Photocatalytic degradation characteristics of different organic compounds at TiO2 nanoporous film electrodes with mixed anatase/ rutile phases.
Nanoporous TiO2 film electrodes with a mixed anatase/ rutile phase were prepared by dip-coating TiO2 nanoparticle colloid onto Indium Tin Oxide (ITO) conducting glass substrates and a subsequent calcination process at 700 degrees C for 16 h. The photocatalytic oxidation of a wide range of organic compounds has been studied using the photoelectrochemical method under the conditions that the photohole capturing step controls the overall photocatalytic processes. The characteristics of the mixed anatase/ rutile phase TiO2 film electrodes were compared with pure anatase phase TiO2 film electrodes to identify the key differences between them. The results revealed that different organic compounds, despite their difference in chemical entities, can be stoichiometrically mineralized at the mixed-phase TiO2 electrode under diffusion-controlled conditions, which is in great contrast to the situation at the pure anatase phase TiO2 electrode. The exceptional ability of the mixed-phase TiO2 electrodes for mineralization of organic compounds and their remarkable resistance to the inhibition by aromatic compounds at higher concentration has been explained by the synergetic effect of the rutile and anatase phases. For this type of mixed phase electrodes, upon absorption of UV light, the electron-transfer pathway from anatase phase to rutile phase facilitates the separation of photoelectron and photohole, extending the lifetime of the photoelectron and photohole.
Jiang
Dianlu
D
Centre for Aquatic Processes and Pollution (CAPP) and School of Environmental and Applied Sciences Gold Coast Campus, Griffith University PMB 50, Gold Coast Mail Center, Queensland 9726 Australia.
Zhang
Shanqing
S
Zhao
Huijun
H
D002384:Catalysis; D004566:Electrodes; D004787:Environmental Pollution / Q000517:prevention & control*; D009930:Organic Chemicals / Q000737:chemistry*; D010084:Oxidation-Reduction; D010777:Photochemistry / Q000295:instrumentation* / Q000379:methods*; D017971:Tin Compounds; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays
D009930:Organic Chemicals; D017971:Tin Compounds; C009495:titanium dioxide; C109984:indium tin oxide; D014025:Titanium