PHOTOCATALYTIC DEGRADATION OF PENTACHLOROPHENOL(PCP) USING Ti02 THIN FILMS PREPARED BY CVD

Jung, Oh-Jin; Kim, Sam-Hyeok; Cheong, Kyung-Hoon

Environmental Engineering Research 2001;6(4): 199-210.

Oh-Jin Jung^†, Sam-Hyeok Kim, and Kyung-Hoon Cheong

School of Environmental Engineering, Chosun University, Kwang-ju 501-759, Korea

Corresponding Author: Oh-Jin Jung ,Tel: +82-62-230-6644, Fax: +82-62-234-6754, Email: ojjung@mail.chosun.ac.kr

Received: May 14, 2001; Accepted: August 14, 2001.

ABSTRACT

Chemical vapor deposition(CVD) and Sol-Gel method were used to prepare TiO₂ thin films for degradation of hazardous organic compounds exemplified by PCP(pentachlorophenol). The effects of supporting materials and coating methods on the photocatalytic activity of the TiO₂ thin films were also studied. TiO₂ thin films were coated onto various supporting materials including stainless steel cloth(SS), quartz glass tube(QGT), and silica gel(SG). Results indicate that SS(400 x 400 mesh)-TiO₂ thin film prepared by CVD method improves the photodegradation of PCP. Among all supporting materials studied, SS(400 x 400 mesh) appears to be the best support. An optimal amount of coating material at 1.0%(w/w) of Ti02 for support gives the best photodegradation of PCP. Intermediates and by-products generated during the process were precisely identified and quantified. The major by-products are four carboxylic acids: tartaric acid, oxalic acid, malic acid, and hydroxymalonic acid. Based on the information concerning the generation of organic acids and other aromatic intermediates, the complete reaction pathways toward mineralization can be proposed.