Photocatalytic Degradation of Chlorinated Compounds in Water. Effect of the Number of the Repeated Dip-coating for the TiO 2 Thin-film on the Degradation of TCE

Photocatalytic degradation of trichloroethylene（TCE）was studied by using TiO2thin film coated on the sur蝕ce of Pyrex ghss tube．Two types of TiO2coated photocatalyst were preparedl one is Pyrex tube coated with thin film only on the㎝tside su血ce ofthe tube and the other ls that coated with TiO2thin film on both sides（inside and outside）of the tube．The TiO2film was coated by means ofdip−coating in sol−gel pr㏄ess．The thic㎞ess ofTiO2was changed by repeat− ing the dip−coa髄ng process．Relations between the thic㎞ess lmd tτansmi伽ce were dete㎜ined， TiO261ms of㎝optimum thic㎞ess showed hlgh photocatalytic ac廿vities under the illumination of blacklight fluorescent lamps fヤom the outside of the tube．The phot㏄atalytic activities of TiO2 thin film on inside of the tube is concemed with the photo−reaction，