and the positively charged surfaces of the TiO2 photocatalyst. The surface charge can be controlled by a surface modification of the TiO2 photocatalyst without controlling the pH of the water. In fact, the isoelectric point of surface-modified TiO2 was higher than that of the unloaded TiO2 photocatalyst, resulting in an increase in the rate of the photocatalytic reduction of BrO3- at a neutral pH. This increase is explained by an increase in the amount of adsorbed BrO3- on the photocatalyst surface.
Noguchi
Hiroshi
H
Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8904, Japan. noguchi-h@ohsaki.meidensha.co.jp
Nakajima
Akira
A
Watanabe
Toshiya
T
Hashimoto
Kazuhito
K
D001959:Bromates / Q000737:chemistry*; D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D018508:Water Purification / Q000379:methods*
D001959:Bromates; D004396:Coloring Agents; C009495:titanium dioxide; D014025:Titanium